Case Reports

Fractures of the clavicle, which account for 2.6% of all fractures, are displaced in 70% of cases and are mid-diaphyseal in 80% of cases.^1-3 Historically, both displaced and nondisplaced fractures were treated nonoperatively with excellent outcomes reported in the majority of patients.^1-3 Traditionally, the indications for surgical fixation of a clavicular fracture include open fractures, which occur infrequently, accounting for only 3.2% of clavicle fractures.⁴ Other indications include floating shoulder girdle or scapulothoracic dissociation, neurovascular injury, and skin “tenting” by the fracture fragments.^3,5 Recently, both meta-analyses and randomized clinical trials have reported reduced malunion rates and improved patient outcomes with open reduction and internal fixation (ORIF).^6-9 Consequently, operative fixation could be considered in patients with 100% displacement or greater than 1.5 cm shortening.^6-9 Open reduction and internal fixation of the clavicle has been demonstrated to have excellent outcomes in pediatric populations as well.¹⁰

The clavicle is subcutaneous for much of its length and, thus, displaced clavicular fractures often result in a visible deformity with a stretch of the soft-tissue envelope over the fracture. While this has been suggested as an operative indication, several recent sources indicate that this concern may only be theoretical. According to the fourth edition of Skeletal Trauma, “It is often stated that open reduction and internal fixation should be considered if the skin is threatened by pressure from a prominent clavicle fracture fragment; however, it is extremely rare of the skin to be perforated from within.”⁵ The most recent Journal of Bone and Joint Surgery Current Concepts Review on the subject stated that “open fractures or soft-tissue tenting sufficient to produce skin necrosis is uncommon.”³ To the best of our knowledge, there is no reported case of a displaced midshaft clavicle fracture with secondary skin necrosis and conversion into an open fracture, validating the conclusion that this complication may be only theoretical. Given that surgical fixation carries a risk of complications including wound complications, infection, nonunion, malunion, and damage to the nearby neurovascular structures and pleural apices,¹¹ some surgeons may be uncertain how to proceed in cases at risk for disturbance of the soft tissues.

We report 2 adolescent cases of displaced, comminuted clavicle fractures in which the skin was initially intact. Both were managed nonoperatively and both secondarily presented with open lesions at the fracture site requiring urgent irrigation and débridement (I&D) and ORIF. The patients and their guardians provided written informed consent for print and electronic publication of these case reports.

Case Reports

Case 1

A 15-year-old boy with no significant medical or surgical history flipped over the handlebars of his bicycle the day prior to presentation and sustained a clavicle fracture on his left nondominant upper extremity. This was an isolated injury. On examination, his skin was intact with an area of tender mild osseous protuberance at the midclavicle with associated surrounding edema. He was neurovascularly intact. Radiographs showed a displaced fracture of the midshaft of the clavicle with 20% shortening with a vertically angulated piece of comminution (Figure 1A). After a discussion of the treatment options with the family, the decision was made to pursue nonoperative treatment with sling immobilization as needed and restriction from gym and sports.

Two and a half weeks later, the patient presented at follow-up with significant reduction but persistence of his pain and a new complaint of drainage from the area of the fracture. On examination, he was found to have a puncture wound of the skin with exposed clavicle protruding through the wound with a 1-cm circumferential area of erythema without purulence present or expressible. The patient denied reinjury and endorsed compliance with sling immobilization. He was taken for urgent I&D and ORIF. After excision of the eschar surrounding the open lesion and full I&D of the soft tissues, the protruding spike was partially excised and the fracture site was débrided. The fracture was reduced and fixated with a lag screw and neutralization plate technique using an anatomically contoured locking clavicle plate (Synthes). Vancomycin powder was sprinkled into the wound at the completion of the procedure to reduce the chance of infection.¹²

Postoperatively, the patient was prescribed oral clindamycin but was subsequently switched to oral cephalexin because of mild signs of an allergic reaction, for a total course of antibiotics of 1 week. The patient was immobilized in a sling for comfort for the first 9 weeks postoperatively until radiographic union occurred. The patient’s wound healed uneventfully and with acceptable cosmesis. He was released to full activities at 10 weeks postoperatively. At final follow-up 6 months after surgery, the patient had returned to all of his regular activities without pain, and with full range of motion and no demonstrable deficits with radiographic union (Figure 1B).

Case 2

An 11-year-old boy with no significant medical or surgical history fell onto his right dominant upper extremity while doing a jump on his dirt bike 1 week prior to presentation, sustaining a clavicle fracture. This was an isolated injury. He was seen and evaluated by an outside orthopedist who noted that the soft-tissue envelope was intact and the patient was neurovascularly intact. Radiographs showed a displaced fracture of the midshaft of the clavicle with 15% shortening and with a vertically angulated piece of comminution (Figure 1C). Nonoperative treatment with a figure-of-8 brace was recommended. The patient’s discomfort completely resolved.

One week later, when he presented to the outside orthopedist for follow-up, the development of a wound overlying the fracture site was noted, and the patient was started on oral trimethoprim/sulfamethoxazole and referred to our office for treatment (Figure 1D). The patient denied reinjury and endorsed compliance with brace immobilization. On examination, the patient was afebrile and was noted to have a puncture wound at the fracture site with a protruding spike of bone and surrounding erythema but without present or expressible discharge (Figure 2). The patient was taken urgently for I&D and ORIF, using a similar technique to case 1, except that no lag screw was employed.

Postoperatively, the patient did well with no complications; he was prescribed oral cephalexin for 1 week. The patient was immobilized in a sling for the first 5 weeks after surgery until radiographic union had occurred, after which the sling was discontinued. The patient’s wound healed uneventfully and with acceptable cosmesis. The patient was released from activity restrictions at 6 weeks postoperatively. At final follow-up 5 weeks after surgery, the patient had full painless range of motion, no tenderness at the fracture site, no signs of infection on examination, and radiographic union (Figure 1D).

Discussion

Optimal treatment of displaced clavicle fractures is controversial. While nonoperative treatment has been recommended,^1-3 especially in skeletally immature populations with a capacity for remodeling,^7-9 2 recent randomized clinical trials have demonstrated improved patient outcomes with ORIF.^6,8,9 Traditionally, ORIF was recommended with tenting of the skin because of concern for an impending open fracture. However, recent review materials have implied that this complication may only be theoretical.^3,5 Indeed, in 2 randomized trials, sufficient displacement to cause concern for impending violation of the skin envelope was not listed as an exclusion criteria.^8,9 We report 2 cases of displaced comminuted clavicle fractures that were initially managed nonoperatively but developed open lesions at the fracture site. This complication, while rare, is possible, and surgeons must consider it as a possibility when assessing patients with displaced clavicle fractures. To the best of the authors’ knowledge, no guidelines exist to direct antibiotic choice and duration in secondarily open fractures.

These 2 cases have several features in common that may serve as risk factors for impending violation of the skin envelope. Both fractures had a vertically angulated segmental piece of comminution with a sharp spike. This feature has been identified as a potential risk factor for subsequent development of an open fracture in a case report of fragment excision without reduction or fixation to allow rapid return to play in a professional jockey.¹³ Both patients in these cases presented with high-velocity mechanisms of injury and significant displacement, both of which may serve as risk factors. In the only similar case the authors could identify, Strauss and colleagues¹⁴ described a distal clavicle fracture with significant displacement and with secondary ulceration of the skin complicated by infection presenting with purulent discharge, cultured positive for methicillin-sensitive Staphylococcus aureus, requiring management with an external fixator and 6 weeks of intravenous antibiotics. Because both cases presented here occurred in healthy adolescent patients who were taken urgently for I&D and ORIF as soon as the wound was discovered, deep infection was avoided in these cases. Finally, in 1 case, a figure-of-8 brace was employed, which may also have placed pressure on the skin overlying the fracture and may have predisposed this patient to this complication.

Conclusion

In displaced midshaft clavicle fractures, tenting of the skin sufficient to cause subsequent violation of the soft-tissue envelope is possible and is more than a theoretical risk. At-risk patients, ie, those with a vertically angulated sharp fragment of comminution, should be counseled appropriately and observed closely or considered for primary ORIF.

Fractures of the clavicle, which account for 2.6% of all fractures, are displaced in 70% of cases and are mid-diaphyseal in 80% of cases.^1-3 Historically, both displaced and nondisplaced fractures were treated nonoperatively with excellent outcomes reported in the majority of patients.^1-3 Traditionally, the indications for surgical fixation of a clavicular fracture include open fractures, which occur infrequently, accounting for only 3.2% of clavicle fractures.⁴ Other indications include floating shoulder girdle or scapulothoracic dissociation, neurovascular injury, and skin “tenting” by the fracture fragments.^3,5 Recently, both meta-analyses and randomized clinical trials have reported reduced malunion rates and improved patient outcomes with open reduction and internal fixation (ORIF).^6-9 Consequently, operative fixation could be considered in patients with 100% displacement or greater than 1.5 cm shortening.^6-9 Open reduction and internal fixation of the clavicle has been demonstrated to have excellent outcomes in pediatric populations as well.¹⁰

The clavicle is subcutaneous for much of its length and, thus, displaced clavicular fractures often result in a visible deformity with a stretch of the soft-tissue envelope over the fracture. While this has been suggested as an operative indication, several recent sources indicate that this concern may only be theoretical. According to the fourth edition of Skeletal Trauma, “It is often stated that open reduction and internal fixation should be considered if the skin is threatened by pressure from a prominent clavicle fracture fragment; however, it is extremely rare of the skin to be perforated from within.”⁵ The most recent Journal of Bone and Joint Surgery Current Concepts Review on the subject stated that “open fractures or soft-tissue tenting sufficient to produce skin necrosis is uncommon.”³ To the best of our knowledge, there is no reported case of a displaced midshaft clavicle fracture with secondary skin necrosis and conversion into an open fracture, validating the conclusion that this complication may be only theoretical. Given that surgical fixation carries a risk of complications including wound complications, infection, nonunion, malunion, and damage to the nearby neurovascular structures and pleural apices,¹¹ some surgeons may be uncertain how to proceed in cases at risk for disturbance of the soft tissues.

We report 2 adolescent cases of displaced, comminuted clavicle fractures in which the skin was initially intact. Both were managed nonoperatively and both secondarily presented with open lesions at the fracture site requiring urgent irrigation and débridement (I&D) and ORIF. The patients and their guardians provided written informed consent for print and electronic publication of these case reports.

Case Reports

Case 1

A 15-year-old boy with no significant medical or surgical history flipped over the handlebars of his bicycle the day prior to presentation and sustained a clavicle fracture on his left nondominant upper extremity. This was an isolated injury. On examination, his skin was intact with an area of tender mild osseous protuberance at the midclavicle with associated surrounding edema. He was neurovascularly intact. Radiographs showed a displaced fracture of the midshaft of the clavicle with 20% shortening with a vertically angulated piece of comminution (Figure 1A). After a discussion of the treatment options with the family, the decision was made to pursue nonoperative treatment with sling immobilization as needed and restriction from gym and sports.

Two and a half weeks later, the patient presented at follow-up with significant reduction but persistence of his pain and a new complaint of drainage from the area of the fracture. On examination, he was found to have a puncture wound of the skin with exposed clavicle protruding through the wound with a 1-cm circumferential area of erythema without purulence present or expressible. The patient denied reinjury and endorsed compliance with sling immobilization. He was taken for urgent I&D and ORIF. After excision of the eschar surrounding the open lesion and full I&D of the soft tissues, the protruding spike was partially excised and the fracture site was débrided. The fracture was reduced and fixated with a lag screw and neutralization plate technique using an anatomically contoured locking clavicle plate (Synthes). Vancomycin powder was sprinkled into the wound at the completion of the procedure to reduce the chance of infection.¹²

Postoperatively, the patient was prescribed oral clindamycin but was subsequently switched to oral cephalexin because of mild signs of an allergic reaction, for a total course of antibiotics of 1 week. The patient was immobilized in a sling for comfort for the first 9 weeks postoperatively until radiographic union occurred. The patient’s wound healed uneventfully and with acceptable cosmesis. He was released to full activities at 10 weeks postoperatively. At final follow-up 6 months after surgery, the patient had returned to all of his regular activities without pain, and with full range of motion and no demonstrable deficits with radiographic union (Figure 1B).

Case 2

An 11-year-old boy with no significant medical or surgical history fell onto his right dominant upper extremity while doing a jump on his dirt bike 1 week prior to presentation, sustaining a clavicle fracture. This was an isolated injury. He was seen and evaluated by an outside orthopedist who noted that the soft-tissue envelope was intact and the patient was neurovascularly intact. Radiographs showed a displaced fracture of the midshaft of the clavicle with 15% shortening and with a vertically angulated piece of comminution (Figure 1C). Nonoperative treatment with a figure-of-8 brace was recommended. The patient’s discomfort completely resolved.

One week later, when he presented to the outside orthopedist for follow-up, the development of a wound overlying the fracture site was noted, and the patient was started on oral trimethoprim/sulfamethoxazole and referred to our office for treatment (Figure 1D). The patient denied reinjury and endorsed compliance with brace immobilization. On examination, the patient was afebrile and was noted to have a puncture wound at the fracture site with a protruding spike of bone and surrounding erythema but without present or expressible discharge (Figure 2). The patient was taken urgently for I&D and ORIF, using a similar technique to case 1, except that no lag screw was employed.

Postoperatively, the patient did well with no complications; he was prescribed oral cephalexin for 1 week. The patient was immobilized in a sling for the first 5 weeks after surgery until radiographic union had occurred, after which the sling was discontinued. The patient’s wound healed uneventfully and with acceptable cosmesis. The patient was released from activity restrictions at 6 weeks postoperatively. At final follow-up 5 weeks after surgery, the patient had full painless range of motion, no tenderness at the fracture site, no signs of infection on examination, and radiographic union (Figure 1D).

Discussion

Optimal treatment of displaced clavicle fractures is controversial. While nonoperative treatment has been recommended,^1-3 especially in skeletally immature populations with a capacity for remodeling,^7-9 2 recent randomized clinical trials have demonstrated improved patient outcomes with ORIF.^6,8,9 Traditionally, ORIF was recommended with tenting of the skin because of concern for an impending open fracture. However, recent review materials have implied that this complication may only be theoretical.^3,5 Indeed, in 2 randomized trials, sufficient displacement to cause concern for impending violation of the skin envelope was not listed as an exclusion criteria.^8,9 We report 2 cases of displaced comminuted clavicle fractures that were initially managed nonoperatively but developed open lesions at the fracture site. This complication, while rare, is possible, and surgeons must consider it as a possibility when assessing patients with displaced clavicle fractures. To the best of the authors’ knowledge, no guidelines exist to direct antibiotic choice and duration in secondarily open fractures.

These 2 cases have several features in common that may serve as risk factors for impending violation of the skin envelope. Both fractures had a vertically angulated segmental piece of comminution with a sharp spike. This feature has been identified as a potential risk factor for subsequent development of an open fracture in a case report of fragment excision without reduction or fixation to allow rapid return to play in a professional jockey.¹³ Both patients in these cases presented with high-velocity mechanisms of injury and significant displacement, both of which may serve as risk factors. In the only similar case the authors could identify, Strauss and colleagues¹⁴ described a distal clavicle fracture with significant displacement and with secondary ulceration of the skin complicated by infection presenting with purulent discharge, cultured positive for methicillin-sensitive Staphylococcus aureus, requiring management with an external fixator and 6 weeks of intravenous antibiotics. Because both cases presented here occurred in healthy adolescent patients who were taken urgently for I&D and ORIF as soon as the wound was discovered, deep infection was avoided in these cases. Finally, in 1 case, a figure-of-8 brace was employed, which may also have placed pressure on the skin overlying the fracture and may have predisposed this patient to this complication.

Conclusion

In displaced midshaft clavicle fractures, tenting of the skin sufficient to cause subsequent violation of the soft-tissue envelope is possible and is more than a theoretical risk. At-risk patients, ie, those with a vertically angulated sharp fragment of comminution, should be counseled appropriately and observed closely or considered for primary ORIF.

Fractures of the clavicle, which account for 2.6% of all fractures, are displaced in 70% of cases and are mid-diaphyseal in 80% of cases.^1-3 Historically, both displaced and nondisplaced fractures were treated nonoperatively with excellent outcomes reported in the majority of patients.^1-3 Traditionally, the indications for surgical fixation of a clavicular fracture include open fractures, which occur infrequently, accounting for only 3.2% of clavicle fractures.⁴ Other indications include floating shoulder girdle or scapulothoracic dissociation, neurovascular injury, and skin “tenting” by the fracture fragments.^3,5 Recently, both meta-analyses and randomized clinical trials have reported reduced malunion rates and improved patient outcomes with open reduction and internal fixation (ORIF).^6-9 Consequently, operative fixation could be considered in patients with 100% displacement or greater than 1.5 cm shortening.^6-9 Open reduction and internal fixation of the clavicle has been demonstrated to have excellent outcomes in pediatric populations as well.¹⁰

The clavicle is subcutaneous for much of its length and, thus, displaced clavicular fractures often result in a visible deformity with a stretch of the soft-tissue envelope over the fracture. While this has been suggested as an operative indication, several recent sources indicate that this concern may only be theoretical. According to the fourth edition of Skeletal Trauma, “It is often stated that open reduction and internal fixation should be considered if the skin is threatened by pressure from a prominent clavicle fracture fragment; however, it is extremely rare of the skin to be perforated from within.”⁵ The most recent Journal of Bone and Joint Surgery Current Concepts Review on the subject stated that “open fractures or soft-tissue tenting sufficient to produce skin necrosis is uncommon.”³ To the best of our knowledge, there is no reported case of a displaced midshaft clavicle fracture with secondary skin necrosis and conversion into an open fracture, validating the conclusion that this complication may be only theoretical. Given that surgical fixation carries a risk of complications including wound complications, infection, nonunion, malunion, and damage to the nearby neurovascular structures and pleural apices,¹¹ some surgeons may be uncertain how to proceed in cases at risk for disturbance of the soft tissues.

We report 2 adolescent cases of displaced, comminuted clavicle fractures in which the skin was initially intact. Both were managed nonoperatively and both secondarily presented with open lesions at the fracture site requiring urgent irrigation and débridement (I&D) and ORIF. The patients and their guardians provided written informed consent for print and electronic publication of these case reports.

Case Reports

Case 1

A 15-year-old boy with no significant medical or surgical history flipped over the handlebars of his bicycle the day prior to presentation and sustained a clavicle fracture on his left nondominant upper extremity. This was an isolated injury. On examination, his skin was intact with an area of tender mild osseous protuberance at the midclavicle with associated surrounding edema. He was neurovascularly intact. Radiographs showed a displaced fracture of the midshaft of the clavicle with 20% shortening with a vertically angulated piece of comminution (Figure 1A). After a discussion of the treatment options with the family, the decision was made to pursue nonoperative treatment with sling immobilization as needed and restriction from gym and sports.

Two and a half weeks later, the patient presented at follow-up with significant reduction but persistence of his pain and a new complaint of drainage from the area of the fracture. On examination, he was found to have a puncture wound of the skin with exposed clavicle protruding through the wound with a 1-cm circumferential area of erythema without purulence present or expressible. The patient denied reinjury and endorsed compliance with sling immobilization. He was taken for urgent I&D and ORIF. After excision of the eschar surrounding the open lesion and full I&D of the soft tissues, the protruding spike was partially excised and the fracture site was débrided. The fracture was reduced and fixated with a lag screw and neutralization plate technique using an anatomically contoured locking clavicle plate (Synthes). Vancomycin powder was sprinkled into the wound at the completion of the procedure to reduce the chance of infection.¹²

Postoperatively, the patient was prescribed oral clindamycin but was subsequently switched to oral cephalexin because of mild signs of an allergic reaction, for a total course of antibiotics of 1 week. The patient was immobilized in a sling for comfort for the first 9 weeks postoperatively until radiographic union occurred. The patient’s wound healed uneventfully and with acceptable cosmesis. He was released to full activities at 10 weeks postoperatively. At final follow-up 6 months after surgery, the patient had returned to all of his regular activities without pain, and with full range of motion and no demonstrable deficits with radiographic union (Figure 1B).

Case 2

An 11-year-old boy with no significant medical or surgical history fell onto his right dominant upper extremity while doing a jump on his dirt bike 1 week prior to presentation, sustaining a clavicle fracture. This was an isolated injury. He was seen and evaluated by an outside orthopedist who noted that the soft-tissue envelope was intact and the patient was neurovascularly intact. Radiographs showed a displaced fracture of the midshaft of the clavicle with 15% shortening and with a vertically angulated piece of comminution (Figure 1C). Nonoperative treatment with a figure-of-8 brace was recommended. The patient’s discomfort completely resolved.

One week later, when he presented to the outside orthopedist for follow-up, the development of a wound overlying the fracture site was noted, and the patient was started on oral trimethoprim/sulfamethoxazole and referred to our office for treatment (Figure 1D). The patient denied reinjury and endorsed compliance with brace immobilization. On examination, the patient was afebrile and was noted to have a puncture wound at the fracture site with a protruding spike of bone and surrounding erythema but without present or expressible discharge (Figure 2). The patient was taken urgently for I&D and ORIF, using a similar technique to case 1, except that no lag screw was employed.

Postoperatively, the patient did well with no complications; he was prescribed oral cephalexin for 1 week. The patient was immobilized in a sling for the first 5 weeks after surgery until radiographic union had occurred, after which the sling was discontinued. The patient’s wound healed uneventfully and with acceptable cosmesis. The patient was released from activity restrictions at 6 weeks postoperatively. At final follow-up 5 weeks after surgery, the patient had full painless range of motion, no tenderness at the fracture site, no signs of infection on examination, and radiographic union (Figure 1D).

Discussion

Optimal treatment of displaced clavicle fractures is controversial. While nonoperative treatment has been recommended,^1-3 especially in skeletally immature populations with a capacity for remodeling,^7-9 2 recent randomized clinical trials have demonstrated improved patient outcomes with ORIF.^6,8,9 Traditionally, ORIF was recommended with tenting of the skin because of concern for an impending open fracture. However, recent review materials have implied that this complication may only be theoretical.^3,5 Indeed, in 2 randomized trials, sufficient displacement to cause concern for impending violation of the skin envelope was not listed as an exclusion criteria.^8,9 We report 2 cases of displaced comminuted clavicle fractures that were initially managed nonoperatively but developed open lesions at the fracture site. This complication, while rare, is possible, and surgeons must consider it as a possibility when assessing patients with displaced clavicle fractures. To the best of the authors’ knowledge, no guidelines exist to direct antibiotic choice and duration in secondarily open fractures.

These 2 cases have several features in common that may serve as risk factors for impending violation of the skin envelope. Both fractures had a vertically angulated segmental piece of comminution with a sharp spike. This feature has been identified as a potential risk factor for subsequent development of an open fracture in a case report of fragment excision without reduction or fixation to allow rapid return to play in a professional jockey.¹³ Both patients in these cases presented with high-velocity mechanisms of injury and significant displacement, both of which may serve as risk factors. In the only similar case the authors could identify, Strauss and colleagues¹⁴ described a distal clavicle fracture with significant displacement and with secondary ulceration of the skin complicated by infection presenting with purulent discharge, cultured positive for methicillin-sensitive Staphylococcus aureus, requiring management with an external fixator and 6 weeks of intravenous antibiotics. Because both cases presented here occurred in healthy adolescent patients who were taken urgently for I&D and ORIF as soon as the wound was discovered, deep infection was avoided in these cases. Finally, in 1 case, a figure-of-8 brace was employed, which may also have placed pressure on the skin overlying the fracture and may have predisposed this patient to this complication.

Conclusion

In displaced midshaft clavicle fractures, tenting of the skin sufficient to cause subsequent violation of the soft-tissue envelope is possible and is more than a theoretical risk. At-risk patients, ie, those with a vertically angulated sharp fragment of comminution, should be counseled appropriately and observed closely or considered for primary ORIF.

Adamantinomas are rare primary malignant bone tumors (less than 1% of all bone tumors) that arise most commonly in the tibia.¹ There is a predilection for adult men aged 20 to 50 years, with rare occurrences in children. These tumors are malignant, highly invasive, and have significant metastatic potential.² A rarely seen, benign variant, known as osteofibrous dysplasia–like adamantinoma, is described in the literature, with fewer than 135 cases reported.^3-5 This variant predominantly has benign characteristics of an osteofibrous dysplasia lesion but has the potential to transform into an adamantinoma.⁶ Osteofibrous dysplasia–like adamantinoma has been observed to regress with age and is also referred to as a regressing adamantinoma or differentiated adamantinoma.⁷ 

We report an uncommon case of an osteofibrous dysplasia–like adamantinoma of the tibia in a 15-year-old girl. We decided to observe the tumor with regular 3- to 6-month follow-ups. Osteofibrous dysplasia–like adamantinoma in our patient has remained stable for 2 years and has an excellent prognosis.⁸ We report this case for its rarity, its short-term stability, and significant treatment implications due to its potential to regress or develop into a malignant form. The patient and the patient’s guardian provided written informed consent for print and electronic publication of this case report. 

Case Report

A healthy 15-year-old girl was referred to our institution for evaluation of anterior left knee pain. She had sustained a fall while playing basketball 3 months earlier and had been having left knee pain since that time. She did not have any swelling, catching, or locking in her left knee. She denied any recent fever, chills, night sweats, weight loss, nausea, vomiting, or diarrhea. On physical examination, her gait was normal and no swelling, erythema, or tenderness was noticed around the left knee.

Plain radiographs revealed a heterogeneous lesion with sclerosis and thickening of the anteromedial cortex of the proximal left tibia (Figures 1A, 1B). A computed tomography (CT) scan of the abdomen, pelvis, and chest showed no osseous abnormalities. A whole-body bone scan showed activity in the anterior aspect of the left proximal tibia. No other areas of activity were noted. Magnetic resonance imaging of the left leg showed an elongated, multiloculated, enhancing mass arising from the anterolateral cortex and extending from the tibial tuberosity to the mid-diaphysis of the left tibia. Histologic examination of the CT-guided core needle biopsy specimen showed that the lesion was composed of dense fibrocollagenous tissue separating irregular bony trabeculae with osteoblastic and osteoclastic activity. There was no evidence of any atypical cells, necrosis, or significant mitotic activity. No epithelial cells were identified on hematoxylin-eosin (H&E) stain (Figure 2). However, immunohistochemical staining was positive for focal cytokeratin-positive epithelial cells (Figure 3). The lesion was diagnosed as an osteofibrous dysplasia–like adamantinoma on the basis of the radiographic and histologic findings. We elected nonoperative intervention given the benign nature of the lesion and its potential to regress. Given the possibility of sampling error and potential for progression, the patient was followed regularly at 3- to 6-month intervals over a 2-year period without disease progression. 

Discussion

Osteofibrous dysplasia, osteofibrous dysplasia–like adamantinoma, and adamantinoma are rare fibro-osseous lesions that largely involve the midshaft of the tibia. Osteofibrous dysplasia accounts for 0.2% of primary bone tumors, whereas adamantinoma accounts for 0.1% to 0.5% of malignant bone tumors.⁹ Osteofibrous dysplasia is a benign lesion composed primarily of fibro-osseous tissue. Adamantinoma, however, is a slow-growing, low-grade, malignant biphasic tumor with intermingled epithelial and fibro-osseous components. It is an aggressive tumor that is locally invasive and can metastasize.² Osteofibrous dysplasia–like adamantinoma (also known as differentiated or regressing adamantinoma) is a benign lesion like osteofibrous dysplasia but has features of both osteofibrous dysplasia and adamantinoma. Osteofibrous dysplasia–like adamantinoma may progress and become a malignant adamantinoma.^6,10

The radiologic features of the 3 lesions are quite similar. It is not possible to distinguish between osteofibrous dysplasia and osteofibrous dysplasia–like adamantinoma based on imaging alone.⁹ Adamantinoma, being highly invasive, can be distinguished from osteofibrous dysplasia and osteofibrous dysplasia–like adamantinoma according to the extent of involvement of the medullary cavity seen on magnetic resonance imaging.⁹ Complete involvement of the medullary cavity is almost always seen in an adamantinoma. Involvement of the medullary cavity is minimal or absent in osteofibrous dysplasia and osteofibrous dysplasia–like adamantinoma lesions. 

Tissue confirmation through biopsy is crucial for accurate diagnosis. A biopsy should always be performed on any suspicious lesion,^3,6 and the fibro-osseous lesion should be treated as an adamantinoma if findings are equivocal. A biopsy also distinctly distinguishes these lesions from benign fibrous cortical defects, which have a similar radiographic appearance. While open biopsy is the gold standard, minimally invasive techniques such as core needle biopsy and fine needle biopsy are increasingly used.⁶ Because of the higher risk of misdiagnosis with minimally invasive techniques, radiographic confirmation is highly recommended.⁵

Histologically, both osteofibrous dysplasia and osteofibrous dysplasia–like adamantinoma do not stain for cytokeratin on H&E stain. However, they can be differentiated based on immunohistochemical staining for cytokeratin. Osteofibrous dysplasia lesions exhibit diffuse staining whereas osteofibrous dysplasia–like adamantinoma lesions show focal staining of small nests of epithelial cells. Adamantinoma, in comparison, exhibits a biphasic pattern on H&E stain, representing areas of epithelial and osteofibrous cells. Immunohistochemical staining for cytokeratin of an adamantinoma reveals large nests of epithelial cells.  

The association between osteofibrous dysplasia, osteofibrous dysplasia–like adamantinoma, and adamantinoma is not clearly established. However, it is widely believed that these 3 lesions represent a spectrum of the same disease and are linearly related in disease progression, with osteofibrous dysplasia at the benign end of the spectrum, osteofibrous dysplasia–like adamantinoma the intermediate form, and adamantinoma at the malignant end of the spectrum.¹¹

Hazelbag and colleagues⁶ and Springfield and colleagues¹⁰ point out that osteofibrous dysplasia and osteofibrous dysplasia–like adamantinoma could be precursor lesions of adamantinoma. We found several studies in the literature that support and document progression from osteofibrous dysplasia and osteofibrous dysplasia–like adamantinoma to an adamantinoma.^4,6,10,12 Other studies, however, showed no progression from either a benign osteofibrous dysplasia or an osteofibrous dysplasia–like adamantinoma lesion to a malignant adamantinoma. Park and colleagues¹³ described 41 cases of osteofibrous dysplasia that did not progress to adamantinoma. Kuruvilla and Steiner⁸ described 5 cases of osteofibrous dysplasia–like adamantinoma that showed no progression to adamantinoma. Additionally, our case has not progressed and has remained radiographically stable over a 2-year follow-up. Czerniak and colleagues⁷ and Ueda and colleagues¹⁴ postulated, based on histologic and immunohistochemical studies, that osteofibrous dysplasia–like adamantinoma might be a regressing form of an adamantinoma that is undergoing reparative processes that could result in complete elimination of all tumor cells.

In general, any lesion with absent to low malignant potential could be managed nonoperatively with periodic observation and without the need for surgical intervention. Thus, identification of a stable or nonprogressing osteofibrous dysplasia–like adamantinoma lesion has significant treatment implications. Campanacci and Laus¹⁵ at the Rizzoli Institute in Milan, through long term follow-up of their patients with osteofibrous dysplasia, found that most lesions had a tendency to regress spontaneously by puberty. They recommended that nonextensive osteofibrous dysplasia lesions should be observed, and surgery should be delayed until puberty. Gleason and colleagues¹⁶ also recommended nonoperative management of osteofibrous dysplasia lesions, with surgery used only for large, deforming, and highly invasive lesions. We recommend a similar treatment approach for osteofibrous dysplasia–like adamantinoma lesions.

Adamantinomas, however, are usually symptomatic, are highly invasive, have a high recurrence rate, and can metastasize.9 In these patients, a wide en bloc resection or amputation should be performed as soon as possible.11 Our case highlights that osteofibrous dysplasia–like adamantinoma lesions can occur in children and can remain stable, especially over the short term. Such lesions can be observed without surgical intervention.

Adamantinomas are rare primary malignant bone tumors (less than 1% of all bone tumors) that arise most commonly in the tibia.¹ There is a predilection for adult men aged 20 to 50 years, with rare occurrences in children. These tumors are malignant, highly invasive, and have significant metastatic potential.² A rarely seen, benign variant, known as osteofibrous dysplasia–like adamantinoma, is described in the literature, with fewer than 135 cases reported.^3-5 This variant predominantly has benign characteristics of an osteofibrous dysplasia lesion but has the potential to transform into an adamantinoma.⁶ Osteofibrous dysplasia–like adamantinoma has been observed to regress with age and is also referred to as a regressing adamantinoma or differentiated adamantinoma.⁷ 

We report an uncommon case of an osteofibrous dysplasia–like adamantinoma of the tibia in a 15-year-old girl. We decided to observe the tumor with regular 3- to 6-month follow-ups. Osteofibrous dysplasia–like adamantinoma in our patient has remained stable for 2 years and has an excellent prognosis.⁸ We report this case for its rarity, its short-term stability, and significant treatment implications due to its potential to regress or develop into a malignant form. The patient and the patient’s guardian provided written informed consent for print and electronic publication of this case report. 

Case Report

A healthy 15-year-old girl was referred to our institution for evaluation of anterior left knee pain. She had sustained a fall while playing basketball 3 months earlier and had been having left knee pain since that time. She did not have any swelling, catching, or locking in her left knee. She denied any recent fever, chills, night sweats, weight loss, nausea, vomiting, or diarrhea. On physical examination, her gait was normal and no swelling, erythema, or tenderness was noticed around the left knee.

Plain radiographs revealed a heterogeneous lesion with sclerosis and thickening of the anteromedial cortex of the proximal left tibia (Figures 1A, 1B). A computed tomography (CT) scan of the abdomen, pelvis, and chest showed no osseous abnormalities. A whole-body bone scan showed activity in the anterior aspect of the left proximal tibia. No other areas of activity were noted. Magnetic resonance imaging of the left leg showed an elongated, multiloculated, enhancing mass arising from the anterolateral cortex and extending from the tibial tuberosity to the mid-diaphysis of the left tibia. Histologic examination of the CT-guided core needle biopsy specimen showed that the lesion was composed of dense fibrocollagenous tissue separating irregular bony trabeculae with osteoblastic and osteoclastic activity. There was no evidence of any atypical cells, necrosis, or significant mitotic activity. No epithelial cells were identified on hematoxylin-eosin (H&E) stain (Figure 2). However, immunohistochemical staining was positive for focal cytokeratin-positive epithelial cells (Figure 3). The lesion was diagnosed as an osteofibrous dysplasia–like adamantinoma on the basis of the radiographic and histologic findings. We elected nonoperative intervention given the benign nature of the lesion and its potential to regress. Given the possibility of sampling error and potential for progression, the patient was followed regularly at 3- to 6-month intervals over a 2-year period without disease progression. 

Discussion

Osteofibrous dysplasia, osteofibrous dysplasia–like adamantinoma, and adamantinoma are rare fibro-osseous lesions that largely involve the midshaft of the tibia. Osteofibrous dysplasia accounts for 0.2% of primary bone tumors, whereas adamantinoma accounts for 0.1% to 0.5% of malignant bone tumors.⁹ Osteofibrous dysplasia is a benign lesion composed primarily of fibro-osseous tissue. Adamantinoma, however, is a slow-growing, low-grade, malignant biphasic tumor with intermingled epithelial and fibro-osseous components. It is an aggressive tumor that is locally invasive and can metastasize.² Osteofibrous dysplasia–like adamantinoma (also known as differentiated or regressing adamantinoma) is a benign lesion like osteofibrous dysplasia but has features of both osteofibrous dysplasia and adamantinoma. Osteofibrous dysplasia–like adamantinoma may progress and become a malignant adamantinoma.^6,10

The radiologic features of the 3 lesions are quite similar. It is not possible to distinguish between osteofibrous dysplasia and osteofibrous dysplasia–like adamantinoma based on imaging alone.⁹ Adamantinoma, being highly invasive, can be distinguished from osteofibrous dysplasia and osteofibrous dysplasia–like adamantinoma according to the extent of involvement of the medullary cavity seen on magnetic resonance imaging.⁹ Complete involvement of the medullary cavity is almost always seen in an adamantinoma. Involvement of the medullary cavity is minimal or absent in osteofibrous dysplasia and osteofibrous dysplasia–like adamantinoma lesions. 

Tissue confirmation through biopsy is crucial for accurate diagnosis. A biopsy should always be performed on any suspicious lesion,^3,6 and the fibro-osseous lesion should be treated as an adamantinoma if findings are equivocal. A biopsy also distinctly distinguishes these lesions from benign fibrous cortical defects, which have a similar radiographic appearance. While open biopsy is the gold standard, minimally invasive techniques such as core needle biopsy and fine needle biopsy are increasingly used.⁶ Because of the higher risk of misdiagnosis with minimally invasive techniques, radiographic confirmation is highly recommended.⁵

Histologically, both osteofibrous dysplasia and osteofibrous dysplasia–like adamantinoma do not stain for cytokeratin on H&E stain. However, they can be differentiated based on immunohistochemical staining for cytokeratin. Osteofibrous dysplasia lesions exhibit diffuse staining whereas osteofibrous dysplasia–like adamantinoma lesions show focal staining of small nests of epithelial cells. Adamantinoma, in comparison, exhibits a biphasic pattern on H&E stain, representing areas of epithelial and osteofibrous cells. Immunohistochemical staining for cytokeratin of an adamantinoma reveals large nests of epithelial cells.  

The association between osteofibrous dysplasia, osteofibrous dysplasia–like adamantinoma, and adamantinoma is not clearly established. However, it is widely believed that these 3 lesions represent a spectrum of the same disease and are linearly related in disease progression, with osteofibrous dysplasia at the benign end of the spectrum, osteofibrous dysplasia–like adamantinoma the intermediate form, and adamantinoma at the malignant end of the spectrum.¹¹

Hazelbag and colleagues⁶ and Springfield and colleagues¹⁰ point out that osteofibrous dysplasia and osteofibrous dysplasia–like adamantinoma could be precursor lesions of adamantinoma. We found several studies in the literature that support and document progression from osteofibrous dysplasia and osteofibrous dysplasia–like adamantinoma to an adamantinoma.^4,6,10,12 Other studies, however, showed no progression from either a benign osteofibrous dysplasia or an osteofibrous dysplasia–like adamantinoma lesion to a malignant adamantinoma. Park and colleagues¹³ described 41 cases of osteofibrous dysplasia that did not progress to adamantinoma. Kuruvilla and Steiner⁸ described 5 cases of osteofibrous dysplasia–like adamantinoma that showed no progression to adamantinoma. Additionally, our case has not progressed and has remained radiographically stable over a 2-year follow-up. Czerniak and colleagues⁷ and Ueda and colleagues¹⁴ postulated, based on histologic and immunohistochemical studies, that osteofibrous dysplasia–like adamantinoma might be a regressing form of an adamantinoma that is undergoing reparative processes that could result in complete elimination of all tumor cells.

In general, any lesion with absent to low malignant potential could be managed nonoperatively with periodic observation and without the need for surgical intervention. Thus, identification of a stable or nonprogressing osteofibrous dysplasia–like adamantinoma lesion has significant treatment implications. Campanacci and Laus¹⁵ at the Rizzoli Institute in Milan, through long term follow-up of their patients with osteofibrous dysplasia, found that most lesions had a tendency to regress spontaneously by puberty. They recommended that nonextensive osteofibrous dysplasia lesions should be observed, and surgery should be delayed until puberty. Gleason and colleagues¹⁶ also recommended nonoperative management of osteofibrous dysplasia lesions, with surgery used only for large, deforming, and highly invasive lesions. We recommend a similar treatment approach for osteofibrous dysplasia–like adamantinoma lesions.

Adamantinomas, however, are usually symptomatic, are highly invasive, have a high recurrence rate, and can metastasize.9 In these patients, a wide en bloc resection or amputation should be performed as soon as possible.11 Our case highlights that osteofibrous dysplasia–like adamantinoma lesions can occur in children and can remain stable, especially over the short term. Such lesions can be observed without surgical intervention.

Adamantinomas are rare primary malignant bone tumors (less than 1% of all bone tumors) that arise most commonly in the tibia.¹ There is a predilection for adult men aged 20 to 50 years, with rare occurrences in children. These tumors are malignant, highly invasive, and have significant metastatic potential.² A rarely seen, benign variant, known as osteofibrous dysplasia–like adamantinoma, is described in the literature, with fewer than 135 cases reported.^3-5 This variant predominantly has benign characteristics of an osteofibrous dysplasia lesion but has the potential to transform into an adamantinoma.⁶ Osteofibrous dysplasia–like adamantinoma has been observed to regress with age and is also referred to as a regressing adamantinoma or differentiated adamantinoma.⁷ 

We report an uncommon case of an osteofibrous dysplasia–like adamantinoma of the tibia in a 15-year-old girl. We decided to observe the tumor with regular 3- to 6-month follow-ups. Osteofibrous dysplasia–like adamantinoma in our patient has remained stable for 2 years and has an excellent prognosis.⁸ We report this case for its rarity, its short-term stability, and significant treatment implications due to its potential to regress or develop into a malignant form. The patient and the patient’s guardian provided written informed consent for print and electronic publication of this case report. 

Case Report

A healthy 15-year-old girl was referred to our institution for evaluation of anterior left knee pain. She had sustained a fall while playing basketball 3 months earlier and had been having left knee pain since that time. She did not have any swelling, catching, or locking in her left knee. She denied any recent fever, chills, night sweats, weight loss, nausea, vomiting, or diarrhea. On physical examination, her gait was normal and no swelling, erythema, or tenderness was noticed around the left knee.

Plain radiographs revealed a heterogeneous lesion with sclerosis and thickening of the anteromedial cortex of the proximal left tibia (Figures 1A, 1B). A computed tomography (CT) scan of the abdomen, pelvis, and chest showed no osseous abnormalities. A whole-body bone scan showed activity in the anterior aspect of the left proximal tibia. No other areas of activity were noted. Magnetic resonance imaging of the left leg showed an elongated, multiloculated, enhancing mass arising from the anterolateral cortex and extending from the tibial tuberosity to the mid-diaphysis of the left tibia. Histologic examination of the CT-guided core needle biopsy specimen showed that the lesion was composed of dense fibrocollagenous tissue separating irregular bony trabeculae with osteoblastic and osteoclastic activity. There was no evidence of any atypical cells, necrosis, or significant mitotic activity. No epithelial cells were identified on hematoxylin-eosin (H&E) stain (Figure 2). However, immunohistochemical staining was positive for focal cytokeratin-positive epithelial cells (Figure 3). The lesion was diagnosed as an osteofibrous dysplasia–like adamantinoma on the basis of the radiographic and histologic findings. We elected nonoperative intervention given the benign nature of the lesion and its potential to regress. Given the possibility of sampling error and potential for progression, the patient was followed regularly at 3- to 6-month intervals over a 2-year period without disease progression. 

Discussion

Osteofibrous dysplasia, osteofibrous dysplasia–like adamantinoma, and adamantinoma are rare fibro-osseous lesions that largely involve the midshaft of the tibia. Osteofibrous dysplasia accounts for 0.2% of primary bone tumors, whereas adamantinoma accounts for 0.1% to 0.5% of malignant bone tumors.⁹ Osteofibrous dysplasia is a benign lesion composed primarily of fibro-osseous tissue. Adamantinoma, however, is a slow-growing, low-grade, malignant biphasic tumor with intermingled epithelial and fibro-osseous components. It is an aggressive tumor that is locally invasive and can metastasize.² Osteofibrous dysplasia–like adamantinoma (also known as differentiated or regressing adamantinoma) is a benign lesion like osteofibrous dysplasia but has features of both osteofibrous dysplasia and adamantinoma. Osteofibrous dysplasia–like adamantinoma may progress and become a malignant adamantinoma.^6,10

The radiologic features of the 3 lesions are quite similar. It is not possible to distinguish between osteofibrous dysplasia and osteofibrous dysplasia–like adamantinoma based on imaging alone.⁹ Adamantinoma, being highly invasive, can be distinguished from osteofibrous dysplasia and osteofibrous dysplasia–like adamantinoma according to the extent of involvement of the medullary cavity seen on magnetic resonance imaging.⁹ Complete involvement of the medullary cavity is almost always seen in an adamantinoma. Involvement of the medullary cavity is minimal or absent in osteofibrous dysplasia and osteofibrous dysplasia–like adamantinoma lesions. 

Tissue confirmation through biopsy is crucial for accurate diagnosis. A biopsy should always be performed on any suspicious lesion,^3,6 and the fibro-osseous lesion should be treated as an adamantinoma if findings are equivocal. A biopsy also distinctly distinguishes these lesions from benign fibrous cortical defects, which have a similar radiographic appearance. While open biopsy is the gold standard, minimally invasive techniques such as core needle biopsy and fine needle biopsy are increasingly used.⁶ Because of the higher risk of misdiagnosis with minimally invasive techniques, radiographic confirmation is highly recommended.⁵

Histologically, both osteofibrous dysplasia and osteofibrous dysplasia–like adamantinoma do not stain for cytokeratin on H&E stain. However, they can be differentiated based on immunohistochemical staining for cytokeratin. Osteofibrous dysplasia lesions exhibit diffuse staining whereas osteofibrous dysplasia–like adamantinoma lesions show focal staining of small nests of epithelial cells. Adamantinoma, in comparison, exhibits a biphasic pattern on H&E stain, representing areas of epithelial and osteofibrous cells. Immunohistochemical staining for cytokeratin of an adamantinoma reveals large nests of epithelial cells.  

The association between osteofibrous dysplasia, osteofibrous dysplasia–like adamantinoma, and adamantinoma is not clearly established. However, it is widely believed that these 3 lesions represent a spectrum of the same disease and are linearly related in disease progression, with osteofibrous dysplasia at the benign end of the spectrum, osteofibrous dysplasia–like adamantinoma the intermediate form, and adamantinoma at the malignant end of the spectrum.¹¹

Hazelbag and colleagues⁶ and Springfield and colleagues¹⁰ point out that osteofibrous dysplasia and osteofibrous dysplasia–like adamantinoma could be precursor lesions of adamantinoma. We found several studies in the literature that support and document progression from osteofibrous dysplasia and osteofibrous dysplasia–like adamantinoma to an adamantinoma.^4,6,10,12 Other studies, however, showed no progression from either a benign osteofibrous dysplasia or an osteofibrous dysplasia–like adamantinoma lesion to a malignant adamantinoma. Park and colleagues¹³ described 41 cases of osteofibrous dysplasia that did not progress to adamantinoma. Kuruvilla and Steiner⁸ described 5 cases of osteofibrous dysplasia–like adamantinoma that showed no progression to adamantinoma. Additionally, our case has not progressed and has remained radiographically stable over a 2-year follow-up. Czerniak and colleagues⁷ and Ueda and colleagues¹⁴ postulated, based on histologic and immunohistochemical studies, that osteofibrous dysplasia–like adamantinoma might be a regressing form of an adamantinoma that is undergoing reparative processes that could result in complete elimination of all tumor cells.

In general, any lesion with absent to low malignant potential could be managed nonoperatively with periodic observation and without the need for surgical intervention. Thus, identification of a stable or nonprogressing osteofibrous dysplasia–like adamantinoma lesion has significant treatment implications. Campanacci and Laus¹⁵ at the Rizzoli Institute in Milan, through long term follow-up of their patients with osteofibrous dysplasia, found that most lesions had a tendency to regress spontaneously by puberty. They recommended that nonextensive osteofibrous dysplasia lesions should be observed, and surgery should be delayed until puberty. Gleason and colleagues¹⁶ also recommended nonoperative management of osteofibrous dysplasia lesions, with surgery used only for large, deforming, and highly invasive lesions. We recommend a similar treatment approach for osteofibrous dysplasia–like adamantinoma lesions.

Adamantinomas, however, are usually symptomatic, are highly invasive, have a high recurrence rate, and can metastasize.9 In these patients, a wide en bloc resection or amputation should be performed as soon as possible.11 Our case highlights that osteofibrous dysplasia–like adamantinoma lesions can occur in children and can remain stable, especially over the short term. Such lesions can be observed without surgical intervention.

Interscalene brachial plexus anesthesia is commonly used for arthroscopic and open procedures of the shoulder. This regional anesthetic targets the trunks of the brachial plexus and anesthetizes the area about the shoulder and proximal arm. Its use may obviate the need for concomitant general anesthesia, potentially reducing the use of postoperative intravenous and oral pain medication. Furthermore, patients often bypass the acute postoperative anesthesia care unit and proceed directly to the ambulatory unit, permitting earlier hospital discharge. Previous reports in the literature have demonstrated higher rates of neurologic, cardiac, and pulmonary complications from this procedure; in particular, the incidence of pneumothorax was reported as high as 3%.¹ Techniques to localize the nerves, such as electrical nerve stimulation and, more recently, ultrasound guidance, have reduced these complication rates.^2,3 Successful administration of the block has been shown to result in satisfactory postoperative pain relief.² However, ultrasound-guided interscalene nerve blocks remain operator-dependent and complications may still occur.

We report a case of tension pneumothorax after arthroscopic rotator cuff repair and subacromial decompression with an ultrasound-guided interscalene block. Immediate recognition and treatment of this complication resulted in a good clinical outcome. The patient provided written informed consent for print and electronic publication of this case report. 

Case Report

A 56-year-old woman presented with 3 months of right shoulder pain after a fall. Examination was pertinent for weakness in forward elevation and positive rotator cuff impingement signs. She remained symptomatic despite a course of nonsurgical management that included cortisone injections and physical therapy. Magnetic resonance imaging of the shoulder showed a full-thickness supraspinatus tear with minimal fatty atrophy. After a discussion of her treatment options, she elected to undergo an arthroscopic rotator cuff repair with subacromial decompression. An evaluation by her internist revealed no pertinent medical history apart from obesity (body mass index, 36). Specifically, there was no reported history of chronic obstructive pulmonary disease or asthma. She denied any prior cigarette smoking.

The patient was evaluated by the regional anesthesia team and was classified as a class 2 airway. An interscalene brachial plexus block was performed using a 2-inch, 22-gauge needle inserted into the interscalene groove. Using an out-of-plane technique under direct ultrasound guidance, 30 mL of 0.52% ropivacaine was injected. The block was considered successful, and no complications, such as resistance, paresthesias, pain, or blood on aspiration, were noted during injection. The patient had no complaints of chest pain or shortness of breath immediately afterward, and all vital signs were stable throughout the procedure.

The patient was brought to the operating room and placed in the beach-chair position. Induction for general anesthesia was started 15 minutes after the regional anesthetic, with 2 intubation attempts necessary because of poor airway visualization. After placement of the endotracheal tube, breath sounds were noted to be equal bilaterally. The arthroscopic procedure consisted of double-row rotator cuff repair, subacromial decompression, and débridement of the glenohumeral joint for synovitis, using standard arthroscopic portals. There were no difficulties with trocar placement, and bleeding was minimal throughout the case. The total surgical time was 150 minutes and a pump pressure of 30 mm Hg was maintained during the arthroscopy.

Within the first 60 minutes of the start of the arthroscopic procedure, the patient was noted to be intermittently hypotensive with mean arterial pressure (MAP) ranging from the 30s to 130s mm Hg and pulse in the 70 to 80 beats/min range. FiO₂ in the 85% to 95% range was maintained throughout the procedure. During that time, 50 μg phenylephrine was administered on 4 separate occasions to maintain her blood pressure. The labile blood pressure was attributed by the anesthesiologist to the beach-chair position. During an attempted extubation upon conclusion of the surgery, the patient became hypotensive with MAP that ranged from the 40s to 60s mm Hg and tachycardic to 90 beats/min. The oxygen saturation was in the low 90s and tidal volume was poor. Absent lung sounds were noted on the right chest. An urgent portable chest radiograph showed a large right-sided tension pneumothorax with mediastinal shift (Figure 1). After an immediate general surgery consultation, a chest tube was placed in the operating room. The patient’s vital signs improved and a repeat chest radiograph revealed successful re-expansion of the lung (Figure 2). She was transferred to the acute postoperative anesthesia care unit and extubated in the intensive care unit later that day.

The patient’s chest tube was removed 2 days later and she was discharged home on hospital day 5 with a completely resolved pneumothorax. She was seen 1 week later in the office for a postoperative visit and reported feeling well without chest pain or shortness of breath.

Discussion

Interscalene brachial plexus anesthesia was first described by Winnie⁴ in 1970. This block targets the trunks of the brachial plexus, which are enclosed in a fascial sheath between the anterior and middle scalene muscles. In this region lie several structures at risk: the phrenic nerve superficially and inferiorly; the carotid sheath located superficially and medially; the subclavian artery parallel to the trunks; and the cupula of the lung that lies deep and inferior to the anterior scalene muscle. Recognized complications of the block include vocal hoarseness, Horner syndrome, and hemidiaphragmatic paresis caused by the temporary blockade of the ipsilateral recurrent laryngeal nerve, stellate ganglion, and phrenic nerve, in that order.⁵ Use of the interscalene block has been associated with minimal risk for pneumothorax, because the needle entry point is superior and directed away from the lung pleura.⁶ This is in contrast to the more inferiorly placed supraclavicular block, located in closer proximity to the lung cupula.⁵

Two different approaches are commonly used during ultrasound-guided nerve blocks. The in-plane approach generates a long-axis view of the needle by advancing the needle parallel with the long axis of the ultrasound probe. While this allows direct visualization of the needle tip, it requires deeper needle insertion from lateral to medial, causing puncture of the middle scalene muscle that may increase patient discomfort and risk nerve injury within the muscle.⁷ The out-of-plane approach used on our patient involves needle insertion parallel to the brachial plexus, but along the short axis of the ultrasound probe. Although this permits the operator to assess the periphery of the nerve, it may lead to poor needle-tip visualization during the procedure. As a result, operators often use a combination of tissue disturbance and “hydrolocation,” in which fluid is injected to indicate the needle-tip location.^8,9

Tension pneumothorax represents the accumulation of air in the pleural space that leads to impaired pulmonary and cardiac function. It is often caused by disruption or puncture of the parietal or visceral pleura, creating a connection between the alveoli and pleural cavity. The gradual buildup of air in the pleural cavity results in increased intrapleural pressure, which compresses and ultimately collapses the ipsilateral lung. Venous compression restricts blood return to the heart and reduces cardiac output. Clinical manifestations include dyspnea, hypoxemia, tachycardia, and hypotension.¹⁰ Multiple techniques were developed to better localize the brachial plexus while reducing injury to nearby structures, including the lung. These include eliciting needle paresthesias, electrical nerve stimulation, and ultrasound guidance. While nerve stimulation was once the gold standard for brachial plexus localization, ultrasound guidance has gained in popularity because of its noninvasive nature and dynamic capability to identify nerves and surrounding structures.¹¹ Perlas and colleagues¹² determined the sensitivity of needle paresthesias and nerve stimulation to be 38% and 75%, respectively, in cases in which plexus localization had been confirmed by ultrasound.

Several studies have reported on the efficacy of interscalene nerve block with either nerve stimulation or ultrasound guidance in the setting of shoulder surgery.^2,3 Bishop and colleagues³ reviewed 547 patients who underwent interscalene regional anesthesia with nerve stimulation for both arthroscopic and open-shoulder procedures. They reported a 97% success rate and 12 (2.3%) minor complications, including sensory neuropathy and complex regional pain syndrome. There were no cases of pneumothorax, cardiac events, or other major complications.³ In a prospective study of 1319 patients, Singh and colleagues² reported a 99.6% success rate using ultrasound-guided interscalene blocks for their shoulder surgeries. A total of 38 adverse events (2.88%) were identified: 14 transient neurologic events, including ear numbness, digital numbness, and brachial plexitis; 1 case of intraoperative bradycardia, and 2 cancellations after the block for chest pain and flank pain, which yielded negative cardiac workups. Other complications included postoperative emergency room visits and hospital admissions for reasons unrelated to the block.² Interscalene regional anesthesia, therefore, provides effective anesthesia for shoulder surgery with low complication rates.

Pneumothorax after ultrasound-guided interscalene block has rarely been reported.^13,14 In a review of 144 ultrasound-guided indwelling interscalene catheter placements, a 98% successful block rate with a single complication of small pneumothorax after total shoulder arthroplasty was reported.¹³ Mandim and colleagues¹⁴ reported a case of pneumothorax in a smoker who underwent an ultrasound-guided brachial plexus block prior to open reduction and internal fixation of an ulnar fracture. While the patient was asymptomatic and vital signs remained stable during the procedure, the patient complained postoperatively of chest pain with hypoxia, tachycardia, and hypotension. A chest radiograph confirmed an ipsilateral pneumothorax, and the patient was treated successfully with chest-tube placement. The authors attributed this complication to a higher pleural dome resulting from a hyperinflated lung caused by chronic smoking. Our patient reported no history of smoking and her preoperative chest radiograph had no evidence of lung disease.

In contrast, several cases of pneumothorax after shoulder surgery have been reported in the absence of nerve block. Oldman and Peng¹ reported a 41-year-old nonsmoker who underwent arthroscopic labral repair and subacromial decompression. The preoperative nerve block was cancelled, and the patient received general endotracheal anesthesia alone. Fifty minutes after the case, the patient developed chest pain and hypoxia. A chest radiograph showed a small pneumothorax that was managed conservatively. The pneumothorax was attributed to spontaneous rupture of a preexisting lung bulla, suggesting that blocks are not always the cause of this complication. Furthermore, Dietzel and Ciullo¹⁵ reported 4 cases of spontaneous pneumothorax within 24 hours of uncomplicated arthroscopic shoulder procedures under general anesthesia in the lateral decubitus position. The patient ages ranged from 22 to 38 years, and medical histories were all significant for preexisting lung disease, remote history of pneumonia, and heavy smoking. Three of the patients experienced symptoms at home the day after surgery. The authors concluded that these cases were likely caused by rupture of blebs or bullae from underlying lung disease; these ruptured blebs or bullae are difficult to detect and usually located in the upper lung. The pressure gradient from the positive pressure of anesthesia and the ipsilateral upper lung is thought to be highest in the lateral decubitus position, increasing their chance of rupture.¹⁵

Finally, Lee and colleagues¹⁶ described 3 patients aged 40 to 45 years who underwent uncomplicated subacromial decompression in the beach-chair position under general anesthesia. Significant shoulder, neck, and axillary swelling were noted after surgery, and a chest radiograph showed tension pneumothorax, subcutaneous emphysema, and pneumomediastinum. The authors speculated that pressure in the subacromial space may become negative relative to atmospheric pressure when the shaver and suction are running, drawing in air through other portals. When the suction is discontinued, fluid infusion may push air into the surrounding tissue, leading to subcutaneous emphysema, which may spread to the mediastinum.¹⁶ 

Conclusion 

Ultrasound-guided interscalene nerve blocks have successfully provided anesthesia for shoulder surgeries with low complication rates. Although the incidence of pneumothorax has decreased significantly with ultrasound guidance, the success of this procedure is highly operator-dependent. We present the case of an otherwise healthy patient without known pulmonary disease who developed a tension pneumothorax after the administration of ultrasound-guided regional and general anesthesia for arthroscopic shoulder surgery. Orthopedic surgeons and anesthesiologists must remain vigilant for pneumothorax during the perioperative period after shoulder surgery performed under interscalene regional aesthesia, particularly in the setting of hypotension, hypoxia, and/or tachycardia. Risk factors, such as history of smoking and preexisting lung disease, may predispose patients to the development of pneumothorax. Timely recognition and placement of a chest tube result in satisfactory clinical outcomes.

Interscalene brachial plexus anesthesia is commonly used for arthroscopic and open procedures of the shoulder. This regional anesthetic targets the trunks of the brachial plexus and anesthetizes the area about the shoulder and proximal arm. Its use may obviate the need for concomitant general anesthesia, potentially reducing the use of postoperative intravenous and oral pain medication. Furthermore, patients often bypass the acute postoperative anesthesia care unit and proceed directly to the ambulatory unit, permitting earlier hospital discharge. Previous reports in the literature have demonstrated higher rates of neurologic, cardiac, and pulmonary complications from this procedure; in particular, the incidence of pneumothorax was reported as high as 3%.¹ Techniques to localize the nerves, such as electrical nerve stimulation and, more recently, ultrasound guidance, have reduced these complication rates.^2,3 Successful administration of the block has been shown to result in satisfactory postoperative pain relief.² However, ultrasound-guided interscalene nerve blocks remain operator-dependent and complications may still occur.

We report a case of tension pneumothorax after arthroscopic rotator cuff repair and subacromial decompression with an ultrasound-guided interscalene block. Immediate recognition and treatment of this complication resulted in a good clinical outcome. The patient provided written informed consent for print and electronic publication of this case report. 

Case Report

A 56-year-old woman presented with 3 months of right shoulder pain after a fall. Examination was pertinent for weakness in forward elevation and positive rotator cuff impingement signs. She remained symptomatic despite a course of nonsurgical management that included cortisone injections and physical therapy. Magnetic resonance imaging of the shoulder showed a full-thickness supraspinatus tear with minimal fatty atrophy. After a discussion of her treatment options, she elected to undergo an arthroscopic rotator cuff repair with subacromial decompression. An evaluation by her internist revealed no pertinent medical history apart from obesity (body mass index, 36). Specifically, there was no reported history of chronic obstructive pulmonary disease or asthma. She denied any prior cigarette smoking.

The patient was evaluated by the regional anesthesia team and was classified as a class 2 airway. An interscalene brachial plexus block was performed using a 2-inch, 22-gauge needle inserted into the interscalene groove. Using an out-of-plane technique under direct ultrasound guidance, 30 mL of 0.52% ropivacaine was injected. The block was considered successful, and no complications, such as resistance, paresthesias, pain, or blood on aspiration, were noted during injection. The patient had no complaints of chest pain or shortness of breath immediately afterward, and all vital signs were stable throughout the procedure.

The patient was brought to the operating room and placed in the beach-chair position. Induction for general anesthesia was started 15 minutes after the regional anesthetic, with 2 intubation attempts necessary because of poor airway visualization. After placement of the endotracheal tube, breath sounds were noted to be equal bilaterally. The arthroscopic procedure consisted of double-row rotator cuff repair, subacromial decompression, and débridement of the glenohumeral joint for synovitis, using standard arthroscopic portals. There were no difficulties with trocar placement, and bleeding was minimal throughout the case. The total surgical time was 150 minutes and a pump pressure of 30 mm Hg was maintained during the arthroscopy.

Within the first 60 minutes of the start of the arthroscopic procedure, the patient was noted to be intermittently hypotensive with mean arterial pressure (MAP) ranging from the 30s to 130s mm Hg and pulse in the 70 to 80 beats/min range. FiO₂ in the 85% to 95% range was maintained throughout the procedure. During that time, 50 μg phenylephrine was administered on 4 separate occasions to maintain her blood pressure. The labile blood pressure was attributed by the anesthesiologist to the beach-chair position. During an attempted extubation upon conclusion of the surgery, the patient became hypotensive with MAP that ranged from the 40s to 60s mm Hg and tachycardic to 90 beats/min. The oxygen saturation was in the low 90s and tidal volume was poor. Absent lung sounds were noted on the right chest. An urgent portable chest radiograph showed a large right-sided tension pneumothorax with mediastinal shift (Figure 1). After an immediate general surgery consultation, a chest tube was placed in the operating room. The patient’s vital signs improved and a repeat chest radiograph revealed successful re-expansion of the lung (Figure 2). She was transferred to the acute postoperative anesthesia care unit and extubated in the intensive care unit later that day.

The patient’s chest tube was removed 2 days later and she was discharged home on hospital day 5 with a completely resolved pneumothorax. She was seen 1 week later in the office for a postoperative visit and reported feeling well without chest pain or shortness of breath.

Discussion

Interscalene brachial plexus anesthesia was first described by Winnie⁴ in 1970. This block targets the trunks of the brachial plexus, which are enclosed in a fascial sheath between the anterior and middle scalene muscles. In this region lie several structures at risk: the phrenic nerve superficially and inferiorly; the carotid sheath located superficially and medially; the subclavian artery parallel to the trunks; and the cupula of the lung that lies deep and inferior to the anterior scalene muscle. Recognized complications of the block include vocal hoarseness, Horner syndrome, and hemidiaphragmatic paresis caused by the temporary blockade of the ipsilateral recurrent laryngeal nerve, stellate ganglion, and phrenic nerve, in that order.⁵ Use of the interscalene block has been associated with minimal risk for pneumothorax, because the needle entry point is superior and directed away from the lung pleura.⁶ This is in contrast to the more inferiorly placed supraclavicular block, located in closer proximity to the lung cupula.⁵

Two different approaches are commonly used during ultrasound-guided nerve blocks. The in-plane approach generates a long-axis view of the needle by advancing the needle parallel with the long axis of the ultrasound probe. While this allows direct visualization of the needle tip, it requires deeper needle insertion from lateral to medial, causing puncture of the middle scalene muscle that may increase patient discomfort and risk nerve injury within the muscle.⁷ The out-of-plane approach used on our patient involves needle insertion parallel to the brachial plexus, but along the short axis of the ultrasound probe. Although this permits the operator to assess the periphery of the nerve, it may lead to poor needle-tip visualization during the procedure. As a result, operators often use a combination of tissue disturbance and “hydrolocation,” in which fluid is injected to indicate the needle-tip location.^8,9

Tension pneumothorax represents the accumulation of air in the pleural space that leads to impaired pulmonary and cardiac function. It is often caused by disruption or puncture of the parietal or visceral pleura, creating a connection between the alveoli and pleural cavity. The gradual buildup of air in the pleural cavity results in increased intrapleural pressure, which compresses and ultimately collapses the ipsilateral lung. Venous compression restricts blood return to the heart and reduces cardiac output. Clinical manifestations include dyspnea, hypoxemia, tachycardia, and hypotension.¹⁰ Multiple techniques were developed to better localize the brachial plexus while reducing injury to nearby structures, including the lung. These include eliciting needle paresthesias, electrical nerve stimulation, and ultrasound guidance. While nerve stimulation was once the gold standard for brachial plexus localization, ultrasound guidance has gained in popularity because of its noninvasive nature and dynamic capability to identify nerves and surrounding structures.¹¹ Perlas and colleagues¹² determined the sensitivity of needle paresthesias and nerve stimulation to be 38% and 75%, respectively, in cases in which plexus localization had been confirmed by ultrasound.

Several studies have reported on the efficacy of interscalene nerve block with either nerve stimulation or ultrasound guidance in the setting of shoulder surgery.^2,3 Bishop and colleagues³ reviewed 547 patients who underwent interscalene regional anesthesia with nerve stimulation for both arthroscopic and open-shoulder procedures. They reported a 97% success rate and 12 (2.3%) minor complications, including sensory neuropathy and complex regional pain syndrome. There were no cases of pneumothorax, cardiac events, or other major complications.³ In a prospective study of 1319 patients, Singh and colleagues² reported a 99.6% success rate using ultrasound-guided interscalene blocks for their shoulder surgeries. A total of 38 adverse events (2.88%) were identified: 14 transient neurologic events, including ear numbness, digital numbness, and brachial plexitis; 1 case of intraoperative bradycardia, and 2 cancellations after the block for chest pain and flank pain, which yielded negative cardiac workups. Other complications included postoperative emergency room visits and hospital admissions for reasons unrelated to the block.² Interscalene regional anesthesia, therefore, provides effective anesthesia for shoulder surgery with low complication rates.

Pneumothorax after ultrasound-guided interscalene block has rarely been reported.^13,14 In a review of 144 ultrasound-guided indwelling interscalene catheter placements, a 98% successful block rate with a single complication of small pneumothorax after total shoulder arthroplasty was reported.¹³ Mandim and colleagues¹⁴ reported a case of pneumothorax in a smoker who underwent an ultrasound-guided brachial plexus block prior to open reduction and internal fixation of an ulnar fracture. While the patient was asymptomatic and vital signs remained stable during the procedure, the patient complained postoperatively of chest pain with hypoxia, tachycardia, and hypotension. A chest radiograph confirmed an ipsilateral pneumothorax, and the patient was treated successfully with chest-tube placement. The authors attributed this complication to a higher pleural dome resulting from a hyperinflated lung caused by chronic smoking. Our patient reported no history of smoking and her preoperative chest radiograph had no evidence of lung disease.

In contrast, several cases of pneumothorax after shoulder surgery have been reported in the absence of nerve block. Oldman and Peng¹ reported a 41-year-old nonsmoker who underwent arthroscopic labral repair and subacromial decompression. The preoperative nerve block was cancelled, and the patient received general endotracheal anesthesia alone. Fifty minutes after the case, the patient developed chest pain and hypoxia. A chest radiograph showed a small pneumothorax that was managed conservatively. The pneumothorax was attributed to spontaneous rupture of a preexisting lung bulla, suggesting that blocks are not always the cause of this complication. Furthermore, Dietzel and Ciullo¹⁵ reported 4 cases of spontaneous pneumothorax within 24 hours of uncomplicated arthroscopic shoulder procedures under general anesthesia in the lateral decubitus position. The patient ages ranged from 22 to 38 years, and medical histories were all significant for preexisting lung disease, remote history of pneumonia, and heavy smoking. Three of the patients experienced symptoms at home the day after surgery. The authors concluded that these cases were likely caused by rupture of blebs or bullae from underlying lung disease; these ruptured blebs or bullae are difficult to detect and usually located in the upper lung. The pressure gradient from the positive pressure of anesthesia and the ipsilateral upper lung is thought to be highest in the lateral decubitus position, increasing their chance of rupture.¹⁵

Finally, Lee and colleagues¹⁶ described 3 patients aged 40 to 45 years who underwent uncomplicated subacromial decompression in the beach-chair position under general anesthesia. Significant shoulder, neck, and axillary swelling were noted after surgery, and a chest radiograph showed tension pneumothorax, subcutaneous emphysema, and pneumomediastinum. The authors speculated that pressure in the subacromial space may become negative relative to atmospheric pressure when the shaver and suction are running, drawing in air through other portals. When the suction is discontinued, fluid infusion may push air into the surrounding tissue, leading to subcutaneous emphysema, which may spread to the mediastinum.¹⁶ 

Conclusion 

Ultrasound-guided interscalene nerve blocks have successfully provided anesthesia for shoulder surgeries with low complication rates. Although the incidence of pneumothorax has decreased significantly with ultrasound guidance, the success of this procedure is highly operator-dependent. We present the case of an otherwise healthy patient without known pulmonary disease who developed a tension pneumothorax after the administration of ultrasound-guided regional and general anesthesia for arthroscopic shoulder surgery. Orthopedic surgeons and anesthesiologists must remain vigilant for pneumothorax during the perioperative period after shoulder surgery performed under interscalene regional aesthesia, particularly in the setting of hypotension, hypoxia, and/or tachycardia. Risk factors, such as history of smoking and preexisting lung disease, may predispose patients to the development of pneumothorax. Timely recognition and placement of a chest tube result in satisfactory clinical outcomes.

Interscalene brachial plexus anesthesia is commonly used for arthroscopic and open procedures of the shoulder. This regional anesthetic targets the trunks of the brachial plexus and anesthetizes the area about the shoulder and proximal arm. Its use may obviate the need for concomitant general anesthesia, potentially reducing the use of postoperative intravenous and oral pain medication. Furthermore, patients often bypass the acute postoperative anesthesia care unit and proceed directly to the ambulatory unit, permitting earlier hospital discharge. Previous reports in the literature have demonstrated higher rates of neurologic, cardiac, and pulmonary complications from this procedure; in particular, the incidence of pneumothorax was reported as high as 3%.¹ Techniques to localize the nerves, such as electrical nerve stimulation and, more recently, ultrasound guidance, have reduced these complication rates.^2,3 Successful administration of the block has been shown to result in satisfactory postoperative pain relief.² However, ultrasound-guided interscalene nerve blocks remain operator-dependent and complications may still occur.

We report a case of tension pneumothorax after arthroscopic rotator cuff repair and subacromial decompression with an ultrasound-guided interscalene block. Immediate recognition and treatment of this complication resulted in a good clinical outcome. The patient provided written informed consent for print and electronic publication of this case report. 

Case Report

A 56-year-old woman presented with 3 months of right shoulder pain after a fall. Examination was pertinent for weakness in forward elevation and positive rotator cuff impingement signs. She remained symptomatic despite a course of nonsurgical management that included cortisone injections and physical therapy. Magnetic resonance imaging of the shoulder showed a full-thickness supraspinatus tear with minimal fatty atrophy. After a discussion of her treatment options, she elected to undergo an arthroscopic rotator cuff repair with subacromial decompression. An evaluation by her internist revealed no pertinent medical history apart from obesity (body mass index, 36). Specifically, there was no reported history of chronic obstructive pulmonary disease or asthma. She denied any prior cigarette smoking.

The patient was evaluated by the regional anesthesia team and was classified as a class 2 airway. An interscalene brachial plexus block was performed using a 2-inch, 22-gauge needle inserted into the interscalene groove. Using an out-of-plane technique under direct ultrasound guidance, 30 mL of 0.52% ropivacaine was injected. The block was considered successful, and no complications, such as resistance, paresthesias, pain, or blood on aspiration, were noted during injection. The patient had no complaints of chest pain or shortness of breath immediately afterward, and all vital signs were stable throughout the procedure.

The patient was brought to the operating room and placed in the beach-chair position. Induction for general anesthesia was started 15 minutes after the regional anesthetic, with 2 intubation attempts necessary because of poor airway visualization. After placement of the endotracheal tube, breath sounds were noted to be equal bilaterally. The arthroscopic procedure consisted of double-row rotator cuff repair, subacromial decompression, and débridement of the glenohumeral joint for synovitis, using standard arthroscopic portals. There were no difficulties with trocar placement, and bleeding was minimal throughout the case. The total surgical time was 150 minutes and a pump pressure of 30 mm Hg was maintained during the arthroscopy.

Within the first 60 minutes of the start of the arthroscopic procedure, the patient was noted to be intermittently hypotensive with mean arterial pressure (MAP) ranging from the 30s to 130s mm Hg and pulse in the 70 to 80 beats/min range. FiO₂ in the 85% to 95% range was maintained throughout the procedure. During that time, 50 μg phenylephrine was administered on 4 separate occasions to maintain her blood pressure. The labile blood pressure was attributed by the anesthesiologist to the beach-chair position. During an attempted extubation upon conclusion of the surgery, the patient became hypotensive with MAP that ranged from the 40s to 60s mm Hg and tachycardic to 90 beats/min. The oxygen saturation was in the low 90s and tidal volume was poor. Absent lung sounds were noted on the right chest. An urgent portable chest radiograph showed a large right-sided tension pneumothorax with mediastinal shift (Figure 1). After an immediate general surgery consultation, a chest tube was placed in the operating room. The patient’s vital signs improved and a repeat chest radiograph revealed successful re-expansion of the lung (Figure 2). She was transferred to the acute postoperative anesthesia care unit and extubated in the intensive care unit later that day.

The patient’s chest tube was removed 2 days later and she was discharged home on hospital day 5 with a completely resolved pneumothorax. She was seen 1 week later in the office for a postoperative visit and reported feeling well without chest pain or shortness of breath.

Discussion

Interscalene brachial plexus anesthesia was first described by Winnie⁴ in 1970. This block targets the trunks of the brachial plexus, which are enclosed in a fascial sheath between the anterior and middle scalene muscles. In this region lie several structures at risk: the phrenic nerve superficially and inferiorly; the carotid sheath located superficially and medially; the subclavian artery parallel to the trunks; and the cupula of the lung that lies deep and inferior to the anterior scalene muscle. Recognized complications of the block include vocal hoarseness, Horner syndrome, and hemidiaphragmatic paresis caused by the temporary blockade of the ipsilateral recurrent laryngeal nerve, stellate ganglion, and phrenic nerve, in that order.⁵ Use of the interscalene block has been associated with minimal risk for pneumothorax, because the needle entry point is superior and directed away from the lung pleura.⁶ This is in contrast to the more inferiorly placed supraclavicular block, located in closer proximity to the lung cupula.⁵

Two different approaches are commonly used during ultrasound-guided nerve blocks. The in-plane approach generates a long-axis view of the needle by advancing the needle parallel with the long axis of the ultrasound probe. While this allows direct visualization of the needle tip, it requires deeper needle insertion from lateral to medial, causing puncture of the middle scalene muscle that may increase patient discomfort and risk nerve injury within the muscle.⁷ The out-of-plane approach used on our patient involves needle insertion parallel to the brachial plexus, but along the short axis of the ultrasound probe. Although this permits the operator to assess the periphery of the nerve, it may lead to poor needle-tip visualization during the procedure. As a result, operators often use a combination of tissue disturbance and “hydrolocation,” in which fluid is injected to indicate the needle-tip location.^8,9

Tension pneumothorax represents the accumulation of air in the pleural space that leads to impaired pulmonary and cardiac function. It is often caused by disruption or puncture of the parietal or visceral pleura, creating a connection between the alveoli and pleural cavity. The gradual buildup of air in the pleural cavity results in increased intrapleural pressure, which compresses and ultimately collapses the ipsilateral lung. Venous compression restricts blood return to the heart and reduces cardiac output. Clinical manifestations include dyspnea, hypoxemia, tachycardia, and hypotension.¹⁰ Multiple techniques were developed to better localize the brachial plexus while reducing injury to nearby structures, including the lung. These include eliciting needle paresthesias, electrical nerve stimulation, and ultrasound guidance. While nerve stimulation was once the gold standard for brachial plexus localization, ultrasound guidance has gained in popularity because of its noninvasive nature and dynamic capability to identify nerves and surrounding structures.¹¹ Perlas and colleagues¹² determined the sensitivity of needle paresthesias and nerve stimulation to be 38% and 75%, respectively, in cases in which plexus localization had been confirmed by ultrasound.

Several studies have reported on the efficacy of interscalene nerve block with either nerve stimulation or ultrasound guidance in the setting of shoulder surgery.^2,3 Bishop and colleagues³ reviewed 547 patients who underwent interscalene regional anesthesia with nerve stimulation for both arthroscopic and open-shoulder procedures. They reported a 97% success rate and 12 (2.3%) minor complications, including sensory neuropathy and complex regional pain syndrome. There were no cases of pneumothorax, cardiac events, or other major complications.³ In a prospective study of 1319 patients, Singh and colleagues² reported a 99.6% success rate using ultrasound-guided interscalene blocks for their shoulder surgeries. A total of 38 adverse events (2.88%) were identified: 14 transient neurologic events, including ear numbness, digital numbness, and brachial plexitis; 1 case of intraoperative bradycardia, and 2 cancellations after the block for chest pain and flank pain, which yielded negative cardiac workups. Other complications included postoperative emergency room visits and hospital admissions for reasons unrelated to the block.² Interscalene regional anesthesia, therefore, provides effective anesthesia for shoulder surgery with low complication rates.

Pneumothorax after ultrasound-guided interscalene block has rarely been reported.^13,14 In a review of 144 ultrasound-guided indwelling interscalene catheter placements, a 98% successful block rate with a single complication of small pneumothorax after total shoulder arthroplasty was reported.¹³ Mandim and colleagues¹⁴ reported a case of pneumothorax in a smoker who underwent an ultrasound-guided brachial plexus block prior to open reduction and internal fixation of an ulnar fracture. While the patient was asymptomatic and vital signs remained stable during the procedure, the patient complained postoperatively of chest pain with hypoxia, tachycardia, and hypotension. A chest radiograph confirmed an ipsilateral pneumothorax, and the patient was treated successfully with chest-tube placement. The authors attributed this complication to a higher pleural dome resulting from a hyperinflated lung caused by chronic smoking. Our patient reported no history of smoking and her preoperative chest radiograph had no evidence of lung disease.

In contrast, several cases of pneumothorax after shoulder surgery have been reported in the absence of nerve block. Oldman and Peng¹ reported a 41-year-old nonsmoker who underwent arthroscopic labral repair and subacromial decompression. The preoperative nerve block was cancelled, and the patient received general endotracheal anesthesia alone. Fifty minutes after the case, the patient developed chest pain and hypoxia. A chest radiograph showed a small pneumothorax that was managed conservatively. The pneumothorax was attributed to spontaneous rupture of a preexisting lung bulla, suggesting that blocks are not always the cause of this complication. Furthermore, Dietzel and Ciullo¹⁵ reported 4 cases of spontaneous pneumothorax within 24 hours of uncomplicated arthroscopic shoulder procedures under general anesthesia in the lateral decubitus position. The patient ages ranged from 22 to 38 years, and medical histories were all significant for preexisting lung disease, remote history of pneumonia, and heavy smoking. Three of the patients experienced symptoms at home the day after surgery. The authors concluded that these cases were likely caused by rupture of blebs or bullae from underlying lung disease; these ruptured blebs or bullae are difficult to detect and usually located in the upper lung. The pressure gradient from the positive pressure of anesthesia and the ipsilateral upper lung is thought to be highest in the lateral decubitus position, increasing their chance of rupture.¹⁵

Finally, Lee and colleagues¹⁶ described 3 patients aged 40 to 45 years who underwent uncomplicated subacromial decompression in the beach-chair position under general anesthesia. Significant shoulder, neck, and axillary swelling were noted after surgery, and a chest radiograph showed tension pneumothorax, subcutaneous emphysema, and pneumomediastinum. The authors speculated that pressure in the subacromial space may become negative relative to atmospheric pressure when the shaver and suction are running, drawing in air through other portals. When the suction is discontinued, fluid infusion may push air into the surrounding tissue, leading to subcutaneous emphysema, which may spread to the mediastinum.¹⁶ 

Conclusion 

Ultrasound-guided interscalene nerve blocks have successfully provided anesthesia for shoulder surgeries with low complication rates. Although the incidence of pneumothorax has decreased significantly with ultrasound guidance, the success of this procedure is highly operator-dependent. We present the case of an otherwise healthy patient without known pulmonary disease who developed a tension pneumothorax after the administration of ultrasound-guided regional and general anesthesia for arthroscopic shoulder surgery. Orthopedic surgeons and anesthesiologists must remain vigilant for pneumothorax during the perioperative period after shoulder surgery performed under interscalene regional aesthesia, particularly in the setting of hypotension, hypoxia, and/or tachycardia. Risk factors, such as history of smoking and preexisting lung disease, may predispose patients to the development of pneumothorax. Timely recognition and placement of a chest tube result in satisfactory clinical outcomes.

Osteoid osteoma of the talar neck is an unusual clinical condition that is often overlooked on initial assessment of patients with ankle pain. Here, we present a case report of an adolescent male with talar neck osteoid osteoma who reported persistent pain after an injury. We discuss the differential diagnosis of persistent anterior ankle pain and assess the treatment options for osteoid osteoma of the talar neck. The patient’s guardian provided written informed consent for print and electronic publication of this case report. 

Case Report

A 13-year-old boy presented to our clinic 3 months after a right ankle sprain. He had visited the emergency department at the time of injury; radiographs of the ankle were reported negative for fractures, dislocations, or bone pathologies. He was treated conservatively with elastic support, icing, rest, elevation, and weight-bearing as tolerated. Upon presentation to our office, his pain involved the entire ankle joint. He had not put weight on it since the injury. On examination, he had a significant limp, anteromedial swelling, and tenderness over the ankle joint anteromedially. His neurologic and vascular examinations were normal.

His plain radiographs showed a cystic mass, located at the dorsal aspect of the talar neck (Figures 1A, 1B). Computed tomography (CT) showed a round lucent lesion involving the superior aspect of the talar neck, measuring 9 mm by 6 mm. A sclerotic radiodense focus was evident in the center (Figures 2A, 2B). Noncontrast multiplanar, multisequence magnetic resonance imaging (MRI) showed abnormal edema throughout the talus and a 9-mm rounded ossicle overlying the superior margin of the neck of the talus (Figures 3A, 3B).

Differential Diagnosis

The differential diagnosis for anterior ankle pain includes ankle sprain, monoarticular arthritis, anterior ankle impingement, and talar neck fractures. Other related findings include the presence of a talar ridge and a talar beak.

Ankle sprains are very common injuries. The mainstay treatment consists of ice, resting, elevation, and elastic or semirigid support, and patients usually recover over the course of a few weeks. These sprains are typically injuries of the lateral or medial ligaments of the ankle. Extension of a ligament tear across the anterior capsule can explain persistent anterior ankle pain. The presence of a bony lesion on plain radiographs, however, makes the diagnosis of an ankle sprain, with or without extension into the anterior capsule, less likely.

Monoarticular arthritis, which may present in the ankle and has a wide differential diagnosis, usually involves the whole joint.

Anterior ankle impingement typically occurs in athletes who participate in sports that involve kicking. It can be a bony or soft-tissue impingent. Clinically, patients present with pain and loss of motion, specifically dorsiflexion.

Talar neck fractures are usually the result of high-energy trauma. Stress fractures of the neck of the talus are uncommon and are associated with a recent sudden increase in physical activity, such as running, dancing, or military training. Radiographs, CT scans, and MRI help define the fracture line.

The talar ridge is the site of capsular and ligamentous attachment on the superior aspect of the talar neck and may become hypertrophic in athletes. A hypertrophic talar ridge is asymptomatic and is not considered a pathologic finding on radiographs.

The talar beak, a flaring of the anterosuperior aspect of the talar head, is an indirect sign of tarsal coalition. When symptomatic, patients complain of subtalar symptoms, typically pain and limitation of motion. It usually does not present acutely.

Treatment

We offered the patient surgical excision, and his guardian consented to left ankle arthroscopy. We performed synovectomy using a combination of 3.5-mm shaver and radiofrequency probe. We identified the mass: round, soft, and located at the superior-medial aspect of the talar neck. We removed it in piecemeal fashion using manual arthroscopic instruments, and cauterized its base using the radiofrequency probe. We allowed the patient weight-bearing as tolerated starting the day after surgery.

We submitted the specimen for pathologic evaluation (Figure 4). It consisted of multiple pieces of tan/brown tissue. Histologic examination showed benign osteoblastic proliferation composed of anastomosing bony trabeculae with variable mineralization, lined by plump osteoblasts, within vascularized connective tissue; benign giant cells were present, consistent with a nidus of an osteoid osteoma.

On the first postoperative visit, the patient was pain-free and bearing weight with crutches. He was gradually weaned from his crutches and returned to full weight-bearing over the next 4 weeks. At 12-month follow-up, he was symptom-free with good range of motion and full return to previous level of activity.

Discussion

Osteoid osteoma is a small, benign, well-circumscribed osteoblastic cortical lesion, typically identified in long bones or, less frequently, in the subperiosteal region.¹ It often affects adolescents. Osteoid osteoma has been described in the talus in a few case series^2-7 and is associated with a typical nidus that can be identified on CT scans. It does not present acutely, however. The typical presentation for osteoid osteoma is bone pain at night that responds to nonsteroidal anti-inflammatory drugs. However, this presentation is not universal and is frequently missed.²

Juxta-articular osteoid osteomas in the ankle and foot can be difficult to diagnose. The most common site is the talus.³ The majority of patients link their pain to a remote ankle injury. The time delay to diagnosis is on average 2.5 years, but it can be as long as 10 years.^4-6 A CT scan is the best method to identify the nidus; MRI can be misleading if it shows only marrow edema but not a nidus.^4,5,7 In our patient, an injury was documented, and the patient denied prior symptoms. We cannot explain how an injury would trigger the formation of an osteoid osteoma or cause a previously asymptomatic osteoid osteoma to become symptomatic.

Medical treatment with nonsteroidal anti-inflammatory drugs has been used but is reported to take 2 to 4 years for resolution of symptoms; many patients may consider the treatment time frame too long when other alternatives are available.⁸ These include open resection, arthroscopic resection, and image-guided ablation. Open surgical techniques include en bloc resection and curettage. Bone grafting or internal fixation may be performed as needed. Arthroscopic excision of juxta-articular osteoid osteomas offers the advantages of good visualization and avoidance of soft-tissue dissection, and allows for complete excision of the lesion as well as synovectomy.^6,9,10 Arthroscopic excision also allows for quicker rehabilitation. Image-guided ablation, such as radionuclide-guided excision, CT-guided thermal ablation, and laser photocoagulation, may be even less invasive but do not allow for direct visualization, complete resection, and biopsy.¹¹

Conclusion

Osteoid osteoma is a small, benign, well-circumscribed osteoblastic cortical lesion, typically identified in long bones or, less frequently, in the subperiosteal region.¹ It often affects adolescents. Osteoid osteoma has been described in the talus in multiple case series and is associated with a typical nidus that can be identified on CT scans. Usually, it does not present acutely. The typical presentation for osteoid osteoma is bone pain at night that responds to nonsteroidal anti-inflammatory drugs. This presentation is not universal, however, and is frequently missed, especially when the pain is associated with a prior injury.² Arthroscopic exploration of the ankle with resection of subperiosteal osteoid osteoma and the associated synovitis using thermal ablation of the base with radiofrequency offers lasting cure with minimal morbidity.

Osteoid osteoma of the talar neck is an unusual clinical condition that is often overlooked on initial assessment of patients with ankle pain. Here, we present a case report of an adolescent male with talar neck osteoid osteoma who reported persistent pain after an injury. We discuss the differential diagnosis of persistent anterior ankle pain and assess the treatment options for osteoid osteoma of the talar neck. The patient’s guardian provided written informed consent for print and electronic publication of this case report. 

Case Report

A 13-year-old boy presented to our clinic 3 months after a right ankle sprain. He had visited the emergency department at the time of injury; radiographs of the ankle were reported negative for fractures, dislocations, or bone pathologies. He was treated conservatively with elastic support, icing, rest, elevation, and weight-bearing as tolerated. Upon presentation to our office, his pain involved the entire ankle joint. He had not put weight on it since the injury. On examination, he had a significant limp, anteromedial swelling, and tenderness over the ankle joint anteromedially. His neurologic and vascular examinations were normal.

His plain radiographs showed a cystic mass, located at the dorsal aspect of the talar neck (Figures 1A, 1B). Computed tomography (CT) showed a round lucent lesion involving the superior aspect of the talar neck, measuring 9 mm by 6 mm. A sclerotic radiodense focus was evident in the center (Figures 2A, 2B). Noncontrast multiplanar, multisequence magnetic resonance imaging (MRI) showed abnormal edema throughout the talus and a 9-mm rounded ossicle overlying the superior margin of the neck of the talus (Figures 3A, 3B).

Differential Diagnosis

The differential diagnosis for anterior ankle pain includes ankle sprain, monoarticular arthritis, anterior ankle impingement, and talar neck fractures. Other related findings include the presence of a talar ridge and a talar beak.

Ankle sprains are very common injuries. The mainstay treatment consists of ice, resting, elevation, and elastic or semirigid support, and patients usually recover over the course of a few weeks. These sprains are typically injuries of the lateral or medial ligaments of the ankle. Extension of a ligament tear across the anterior capsule can explain persistent anterior ankle pain. The presence of a bony lesion on plain radiographs, however, makes the diagnosis of an ankle sprain, with or without extension into the anterior capsule, less likely.

Monoarticular arthritis, which may present in the ankle and has a wide differential diagnosis, usually involves the whole joint.

Anterior ankle impingement typically occurs in athletes who participate in sports that involve kicking. It can be a bony or soft-tissue impingent. Clinically, patients present with pain and loss of motion, specifically dorsiflexion.

Talar neck fractures are usually the result of high-energy trauma. Stress fractures of the neck of the talus are uncommon and are associated with a recent sudden increase in physical activity, such as running, dancing, or military training. Radiographs, CT scans, and MRI help define the fracture line.

The talar ridge is the site of capsular and ligamentous attachment on the superior aspect of the talar neck and may become hypertrophic in athletes. A hypertrophic talar ridge is asymptomatic and is not considered a pathologic finding on radiographs.

The talar beak, a flaring of the anterosuperior aspect of the talar head, is an indirect sign of tarsal coalition. When symptomatic, patients complain of subtalar symptoms, typically pain and limitation of motion. It usually does not present acutely.

Treatment

We offered the patient surgical excision, and his guardian consented to left ankle arthroscopy. We performed synovectomy using a combination of 3.5-mm shaver and radiofrequency probe. We identified the mass: round, soft, and located at the superior-medial aspect of the talar neck. We removed it in piecemeal fashion using manual arthroscopic instruments, and cauterized its base using the radiofrequency probe. We allowed the patient weight-bearing as tolerated starting the day after surgery.

We submitted the specimen for pathologic evaluation (Figure 4). It consisted of multiple pieces of tan/brown tissue. Histologic examination showed benign osteoblastic proliferation composed of anastomosing bony trabeculae with variable mineralization, lined by plump osteoblasts, within vascularized connective tissue; benign giant cells were present, consistent with a nidus of an osteoid osteoma.

On the first postoperative visit, the patient was pain-free and bearing weight with crutches. He was gradually weaned from his crutches and returned to full weight-bearing over the next 4 weeks. At 12-month follow-up, he was symptom-free with good range of motion and full return to previous level of activity.

Discussion

Osteoid osteoma is a small, benign, well-circumscribed osteoblastic cortical lesion, typically identified in long bones or, less frequently, in the subperiosteal region.¹ It often affects adolescents. Osteoid osteoma has been described in the talus in a few case series^2-7 and is associated with a typical nidus that can be identified on CT scans. It does not present acutely, however. The typical presentation for osteoid osteoma is bone pain at night that responds to nonsteroidal anti-inflammatory drugs. However, this presentation is not universal and is frequently missed.²

Juxta-articular osteoid osteomas in the ankle and foot can be difficult to diagnose. The most common site is the talus.³ The majority of patients link their pain to a remote ankle injury. The time delay to diagnosis is on average 2.5 years, but it can be as long as 10 years.^4-6 A CT scan is the best method to identify the nidus; MRI can be misleading if it shows only marrow edema but not a nidus.^4,5,7 In our patient, an injury was documented, and the patient denied prior symptoms. We cannot explain how an injury would trigger the formation of an osteoid osteoma or cause a previously asymptomatic osteoid osteoma to become symptomatic.

Medical treatment with nonsteroidal anti-inflammatory drugs has been used but is reported to take 2 to 4 years for resolution of symptoms; many patients may consider the treatment time frame too long when other alternatives are available.⁸ These include open resection, arthroscopic resection, and image-guided ablation. Open surgical techniques include en bloc resection and curettage. Bone grafting or internal fixation may be performed as needed. Arthroscopic excision of juxta-articular osteoid osteomas offers the advantages of good visualization and avoidance of soft-tissue dissection, and allows for complete excision of the lesion as well as synovectomy.^6,9,10 Arthroscopic excision also allows for quicker rehabilitation. Image-guided ablation, such as radionuclide-guided excision, CT-guided thermal ablation, and laser photocoagulation, may be even less invasive but do not allow for direct visualization, complete resection, and biopsy.¹¹

Conclusion

Osteoid osteoma is a small, benign, well-circumscribed osteoblastic cortical lesion, typically identified in long bones or, less frequently, in the subperiosteal region.¹ It often affects adolescents. Osteoid osteoma has been described in the talus in multiple case series and is associated with a typical nidus that can be identified on CT scans. Usually, it does not present acutely. The typical presentation for osteoid osteoma is bone pain at night that responds to nonsteroidal anti-inflammatory drugs. This presentation is not universal, however, and is frequently missed, especially when the pain is associated with a prior injury.² Arthroscopic exploration of the ankle with resection of subperiosteal osteoid osteoma and the associated synovitis using thermal ablation of the base with radiofrequency offers lasting cure with minimal morbidity.

Osteoid osteoma of the talar neck is an unusual clinical condition that is often overlooked on initial assessment of patients with ankle pain. Here, we present a case report of an adolescent male with talar neck osteoid osteoma who reported persistent pain after an injury. We discuss the differential diagnosis of persistent anterior ankle pain and assess the treatment options for osteoid osteoma of the talar neck. The patient’s guardian provided written informed consent for print and electronic publication of this case report. 

Case Report

A 13-year-old boy presented to our clinic 3 months after a right ankle sprain. He had visited the emergency department at the time of injury; radiographs of the ankle were reported negative for fractures, dislocations, or bone pathologies. He was treated conservatively with elastic support, icing, rest, elevation, and weight-bearing as tolerated. Upon presentation to our office, his pain involved the entire ankle joint. He had not put weight on it since the injury. On examination, he had a significant limp, anteromedial swelling, and tenderness over the ankle joint anteromedially. His neurologic and vascular examinations were normal.

His plain radiographs showed a cystic mass, located at the dorsal aspect of the talar neck (Figures 1A, 1B). Computed tomography (CT) showed a round lucent lesion involving the superior aspect of the talar neck, measuring 9 mm by 6 mm. A sclerotic radiodense focus was evident in the center (Figures 2A, 2B). Noncontrast multiplanar, multisequence magnetic resonance imaging (MRI) showed abnormal edema throughout the talus and a 9-mm rounded ossicle overlying the superior margin of the neck of the talus (Figures 3A, 3B).

Differential Diagnosis

The differential diagnosis for anterior ankle pain includes ankle sprain, monoarticular arthritis, anterior ankle impingement, and talar neck fractures. Other related findings include the presence of a talar ridge and a talar beak.

Ankle sprains are very common injuries. The mainstay treatment consists of ice, resting, elevation, and elastic or semirigid support, and patients usually recover over the course of a few weeks. These sprains are typically injuries of the lateral or medial ligaments of the ankle. Extension of a ligament tear across the anterior capsule can explain persistent anterior ankle pain. The presence of a bony lesion on plain radiographs, however, makes the diagnosis of an ankle sprain, with or without extension into the anterior capsule, less likely.

Monoarticular arthritis, which may present in the ankle and has a wide differential diagnosis, usually involves the whole joint.

Anterior ankle impingement typically occurs in athletes who participate in sports that involve kicking. It can be a bony or soft-tissue impingent. Clinically, patients present with pain and loss of motion, specifically dorsiflexion.

Talar neck fractures are usually the result of high-energy trauma. Stress fractures of the neck of the talus are uncommon and are associated with a recent sudden increase in physical activity, such as running, dancing, or military training. Radiographs, CT scans, and MRI help define the fracture line.

The talar ridge is the site of capsular and ligamentous attachment on the superior aspect of the talar neck and may become hypertrophic in athletes. A hypertrophic talar ridge is asymptomatic and is not considered a pathologic finding on radiographs.

The talar beak, a flaring of the anterosuperior aspect of the talar head, is an indirect sign of tarsal coalition. When symptomatic, patients complain of subtalar symptoms, typically pain and limitation of motion. It usually does not present acutely.

Treatment

We offered the patient surgical excision, and his guardian consented to left ankle arthroscopy. We performed synovectomy using a combination of 3.5-mm shaver and radiofrequency probe. We identified the mass: round, soft, and located at the superior-medial aspect of the talar neck. We removed it in piecemeal fashion using manual arthroscopic instruments, and cauterized its base using the radiofrequency probe. We allowed the patient weight-bearing as tolerated starting the day after surgery.

We submitted the specimen for pathologic evaluation (Figure 4). It consisted of multiple pieces of tan/brown tissue. Histologic examination showed benign osteoblastic proliferation composed of anastomosing bony trabeculae with variable mineralization, lined by plump osteoblasts, within vascularized connective tissue; benign giant cells were present, consistent with a nidus of an osteoid osteoma.

On the first postoperative visit, the patient was pain-free and bearing weight with crutches. He was gradually weaned from his crutches and returned to full weight-bearing over the next 4 weeks. At 12-month follow-up, he was symptom-free with good range of motion and full return to previous level of activity.

Discussion

Osteoid osteoma is a small, benign, well-circumscribed osteoblastic cortical lesion, typically identified in long bones or, less frequently, in the subperiosteal region.¹ It often affects adolescents. Osteoid osteoma has been described in the talus in a few case series^2-7 and is associated with a typical nidus that can be identified on CT scans. It does not present acutely, however. The typical presentation for osteoid osteoma is bone pain at night that responds to nonsteroidal anti-inflammatory drugs. However, this presentation is not universal and is frequently missed.²

Juxta-articular osteoid osteomas in the ankle and foot can be difficult to diagnose. The most common site is the talus.³ The majority of patients link their pain to a remote ankle injury. The time delay to diagnosis is on average 2.5 years, but it can be as long as 10 years.^4-6 A CT scan is the best method to identify the nidus; MRI can be misleading if it shows only marrow edema but not a nidus.^4,5,7 In our patient, an injury was documented, and the patient denied prior symptoms. We cannot explain how an injury would trigger the formation of an osteoid osteoma or cause a previously asymptomatic osteoid osteoma to become symptomatic.

Medical treatment with nonsteroidal anti-inflammatory drugs has been used but is reported to take 2 to 4 years for resolution of symptoms; many patients may consider the treatment time frame too long when other alternatives are available.⁸ These include open resection, arthroscopic resection, and image-guided ablation. Open surgical techniques include en bloc resection and curettage. Bone grafting or internal fixation may be performed as needed. Arthroscopic excision of juxta-articular osteoid osteomas offers the advantages of good visualization and avoidance of soft-tissue dissection, and allows for complete excision of the lesion as well as synovectomy.^6,9,10 Arthroscopic excision also allows for quicker rehabilitation. Image-guided ablation, such as radionuclide-guided excision, CT-guided thermal ablation, and laser photocoagulation, may be even less invasive but do not allow for direct visualization, complete resection, and biopsy.¹¹

Conclusion

Osteoid osteoma is a small, benign, well-circumscribed osteoblastic cortical lesion, typically identified in long bones or, less frequently, in the subperiosteal region.¹ It often affects adolescents. Osteoid osteoma has been described in the talus in multiple case series and is associated with a typical nidus that can be identified on CT scans. Usually, it does not present acutely. The typical presentation for osteoid osteoma is bone pain at night that responds to nonsteroidal anti-inflammatory drugs. This presentation is not universal, however, and is frequently missed, especially when the pain is associated with a prior injury.² Arthroscopic exploration of the ankle with resection of subperiosteal osteoid osteoma and the associated synovitis using thermal ablation of the base with radiofrequency offers lasting cure with minimal morbidity.

Revision total knee arthroplasty (TKA) is frequently complicated by bone loss and ligament instability, necessitating specialized implants to increase constraint and transmit forces away from the joint surface. Femoral stems are commonly used to enhance fixation and distribute force from the condyles to the metaphysis or diaphysis, to higher-quality bone capable of sustaining the forces at the knee joint.

Modular implants are now commonplace in revision surgery, because they allow intraoperative customization of the implant to the patient’s anatomy, degree of bone loss, and need for metaphyseal or diaphyseal fixation. However, these advantages are not without a downside. The modular junction introduces potential weaknesses in the implant, which may lead to early failure.

We report a case of loosening of a Triathlon TS (Stryker) femoral component that was not evident on preoperative radiographs. To our knowledge, this complication has not been reported with this particular revision knee system. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 56-year-old woman underwent 2-stage revision left TKA secondary to infection at an outside institution. She had undergone 17 prior knee surgeries with multiple revisions prior to this most recent revision surgery. A constrained implant was used at her last reimplantation secondary to ligamentous laxity after extensive débridement for infection. A Triathlon TS revision knee system with cemented stemmed tibial and femoral components was implanted; stems designed for uncemented fixation were cemented. She had a history of a quadriceps tendon tear, which was repaired prior to her revision, and quadricepsplasty was performed at the time of revision.

Seven years after this revision surgery, the patient presented to our clinic with progressive global instability, occasional effusions, and 2 documented episodes of frank dislocation. On examination, she was unstable in flexion and extension. Her extensor mechanism was intact, although with 7º active lag. She had a palpable quadriceps tendon defect. Her passive range of motion was 0º to 130º. Her active range of motion was 7º to 130º. Her erythrocyte sedimentation rate and C-reactive protein levels were within normal limits, and aspiration was negative for infection. Radiographs showed apparently well-fixed components with cemented femoral and tibial stems (Figures 1A, 1B).

The patient underwent revision surgery for global instability with the surgical goal to upsize the polyethylene insert and advance the quadriceps to improve stability. In the operating room, a defect in the quadriceps mechanism was seen between the vastus medialis obliquus (VMO) and the patella, as well as a large effusion. Upon removal of the polyethylene insert, the tibial and patellar components were examined and found to be well fixed. The femoral component was grossly loose. On closer inspection, the condylar portion was found to be rotating in the axial plane freely on the well-fixed cemented stem in the femoral canal (Figures 2A-2D). The entire femoral component was removed with some difficulty because the well-fixed uncemented stem design was cemented in place. This required a small, anterior episiotomy of the femur. Reconstruction of the femur was performed using a trabecular metal cone, a cemented stem, and condylar component with distal and posterior augments (Figures 3A, 3B). A shorter, thinner stem was implanted and cemented into the previous cement mantle. A 19-mm constrained polyethylene liner was selected (the prior liner was 13 mm), which gave adequate stability with range of motion 0º to 130º. The VMO was advanced approximately 1.5 cm at the time of closure of the arthrotomy. The patient was implanted with the same Triathlon TS system, because the tibial component was well fixed, well positioned, and did not require revision.

Discussion

The need and use of stemmed, modular femoral components for revision TKA is neither questioned nor a novel concept in arthroplasty.¹ Femoral bone defects encountered in revision arthroplasty generally lack sufficient cortical integrity to support an unstemmed component. Biomechanical analyses have reliably demonstrated improved initial stability and reduced relative motion provided by femoral stem extension.^2,3 Correspondingly, significant translational and rotational movements of the femoral component when disconnected from the stem presumably correspond with clinical observations of instability.³ We report a unique case of failure of the modular junction of a stemmed femoral component in revision TKA that was not readily apparent on plain radiographs.

Dissociation of a cemented stem from the condylar portion of the component has been described at our institution with a different implant design.⁴ To our knowledge, we describe the first report of failure at the modular junction of the Triathlon TS femoral component. 

Interestingly, relative motion has been shown to increase with increasing flexion in a biomechanical study² using the same Triathlon TS system. The authors of that study found they were unable to complete testing at flexion greater than 30º because, absent the stabilizing influence of surrounding ligament and muscle, the sample deformation was so significant that it caused fracture.² In the case of our patient, the incompetence of her extensor mechanism likely resulted in increased forces transmitted through the implant than might be expected in more physiologic circumstances. This higher stress may account in part for the failure of the implant at the known weakest point, the stem-condyle modular junction.

Modular implants are routinely used, given the variability of scenarios encountered in revision surgery and the need for customization to provide the best approximation of physiologic functioning of the joint. However, modular components introduce junctional points, which are potential points of failure. Stresses on the femoral component occur in multiple dimensions besides the axial loading and medial-lateral, anterior-posterior rocking seen with the tibial component. The maximum stress is observed at the distal-most aspect of the stiffest or most well-fixed components, in this case, the articulation between the cemented stem and the cemented condylar component. Poor distal femoral fixation compounds the problem.

Numerous case reports have documented such failures in other knee systems. Issack and colleagues⁵ described 2 cases of fracture through the taper lock between the femoral component and the stem extension in the Optetrak stemmed-constrained condylar knee prosthesis (Exactech). Westrich and colleagues⁶ reported disengagement of the locking bolt of the Insall-Burstein II Constrained Condylar Knee (Zimmer) leading to failure. Lim and colleagues⁴ reported stem-condyle junctional failure of the Total Condylar III (DePuy, Johnson & Johnson) due to locking-screw failure. Butt and colleagues⁷ reported a case of failure at the femoral component–stem junction caused by screw breakage. All of these cases involved failure at the condylar-stem junction that was readily apparent on routine preoperative imaging.

Our case is noteworthy because there was no preoperative radiographic evidence that the components were loose or the junction had failed. As with many revision systems observed by Fehring and colleagues,⁸ determination of fixation is often based on the appearance of the stem because the distal femoral interfaces may be obscured by the intercondylar box. This suggests that a loose component at the stem-condylar junction could easily be overlooked and not appropriately revised based on imaging alone. A solution for achieving stability at the time of revision surgery is to obtain good distal bone apposition and fixation. In this case, a cemented stem with a metaphyseal cone was used for femoral fixation (Figures 3A, 3B).

While long-term, abnormally high stress transmitted through the modular junction may account for the implant’s failure, to our knowledge, this is the first report of its kind related to this particular implant. If quadriceps weakness contributed to this failure, it is worth considering that quadriceps weakness is common after TKA and may persist without appropriate rehabilitation and activity. Furthermore, the lack of evidence on plain radiographs makes this particular form of failure very difficult to screen. A high degree of suspicion for loosening should be maintained in patients with pain and instability after revision TKA with this implant as well as with other modular revision knee systems.

Revision total knee arthroplasty (TKA) is frequently complicated by bone loss and ligament instability, necessitating specialized implants to increase constraint and transmit forces away from the joint surface. Femoral stems are commonly used to enhance fixation and distribute force from the condyles to the metaphysis or diaphysis, to higher-quality bone capable of sustaining the forces at the knee joint.

Modular implants are now commonplace in revision surgery, because they allow intraoperative customization of the implant to the patient’s anatomy, degree of bone loss, and need for metaphyseal or diaphyseal fixation. However, these advantages are not without a downside. The modular junction introduces potential weaknesses in the implant, which may lead to early failure.

We report a case of loosening of a Triathlon TS (Stryker) femoral component that was not evident on preoperative radiographs. To our knowledge, this complication has not been reported with this particular revision knee system. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 56-year-old woman underwent 2-stage revision left TKA secondary to infection at an outside institution. She had undergone 17 prior knee surgeries with multiple revisions prior to this most recent revision surgery. A constrained implant was used at her last reimplantation secondary to ligamentous laxity after extensive débridement for infection. A Triathlon TS revision knee system with cemented stemmed tibial and femoral components was implanted; stems designed for uncemented fixation were cemented. She had a history of a quadriceps tendon tear, which was repaired prior to her revision, and quadricepsplasty was performed at the time of revision.

Seven years after this revision surgery, the patient presented to our clinic with progressive global instability, occasional effusions, and 2 documented episodes of frank dislocation. On examination, she was unstable in flexion and extension. Her extensor mechanism was intact, although with 7º active lag. She had a palpable quadriceps tendon defect. Her passive range of motion was 0º to 130º. Her active range of motion was 7º to 130º. Her erythrocyte sedimentation rate and C-reactive protein levels were within normal limits, and aspiration was negative for infection. Radiographs showed apparently well-fixed components with cemented femoral and tibial stems (Figures 1A, 1B).

The patient underwent revision surgery for global instability with the surgical goal to upsize the polyethylene insert and advance the quadriceps to improve stability. In the operating room, a defect in the quadriceps mechanism was seen between the vastus medialis obliquus (VMO) and the patella, as well as a large effusion. Upon removal of the polyethylene insert, the tibial and patellar components were examined and found to be well fixed. The femoral component was grossly loose. On closer inspection, the condylar portion was found to be rotating in the axial plane freely on the well-fixed cemented stem in the femoral canal (Figures 2A-2D). The entire femoral component was removed with some difficulty because the well-fixed uncemented stem design was cemented in place. This required a small, anterior episiotomy of the femur. Reconstruction of the femur was performed using a trabecular metal cone, a cemented stem, and condylar component with distal and posterior augments (Figures 3A, 3B). A shorter, thinner stem was implanted and cemented into the previous cement mantle. A 19-mm constrained polyethylene liner was selected (the prior liner was 13 mm), which gave adequate stability with range of motion 0º to 130º. The VMO was advanced approximately 1.5 cm at the time of closure of the arthrotomy. The patient was implanted with the same Triathlon TS system, because the tibial component was well fixed, well positioned, and did not require revision.

Discussion

The need and use of stemmed, modular femoral components for revision TKA is neither questioned nor a novel concept in arthroplasty.¹ Femoral bone defects encountered in revision arthroplasty generally lack sufficient cortical integrity to support an unstemmed component. Biomechanical analyses have reliably demonstrated improved initial stability and reduced relative motion provided by femoral stem extension.^2,3 Correspondingly, significant translational and rotational movements of the femoral component when disconnected from the stem presumably correspond with clinical observations of instability.³ We report a unique case of failure of the modular junction of a stemmed femoral component in revision TKA that was not readily apparent on plain radiographs.

Dissociation of a cemented stem from the condylar portion of the component has been described at our institution with a different implant design.⁴ To our knowledge, we describe the first report of failure at the modular junction of the Triathlon TS femoral component. 

Interestingly, relative motion has been shown to increase with increasing flexion in a biomechanical study² using the same Triathlon TS system. The authors of that study found they were unable to complete testing at flexion greater than 30º because, absent the stabilizing influence of surrounding ligament and muscle, the sample deformation was so significant that it caused fracture.² In the case of our patient, the incompetence of her extensor mechanism likely resulted in increased forces transmitted through the implant than might be expected in more physiologic circumstances. This higher stress may account in part for the failure of the implant at the known weakest point, the stem-condyle modular junction.

Modular implants are routinely used, given the variability of scenarios encountered in revision surgery and the need for customization to provide the best approximation of physiologic functioning of the joint. However, modular components introduce junctional points, which are potential points of failure. Stresses on the femoral component occur in multiple dimensions besides the axial loading and medial-lateral, anterior-posterior rocking seen with the tibial component. The maximum stress is observed at the distal-most aspect of the stiffest or most well-fixed components, in this case, the articulation between the cemented stem and the cemented condylar component. Poor distal femoral fixation compounds the problem.

Numerous case reports have documented such failures in other knee systems. Issack and colleagues⁵ described 2 cases of fracture through the taper lock between the femoral component and the stem extension in the Optetrak stemmed-constrained condylar knee prosthesis (Exactech). Westrich and colleagues⁶ reported disengagement of the locking bolt of the Insall-Burstein II Constrained Condylar Knee (Zimmer) leading to failure. Lim and colleagues⁴ reported stem-condyle junctional failure of the Total Condylar III (DePuy, Johnson & Johnson) due to locking-screw failure. Butt and colleagues⁷ reported a case of failure at the femoral component–stem junction caused by screw breakage. All of these cases involved failure at the condylar-stem junction that was readily apparent on routine preoperative imaging.

Our case is noteworthy because there was no preoperative radiographic evidence that the components were loose or the junction had failed. As with many revision systems observed by Fehring and colleagues,⁸ determination of fixation is often based on the appearance of the stem because the distal femoral interfaces may be obscured by the intercondylar box. This suggests that a loose component at the stem-condylar junction could easily be overlooked and not appropriately revised based on imaging alone. A solution for achieving stability at the time of revision surgery is to obtain good distal bone apposition and fixation. In this case, a cemented stem with a metaphyseal cone was used for femoral fixation (Figures 3A, 3B).

While long-term, abnormally high stress transmitted through the modular junction may account for the implant’s failure, to our knowledge, this is the first report of its kind related to this particular implant. If quadriceps weakness contributed to this failure, it is worth considering that quadriceps weakness is common after TKA and may persist without appropriate rehabilitation and activity. Furthermore, the lack of evidence on plain radiographs makes this particular form of failure very difficult to screen. A high degree of suspicion for loosening should be maintained in patients with pain and instability after revision TKA with this implant as well as with other modular revision knee systems.

Revision total knee arthroplasty (TKA) is frequently complicated by bone loss and ligament instability, necessitating specialized implants to increase constraint and transmit forces away from the joint surface. Femoral stems are commonly used to enhance fixation and distribute force from the condyles to the metaphysis or diaphysis, to higher-quality bone capable of sustaining the forces at the knee joint.

Modular implants are now commonplace in revision surgery, because they allow intraoperative customization of the implant to the patient’s anatomy, degree of bone loss, and need for metaphyseal or diaphyseal fixation. However, these advantages are not without a downside. The modular junction introduces potential weaknesses in the implant, which may lead to early failure.

We report a case of loosening of a Triathlon TS (Stryker) femoral component that was not evident on preoperative radiographs. To our knowledge, this complication has not been reported with this particular revision knee system. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 56-year-old woman underwent 2-stage revision left TKA secondary to infection at an outside institution. She had undergone 17 prior knee surgeries with multiple revisions prior to this most recent revision surgery. A constrained implant was used at her last reimplantation secondary to ligamentous laxity after extensive débridement for infection. A Triathlon TS revision knee system with cemented stemmed tibial and femoral components was implanted; stems designed for uncemented fixation were cemented. She had a history of a quadriceps tendon tear, which was repaired prior to her revision, and quadricepsplasty was performed at the time of revision.

Seven years after this revision surgery, the patient presented to our clinic with progressive global instability, occasional effusions, and 2 documented episodes of frank dislocation. On examination, she was unstable in flexion and extension. Her extensor mechanism was intact, although with 7º active lag. She had a palpable quadriceps tendon defect. Her passive range of motion was 0º to 130º. Her active range of motion was 7º to 130º. Her erythrocyte sedimentation rate and C-reactive protein levels were within normal limits, and aspiration was negative for infection. Radiographs showed apparently well-fixed components with cemented femoral and tibial stems (Figures 1A, 1B).

The patient underwent revision surgery for global instability with the surgical goal to upsize the polyethylene insert and advance the quadriceps to improve stability. In the operating room, a defect in the quadriceps mechanism was seen between the vastus medialis obliquus (VMO) and the patella, as well as a large effusion. Upon removal of the polyethylene insert, the tibial and patellar components were examined and found to be well fixed. The femoral component was grossly loose. On closer inspection, the condylar portion was found to be rotating in the axial plane freely on the well-fixed cemented stem in the femoral canal (Figures 2A-2D). The entire femoral component was removed with some difficulty because the well-fixed uncemented stem design was cemented in place. This required a small, anterior episiotomy of the femur. Reconstruction of the femur was performed using a trabecular metal cone, a cemented stem, and condylar component with distal and posterior augments (Figures 3A, 3B). A shorter, thinner stem was implanted and cemented into the previous cement mantle. A 19-mm constrained polyethylene liner was selected (the prior liner was 13 mm), which gave adequate stability with range of motion 0º to 130º. The VMO was advanced approximately 1.5 cm at the time of closure of the arthrotomy. The patient was implanted with the same Triathlon TS system, because the tibial component was well fixed, well positioned, and did not require revision.

Discussion

The need and use of stemmed, modular femoral components for revision TKA is neither questioned nor a novel concept in arthroplasty.¹ Femoral bone defects encountered in revision arthroplasty generally lack sufficient cortical integrity to support an unstemmed component. Biomechanical analyses have reliably demonstrated improved initial stability and reduced relative motion provided by femoral stem extension.^2,3 Correspondingly, significant translational and rotational movements of the femoral component when disconnected from the stem presumably correspond with clinical observations of instability.³ We report a unique case of failure of the modular junction of a stemmed femoral component in revision TKA that was not readily apparent on plain radiographs.

Dissociation of a cemented stem from the condylar portion of the component has been described at our institution with a different implant design.⁴ To our knowledge, we describe the first report of failure at the modular junction of the Triathlon TS femoral component. 

Interestingly, relative motion has been shown to increase with increasing flexion in a biomechanical study² using the same Triathlon TS system. The authors of that study found they were unable to complete testing at flexion greater than 30º because, absent the stabilizing influence of surrounding ligament and muscle, the sample deformation was so significant that it caused fracture.² In the case of our patient, the incompetence of her extensor mechanism likely resulted in increased forces transmitted through the implant than might be expected in more physiologic circumstances. This higher stress may account in part for the failure of the implant at the known weakest point, the stem-condyle modular junction.

Modular implants are routinely used, given the variability of scenarios encountered in revision surgery and the need for customization to provide the best approximation of physiologic functioning of the joint. However, modular components introduce junctional points, which are potential points of failure. Stresses on the femoral component occur in multiple dimensions besides the axial loading and medial-lateral, anterior-posterior rocking seen with the tibial component. The maximum stress is observed at the distal-most aspect of the stiffest or most well-fixed components, in this case, the articulation between the cemented stem and the cemented condylar component. Poor distal femoral fixation compounds the problem.

Numerous case reports have documented such failures in other knee systems. Issack and colleagues⁵ described 2 cases of fracture through the taper lock between the femoral component and the stem extension in the Optetrak stemmed-constrained condylar knee prosthesis (Exactech). Westrich and colleagues⁶ reported disengagement of the locking bolt of the Insall-Burstein II Constrained Condylar Knee (Zimmer) leading to failure. Lim and colleagues⁴ reported stem-condyle junctional failure of the Total Condylar III (DePuy, Johnson & Johnson) due to locking-screw failure. Butt and colleagues⁷ reported a case of failure at the femoral component–stem junction caused by screw breakage. All of these cases involved failure at the condylar-stem junction that was readily apparent on routine preoperative imaging.

Our case is noteworthy because there was no preoperative radiographic evidence that the components were loose or the junction had failed. As with many revision systems observed by Fehring and colleagues,⁸ determination of fixation is often based on the appearance of the stem because the distal femoral interfaces may be obscured by the intercondylar box. This suggests that a loose component at the stem-condylar junction could easily be overlooked and not appropriately revised based on imaging alone. A solution for achieving stability at the time of revision surgery is to obtain good distal bone apposition and fixation. In this case, a cemented stem with a metaphyseal cone was used for femoral fixation (Figures 3A, 3B).

While long-term, abnormally high stress transmitted through the modular junction may account for the implant’s failure, to our knowledge, this is the first report of its kind related to this particular implant. If quadriceps weakness contributed to this failure, it is worth considering that quadriceps weakness is common after TKA and may persist without appropriate rehabilitation and activity. Furthermore, the lack of evidence on plain radiographs makes this particular form of failure very difficult to screen. A high degree of suspicion for loosening should be maintained in patients with pain and instability after revision TKA with this implant as well as with other modular revision knee systems.

The sesamoid bones are a major contributor to normal gait, with more than 50% of body weight transmitted through the hallux metatarsophalangeal joint (MTPJ) complex. There are varying amounts of stress on the sesamoids, dependent on the gait cycle.^1,2 The sesamoids act as a fulcrum to increase the mechanical force of the flexor hallucis brevis tendon.³ Sesamoid pathology can be a source of significant morbidity in patients, especially young athletes or laborers who spend long hours on their feet. More common causes of isolated sesamoid discomfort include sesamoiditis, fracture, and avascular necrosis, with neoplastic, infectious, and inflammatory conditions rarely isolated to the sesamoid.

Gout is a systemic disorder of uric acid metabolism characterized by deposition of monosodium urate crystals in soft tissues and joints.¹ This deposition leads to tophus formation with an accompanying inflammatory response. Gout progresses through 3 stages, beginning with acute gout, which may end with chronic, recurrent, and tophaceous gouty arthritis. The hallux MTPJ is the most common joint affected by gout, with few case reports of primary sesamoid gout.^1-2,4 We present a case of gout, with radiographic findings isolated to the medial sesamoid, that mimicked a neoplastic process in a patient with no known history of gout. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 37-year-old laborer presented for evaluation of a right sesamoid injury he sustained 4 months earlier when he fell off a ladder and had acute onset plantar hallux MTPJ pain and swelling. He was treated by an outside physician for a presumptive diagnosis of a medial sesamoid fracture with rest and controlled ankle movement (CAM) boot immobilization that resulted in slowly improving symptoms. In discussion of the patient’s history, he reported that 1 year earlier he had a traumatic event with similar symptoms of MTPJ pain and swelling. At that time, treatment with a CAM boot resulted in complete resolution of pain. His outside physician performed a hematologic workup for gout, which showed a normal uric acid level.

On examination, the patient presented with edema to the right hallux MTPJ and mild tenderness to palpation of the medial sesamoid. He had no pain with motion of the hallux MTPJ or with palpation of the lateral sesamoid. His radiographs showed a bipartite versus fractured sesamoid (Figures 1A, 1B) and serial magnetic resonance imaging (MRI) showed an MTPJ effusion and hyperintense signal in the medial sesamoid, but no erosive findings or soft-tissue masses (Figures 2A, 2B).

The patient was treated with wedge-sandal forefoot offloading, leading to resolution of symptoms over 6 weeks, at which point he was transitioned to normal shoe wear and allowed to progress in his activity as dictated by his symptoms. He presented for reevaluation approximately 2 weeks later with acute, atraumatic onset of plantar left hallux pain and swelling. His examination showed diffuse hallux MTPJ swelling and tenderness isolated to the medial sesamoid. An attempt at aspiration of the MTPJ yielded no fluid, and the patient again was placed in a forefoot-offloading sandal.

Radiographs of the left foot showed an expansile destructive lesion of the medial sesamoid with interval change from his previous imaging approximately 3 months earlier, obtained as part of his contralateral foot evaluation (Figure 3). MRI with and without contrast showed an expansile process isolated to the medial sesamoid with cortical thinning and marrow replacement (Figures 4A-4D). 

Because of continued discomfort and lack of a definitive diagnosis, an excisional biopsy of the sesamoid was performed. Intraoperatively, the sesamoid was extensively fragmented with near complete replacement by a chalky tophus, as well as chalky deposition throughout the hallux MTPJ. No significant degenerative changes were observed. Surgical pathology showed bone and fibroconnective tissue with deposits of negative birefringement needle-shaped crystals consistent with monosodium urate deposition and foreign body histocytic reaction, as well as repair reaction of bone (Figures 5A, 5B).

Postoperatively, the patient was again placed in a forefoot-offloading wedge sandal for 6 weeks, followed by progression of activity as dictated by his symptoms. He was also evaluated by a rheumatologist and started on medical treatment for gout, with complete resolution of his bilateral hallux pain. He has been able to return to his previous employment.

Discussion

The sesamoid bones are an important component of the hallux MTPJ complex, giving a mechanical advantage to the flexor hallucis brevis tendons in plantar flexion of the hallux.⁵ Many pathologic conditions have been well described in the literature, including fracture, sesamoiditis, nonunion, avascular necrosis, and plantar keratosis. There is also a 10% incidence of bipartite sesamoids, most commonly isolated to the medial sesamoid, with up to 25% of patients presenting with bilateral bipartite sesamoids.⁵ Neoplastic processes of the sesamoid are rare, with a paucity of reports in the literature.^6,7  Gout is a condition in which hyperuricemia, due to an imbalance in uric acid production and excretion, leads to deposition of monosodium urate crystals in joints, bones, and soft tissues, causing an inflammatory reaction. Risk factors for gout are male sex, advanced age, and ethnicity, as well as obesity, high protein diet, alcohol use, hypertension, and certain medications. Precipitation of acute attacks has been associated with acute trauma, and the first MTPJ is the most common location for an acute attack.⁸

Isolated sesamoid lesions are rare, with few isolated case reports in the literature. Benign and malignant lesions appear most often in the metatarsals, with the calcaneus being the second most commonly afflicted site.⁹ The typical differential diagnosis for isolated lytic bone lesions includes fibrous dysplasia, osteoblastoma, giant cell tumor, metastatic lesion, multiple myeloma, aneurysmal bone cyst, chondroblastoma, brown tumor, infection, eosinophilic granuloma, enchondroma, and bone cyst, with no reports in the literature to our knowledge of these entities presenting in the hallux MTPJ sesamoid. In contrast, gout typically begins with normal radiographic findings, and later leads to erosive, “punched out” lesions on either side of the MTPJ.²

Hyperuricemia is an essential part of the pathophysiology of gout, but not all patients with an acute gouty attack have elevated uric acid levels and, in contrast, may actually have normal or low levels in 12% to 43% of cases.⁸ The most accurate time frame for assessment of serum uric acid levels is 2 weeks or more after subsidence of an acute event.⁸ The normal uric acid levels seen in our patient were most likely due to the fact that the workup was undertaken during an acute attack. The difficulty with establishing the diagnosis was compounded by bilateral involvement, history of trauma, negative joint aspiration, and atypical radiographic findings. A number of reports have described patients with tophus deposits prior to or in the absence of gouty arthritis or a gouty attack.¹⁰ Risk factors for this presentation include female sex, the predominant or exclusive involvement of fingers, chronic kidney disease, and treatment with a diuretic or anti-inflammatory drug.¹⁰

Conclusion

Our case report illustrates the difficulty in diagnosing an acute gouty attack in a patient with a history of trauma and atypical radiographic findings. The hallux MTPJ is the most common location of acute gouty attacks, but the medial sesamoid as an isolated location is a rare site of presentation. The combination of pain isolated to palpation of the sesamoid and radiographs that showed an aggressive and rapidly expansile lesion of the medial sesamoid raised concerns about a neoplastic lesion. Practitioners should consider acute gout in patients with sesamoid pain and with radiographs showing an expansile sesamoid lesion.

The sesamoid bones are a major contributor to normal gait, with more than 50% of body weight transmitted through the hallux metatarsophalangeal joint (MTPJ) complex. There are varying amounts of stress on the sesamoids, dependent on the gait cycle.^1,2 The sesamoids act as a fulcrum to increase the mechanical force of the flexor hallucis brevis tendon.³ Sesamoid pathology can be a source of significant morbidity in patients, especially young athletes or laborers who spend long hours on their feet. More common causes of isolated sesamoid discomfort include sesamoiditis, fracture, and avascular necrosis, with neoplastic, infectious, and inflammatory conditions rarely isolated to the sesamoid.

Gout is a systemic disorder of uric acid metabolism characterized by deposition of monosodium urate crystals in soft tissues and joints.¹ This deposition leads to tophus formation with an accompanying inflammatory response. Gout progresses through 3 stages, beginning with acute gout, which may end with chronic, recurrent, and tophaceous gouty arthritis. The hallux MTPJ is the most common joint affected by gout, with few case reports of primary sesamoid gout.^1-2,4 We present a case of gout, with radiographic findings isolated to the medial sesamoid, that mimicked a neoplastic process in a patient with no known history of gout. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 37-year-old laborer presented for evaluation of a right sesamoid injury he sustained 4 months earlier when he fell off a ladder and had acute onset plantar hallux MTPJ pain and swelling. He was treated by an outside physician for a presumptive diagnosis of a medial sesamoid fracture with rest and controlled ankle movement (CAM) boot immobilization that resulted in slowly improving symptoms. In discussion of the patient’s history, he reported that 1 year earlier he had a traumatic event with similar symptoms of MTPJ pain and swelling. At that time, treatment with a CAM boot resulted in complete resolution of pain. His outside physician performed a hematologic workup for gout, which showed a normal uric acid level.

On examination, the patient presented with edema to the right hallux MTPJ and mild tenderness to palpation of the medial sesamoid. He had no pain with motion of the hallux MTPJ or with palpation of the lateral sesamoid. His radiographs showed a bipartite versus fractured sesamoid (Figures 1A, 1B) and serial magnetic resonance imaging (MRI) showed an MTPJ effusion and hyperintense signal in the medial sesamoid, but no erosive findings or soft-tissue masses (Figures 2A, 2B).

The patient was treated with wedge-sandal forefoot offloading, leading to resolution of symptoms over 6 weeks, at which point he was transitioned to normal shoe wear and allowed to progress in his activity as dictated by his symptoms. He presented for reevaluation approximately 2 weeks later with acute, atraumatic onset of plantar left hallux pain and swelling. His examination showed diffuse hallux MTPJ swelling and tenderness isolated to the medial sesamoid. An attempt at aspiration of the MTPJ yielded no fluid, and the patient again was placed in a forefoot-offloading sandal.

Radiographs of the left foot showed an expansile destructive lesion of the medial sesamoid with interval change from his previous imaging approximately 3 months earlier, obtained as part of his contralateral foot evaluation (Figure 3). MRI with and without contrast showed an expansile process isolated to the medial sesamoid with cortical thinning and marrow replacement (Figures 4A-4D). 

Because of continued discomfort and lack of a definitive diagnosis, an excisional biopsy of the sesamoid was performed. Intraoperatively, the sesamoid was extensively fragmented with near complete replacement by a chalky tophus, as well as chalky deposition throughout the hallux MTPJ. No significant degenerative changes were observed. Surgical pathology showed bone and fibroconnective tissue with deposits of negative birefringement needle-shaped crystals consistent with monosodium urate deposition and foreign body histocytic reaction, as well as repair reaction of bone (Figures 5A, 5B).

Postoperatively, the patient was again placed in a forefoot-offloading wedge sandal for 6 weeks, followed by progression of activity as dictated by his symptoms. He was also evaluated by a rheumatologist and started on medical treatment for gout, with complete resolution of his bilateral hallux pain. He has been able to return to his previous employment.

Discussion

The sesamoid bones are an important component of the hallux MTPJ complex, giving a mechanical advantage to the flexor hallucis brevis tendons in plantar flexion of the hallux.⁵ Many pathologic conditions have been well described in the literature, including fracture, sesamoiditis, nonunion, avascular necrosis, and plantar keratosis. There is also a 10% incidence of bipartite sesamoids, most commonly isolated to the medial sesamoid, with up to 25% of patients presenting with bilateral bipartite sesamoids.⁵ Neoplastic processes of the sesamoid are rare, with a paucity of reports in the literature.^6,7  Gout is a condition in which hyperuricemia, due to an imbalance in uric acid production and excretion, leads to deposition of monosodium urate crystals in joints, bones, and soft tissues, causing an inflammatory reaction. Risk factors for gout are male sex, advanced age, and ethnicity, as well as obesity, high protein diet, alcohol use, hypertension, and certain medications. Precipitation of acute attacks has been associated with acute trauma, and the first MTPJ is the most common location for an acute attack.⁸

Isolated sesamoid lesions are rare, with few isolated case reports in the literature. Benign and malignant lesions appear most often in the metatarsals, with the calcaneus being the second most commonly afflicted site.⁹ The typical differential diagnosis for isolated lytic bone lesions includes fibrous dysplasia, osteoblastoma, giant cell tumor, metastatic lesion, multiple myeloma, aneurysmal bone cyst, chondroblastoma, brown tumor, infection, eosinophilic granuloma, enchondroma, and bone cyst, with no reports in the literature to our knowledge of these entities presenting in the hallux MTPJ sesamoid. In contrast, gout typically begins with normal radiographic findings, and later leads to erosive, “punched out” lesions on either side of the MTPJ.²

Hyperuricemia is an essential part of the pathophysiology of gout, but not all patients with an acute gouty attack have elevated uric acid levels and, in contrast, may actually have normal or low levels in 12% to 43% of cases.⁸ The most accurate time frame for assessment of serum uric acid levels is 2 weeks or more after subsidence of an acute event.⁸ The normal uric acid levels seen in our patient were most likely due to the fact that the workup was undertaken during an acute attack. The difficulty with establishing the diagnosis was compounded by bilateral involvement, history of trauma, negative joint aspiration, and atypical radiographic findings. A number of reports have described patients with tophus deposits prior to or in the absence of gouty arthritis or a gouty attack.¹⁰ Risk factors for this presentation include female sex, the predominant or exclusive involvement of fingers, chronic kidney disease, and treatment with a diuretic or anti-inflammatory drug.¹⁰

Conclusion

Our case report illustrates the difficulty in diagnosing an acute gouty attack in a patient with a history of trauma and atypical radiographic findings. The hallux MTPJ is the most common location of acute gouty attacks, but the medial sesamoid as an isolated location is a rare site of presentation. The combination of pain isolated to palpation of the sesamoid and radiographs that showed an aggressive and rapidly expansile lesion of the medial sesamoid raised concerns about a neoplastic lesion. Practitioners should consider acute gout in patients with sesamoid pain and with radiographs showing an expansile sesamoid lesion.

The sesamoid bones are a major contributor to normal gait, with more than 50% of body weight transmitted through the hallux metatarsophalangeal joint (MTPJ) complex. There are varying amounts of stress on the sesamoids, dependent on the gait cycle.^1,2 The sesamoids act as a fulcrum to increase the mechanical force of the flexor hallucis brevis tendon.³ Sesamoid pathology can be a source of significant morbidity in patients, especially young athletes or laborers who spend long hours on their feet. More common causes of isolated sesamoid discomfort include sesamoiditis, fracture, and avascular necrosis, with neoplastic, infectious, and inflammatory conditions rarely isolated to the sesamoid.

Gout is a systemic disorder of uric acid metabolism characterized by deposition of monosodium urate crystals in soft tissues and joints.¹ This deposition leads to tophus formation with an accompanying inflammatory response. Gout progresses through 3 stages, beginning with acute gout, which may end with chronic, recurrent, and tophaceous gouty arthritis. The hallux MTPJ is the most common joint affected by gout, with few case reports of primary sesamoid gout.^1-2,4 We present a case of gout, with radiographic findings isolated to the medial sesamoid, that mimicked a neoplastic process in a patient with no known history of gout. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 37-year-old laborer presented for evaluation of a right sesamoid injury he sustained 4 months earlier when he fell off a ladder and had acute onset plantar hallux MTPJ pain and swelling. He was treated by an outside physician for a presumptive diagnosis of a medial sesamoid fracture with rest and controlled ankle movement (CAM) boot immobilization that resulted in slowly improving symptoms. In discussion of the patient’s history, he reported that 1 year earlier he had a traumatic event with similar symptoms of MTPJ pain and swelling. At that time, treatment with a CAM boot resulted in complete resolution of pain. His outside physician performed a hematologic workup for gout, which showed a normal uric acid level.

On examination, the patient presented with edema to the right hallux MTPJ and mild tenderness to palpation of the medial sesamoid. He had no pain with motion of the hallux MTPJ or with palpation of the lateral sesamoid. His radiographs showed a bipartite versus fractured sesamoid (Figures 1A, 1B) and serial magnetic resonance imaging (MRI) showed an MTPJ effusion and hyperintense signal in the medial sesamoid, but no erosive findings or soft-tissue masses (Figures 2A, 2B).

The patient was treated with wedge-sandal forefoot offloading, leading to resolution of symptoms over 6 weeks, at which point he was transitioned to normal shoe wear and allowed to progress in his activity as dictated by his symptoms. He presented for reevaluation approximately 2 weeks later with acute, atraumatic onset of plantar left hallux pain and swelling. His examination showed diffuse hallux MTPJ swelling and tenderness isolated to the medial sesamoid. An attempt at aspiration of the MTPJ yielded no fluid, and the patient again was placed in a forefoot-offloading sandal.

Radiographs of the left foot showed an expansile destructive lesion of the medial sesamoid with interval change from his previous imaging approximately 3 months earlier, obtained as part of his contralateral foot evaluation (Figure 3). MRI with and without contrast showed an expansile process isolated to the medial sesamoid with cortical thinning and marrow replacement (Figures 4A-4D). 

Because of continued discomfort and lack of a definitive diagnosis, an excisional biopsy of the sesamoid was performed. Intraoperatively, the sesamoid was extensively fragmented with near complete replacement by a chalky tophus, as well as chalky deposition throughout the hallux MTPJ. No significant degenerative changes were observed. Surgical pathology showed bone and fibroconnective tissue with deposits of negative birefringement needle-shaped crystals consistent with monosodium urate deposition and foreign body histocytic reaction, as well as repair reaction of bone (Figures 5A, 5B).

Postoperatively, the patient was again placed in a forefoot-offloading wedge sandal for 6 weeks, followed by progression of activity as dictated by his symptoms. He was also evaluated by a rheumatologist and started on medical treatment for gout, with complete resolution of his bilateral hallux pain. He has been able to return to his previous employment.

Discussion

The sesamoid bones are an important component of the hallux MTPJ complex, giving a mechanical advantage to the flexor hallucis brevis tendons in plantar flexion of the hallux.⁵ Many pathologic conditions have been well described in the literature, including fracture, sesamoiditis, nonunion, avascular necrosis, and plantar keratosis. There is also a 10% incidence of bipartite sesamoids, most commonly isolated to the medial sesamoid, with up to 25% of patients presenting with bilateral bipartite sesamoids.⁵ Neoplastic processes of the sesamoid are rare, with a paucity of reports in the literature.^6,7  Gout is a condition in which hyperuricemia, due to an imbalance in uric acid production and excretion, leads to deposition of monosodium urate crystals in joints, bones, and soft tissues, causing an inflammatory reaction. Risk factors for gout are male sex, advanced age, and ethnicity, as well as obesity, high protein diet, alcohol use, hypertension, and certain medications. Precipitation of acute attacks has been associated with acute trauma, and the first MTPJ is the most common location for an acute attack.⁸

Isolated sesamoid lesions are rare, with few isolated case reports in the literature. Benign and malignant lesions appear most often in the metatarsals, with the calcaneus being the second most commonly afflicted site.⁹ The typical differential diagnosis for isolated lytic bone lesions includes fibrous dysplasia, osteoblastoma, giant cell tumor, metastatic lesion, multiple myeloma, aneurysmal bone cyst, chondroblastoma, brown tumor, infection, eosinophilic granuloma, enchondroma, and bone cyst, with no reports in the literature to our knowledge of these entities presenting in the hallux MTPJ sesamoid. In contrast, gout typically begins with normal radiographic findings, and later leads to erosive, “punched out” lesions on either side of the MTPJ.²

Hyperuricemia is an essential part of the pathophysiology of gout, but not all patients with an acute gouty attack have elevated uric acid levels and, in contrast, may actually have normal or low levels in 12% to 43% of cases.⁸ The most accurate time frame for assessment of serum uric acid levels is 2 weeks or more after subsidence of an acute event.⁸ The normal uric acid levels seen in our patient were most likely due to the fact that the workup was undertaken during an acute attack. The difficulty with establishing the diagnosis was compounded by bilateral involvement, history of trauma, negative joint aspiration, and atypical radiographic findings. A number of reports have described patients with tophus deposits prior to or in the absence of gouty arthritis or a gouty attack.¹⁰ Risk factors for this presentation include female sex, the predominant or exclusive involvement of fingers, chronic kidney disease, and treatment with a diuretic or anti-inflammatory drug.¹⁰

Conclusion

Our case report illustrates the difficulty in diagnosing an acute gouty attack in a patient with a history of trauma and atypical radiographic findings. The hallux MTPJ is the most common location of acute gouty attacks, but the medial sesamoid as an isolated location is a rare site of presentation. The combination of pain isolated to palpation of the sesamoid and radiographs that showed an aggressive and rapidly expansile lesion of the medial sesamoid raised concerns about a neoplastic lesion. Practitioners should consider acute gout in patients with sesamoid pain and with radiographs showing an expansile sesamoid lesion.

The literature includes only 2 case reports of bony avulsion fracture of the origin of the brachioradialis^1,2 and, up until now, no case reports of isolated avulsion of the extensor carpi radialis longus and brachioradialis origins from the lateral epicondyle and lateral supracondylar ridge. In this article, we report the case of a 31-year-old man who sustained this injury during a fall onto his outstretched right hand, and we present our surgical repair technique. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 31-year-old right hand–dominant garbage truck worker sustained a right elbow injury and presented 2 months later. He described slipping and falling onto his outstretched right hand while doing his work. He could not describe the exact mechanism or action or position of the arm at time of impact but thought he tried to catch himself on the truck during the fall. At time of injury, he had immediate pain and swelling to the lateral aspect of the right elbow and difficulty when he attempted lifting. He denied antecedent elbow symptoms before the injury. After evaluation by an outside occupational medicine physician, he engaged in treatment consisting of activity modification and physical therapy, including range-of-motion (ROM) exercises and iontophoresis. This course of management failed to completely relieve his symptoms, and he was unable to return to work.

The patient presented to our institution 9 weeks after injury with complaints of pain along the lateral aspect of the elbow, painful flexion-extension, and continued swelling. The pain had been unrelieved with anti-inflammatory medications and opioids. Physical examination revealed tenderness and swelling along the lateral epicondyle and extensor mass of the right elbow. The patient had tenderness, marked weakness, and a palpable soft-tissue defect at the origin of the extensor mass with resisted extension of the wrist (Figure 1). Elbow ROM was from 20° to 120° of flexion, 60° of pronation, and 60° of supination. No varus or valgus instability was present about the elbow. Radiographs did not show any fracture or dislocation. Magnetic resonance imaging (MRI) did not definitively show extensor tendon avulsion but did identify signal change of the common extensor tendon (Figures 2A, 2B). Advanced imaging was inconclusive, but, given the patient’s history and physical examination findings, he was diagnosed with an avulsion injury of the origin of the extensor mass of the right elbow.

The patient was brought to the operating room, administered general anesthesia, and placed supine on the operating table with a tourniquet on the upper arm. A lateral 4.5-cm incision was made centered over the lateral epicondyle. The origin of the extensor mass was exposed, and isolated avulsions of the extensor carpi radialis longus and the brachioradialis were identified (Figures 3, 4). Underlying the avulsed sleeve of tissue, the origin of the extensor carpi radialis brevis was found intact. The lateral supracondylar ridge and the lateral epicondyle of the humerus were débrided, and 3 transosseous holes were drilled (using a 2.3-mm bit) through the lateral epicondyle. Four Mason-Allen sutures were placed into the tendon of the common extensor origin using No. 2 braided polyester suture (Ethibond Excel, Ethicon) (Figure 5). The tendon was reduced down to the native footprint, and the sutures were passed through the drill holes and tied down securely (Figure 6). The skin was then closed using layered 4-0 absorbable monofilament suture (Monocryl, Ethicon). The patient was placed in a posterior mold plaster splint with 90° of elbow flexion and with the wrist in 30° of extension.

On postoperative day 3, the patient was seen for a wound check and was placed in a long-arm fiberglass cast (90° of elbow flexion, forearm in neutral, 25° of wrist extension) for immobilization. One week after surgery, he was transitioned to a removable thermoplastic splint, and physical therapy for ROM was initiated. He was allowed therapist-guided active extension of the elbow and flexion of the wrist but was restricted to passive flexion of the elbow and extension of the wrist. Seven weeks after surgery, passive ROM about the elbow was measured, and he was found to have 120° of flexion, 0° extension, 80° pronation, and 80° supination. At 12 weeks, the physical therapy regimen was advanced to include muscle strengthening and active wrist extension and elbow flexion. At 16 weeks, the wrist extensors demonstrated 5/5 strength (Medical Research Council grading system), and the patient was cleared for full activity and weight-bearing without restriction. He returned to work pain-free and without restrictions 18 weeks after surgery. At 2-year follow-up, he had a Mayo performance elbow score of 100 and an Oxford elbow score of 48.^3,4 He had full active ROM, full strength, and no subjective pain and was back doing heavy lifting at his job.

Discussion

The brachioradialis, extensor carpi radialis longus, and extensor carpi radialis brevis originate from the anterolateral aspect of the lateral column of the distal humeral metaphysis and form the dorsal mobile wad. The origin of the brachioradialis is about 7 cm in length and begins about 10 to 11 cm above the elbow.⁵ The origin and insertions of the mobile wad, specifically the brachioradialis, provide a tremendous mechanical advantage with respect to elbow flexion against resistance, particularly with the forearm in the pronated and semipronated positions.⁶ With the elbow in 30° of flexion, a force 3 times the body weight can be encountered during strenuous lifting.^6,7 We hypothesized these large forces likely led to this injury pattern in the patient we have described.

The literature includes 2 case reports of avulsion fracture of the brachioradialis muscle from its origin on the lateral supracondylar humeral ridge.^1,2 To our knowledge, however, there have been no reports of pure avulsion. In our patient’s case, there was no bony fracture, but rather avulsion of the extensor carpi radialis longus and brachioradialis at their origin, with the underlying fibers of the extensor carpi radialis brevis remaining in continuity. Because of the rarity of this injury pattern, there was a significant delay in diagnosis. On initial presentation, the differential diagnosis for lateral elbow pain and tenderness included occult fracture, intracapsular plica, osteochondritis dissecans lesion, radial tunnel syndrome, lateral or posterolateral instability, and lateral epicondylitis. Given the absence of antecedent elbow symptoms before the injury, the dynamic soft-tissue asymmetry of the mobile wad with wrist extension, and the palpable soft-tissue defect, we thought the presentation was inconsistent with a simple inflammatory or overuse syndrome, such as lateral epicondylitis. In addition, the physical examination findings were inconsistent with radial tunnel syndrome or disruption of the lateral collateral ligament complex. Elbow MRI did not show an occult fracture, plica, or osteochondritis dissecans lesion but did reveal joint effusion and signal change in the common extensor tendon origin. Interestingly, MRI did not definitively show a tear of the mobile wad. This may be explained by the fact that the fibers of the underlying extensor carpi radialis brevis remained intact. Also potentially involved are the static nature of MRI and potentially suboptimal sequencing and axis of acquisition resulting from the relative infrequency of imaging this joint at certain health care institutions. Our case demonstrates the limitations of MRI in this setting and highlights the need for a detailed history and thorough physical examination for diagnosis.

Funk and colleagues⁸ used electromyography (EMG) to study the activity of the elbow musculature in uninjured subjects. EMG data were obtained with the elbow joint subjected to resisted flexion, extension, abduction, and adduction. During resisted elbow flexion, there was an increasing amount of activity in the extensor carpi radialis with larger angles of elbow flexion. In addition, the brachioradialis demonstrated the most muscle activity of any of the elbow flexors with 90° or more of elbow flexion and forearm pronation, as opposed to other positions in which the brachialis was the primary flexor. For this reason, we hypothesized that our patient’s forearm was pronated and his elbow flexed to 90° or more when he braced for impact. The ensuing injury resulted from a violent eccentric contraction that caused extensive rupture of the lateral elbow musculature from its broad origin. With the forearm in supination or neutral position, we would have expected a possible injury to the distal biceps as opposed to the brachioradialis and extensor carpi radialis.

In our patient, this injury caused much functional disability, especially with elbow flexion and wrist extension. We hypothesized that, for the muscles to function properly, anatomical restoration would have to be achieved at their known footprint to maintain their mechanical advantage. Therefore, surgical intervention was indicated in our patient, an active laborer. Given the absence of an osseous fracture fragment in this injury pattern, healing must occur at the bone–tendon interface. As tendinous healing is more tenuous and protracted than osseous healing, we preferred transosseous repair. We believed that better tendon-to-bone healing would be possible with drilled osseous tunnels rather than with suture anchors. New studies describing alternative successful methods of treatment would add to our limited body of knowledge regarding this rare injury.

Conclusion

This is the first report of avulsion of the extensor carpi radialis longus and brachioradialis from their origins. Given the biomechanics and anatomy of the dorsal mobile wad, we posit that our patient’s injury occurred when he fell onto his outstretched hand secondary to overwhelming eccentric muscle contracture at time of impact. This injury caused significant upper extremity dysfunction, and surgical intervention was required.

The literature includes only 2 case reports of bony avulsion fracture of the origin of the brachioradialis^1,2 and, up until now, no case reports of isolated avulsion of the extensor carpi radialis longus and brachioradialis origins from the lateral epicondyle and lateral supracondylar ridge. In this article, we report the case of a 31-year-old man who sustained this injury during a fall onto his outstretched right hand, and we present our surgical repair technique. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 31-year-old right hand–dominant garbage truck worker sustained a right elbow injury and presented 2 months later. He described slipping and falling onto his outstretched right hand while doing his work. He could not describe the exact mechanism or action or position of the arm at time of impact but thought he tried to catch himself on the truck during the fall. At time of injury, he had immediate pain and swelling to the lateral aspect of the right elbow and difficulty when he attempted lifting. He denied antecedent elbow symptoms before the injury. After evaluation by an outside occupational medicine physician, he engaged in treatment consisting of activity modification and physical therapy, including range-of-motion (ROM) exercises and iontophoresis. This course of management failed to completely relieve his symptoms, and he was unable to return to work.

The patient presented to our institution 9 weeks after injury with complaints of pain along the lateral aspect of the elbow, painful flexion-extension, and continued swelling. The pain had been unrelieved with anti-inflammatory medications and opioids. Physical examination revealed tenderness and swelling along the lateral epicondyle and extensor mass of the right elbow. The patient had tenderness, marked weakness, and a palpable soft-tissue defect at the origin of the extensor mass with resisted extension of the wrist (Figure 1). Elbow ROM was from 20° to 120° of flexion, 60° of pronation, and 60° of supination. No varus or valgus instability was present about the elbow. Radiographs did not show any fracture or dislocation. Magnetic resonance imaging (MRI) did not definitively show extensor tendon avulsion but did identify signal change of the common extensor tendon (Figures 2A, 2B). Advanced imaging was inconclusive, but, given the patient’s history and physical examination findings, he was diagnosed with an avulsion injury of the origin of the extensor mass of the right elbow.

The patient was brought to the operating room, administered general anesthesia, and placed supine on the operating table with a tourniquet on the upper arm. A lateral 4.5-cm incision was made centered over the lateral epicondyle. The origin of the extensor mass was exposed, and isolated avulsions of the extensor carpi radialis longus and the brachioradialis were identified (Figures 3, 4). Underlying the avulsed sleeve of tissue, the origin of the extensor carpi radialis brevis was found intact. The lateral supracondylar ridge and the lateral epicondyle of the humerus were débrided, and 3 transosseous holes were drilled (using a 2.3-mm bit) through the lateral epicondyle. Four Mason-Allen sutures were placed into the tendon of the common extensor origin using No. 2 braided polyester suture (Ethibond Excel, Ethicon) (Figure 5). The tendon was reduced down to the native footprint, and the sutures were passed through the drill holes and tied down securely (Figure 6). The skin was then closed using layered 4-0 absorbable monofilament suture (Monocryl, Ethicon). The patient was placed in a posterior mold plaster splint with 90° of elbow flexion and with the wrist in 30° of extension.

On postoperative day 3, the patient was seen for a wound check and was placed in a long-arm fiberglass cast (90° of elbow flexion, forearm in neutral, 25° of wrist extension) for immobilization. One week after surgery, he was transitioned to a removable thermoplastic splint, and physical therapy for ROM was initiated. He was allowed therapist-guided active extension of the elbow and flexion of the wrist but was restricted to passive flexion of the elbow and extension of the wrist. Seven weeks after surgery, passive ROM about the elbow was measured, and he was found to have 120° of flexion, 0° extension, 80° pronation, and 80° supination. At 12 weeks, the physical therapy regimen was advanced to include muscle strengthening and active wrist extension and elbow flexion. At 16 weeks, the wrist extensors demonstrated 5/5 strength (Medical Research Council grading system), and the patient was cleared for full activity and weight-bearing without restriction. He returned to work pain-free and without restrictions 18 weeks after surgery. At 2-year follow-up, he had a Mayo performance elbow score of 100 and an Oxford elbow score of 48.^3,4 He had full active ROM, full strength, and no subjective pain and was back doing heavy lifting at his job.

Discussion

The brachioradialis, extensor carpi radialis longus, and extensor carpi radialis brevis originate from the anterolateral aspect of the lateral column of the distal humeral metaphysis and form the dorsal mobile wad. The origin of the brachioradialis is about 7 cm in length and begins about 10 to 11 cm above the elbow.⁵ The origin and insertions of the mobile wad, specifically the brachioradialis, provide a tremendous mechanical advantage with respect to elbow flexion against resistance, particularly with the forearm in the pronated and semipronated positions.⁶ With the elbow in 30° of flexion, a force 3 times the body weight can be encountered during strenuous lifting.^6,7 We hypothesized these large forces likely led to this injury pattern in the patient we have described.

The literature includes 2 case reports of avulsion fracture of the brachioradialis muscle from its origin on the lateral supracondylar humeral ridge.^1,2 To our knowledge, however, there have been no reports of pure avulsion. In our patient’s case, there was no bony fracture, but rather avulsion of the extensor carpi radialis longus and brachioradialis at their origin, with the underlying fibers of the extensor carpi radialis brevis remaining in continuity. Because of the rarity of this injury pattern, there was a significant delay in diagnosis. On initial presentation, the differential diagnosis for lateral elbow pain and tenderness included occult fracture, intracapsular plica, osteochondritis dissecans lesion, radial tunnel syndrome, lateral or posterolateral instability, and lateral epicondylitis. Given the absence of antecedent elbow symptoms before the injury, the dynamic soft-tissue asymmetry of the mobile wad with wrist extension, and the palpable soft-tissue defect, we thought the presentation was inconsistent with a simple inflammatory or overuse syndrome, such as lateral epicondylitis. In addition, the physical examination findings were inconsistent with radial tunnel syndrome or disruption of the lateral collateral ligament complex. Elbow MRI did not show an occult fracture, plica, or osteochondritis dissecans lesion but did reveal joint effusion and signal change in the common extensor tendon origin. Interestingly, MRI did not definitively show a tear of the mobile wad. This may be explained by the fact that the fibers of the underlying extensor carpi radialis brevis remained intact. Also potentially involved are the static nature of MRI and potentially suboptimal sequencing and axis of acquisition resulting from the relative infrequency of imaging this joint at certain health care institutions. Our case demonstrates the limitations of MRI in this setting and highlights the need for a detailed history and thorough physical examination for diagnosis.

Funk and colleagues⁸ used electromyography (EMG) to study the activity of the elbow musculature in uninjured subjects. EMG data were obtained with the elbow joint subjected to resisted flexion, extension, abduction, and adduction. During resisted elbow flexion, there was an increasing amount of activity in the extensor carpi radialis with larger angles of elbow flexion. In addition, the brachioradialis demonstrated the most muscle activity of any of the elbow flexors with 90° or more of elbow flexion and forearm pronation, as opposed to other positions in which the brachialis was the primary flexor. For this reason, we hypothesized that our patient’s forearm was pronated and his elbow flexed to 90° or more when he braced for impact. The ensuing injury resulted from a violent eccentric contraction that caused extensive rupture of the lateral elbow musculature from its broad origin. With the forearm in supination or neutral position, we would have expected a possible injury to the distal biceps as opposed to the brachioradialis and extensor carpi radialis.

In our patient, this injury caused much functional disability, especially with elbow flexion and wrist extension. We hypothesized that, for the muscles to function properly, anatomical restoration would have to be achieved at their known footprint to maintain their mechanical advantage. Therefore, surgical intervention was indicated in our patient, an active laborer. Given the absence of an osseous fracture fragment in this injury pattern, healing must occur at the bone–tendon interface. As tendinous healing is more tenuous and protracted than osseous healing, we preferred transosseous repair. We believed that better tendon-to-bone healing would be possible with drilled osseous tunnels rather than with suture anchors. New studies describing alternative successful methods of treatment would add to our limited body of knowledge regarding this rare injury.

Conclusion

This is the first report of avulsion of the extensor carpi radialis longus and brachioradialis from their origins. Given the biomechanics and anatomy of the dorsal mobile wad, we posit that our patient’s injury occurred when he fell onto his outstretched hand secondary to overwhelming eccentric muscle contracture at time of impact. This injury caused significant upper extremity dysfunction, and surgical intervention was required.

The literature includes only 2 case reports of bony avulsion fracture of the origin of the brachioradialis^1,2 and, up until now, no case reports of isolated avulsion of the extensor carpi radialis longus and brachioradialis origins from the lateral epicondyle and lateral supracondylar ridge. In this article, we report the case of a 31-year-old man who sustained this injury during a fall onto his outstretched right hand, and we present our surgical repair technique. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 31-year-old right hand–dominant garbage truck worker sustained a right elbow injury and presented 2 months later. He described slipping and falling onto his outstretched right hand while doing his work. He could not describe the exact mechanism or action or position of the arm at time of impact but thought he tried to catch himself on the truck during the fall. At time of injury, he had immediate pain and swelling to the lateral aspect of the right elbow and difficulty when he attempted lifting. He denied antecedent elbow symptoms before the injury. After evaluation by an outside occupational medicine physician, he engaged in treatment consisting of activity modification and physical therapy, including range-of-motion (ROM) exercises and iontophoresis. This course of management failed to completely relieve his symptoms, and he was unable to return to work.

The patient presented to our institution 9 weeks after injury with complaints of pain along the lateral aspect of the elbow, painful flexion-extension, and continued swelling. The pain had been unrelieved with anti-inflammatory medications and opioids. Physical examination revealed tenderness and swelling along the lateral epicondyle and extensor mass of the right elbow. The patient had tenderness, marked weakness, and a palpable soft-tissue defect at the origin of the extensor mass with resisted extension of the wrist (Figure 1). Elbow ROM was from 20° to 120° of flexion, 60° of pronation, and 60° of supination. No varus or valgus instability was present about the elbow. Radiographs did not show any fracture or dislocation. Magnetic resonance imaging (MRI) did not definitively show extensor tendon avulsion but did identify signal change of the common extensor tendon (Figures 2A, 2B). Advanced imaging was inconclusive, but, given the patient’s history and physical examination findings, he was diagnosed with an avulsion injury of the origin of the extensor mass of the right elbow.

The patient was brought to the operating room, administered general anesthesia, and placed supine on the operating table with a tourniquet on the upper arm. A lateral 4.5-cm incision was made centered over the lateral epicondyle. The origin of the extensor mass was exposed, and isolated avulsions of the extensor carpi radialis longus and the brachioradialis were identified (Figures 3, 4). Underlying the avulsed sleeve of tissue, the origin of the extensor carpi radialis brevis was found intact. The lateral supracondylar ridge and the lateral epicondyle of the humerus were débrided, and 3 transosseous holes were drilled (using a 2.3-mm bit) through the lateral epicondyle. Four Mason-Allen sutures were placed into the tendon of the common extensor origin using No. 2 braided polyester suture (Ethibond Excel, Ethicon) (Figure 5). The tendon was reduced down to the native footprint, and the sutures were passed through the drill holes and tied down securely (Figure 6). The skin was then closed using layered 4-0 absorbable monofilament suture (Monocryl, Ethicon). The patient was placed in a posterior mold plaster splint with 90° of elbow flexion and with the wrist in 30° of extension.

On postoperative day 3, the patient was seen for a wound check and was placed in a long-arm fiberglass cast (90° of elbow flexion, forearm in neutral, 25° of wrist extension) for immobilization. One week after surgery, he was transitioned to a removable thermoplastic splint, and physical therapy for ROM was initiated. He was allowed therapist-guided active extension of the elbow and flexion of the wrist but was restricted to passive flexion of the elbow and extension of the wrist. Seven weeks after surgery, passive ROM about the elbow was measured, and he was found to have 120° of flexion, 0° extension, 80° pronation, and 80° supination. At 12 weeks, the physical therapy regimen was advanced to include muscle strengthening and active wrist extension and elbow flexion. At 16 weeks, the wrist extensors demonstrated 5/5 strength (Medical Research Council grading system), and the patient was cleared for full activity and weight-bearing without restriction. He returned to work pain-free and without restrictions 18 weeks after surgery. At 2-year follow-up, he had a Mayo performance elbow score of 100 and an Oxford elbow score of 48.^3,4 He had full active ROM, full strength, and no subjective pain and was back doing heavy lifting at his job.

Discussion

The brachioradialis, extensor carpi radialis longus, and extensor carpi radialis brevis originate from the anterolateral aspect of the lateral column of the distal humeral metaphysis and form the dorsal mobile wad. The origin of the brachioradialis is about 7 cm in length and begins about 10 to 11 cm above the elbow.⁵ The origin and insertions of the mobile wad, specifically the brachioradialis, provide a tremendous mechanical advantage with respect to elbow flexion against resistance, particularly with the forearm in the pronated and semipronated positions.⁶ With the elbow in 30° of flexion, a force 3 times the body weight can be encountered during strenuous lifting.^6,7 We hypothesized these large forces likely led to this injury pattern in the patient we have described.

The literature includes 2 case reports of avulsion fracture of the brachioradialis muscle from its origin on the lateral supracondylar humeral ridge.^1,2 To our knowledge, however, there have been no reports of pure avulsion. In our patient’s case, there was no bony fracture, but rather avulsion of the extensor carpi radialis longus and brachioradialis at their origin, with the underlying fibers of the extensor carpi radialis brevis remaining in continuity. Because of the rarity of this injury pattern, there was a significant delay in diagnosis. On initial presentation, the differential diagnosis for lateral elbow pain and tenderness included occult fracture, intracapsular plica, osteochondritis dissecans lesion, radial tunnel syndrome, lateral or posterolateral instability, and lateral epicondylitis. Given the absence of antecedent elbow symptoms before the injury, the dynamic soft-tissue asymmetry of the mobile wad with wrist extension, and the palpable soft-tissue defect, we thought the presentation was inconsistent with a simple inflammatory or overuse syndrome, such as lateral epicondylitis. In addition, the physical examination findings were inconsistent with radial tunnel syndrome or disruption of the lateral collateral ligament complex. Elbow MRI did not show an occult fracture, plica, or osteochondritis dissecans lesion but did reveal joint effusion and signal change in the common extensor tendon origin. Interestingly, MRI did not definitively show a tear of the mobile wad. This may be explained by the fact that the fibers of the underlying extensor carpi radialis brevis remained intact. Also potentially involved are the static nature of MRI and potentially suboptimal sequencing and axis of acquisition resulting from the relative infrequency of imaging this joint at certain health care institutions. Our case demonstrates the limitations of MRI in this setting and highlights the need for a detailed history and thorough physical examination for diagnosis.

Funk and colleagues⁸ used electromyography (EMG) to study the activity of the elbow musculature in uninjured subjects. EMG data were obtained with the elbow joint subjected to resisted flexion, extension, abduction, and adduction. During resisted elbow flexion, there was an increasing amount of activity in the extensor carpi radialis with larger angles of elbow flexion. In addition, the brachioradialis demonstrated the most muscle activity of any of the elbow flexors with 90° or more of elbow flexion and forearm pronation, as opposed to other positions in which the brachialis was the primary flexor. For this reason, we hypothesized that our patient’s forearm was pronated and his elbow flexed to 90° or more when he braced for impact. The ensuing injury resulted from a violent eccentric contraction that caused extensive rupture of the lateral elbow musculature from its broad origin. With the forearm in supination or neutral position, we would have expected a possible injury to the distal biceps as opposed to the brachioradialis and extensor carpi radialis.

In our patient, this injury caused much functional disability, especially with elbow flexion and wrist extension. We hypothesized that, for the muscles to function properly, anatomical restoration would have to be achieved at their known footprint to maintain their mechanical advantage. Therefore, surgical intervention was indicated in our patient, an active laborer. Given the absence of an osseous fracture fragment in this injury pattern, healing must occur at the bone–tendon interface. As tendinous healing is more tenuous and protracted than osseous healing, we preferred transosseous repair. We believed that better tendon-to-bone healing would be possible with drilled osseous tunnels rather than with suture anchors. New studies describing alternative successful methods of treatment would add to our limited body of knowledge regarding this rare injury.

Conclusion

This is the first report of avulsion of the extensor carpi radialis longus and brachioradialis from their origins. Given the biomechanics and anatomy of the dorsal mobile wad, we posit that our patient’s injury occurred when he fell onto his outstretched hand secondary to overwhelming eccentric muscle contracture at time of impact. This injury caused significant upper extremity dysfunction, and surgical intervention was required.

THE CASE

A 3-year-old girl was brought to our clinic with a generalized rash over her scalp, face, neck, chest, abdomen, back, perianal area, extremities, and the plantar surface of her right foot. On physical examination, we noted many round, hyperpigmented, brown and reddish pink, well-circumscribed macules on her body (FIGURE). Only a few of these macules had appeared on the girl’s trunk within the first 3 months of her life, but since then they’d increased in number and spread to other parts of her body as she’d aged. The lesions became edematous and erythematous with tactile irritation. Darier’s sign (the development of a hive or wheal when a lesion is stroked) was present.

The patient’s vitals at the time of examination included a temperature of 98.2°F, respiratory rate of 17 breaths/min, heart rate of 92 beats/min, blood pressure of 100/66 mm Hg, and oxygen saturation level of 100% on room air. The girl’s parents said they hadn’t traveled. There was no mucosal involvement and no systemic involvement. The patient had no past surgical or medical history, was not taking any medications, and had no significant birth history. A skin biopsy was performed.

THE DIAGNOSIS

Based on the presence of a positive Darier’s sign and the results of the skin biopsy (which showed increased mast cells), we diagnosed urticaria pigmentosa (UP), which is the most common form of cutaneous mastocytosis.¹

The diagnosis had been delayed for almost 3 years because of several factors. For one thing, there had been few lesions present early in the child’s life, and as a result, the parents chalked them up to “beauty marks.” Then, as the lesions started to increase in number, the parents thought bed bugs were to blame.

As time went on, the parents attempted to treat their daughter’s hives with homeopathic remedies suggested by family members. When the lesions didn’t resolve with homeopathic remedies, the parents tried over-the-counter H1 and H2 antihistamines such as diphenhydramine, loratadine, and ranitidine. When these treatments failed, the parents brought their child to our office for medical evaluation.

DISCUSSION

UP is a chronic skin disorder in which there is an abnormal proliferation of mast cells in the dermis of the skin. It is considered an orphan disease.¹ UP that presents in children is most often benign. Approximately 50% of cases occur before 6 months of age and 25% occur before puberty.² The lesions are often self-limited and completely resolve in approximately 50% of patients by puberty.³ By adulthood, the lesions either resolve or some lightly colored non-urticating macules remain; however, some patients will continue to have a positive Darier’s sign.⁴

Dermatologic symptoms. A patient with UP may present with brown or reddish maculopapules, papules, nodules, pruritus, and flushing of the face. Darier’s sign is usually seen in cases of UP; in a study of mastocytosis in children, Darier’s sign was present in 94% of cases.⁵ Lesions are more prominent in areas where clothes can rub the skin, and they often vary in size and appearance. The presence of lesions can vary from localized and scant to hundreds located over the entire body. UP can be difficult to identify when the lesions are limited, which can lead to delayed diagnosis and treatment.⁶

Systemic involvement. UP also can affect the skeleton, bone marrow, liver, spleen, lymph nodes, gastrointestinal tract, kidneys, cardiovascular system, and/or central nervous system. Skeletal involvement may manifest as osteoporosis or bone pain in 10% to 20% of patients with UP.⁷ Bone marrow involvement may progress to anemia or mast cell leukemia. UP can result in hepatomegaly or enlarged lymph nodes. Patients may experience nausea, diarrhea, or abdominal pain if the gastrointestinal tract is affected. Cardiovascular involvement may manifest as tachycardia and shock.⁸

Urticaria pigmentosa lesions are often self-limited and completely resolve in about half of patients by puberty.

Diagnosis of UP is made based on the physical exam findings noted earlier, as well as skin biopsy laboratory results. Skin biopsy will reveal increased mast cells. In up to two-thirds of patients who have systemic involvement, laboratory testing will show elevated urine histamine levels, as well as elevated serum concentrations of tryptase.⁹

UP can appear similar to many other skin conditions

The differential diagnosis of UP can include urticaria, atopic dermatitis, contact dermatitis, pityriasis rosea, an allergic reaction/drug eruption, Henoch-Schonlein purpura, erythema multiforme, fifth disease, folliculitis, guttate psoriasis, miliaria rubra, insect bites, viral exanthem, lichen planus, and scabies.^10,11 In addition to the clinical appearance of the rash, these conditions can be distinguished from UP by skin biopsy and other relevant tests, as well as a thorough history.

Treatment options include antihistamines, corticosteroids, PUVA

Patients with UP should be instructed to avoid precipitating factors such as temperature changes, friction, alcohol ingestion, aspirin, physical exertion, or opiates. Treatment options include H1 and H2 antihistamines, cromolyn sodium, topical corticosteroids, and PUVA (psoralen plus ultraviolet A photochemotherapy).³ PUVA is normally avoided in pediatric patients because it is associated with an increased risk of skin cancer later in life.¹²

Our patient. We prescribed a topical corticosteroid, 0.05% betamethasone dipropionate cream, and oral cromolyn sodium 100 mg qid for our patient, but this failed to significantly improve the macules. The patient and parents grew increasingly anxious. Ultimately, the parents decided to have their daughter treated with PUVA in limited amounts. Topical psoralen was also used. After 2 months of treatment, the patient’s lesions substantially improved and many of them disappeared. In addition, the parents were educated on the importance of sunscreen and limiting their daughter’s exposure to the sun, when possible.

THE TAKEAWAY

UP can be diagnosed by taking a thorough history and conducting a physical examination; a skin biopsy that reveals increased mast cells will confirm the diagnosis. UP is usually self-limited and resolves in about one-half of patients by puberty. Treatment options include H1 and H2 antihistamines, cromolyn sodium, topical corticosteroids, and PUVA. Patients should be referred to a specialist if their symptoms become severe, systemic UP is suspected, or they do not respond to therapy.

THE CASE

A 3-year-old girl was brought to our clinic with a generalized rash over her scalp, face, neck, chest, abdomen, back, perianal area, extremities, and the plantar surface of her right foot. On physical examination, we noted many round, hyperpigmented, brown and reddish pink, well-circumscribed macules on her body (FIGURE). Only a few of these macules had appeared on the girl’s trunk within the first 3 months of her life, but since then they’d increased in number and spread to other parts of her body as she’d aged. The lesions became edematous and erythematous with tactile irritation. Darier’s sign (the development of a hive or wheal when a lesion is stroked) was present.

The patient’s vitals at the time of examination included a temperature of 98.2°F, respiratory rate of 17 breaths/min, heart rate of 92 beats/min, blood pressure of 100/66 mm Hg, and oxygen saturation level of 100% on room air. The girl’s parents said they hadn’t traveled. There was no mucosal involvement and no systemic involvement. The patient had no past surgical or medical history, was not taking any medications, and had no significant birth history. A skin biopsy was performed.

THE DIAGNOSIS

Based on the presence of a positive Darier’s sign and the results of the skin biopsy (which showed increased mast cells), we diagnosed urticaria pigmentosa (UP), which is the most common form of cutaneous mastocytosis.¹

The diagnosis had been delayed for almost 3 years because of several factors. For one thing, there had been few lesions present early in the child’s life, and as a result, the parents chalked them up to “beauty marks.” Then, as the lesions started to increase in number, the parents thought bed bugs were to blame.

As time went on, the parents attempted to treat their daughter’s hives with homeopathic remedies suggested by family members. When the lesions didn’t resolve with homeopathic remedies, the parents tried over-the-counter H1 and H2 antihistamines such as diphenhydramine, loratadine, and ranitidine. When these treatments failed, the parents brought their child to our office for medical evaluation.

DISCUSSION

UP is a chronic skin disorder in which there is an abnormal proliferation of mast cells in the dermis of the skin. It is considered an orphan disease.¹ UP that presents in children is most often benign. Approximately 50% of cases occur before 6 months of age and 25% occur before puberty.² The lesions are often self-limited and completely resolve in approximately 50% of patients by puberty.³ By adulthood, the lesions either resolve or some lightly colored non-urticating macules remain; however, some patients will continue to have a positive Darier’s sign.⁴

Dermatologic symptoms. A patient with UP may present with brown or reddish maculopapules, papules, nodules, pruritus, and flushing of the face. Darier’s sign is usually seen in cases of UP; in a study of mastocytosis in children, Darier’s sign was present in 94% of cases.⁵ Lesions are more prominent in areas where clothes can rub the skin, and they often vary in size and appearance. The presence of lesions can vary from localized and scant to hundreds located over the entire body. UP can be difficult to identify when the lesions are limited, which can lead to delayed diagnosis and treatment.⁶

Systemic involvement. UP also can affect the skeleton, bone marrow, liver, spleen, lymph nodes, gastrointestinal tract, kidneys, cardiovascular system, and/or central nervous system. Skeletal involvement may manifest as osteoporosis or bone pain in 10% to 20% of patients with UP.⁷ Bone marrow involvement may progress to anemia or mast cell leukemia. UP can result in hepatomegaly or enlarged lymph nodes. Patients may experience nausea, diarrhea, or abdominal pain if the gastrointestinal tract is affected. Cardiovascular involvement may manifest as tachycardia and shock.⁸

Urticaria pigmentosa lesions are often self-limited and completely resolve in about half of patients by puberty.

Diagnosis of UP is made based on the physical exam findings noted earlier, as well as skin biopsy laboratory results. Skin biopsy will reveal increased mast cells. In up to two-thirds of patients who have systemic involvement, laboratory testing will show elevated urine histamine levels, as well as elevated serum concentrations of tryptase.⁹

UP can appear similar to many other skin conditions

The differential diagnosis of UP can include urticaria, atopic dermatitis, contact dermatitis, pityriasis rosea, an allergic reaction/drug eruption, Henoch-Schonlein purpura, erythema multiforme, fifth disease, folliculitis, guttate psoriasis, miliaria rubra, insect bites, viral exanthem, lichen planus, and scabies.^10,11 In addition to the clinical appearance of the rash, these conditions can be distinguished from UP by skin biopsy and other relevant tests, as well as a thorough history.

Treatment options include antihistamines, corticosteroids, PUVA

Patients with UP should be instructed to avoid precipitating factors such as temperature changes, friction, alcohol ingestion, aspirin, physical exertion, or opiates. Treatment options include H1 and H2 antihistamines, cromolyn sodium, topical corticosteroids, and PUVA (psoralen plus ultraviolet A photochemotherapy).³ PUVA is normally avoided in pediatric patients because it is associated with an increased risk of skin cancer later in life.¹²

Our patient. We prescribed a topical corticosteroid, 0.05% betamethasone dipropionate cream, and oral cromolyn sodium 100 mg qid for our patient, but this failed to significantly improve the macules. The patient and parents grew increasingly anxious. Ultimately, the parents decided to have their daughter treated with PUVA in limited amounts. Topical psoralen was also used. After 2 months of treatment, the patient’s lesions substantially improved and many of them disappeared. In addition, the parents were educated on the importance of sunscreen and limiting their daughter’s exposure to the sun, when possible.

THE TAKEAWAY

UP can be diagnosed by taking a thorough history and conducting a physical examination; a skin biopsy that reveals increased mast cells will confirm the diagnosis. UP is usually self-limited and resolves in about one-half of patients by puberty. Treatment options include H1 and H2 antihistamines, cromolyn sodium, topical corticosteroids, and PUVA. Patients should be referred to a specialist if their symptoms become severe, systemic UP is suspected, or they do not respond to therapy.

THE CASE

A 3-year-old girl was brought to our clinic with a generalized rash over her scalp, face, neck, chest, abdomen, back, perianal area, extremities, and the plantar surface of her right foot. On physical examination, we noted many round, hyperpigmented, brown and reddish pink, well-circumscribed macules on her body (FIGURE). Only a few of these macules had appeared on the girl’s trunk within the first 3 months of her life, but since then they’d increased in number and spread to other parts of her body as she’d aged. The lesions became edematous and erythematous with tactile irritation. Darier’s sign (the development of a hive or wheal when a lesion is stroked) was present.

The patient’s vitals at the time of examination included a temperature of 98.2°F, respiratory rate of 17 breaths/min, heart rate of 92 beats/min, blood pressure of 100/66 mm Hg, and oxygen saturation level of 100% on room air. The girl’s parents said they hadn’t traveled. There was no mucosal involvement and no systemic involvement. The patient had no past surgical or medical history, was not taking any medications, and had no significant birth history. A skin biopsy was performed.

THE DIAGNOSIS

Based on the presence of a positive Darier’s sign and the results of the skin biopsy (which showed increased mast cells), we diagnosed urticaria pigmentosa (UP), which is the most common form of cutaneous mastocytosis.¹

The diagnosis had been delayed for almost 3 years because of several factors. For one thing, there had been few lesions present early in the child’s life, and as a result, the parents chalked them up to “beauty marks.” Then, as the lesions started to increase in number, the parents thought bed bugs were to blame.

As time went on, the parents attempted to treat their daughter’s hives with homeopathic remedies suggested by family members. When the lesions didn’t resolve with homeopathic remedies, the parents tried over-the-counter H1 and H2 antihistamines such as diphenhydramine, loratadine, and ranitidine. When these treatments failed, the parents brought their child to our office for medical evaluation.

DISCUSSION

UP is a chronic skin disorder in which there is an abnormal proliferation of mast cells in the dermis of the skin. It is considered an orphan disease.¹ UP that presents in children is most often benign. Approximately 50% of cases occur before 6 months of age and 25% occur before puberty.² The lesions are often self-limited and completely resolve in approximately 50% of patients by puberty.³ By adulthood, the lesions either resolve or some lightly colored non-urticating macules remain; however, some patients will continue to have a positive Darier’s sign.⁴

Dermatologic symptoms. A patient with UP may present with brown or reddish maculopapules, papules, nodules, pruritus, and flushing of the face. Darier’s sign is usually seen in cases of UP; in a study of mastocytosis in children, Darier’s sign was present in 94% of cases.⁵ Lesions are more prominent in areas where clothes can rub the skin, and they often vary in size and appearance. The presence of lesions can vary from localized and scant to hundreds located over the entire body. UP can be difficult to identify when the lesions are limited, which can lead to delayed diagnosis and treatment.⁶

Systemic involvement. UP also can affect the skeleton, bone marrow, liver, spleen, lymph nodes, gastrointestinal tract, kidneys, cardiovascular system, and/or central nervous system. Skeletal involvement may manifest as osteoporosis or bone pain in 10% to 20% of patients with UP.⁷ Bone marrow involvement may progress to anemia or mast cell leukemia. UP can result in hepatomegaly or enlarged lymph nodes. Patients may experience nausea, diarrhea, or abdominal pain if the gastrointestinal tract is affected. Cardiovascular involvement may manifest as tachycardia and shock.⁸

Urticaria pigmentosa lesions are often self-limited and completely resolve in about half of patients by puberty.

Diagnosis of UP is made based on the physical exam findings noted earlier, as well as skin biopsy laboratory results. Skin biopsy will reveal increased mast cells. In up to two-thirds of patients who have systemic involvement, laboratory testing will show elevated urine histamine levels, as well as elevated serum concentrations of tryptase.⁹

UP can appear similar to many other skin conditions

The differential diagnosis of UP can include urticaria, atopic dermatitis, contact dermatitis, pityriasis rosea, an allergic reaction/drug eruption, Henoch-Schonlein purpura, erythema multiforme, fifth disease, folliculitis, guttate psoriasis, miliaria rubra, insect bites, viral exanthem, lichen planus, and scabies.^10,11 In addition to the clinical appearance of the rash, these conditions can be distinguished from UP by skin biopsy and other relevant tests, as well as a thorough history.

Treatment options include antihistamines, corticosteroids, PUVA

Patients with UP should be instructed to avoid precipitating factors such as temperature changes, friction, alcohol ingestion, aspirin, physical exertion, or opiates. Treatment options include H1 and H2 antihistamines, cromolyn sodium, topical corticosteroids, and PUVA (psoralen plus ultraviolet A photochemotherapy).³ PUVA is normally avoided in pediatric patients because it is associated with an increased risk of skin cancer later in life.¹²

Our patient. We prescribed a topical corticosteroid, 0.05% betamethasone dipropionate cream, and oral cromolyn sodium 100 mg qid for our patient, but this failed to significantly improve the macules. The patient and parents grew increasingly anxious. Ultimately, the parents decided to have their daughter treated with PUVA in limited amounts. Topical psoralen was also used. After 2 months of treatment, the patient’s lesions substantially improved and many of them disappeared. In addition, the parents were educated on the importance of sunscreen and limiting their daughter’s exposure to the sun, when possible.

THE TAKEAWAY

UP can be diagnosed by taking a thorough history and conducting a physical examination; a skin biopsy that reveals increased mast cells will confirm the diagnosis. UP is usually self-limited and resolves in about one-half of patients by puberty. Treatment options include H1 and H2 antihistamines, cromolyn sodium, topical corticosteroids, and PUVA. Patients should be referred to a specialist if their symptoms become severe, systemic UP is suspected, or they do not respond to therapy.

Osteochondromas are common benign bone tumors composed of a bony protrusion with an overlying cartilage cap.¹ This lesion constitutes 24% to 40% of all benign bone tumors, and the great majority arise from the metaphyseal region of long bones.² The scapula accounts for only 3% to 5% of all osteochondromas; however, this lesion is the most common benign bone tumor to involve the scapula.³

In contrast, cutaneous bronchogenic cyst of the scapula is an exceedingly rare pathology. The bronchogenic cyst is a congenital cystic mass lined by tracheobronchial structures and respiratory epithelium.⁴ These are most commonly located in the thorax, although numerous remote locations have also been described, including cutaneous cysts.⁵ The overall incidence of bronchogenic cysts is thought to be 1 in 42,000 to 1 in 68,000.⁶ There are only 15 case reports of cutaneous bronchogenic cysts in the scapular region.⁷

We report the case of a novel dual lesion of both an osteochondroma and a contiguous cutaneous bronchogenic cyst in the scapula. The patient’s guardian provided written informed consent for print and electronic publication of this case report.

Case Report

A 12-month-old boy presented to our clinic with the complaint of a mass over the left scapula. The mass was first noted incidentally several weeks earlier during bathing. Examination revealed a firm, subcutaneous, nontender mass measuring 1×2 cm located over the spine of the scapula. There were no overlying skin changes, and there was normal function of the ipsilateral upper extremity. Anteroposterior and lateral chest radiographs revealed no abnormality. Magnetic resonance imaging (MRI) showed an exostosis projecting from the scapular spine measuring 2×6×7 mm with an adjacent cystic mass measuring 5×8×9 mm that was thought to represent bursitis (Figure 1). The decision was made to observe the mass. 

The patient returned to clinic at age 31 months with a new complaint of scant drainage of serous fluid from a pinprick-sized hole located just superolateral to the scapular mass. The child’s mother reported daily manual expression of fluid from the mass via the hole, without which the mass would enlarge. There were no local or systemic signs of infection. A repeat MRI again revealed an exostosis with an adjacent cystic mass with interval enlargement of the cyst (Figure 2). At age 4.5 years, the decision was made to proceed with excision of the osteochondroma and adjacent cystic mass.

The mass was approached via a 2-cm incision designed to excise the tract to the skin. Dissection revealed a sinus tract connecting to a well-defined cystic sac. This sac was attached to the underlying exostosis. The exostosis and attached cyst were excised en bloc. The cyst was opened, revealing foul-smelling, cloudy white fluid that was sent for culture; the specimen was sent for pathology.

The fluid culture grew mixed flora, with no Staphylococcus aureus, group A streptococcus, or Pseudomonas aeruginosa identified. The pathologic examination identified bone with a cartilaginous cap, consistent with osteochondroma (Figure 3), as well as a cyst lined by respiratory epithelium with patchy areas of squamous epithelium and surrounding mucus glands, consistent with bronchogenic cyst (Figure 4). Figure 5 shows the contiguous nature of the 2 lesions.

The postoperative course was uneventful. The patient returned to full use of the left upper extremity and had resolution of all drainage. 

Discussion

Osteochondromas are thought to arise from aberrant growth of the epiphyseal growth plate cartilage. A small portion of the physis herniates past the groove of Ranvier and grows parallel to the normal physis with medullary continuity. This can occur idiopathically or, more rarely, secondary to an identified injury to the growth plate.¹

The formation of bronchogenic cysts is most often attributed to anomalous budding of the ventral foregut during fetal development,⁴ hence the alternative designation of these cysts as foregut cysts. An extrathoracic location of the cyst has been postulated to stem from 2 possible events: a preexisting cyst may migrate out of the thorax prior to closure of the sternal plates, or sternal plate closure may itself pinch off the cyst.^8,9 An alternative explanation is in situ metaplastic development of respiratory epithelium.¹⁰ When located near the skin, these cysts often drain clear fluid.¹¹

Scapular osteochondromas are known to cause various pathologies of the shoulder girdle, including snapping scapula syndrome, chest wall deformity, shoulder impingement, and bursa formation.^12-17 This case, however, is the first known finding of a scapular osteochondroma with a contiguous cutaneous bronchogenic cyst. A putative explanation for their co-occurrence is that local disturbances caused by one lesion stimulated the formation of the second. The direct connection between the bronchogenic cyst and the bone, as has been reported in 3 cases,^7,9,18 seems to favor this explanation. Definitive conclusions regarding any causal relationship are beyond the scope of this single case report.

Definitive management of bronchogenic cysts is complete excision, although the diagnosis is often not made until histopathologic examination has been completed.¹⁹ Osteochondromas are managed with observation unless they are symptomatic.² Malignant degeneration is a rare but documented occurrence in both lesions.^2,20

Conclusion

In approaching the pediatric patient with a cystic mass over the scapula, a cutaneous bronchogenic cyst may be included in the differential diagnosis. This lesion can occur in isolation or can be found with another pathology, such as osteochondroma, as reported here.

Osteochondromas are common benign bone tumors composed of a bony protrusion with an overlying cartilage cap.¹ This lesion constitutes 24% to 40% of all benign bone tumors, and the great majority arise from the metaphyseal region of long bones.² The scapula accounts for only 3% to 5% of all osteochondromas; however, this lesion is the most common benign bone tumor to involve the scapula.³

In contrast, cutaneous bronchogenic cyst of the scapula is an exceedingly rare pathology. The bronchogenic cyst is a congenital cystic mass lined by tracheobronchial structures and respiratory epithelium.⁴ These are most commonly located in the thorax, although numerous remote locations have also been described, including cutaneous cysts.⁵ The overall incidence of bronchogenic cysts is thought to be 1 in 42,000 to 1 in 68,000.⁶ There are only 15 case reports of cutaneous bronchogenic cysts in the scapular region.⁷

We report the case of a novel dual lesion of both an osteochondroma and a contiguous cutaneous bronchogenic cyst in the scapula. The patient’s guardian provided written informed consent for print and electronic publication of this case report.

Case Report

A 12-month-old boy presented to our clinic with the complaint of a mass over the left scapula. The mass was first noted incidentally several weeks earlier during bathing. Examination revealed a firm, subcutaneous, nontender mass measuring 1×2 cm located over the spine of the scapula. There were no overlying skin changes, and there was normal function of the ipsilateral upper extremity. Anteroposterior and lateral chest radiographs revealed no abnormality. Magnetic resonance imaging (MRI) showed an exostosis projecting from the scapular spine measuring 2×6×7 mm with an adjacent cystic mass measuring 5×8×9 mm that was thought to represent bursitis (Figure 1). The decision was made to observe the mass. 

The patient returned to clinic at age 31 months with a new complaint of scant drainage of serous fluid from a pinprick-sized hole located just superolateral to the scapular mass. The child’s mother reported daily manual expression of fluid from the mass via the hole, without which the mass would enlarge. There were no local or systemic signs of infection. A repeat MRI again revealed an exostosis with an adjacent cystic mass with interval enlargement of the cyst (Figure 2). At age 4.5 years, the decision was made to proceed with excision of the osteochondroma and adjacent cystic mass.

The mass was approached via a 2-cm incision designed to excise the tract to the skin. Dissection revealed a sinus tract connecting to a well-defined cystic sac. This sac was attached to the underlying exostosis. The exostosis and attached cyst were excised en bloc. The cyst was opened, revealing foul-smelling, cloudy white fluid that was sent for culture; the specimen was sent for pathology.

The fluid culture grew mixed flora, with no Staphylococcus aureus, group A streptococcus, or Pseudomonas aeruginosa identified. The pathologic examination identified bone with a cartilaginous cap, consistent with osteochondroma (Figure 3), as well as a cyst lined by respiratory epithelium with patchy areas of squamous epithelium and surrounding mucus glands, consistent with bronchogenic cyst (Figure 4). Figure 5 shows the contiguous nature of the 2 lesions.

The postoperative course was uneventful. The patient returned to full use of the left upper extremity and had resolution of all drainage. 

Discussion

Osteochondromas are thought to arise from aberrant growth of the epiphyseal growth plate cartilage. A small portion of the physis herniates past the groove of Ranvier and grows parallel to the normal physis with medullary continuity. This can occur idiopathically or, more rarely, secondary to an identified injury to the growth plate.¹

The formation of bronchogenic cysts is most often attributed to anomalous budding of the ventral foregut during fetal development,⁴ hence the alternative designation of these cysts as foregut cysts. An extrathoracic location of the cyst has been postulated to stem from 2 possible events: a preexisting cyst may migrate out of the thorax prior to closure of the sternal plates, or sternal plate closure may itself pinch off the cyst.^8,9 An alternative explanation is in situ metaplastic development of respiratory epithelium.¹⁰ When located near the skin, these cysts often drain clear fluid.¹¹

Scapular osteochondromas are known to cause various pathologies of the shoulder girdle, including snapping scapula syndrome, chest wall deformity, shoulder impingement, and bursa formation.^12-17 This case, however, is the first known finding of a scapular osteochondroma with a contiguous cutaneous bronchogenic cyst. A putative explanation for their co-occurrence is that local disturbances caused by one lesion stimulated the formation of the second. The direct connection between the bronchogenic cyst and the bone, as has been reported in 3 cases,^7,9,18 seems to favor this explanation. Definitive conclusions regarding any causal relationship are beyond the scope of this single case report.

Definitive management of bronchogenic cysts is complete excision, although the diagnosis is often not made until histopathologic examination has been completed.¹⁹ Osteochondromas are managed with observation unless they are symptomatic.² Malignant degeneration is a rare but documented occurrence in both lesions.^2,20

Conclusion

In approaching the pediatric patient with a cystic mass over the scapula, a cutaneous bronchogenic cyst may be included in the differential diagnosis. This lesion can occur in isolation or can be found with another pathology, such as osteochondroma, as reported here.

Osteochondromas are common benign bone tumors composed of a bony protrusion with an overlying cartilage cap.¹ This lesion constitutes 24% to 40% of all benign bone tumors, and the great majority arise from the metaphyseal region of long bones.² The scapula accounts for only 3% to 5% of all osteochondromas; however, this lesion is the most common benign bone tumor to involve the scapula.³

In contrast, cutaneous bronchogenic cyst of the scapula is an exceedingly rare pathology. The bronchogenic cyst is a congenital cystic mass lined by tracheobronchial structures and respiratory epithelium.⁴ These are most commonly located in the thorax, although numerous remote locations have also been described, including cutaneous cysts.⁵ The overall incidence of bronchogenic cysts is thought to be 1 in 42,000 to 1 in 68,000.⁶ There are only 15 case reports of cutaneous bronchogenic cysts in the scapular region.⁷

We report the case of a novel dual lesion of both an osteochondroma and a contiguous cutaneous bronchogenic cyst in the scapula. The patient’s guardian provided written informed consent for print and electronic publication of this case report.

Case Report

A 12-month-old boy presented to our clinic with the complaint of a mass over the left scapula. The mass was first noted incidentally several weeks earlier during bathing. Examination revealed a firm, subcutaneous, nontender mass measuring 1×2 cm located over the spine of the scapula. There were no overlying skin changes, and there was normal function of the ipsilateral upper extremity. Anteroposterior and lateral chest radiographs revealed no abnormality. Magnetic resonance imaging (MRI) showed an exostosis projecting from the scapular spine measuring 2×6×7 mm with an adjacent cystic mass measuring 5×8×9 mm that was thought to represent bursitis (Figure 1). The decision was made to observe the mass. 

The patient returned to clinic at age 31 months with a new complaint of scant drainage of serous fluid from a pinprick-sized hole located just superolateral to the scapular mass. The child’s mother reported daily manual expression of fluid from the mass via the hole, without which the mass would enlarge. There were no local or systemic signs of infection. A repeat MRI again revealed an exostosis with an adjacent cystic mass with interval enlargement of the cyst (Figure 2). At age 4.5 years, the decision was made to proceed with excision of the osteochondroma and adjacent cystic mass.

The mass was approached via a 2-cm incision designed to excise the tract to the skin. Dissection revealed a sinus tract connecting to a well-defined cystic sac. This sac was attached to the underlying exostosis. The exostosis and attached cyst were excised en bloc. The cyst was opened, revealing foul-smelling, cloudy white fluid that was sent for culture; the specimen was sent for pathology.

The fluid culture grew mixed flora, with no Staphylococcus aureus, group A streptococcus, or Pseudomonas aeruginosa identified. The pathologic examination identified bone with a cartilaginous cap, consistent with osteochondroma (Figure 3), as well as a cyst lined by respiratory epithelium with patchy areas of squamous epithelium and surrounding mucus glands, consistent with bronchogenic cyst (Figure 4). Figure 5 shows the contiguous nature of the 2 lesions.

The postoperative course was uneventful. The patient returned to full use of the left upper extremity and had resolution of all drainage. 

Discussion

Osteochondromas are thought to arise from aberrant growth of the epiphyseal growth plate cartilage. A small portion of the physis herniates past the groove of Ranvier and grows parallel to the normal physis with medullary continuity. This can occur idiopathically or, more rarely, secondary to an identified injury to the growth plate.¹

The formation of bronchogenic cysts is most often attributed to anomalous budding of the ventral foregut during fetal development,⁴ hence the alternative designation of these cysts as foregut cysts. An extrathoracic location of the cyst has been postulated to stem from 2 possible events: a preexisting cyst may migrate out of the thorax prior to closure of the sternal plates, or sternal plate closure may itself pinch off the cyst.^8,9 An alternative explanation is in situ metaplastic development of respiratory epithelium.¹⁰ When located near the skin, these cysts often drain clear fluid.¹¹

Scapular osteochondromas are known to cause various pathologies of the shoulder girdle, including snapping scapula syndrome, chest wall deformity, shoulder impingement, and bursa formation.^12-17 This case, however, is the first known finding of a scapular osteochondroma with a contiguous cutaneous bronchogenic cyst. A putative explanation for their co-occurrence is that local disturbances caused by one lesion stimulated the formation of the second. The direct connection between the bronchogenic cyst and the bone, as has been reported in 3 cases,^7,9,18 seems to favor this explanation. Definitive conclusions regarding any causal relationship are beyond the scope of this single case report.

Definitive management of bronchogenic cysts is complete excision, although the diagnosis is often not made until histopathologic examination has been completed.¹⁹ Osteochondromas are managed with observation unless they are symptomatic.² Malignant degeneration is a rare but documented occurrence in both lesions.^2,20

Conclusion

In approaching the pediatric patient with a cystic mass over the scapula, a cutaneous bronchogenic cyst may be included in the differential diagnosis. This lesion can occur in isolation or can be found with another pathology, such as osteochondroma, as reported here.