Case Reports

Onychomatricoma (OM) is a rare benign neoplasm of the nail matrix. Even less common is its possible association with both trauma to the nail apparatus and onychomycosis. This case illustrates both of these findings.

Case Report
A 72-year-old white man presented to the dermatology clinic with a 26-year history of a thickened nail plate on the right third finger that had developed soon after a baseball injury. The patient reported that the nail was completely normal prior to the trauma. According to the patient, the distal aspect of the finger was directly hit by a baseball and subsequently was wrapped by the patient for a few weeks. The nail then turned black and eventually fell off. When the nail grew back, it appeared abnormal and in its current state. The patient stated the lesion was asymptomatic at the time of presentation.

Physical examination revealed thickening, yellow discoloration, and transverse overcurvature of the nail plate on the right third finger with longitudinal ridging (Figure 1). A culture of the nail plate grew Chaetomium species. Application of topical clotrimazole for 3 months followed by a 6-week course of oral terbinafine produced no improvement. The patient then consented to a nail matrix incisional biopsy 6 months after initial presentation. After a digital nerve block was administered and a tourniquet of the proximal digit was applied, a nail avulsion was performed. Subsequently, a 3-mm punch biopsy was taken of the clinically apparent tumor in the nail matrix.

On microscopic examination of the removed tissue, a benign mixed epithelial and stromal proliferative lesion was noted. The basaloid epithelium, lacking a granular layer, arose from the surface epithelial layer and formed a reticulated pattern extending into the stromal component, which was moderately cellular with spindle to fusiform nuclei dissecting between collagen bundles arranged in parallel arrays (Figure 2). The stromal component predominated over the epithelial component in this neoplasm. The nail was preserved in formalin and underwent hematoxylin and eosin staining. It was thickened and grossly showed filiform fibrous projections extending into the nail plate. Histologically, the nail displayed prominent oval clear channels. Periodic acid–Schiff staining was negative for fungal organisms.

A diagnosis of unguioblastic fibroma–type OM was made. After receiving the diagnosis, expected course, and treatment options, the patient was offered conservative surgical excision but preferred clinical monitoring. At his last visit (6 months after the biopsy), the nail plate distal to the biopsy site had thinning and improvement, while the nail plate distal to the matrix that was not removed continued to show thickening, yellow discoloration, overcurvature, and longitudinal ridging (Figure 3).

Figure 2. The basaloid epithelium arose from the surface epithelial layer and formed a reticulated pattern extending into the stromal component (A)(H&E, original magnification ×2). At higher magnification, the stromal component was moderately cellular with spindle to fusiform nuclei dissecting between collagen bundles arranged in parallel arrays (B)(H&E, original magnification ×10).

Comment
Onychomatricoma is a rare tumor originating from the nail matrix. The tumor was first described by Baran and Kint¹ in 1992 using the term onychomatrixoma, but later the term onychomatricoma became more widely used.² Onychomatricomas are more common in adults (mean age, 48 years) and white individuals with no gender predilection.^3,4 Fingernail involvement is twice as common as toenail involvement.³ Onychomatricoma is the only tumor that actively produces a nail plate.⁴

Clinically, OM presents with yellow discoloration along the entire nail plate and proximal splinter hemorrhages. It has a tendency toward transverse overcurvature of the nail plate with prominent longitudinal ridging.⁴ Trauma has been associated in at least 3 cases reported in the literature, though the association was sometimes weak.^3,4 Xanthonychia and onychodystrophy of the nail are common.³ Pterygium, melanonychia, nail bleeding, and cutaneous horns have been reported but are rare.^3-5 The tumor typically is painless with no radiographic bone involvement.³ Onychomycosis can be present,³ which may either be a predisposing factor for the tumor or secondary due to the deformed nail plate.⁴

When the nail plate is avulsed and the proximal nail fold is turned back, the matrix tumor is exposed. This polypoid and filiform tumor has characteristic fingerlike fibrokeratogenous projections extending from the nail matrix into the nail plate.³

Histologically, the tumor is fibroepithelial or biphasic with stromal and epithelial components. It has a lobulated and papillary growth pattern with 2 distinct areas that correspond to 2 anatomic zones.³ The base of the tumor corresponds to the proximal anatomic zone, which begins at the root of the nail and extends to the cuticle. This area is composed of V-shaped keratinous zones similar to the normal matrix. If the nail is removed prior to excision, these areas can be avulsed, leaving clear clefts. The superficial aspect of the tumor corresponds to the distal anatomic zone, which is located in the region of the lunula. This area is composed of multiple digitate or fingerlike projections with a fibrous core and a thick matrical epithelial covering.³ These digitations extend into small cavities in the nail plate, which can be visualized as clear channels or woodwormlike holes in hematoxylin and eosin–stained specimens. A biphasic fibrous stroma also can be observed with the superficial dermis being cellular with fibrillary collagen and the deep dermis more hypocellular with thicker collagen bundles.^3,4

An analysis of keratins in the nail matrix, bed, and isthmus showed that OM has the capacity to recapitulate the entire nail unit with differentiation toward the nail bed and isthmus.⁶ It appears that the mesenchymal component has an inductive effect that can lead to complete epithelial onychogenic differentiation.⁶

Due to the histological differences among the described cases of OM in the literature, a new classification based on the spectrum of epithelial to stromal ratio of stromal cellularity and the extent of nuclear pleomorphism was proposed in 2004.⁷ The prominent feature of the unguioblastoma type of OM is epithelial, while the cellular stroma is the prominent feature in the unguioblastic fibroma type. Atypical unguioblastic fibroma refers to a tumor with increased mitotic activity and nuclear pleomorphism among the stroma.⁷

Most OM tumors follow a benign clinical course; however, complete excision is advised to include the normal nail matrix proximal to the lesion, which may prevent recurrence and serves as a primary treatment.

Conclusion
Onychomatricoma is a benign neoplasm of the nail matrix that may be triggered by trauma; however, due to the weak association, further observations and studies should be conducted to substantiate this possibility. Patients with the classic clinical presentation possibly may be spared a nail avulsion and biopsy. Onychomycosis occurs in the setting of OM, and culture and treatment are unlikely to change the appearance or course of this nail condition.

Onychomatricoma (OM) is a rare benign neoplasm of the nail matrix. Even less common is its possible association with both trauma to the nail apparatus and onychomycosis. This case illustrates both of these findings.

Case Report
A 72-year-old white man presented to the dermatology clinic with a 26-year history of a thickened nail plate on the right third finger that had developed soon after a baseball injury. The patient reported that the nail was completely normal prior to the trauma. According to the patient, the distal aspect of the finger was directly hit by a baseball and subsequently was wrapped by the patient for a few weeks. The nail then turned black and eventually fell off. When the nail grew back, it appeared abnormal and in its current state. The patient stated the lesion was asymptomatic at the time of presentation.

Physical examination revealed thickening, yellow discoloration, and transverse overcurvature of the nail plate on the right third finger with longitudinal ridging (Figure 1). A culture of the nail plate grew Chaetomium species. Application of topical clotrimazole for 3 months followed by a 6-week course of oral terbinafine produced no improvement. The patient then consented to a nail matrix incisional biopsy 6 months after initial presentation. After a digital nerve block was administered and a tourniquet of the proximal digit was applied, a nail avulsion was performed. Subsequently, a 3-mm punch biopsy was taken of the clinically apparent tumor in the nail matrix.

On microscopic examination of the removed tissue, a benign mixed epithelial and stromal proliferative lesion was noted. The basaloid epithelium, lacking a granular layer, arose from the surface epithelial layer and formed a reticulated pattern extending into the stromal component, which was moderately cellular with spindle to fusiform nuclei dissecting between collagen bundles arranged in parallel arrays (Figure 2). The stromal component predominated over the epithelial component in this neoplasm. The nail was preserved in formalin and underwent hematoxylin and eosin staining. It was thickened and grossly showed filiform fibrous projections extending into the nail plate. Histologically, the nail displayed prominent oval clear channels. Periodic acid–Schiff staining was negative for fungal organisms.

A diagnosis of unguioblastic fibroma–type OM was made. After receiving the diagnosis, expected course, and treatment options, the patient was offered conservative surgical excision but preferred clinical monitoring. At his last visit (6 months after the biopsy), the nail plate distal to the biopsy site had thinning and improvement, while the nail plate distal to the matrix that was not removed continued to show thickening, yellow discoloration, overcurvature, and longitudinal ridging (Figure 3).

Figure 2. The basaloid epithelium arose from the surface epithelial layer and formed a reticulated pattern extending into the stromal component (A)(H&E, original magnification ×2). At higher magnification, the stromal component was moderately cellular with spindle to fusiform nuclei dissecting between collagen bundles arranged in parallel arrays (B)(H&E, original magnification ×10).

Comment
Onychomatricoma is a rare tumor originating from the nail matrix. The tumor was first described by Baran and Kint¹ in 1992 using the term onychomatrixoma, but later the term onychomatricoma became more widely used.² Onychomatricomas are more common in adults (mean age, 48 years) and white individuals with no gender predilection.^3,4 Fingernail involvement is twice as common as toenail involvement.³ Onychomatricoma is the only tumor that actively produces a nail plate.⁴

Clinically, OM presents with yellow discoloration along the entire nail plate and proximal splinter hemorrhages. It has a tendency toward transverse overcurvature of the nail plate with prominent longitudinal ridging.⁴ Trauma has been associated in at least 3 cases reported in the literature, though the association was sometimes weak.^3,4 Xanthonychia and onychodystrophy of the nail are common.³ Pterygium, melanonychia, nail bleeding, and cutaneous horns have been reported but are rare.^3-5 The tumor typically is painless with no radiographic bone involvement.³ Onychomycosis can be present,³ which may either be a predisposing factor for the tumor or secondary due to the deformed nail plate.⁴

When the nail plate is avulsed and the proximal nail fold is turned back, the matrix tumor is exposed. This polypoid and filiform tumor has characteristic fingerlike fibrokeratogenous projections extending from the nail matrix into the nail plate.³

Histologically, the tumor is fibroepithelial or biphasic with stromal and epithelial components. It has a lobulated and papillary growth pattern with 2 distinct areas that correspond to 2 anatomic zones.³ The base of the tumor corresponds to the proximal anatomic zone, which begins at the root of the nail and extends to the cuticle. This area is composed of V-shaped keratinous zones similar to the normal matrix. If the nail is removed prior to excision, these areas can be avulsed, leaving clear clefts. The superficial aspect of the tumor corresponds to the distal anatomic zone, which is located in the region of the lunula. This area is composed of multiple digitate or fingerlike projections with a fibrous core and a thick matrical epithelial covering.³ These digitations extend into small cavities in the nail plate, which can be visualized as clear channels or woodwormlike holes in hematoxylin and eosin–stained specimens. A biphasic fibrous stroma also can be observed with the superficial dermis being cellular with fibrillary collagen and the deep dermis more hypocellular with thicker collagen bundles.^3,4

An analysis of keratins in the nail matrix, bed, and isthmus showed that OM has the capacity to recapitulate the entire nail unit with differentiation toward the nail bed and isthmus.⁶ It appears that the mesenchymal component has an inductive effect that can lead to complete epithelial onychogenic differentiation.⁶

Due to the histological differences among the described cases of OM in the literature, a new classification based on the spectrum of epithelial to stromal ratio of stromal cellularity and the extent of nuclear pleomorphism was proposed in 2004.⁷ The prominent feature of the unguioblastoma type of OM is epithelial, while the cellular stroma is the prominent feature in the unguioblastic fibroma type. Atypical unguioblastic fibroma refers to a tumor with increased mitotic activity and nuclear pleomorphism among the stroma.⁷

Most OM tumors follow a benign clinical course; however, complete excision is advised to include the normal nail matrix proximal to the lesion, which may prevent recurrence and serves as a primary treatment.

Conclusion
Onychomatricoma is a benign neoplasm of the nail matrix that may be triggered by trauma; however, due to the weak association, further observations and studies should be conducted to substantiate this possibility. Patients with the classic clinical presentation possibly may be spared a nail avulsion and biopsy. Onychomycosis occurs in the setting of OM, and culture and treatment are unlikely to change the appearance or course of this nail condition.

Onychomatricoma (OM) is a rare benign neoplasm of the nail matrix. Even less common is its possible association with both trauma to the nail apparatus and onychomycosis. This case illustrates both of these findings.

Case Report
A 72-year-old white man presented to the dermatology clinic with a 26-year history of a thickened nail plate on the right third finger that had developed soon after a baseball injury. The patient reported that the nail was completely normal prior to the trauma. According to the patient, the distal aspect of the finger was directly hit by a baseball and subsequently was wrapped by the patient for a few weeks. The nail then turned black and eventually fell off. When the nail grew back, it appeared abnormal and in its current state. The patient stated the lesion was asymptomatic at the time of presentation.

Physical examination revealed thickening, yellow discoloration, and transverse overcurvature of the nail plate on the right third finger with longitudinal ridging (Figure 1). A culture of the nail plate grew Chaetomium species. Application of topical clotrimazole for 3 months followed by a 6-week course of oral terbinafine produced no improvement. The patient then consented to a nail matrix incisional biopsy 6 months after initial presentation. After a digital nerve block was administered and a tourniquet of the proximal digit was applied, a nail avulsion was performed. Subsequently, a 3-mm punch biopsy was taken of the clinically apparent tumor in the nail matrix.

On microscopic examination of the removed tissue, a benign mixed epithelial and stromal proliferative lesion was noted. The basaloid epithelium, lacking a granular layer, arose from the surface epithelial layer and formed a reticulated pattern extending into the stromal component, which was moderately cellular with spindle to fusiform nuclei dissecting between collagen bundles arranged in parallel arrays (Figure 2). The stromal component predominated over the epithelial component in this neoplasm. The nail was preserved in formalin and underwent hematoxylin and eosin staining. It was thickened and grossly showed filiform fibrous projections extending into the nail plate. Histologically, the nail displayed prominent oval clear channels. Periodic acid–Schiff staining was negative for fungal organisms.

A diagnosis of unguioblastic fibroma–type OM was made. After receiving the diagnosis, expected course, and treatment options, the patient was offered conservative surgical excision but preferred clinical monitoring. At his last visit (6 months after the biopsy), the nail plate distal to the biopsy site had thinning and improvement, while the nail plate distal to the matrix that was not removed continued to show thickening, yellow discoloration, overcurvature, and longitudinal ridging (Figure 3).

Figure 2. The basaloid epithelium arose from the surface epithelial layer and formed a reticulated pattern extending into the stromal component (A)(H&E, original magnification ×2). At higher magnification, the stromal component was moderately cellular with spindle to fusiform nuclei dissecting between collagen bundles arranged in parallel arrays (B)(H&E, original magnification ×10).

Comment
Onychomatricoma is a rare tumor originating from the nail matrix. The tumor was first described by Baran and Kint¹ in 1992 using the term onychomatrixoma, but later the term onychomatricoma became more widely used.² Onychomatricomas are more common in adults (mean age, 48 years) and white individuals with no gender predilection.^3,4 Fingernail involvement is twice as common as toenail involvement.³ Onychomatricoma is the only tumor that actively produces a nail plate.⁴

Clinically, OM presents with yellow discoloration along the entire nail plate and proximal splinter hemorrhages. It has a tendency toward transverse overcurvature of the nail plate with prominent longitudinal ridging.⁴ Trauma has been associated in at least 3 cases reported in the literature, though the association was sometimes weak.^3,4 Xanthonychia and onychodystrophy of the nail are common.³ Pterygium, melanonychia, nail bleeding, and cutaneous horns have been reported but are rare.^3-5 The tumor typically is painless with no radiographic bone involvement.³ Onychomycosis can be present,³ which may either be a predisposing factor for the tumor or secondary due to the deformed nail plate.⁴

When the nail plate is avulsed and the proximal nail fold is turned back, the matrix tumor is exposed. This polypoid and filiform tumor has characteristic fingerlike fibrokeratogenous projections extending from the nail matrix into the nail plate.³

Histologically, the tumor is fibroepithelial or biphasic with stromal and epithelial components. It has a lobulated and papillary growth pattern with 2 distinct areas that correspond to 2 anatomic zones.³ The base of the tumor corresponds to the proximal anatomic zone, which begins at the root of the nail and extends to the cuticle. This area is composed of V-shaped keratinous zones similar to the normal matrix. If the nail is removed prior to excision, these areas can be avulsed, leaving clear clefts. The superficial aspect of the tumor corresponds to the distal anatomic zone, which is located in the region of the lunula. This area is composed of multiple digitate or fingerlike projections with a fibrous core and a thick matrical epithelial covering.³ These digitations extend into small cavities in the nail plate, which can be visualized as clear channels or woodwormlike holes in hematoxylin and eosin–stained specimens. A biphasic fibrous stroma also can be observed with the superficial dermis being cellular with fibrillary collagen and the deep dermis more hypocellular with thicker collagen bundles.^3,4

An analysis of keratins in the nail matrix, bed, and isthmus showed that OM has the capacity to recapitulate the entire nail unit with differentiation toward the nail bed and isthmus.⁶ It appears that the mesenchymal component has an inductive effect that can lead to complete epithelial onychogenic differentiation.⁶

Due to the histological differences among the described cases of OM in the literature, a new classification based on the spectrum of epithelial to stromal ratio of stromal cellularity and the extent of nuclear pleomorphism was proposed in 2004.⁷ The prominent feature of the unguioblastoma type of OM is epithelial, while the cellular stroma is the prominent feature in the unguioblastic fibroma type. Atypical unguioblastic fibroma refers to a tumor with increased mitotic activity and nuclear pleomorphism among the stroma.⁷

Most OM tumors follow a benign clinical course; however, complete excision is advised to include the normal nail matrix proximal to the lesion, which may prevent recurrence and serves as a primary treatment.

Conclusion
Onychomatricoma is a benign neoplasm of the nail matrix that may be triggered by trauma; however, due to the weak association, further observations and studies should be conducted to substantiate this possibility. Patients with the classic clinical presentation possibly may be spared a nail avulsion and biopsy. Onychomycosis occurs in the setting of OM, and culture and treatment are unlikely to change the appearance or course of this nail condition.

THE CASE

A 45-year-old airman presented to our medical group with acute onset of sharp, positional left lateral chest wall pain that he’d had for 2 days. The pain began after an extreme core body workout. Treatment with ibuprofen 800 mg and local electrical stimulation one day prior provided no benefit. The patient reported the pain to be a 6 out of 10 when still and a 9 to 10 when sitting for more than a few minutes, turning, or taking a medium to deep breath. The patient felt “dangerously distracted by the pain” while driving in for his appointment.

We noted focal left lower lateral intercostal muscle tenderness without trigger point-like thickness or spasm. The patient also had restricted inspiration, secondary to the severe pain, and decreased left lower field breath sounds. His vital signs were normal, as was his cardiac exam.

THE DIAGNOSIS

While awaiting a chest x-ray, the patient was offered and opted to try acupuncture for pain relief. (We have medical acupuncturists on staff.) Analgesics had already been used, but had provided little relief.

We identified 4 acupuncture sites in the ear: 2 were battlefield acupuncture (BFA) points (more on this in a bit) and 2 points were deemed active by a skin conductance point finder (a handheld device that assesses changes in electrical skin resistance at auricular acupuncture points). The left ear points that were treated included the cingulate gyrus (intertragic notch), Shen Men (triangular fossa), and chest and abdomen regional points (antihelix) (FIGURE 1).

Within 15 minutes, the patient reported significant pain relief and was able to inspire deeply without pain. The patient also underwent a chest x-ray, which revealed atelectasis of the left lower lobe (FIGURE 2A) caused by pain-induced hypoventilation.

Because the patient’s pain was so well controlled, he returned to work immediately after the appointment. At the end of his shift 6 hours later he returned, unscheduled, to report pain at a level of one out of 10 and said he was able to breathe normally. In addition, lung auscultation was normal and a repeat chest x-ray revealed that the atelectasis had almost completely resolved (FIGURE 2B). This occurred without medication or other therapy. The pain did not return.

DISCUSSION

Although acupuncture is over 2000 years old, it has been largely disregarded in the United States due to a lack of mainstream evidence supporting its efficacy. Research is hindered by significant variation in approach between providers, the difficulties inherent to blinding patients and providers to treatment vs placebo, and poor insurance coverage and reimbursement.

Acupuncture research is burgeoning. A 2012 meta-analysis concluded that patients receiving acupuncture had less pain than those receiving sham or no acupuncture for several pain conditions. Specifically, scores for back and neck pain, osteoarthritis, and chronic headache were 0.23, 0.16, and 0.15 standard deviations (SDs), respectively, lower for patients receiving acupuncture than for those who got sham acupuncture. The effect sizes for acupuncture patients compared to no acupuncture controls were 0.55, 0.57, and 0.42 respectively (all P<.001).¹

Several theories explain how auricular acupuncture may work. Paul Nogier, MD, noted that the ear is composed of ectodermal, mesodermal, and endodermal tissues, and mapped the “inverted fetus” homunculus in the ear, which corresponds to specific body points.² Functional magnetic resonance imaging has demonstrated increased brain activity in the cingulate gyrus and thalamic regions in response to a painful stimulus, as well as attenuation of this activity after the placement of needles in corresponding auricular cingulate gyrus and thalamus points.³ In addition, research has confirmed that acupuncture raises serum and cerebrospinal levels of endorphins and enkephalins.⁴

Less than 15 minutes after needle placement, our patient reported significant pain relief and was able to inspire deeply without pain.

Battlefield acupuncture (BFA) was developed by Richard Niemtzow, MD, and has been used for acute injuries in the front lines of battle as well as for many health conditions. BFA treats pain using a sequence of 5 predetermined auricular acupuncture points.⁵ Onset and duration of pain relief vary depending on the location and nature of the pathology. We’ve noted that BFA for chronic pain has a shorter duration of benefit and is more likely to need to be repeated.

One randomized pilot study involving 87 patients presenting to the emergency room blinded emergency health care providers to the inclusion of the first 2 BFA points in their otherwise usual care of acute pain patients. Participants in the acupuncture group experienced a 23% reduction in pain before discharge compared to no change in the standard care group (P<.0005).⁶

Our patient. We inserted semi-permanent needles with a needle length of 2 mm into 4 locations on the ear. (These needles can remain in the ear for several days and fall out on their own or they may be removed by pulling the stud ends.) As noted earlier, our patient reported pain relief within 15 minutes and was pain free by the next day.

THE TAKEAWAY

Research confirms that acupuncture raises serum and cerebrospinal levels of endorphins and enkephalins.

Auricular acupuncture can treat acute and chronic pain. As proof, the BFA technique is widely used by health care providers throughout the US military and Department of Veterans Affairs. In this case, the immediate pain relief and x-ray documentation of atelectasis resolution within 6 hours of treatment provide support that auricular acupuncture was beneficial in reversing the cause of this atelectasis, which was pain-induced hypoventilation.

While the acute pain control observed with this patient is not unusual in our experience, what is unusual is the rare visual confirmation of the striking degree of pain reduction possible with auricular acupuncture.

THE CASE

A 45-year-old airman presented to our medical group with acute onset of sharp, positional left lateral chest wall pain that he’d had for 2 days. The pain began after an extreme core body workout. Treatment with ibuprofen 800 mg and local electrical stimulation one day prior provided no benefit. The patient reported the pain to be a 6 out of 10 when still and a 9 to 10 when sitting for more than a few minutes, turning, or taking a medium to deep breath. The patient felt “dangerously distracted by the pain” while driving in for his appointment.

We noted focal left lower lateral intercostal muscle tenderness without trigger point-like thickness or spasm. The patient also had restricted inspiration, secondary to the severe pain, and decreased left lower field breath sounds. His vital signs were normal, as was his cardiac exam.

THE DIAGNOSIS

While awaiting a chest x-ray, the patient was offered and opted to try acupuncture for pain relief. (We have medical acupuncturists on staff.) Analgesics had already been used, but had provided little relief.

We identified 4 acupuncture sites in the ear: 2 were battlefield acupuncture (BFA) points (more on this in a bit) and 2 points were deemed active by a skin conductance point finder (a handheld device that assesses changes in electrical skin resistance at auricular acupuncture points). The left ear points that were treated included the cingulate gyrus (intertragic notch), Shen Men (triangular fossa), and chest and abdomen regional points (antihelix) (FIGURE 1).

Within 15 minutes, the patient reported significant pain relief and was able to inspire deeply without pain. The patient also underwent a chest x-ray, which revealed atelectasis of the left lower lobe (FIGURE 2A) caused by pain-induced hypoventilation.

Because the patient’s pain was so well controlled, he returned to work immediately after the appointment. At the end of his shift 6 hours later he returned, unscheduled, to report pain at a level of one out of 10 and said he was able to breathe normally. In addition, lung auscultation was normal and a repeat chest x-ray revealed that the atelectasis had almost completely resolved (FIGURE 2B). This occurred without medication or other therapy. The pain did not return.

DISCUSSION

Although acupuncture is over 2000 years old, it has been largely disregarded in the United States due to a lack of mainstream evidence supporting its efficacy. Research is hindered by significant variation in approach between providers, the difficulties inherent to blinding patients and providers to treatment vs placebo, and poor insurance coverage and reimbursement.

Acupuncture research is burgeoning. A 2012 meta-analysis concluded that patients receiving acupuncture had less pain than those receiving sham or no acupuncture for several pain conditions. Specifically, scores for back and neck pain, osteoarthritis, and chronic headache were 0.23, 0.16, and 0.15 standard deviations (SDs), respectively, lower for patients receiving acupuncture than for those who got sham acupuncture. The effect sizes for acupuncture patients compared to no acupuncture controls were 0.55, 0.57, and 0.42 respectively (all P<.001).¹

Several theories explain how auricular acupuncture may work. Paul Nogier, MD, noted that the ear is composed of ectodermal, mesodermal, and endodermal tissues, and mapped the “inverted fetus” homunculus in the ear, which corresponds to specific body points.² Functional magnetic resonance imaging has demonstrated increased brain activity in the cingulate gyrus and thalamic regions in response to a painful stimulus, as well as attenuation of this activity after the placement of needles in corresponding auricular cingulate gyrus and thalamus points.³ In addition, research has confirmed that acupuncture raises serum and cerebrospinal levels of endorphins and enkephalins.⁴

Less than 15 minutes after needle placement, our patient reported significant pain relief and was able to inspire deeply without pain.

Battlefield acupuncture (BFA) was developed by Richard Niemtzow, MD, and has been used for acute injuries in the front lines of battle as well as for many health conditions. BFA treats pain using a sequence of 5 predetermined auricular acupuncture points.⁵ Onset and duration of pain relief vary depending on the location and nature of the pathology. We’ve noted that BFA for chronic pain has a shorter duration of benefit and is more likely to need to be repeated.

One randomized pilot study involving 87 patients presenting to the emergency room blinded emergency health care providers to the inclusion of the first 2 BFA points in their otherwise usual care of acute pain patients. Participants in the acupuncture group experienced a 23% reduction in pain before discharge compared to no change in the standard care group (P<.0005).⁶

Our patient. We inserted semi-permanent needles with a needle length of 2 mm into 4 locations on the ear. (These needles can remain in the ear for several days and fall out on their own or they may be removed by pulling the stud ends.) As noted earlier, our patient reported pain relief within 15 minutes and was pain free by the next day.

THE TAKEAWAY

Research confirms that acupuncture raises serum and cerebrospinal levels of endorphins and enkephalins.

Auricular acupuncture can treat acute and chronic pain. As proof, the BFA technique is widely used by health care providers throughout the US military and Department of Veterans Affairs. In this case, the immediate pain relief and x-ray documentation of atelectasis resolution within 6 hours of treatment provide support that auricular acupuncture was beneficial in reversing the cause of this atelectasis, which was pain-induced hypoventilation.

While the acute pain control observed with this patient is not unusual in our experience, what is unusual is the rare visual confirmation of the striking degree of pain reduction possible with auricular acupuncture.

THE CASE

A 45-year-old airman presented to our medical group with acute onset of sharp, positional left lateral chest wall pain that he’d had for 2 days. The pain began after an extreme core body workout. Treatment with ibuprofen 800 mg and local electrical stimulation one day prior provided no benefit. The patient reported the pain to be a 6 out of 10 when still and a 9 to 10 when sitting for more than a few minutes, turning, or taking a medium to deep breath. The patient felt “dangerously distracted by the pain” while driving in for his appointment.

We noted focal left lower lateral intercostal muscle tenderness without trigger point-like thickness or spasm. The patient also had restricted inspiration, secondary to the severe pain, and decreased left lower field breath sounds. His vital signs were normal, as was his cardiac exam.

THE DIAGNOSIS

While awaiting a chest x-ray, the patient was offered and opted to try acupuncture for pain relief. (We have medical acupuncturists on staff.) Analgesics had already been used, but had provided little relief.

We identified 4 acupuncture sites in the ear: 2 were battlefield acupuncture (BFA) points (more on this in a bit) and 2 points were deemed active by a skin conductance point finder (a handheld device that assesses changes in electrical skin resistance at auricular acupuncture points). The left ear points that were treated included the cingulate gyrus (intertragic notch), Shen Men (triangular fossa), and chest and abdomen regional points (antihelix) (FIGURE 1).

Within 15 minutes, the patient reported significant pain relief and was able to inspire deeply without pain. The patient also underwent a chest x-ray, which revealed atelectasis of the left lower lobe (FIGURE 2A) caused by pain-induced hypoventilation.

Because the patient’s pain was so well controlled, he returned to work immediately after the appointment. At the end of his shift 6 hours later he returned, unscheduled, to report pain at a level of one out of 10 and said he was able to breathe normally. In addition, lung auscultation was normal and a repeat chest x-ray revealed that the atelectasis had almost completely resolved (FIGURE 2B). This occurred without medication or other therapy. The pain did not return.

DISCUSSION

Although acupuncture is over 2000 years old, it has been largely disregarded in the United States due to a lack of mainstream evidence supporting its efficacy. Research is hindered by significant variation in approach between providers, the difficulties inherent to blinding patients and providers to treatment vs placebo, and poor insurance coverage and reimbursement.

Acupuncture research is burgeoning. A 2012 meta-analysis concluded that patients receiving acupuncture had less pain than those receiving sham or no acupuncture for several pain conditions. Specifically, scores for back and neck pain, osteoarthritis, and chronic headache were 0.23, 0.16, and 0.15 standard deviations (SDs), respectively, lower for patients receiving acupuncture than for those who got sham acupuncture. The effect sizes for acupuncture patients compared to no acupuncture controls were 0.55, 0.57, and 0.42 respectively (all P<.001).¹

Several theories explain how auricular acupuncture may work. Paul Nogier, MD, noted that the ear is composed of ectodermal, mesodermal, and endodermal tissues, and mapped the “inverted fetus” homunculus in the ear, which corresponds to specific body points.² Functional magnetic resonance imaging has demonstrated increased brain activity in the cingulate gyrus and thalamic regions in response to a painful stimulus, as well as attenuation of this activity after the placement of needles in corresponding auricular cingulate gyrus and thalamus points.³ In addition, research has confirmed that acupuncture raises serum and cerebrospinal levels of endorphins and enkephalins.⁴

Less than 15 minutes after needle placement, our patient reported significant pain relief and was able to inspire deeply without pain.

Battlefield acupuncture (BFA) was developed by Richard Niemtzow, MD, and has been used for acute injuries in the front lines of battle as well as for many health conditions. BFA treats pain using a sequence of 5 predetermined auricular acupuncture points.⁵ Onset and duration of pain relief vary depending on the location and nature of the pathology. We’ve noted that BFA for chronic pain has a shorter duration of benefit and is more likely to need to be repeated.

One randomized pilot study involving 87 patients presenting to the emergency room blinded emergency health care providers to the inclusion of the first 2 BFA points in their otherwise usual care of acute pain patients. Participants in the acupuncture group experienced a 23% reduction in pain before discharge compared to no change in the standard care group (P<.0005).⁶

Our patient. We inserted semi-permanent needles with a needle length of 2 mm into 4 locations on the ear. (These needles can remain in the ear for several days and fall out on their own or they may be removed by pulling the stud ends.) As noted earlier, our patient reported pain relief within 15 minutes and was pain free by the next day.

THE TAKEAWAY

Research confirms that acupuncture raises serum and cerebrospinal levels of endorphins and enkephalins.

Auricular acupuncture can treat acute and chronic pain. As proof, the BFA technique is widely used by health care providers throughout the US military and Department of Veterans Affairs. In this case, the immediate pain relief and x-ray documentation of atelectasis resolution within 6 hours of treatment provide support that auricular acupuncture was beneficial in reversing the cause of this atelectasis, which was pain-induced hypoventilation.

While the acute pain control observed with this patient is not unusual in our experience, what is unusual is the rare visual confirmation of the striking degree of pain reduction possible with auricular acupuncture.

THE CASE

A 16-year-old boy presented to the emergency room (ER) with pain, redness, and swelling of his right upper arm that had been bothering him for 2 days. He was the quarterback of his high school football team, a sport that he’d been playing since he was 8 years old. He indicated that his football training—which involved repetitive throwing with his right arm—had intensified over the previous 2 months.

Prior to the ER visit, the patient was healthy and active with no significant medical history. He’d had no shoulder trauma and there was no family history of any coagulopathies, venous thrombosis, or pulmonary embolism. He denied chest pain, shortness of breath, palpitations, and fever, and said that he did not smoke cigarettes or drink alcohol.

On physical examination, his blood pressure was 118/70 mm Hg and his heart rate was 74 beats per minute. He had nonpitting edema and erythema of his right upper arm. His radial and brachial pulses were strong and equal in both arms. Assessment of neurologic and vascular integrity produced positive Wright’s and Adson’s tests, but a negative Halstead’s test. (For more on these tests, see: Wright’s test, Adson’s test, and Halstead’s test.) The circumference of the patient’s right upper arm was 2.5 cm greater than the left upper arm. The remainder of the physical exam was normal.

THE DIAGNOSIS

A duplex ultrasound of the right upper arm revealed an acute occlusive thrombus in the axillary vein. We started the patient on intravenous heparin. A venogram confirmed thrombosis of the axillary-subclavian vein (FIGURE 1A). Based on the patient’s clinical presentation and the results of the venogram, we diagnosed Paget-Schroetter syndrome. The venogram was followed by thrombolysis with alteplase (FIGURE 1B) and a balloon angioplasty (FIGURE 1C). One week later, a repeat venogram demonstrated partial removal of the thrombus and an area of compression on the inferior aspect of the subclavian vein due to a cervical band (FIGURE 1D).

DISCUSSION

Paget-Schroetter syndrome (PSS), or effort thrombosis of the upper extremities, is defined as spontaneous thrombus in the axillary and subclavian veins that occurs as a consequence of strenuous upper-extremity activity. It is a rare condition with an incidence of one to 2 cases per 100,000 people per year, and represents 1% to 4% of all cases of deep vein thrombosis (DVT).¹

Spontaneous thrombosis of the upper extremities typically presents in young, otherwise healthy individuals. It has been described in athletes who are involved in ball games, games with rackets or clubs, aquatic sports, combatant sports, and in violin players.² The repetitive movements used in these activities can lead to compression of the axillary and subclavian veins by hypertrophied muscles. Repetitive trauma causes intimal damage and thrombogenesis.³

PSS is characterized by the abrupt, spontaneous swelling of the entire arm, cyanosis, and pain that occurs with use or overhead positioning. Enlarged subcutaneous veins are present in the upper arm, around the shoulder, or in the upper anterior chest wall (Urschel’s sign). The classic presentation is acute onset of upper extremity pain and swelling in the dominant arm following a particularly strenuous activity.⁴ A low-grade fever, superficial thrombophlebitis, or neurologic symptoms may coexist. Certain provocative maneuvers can help reproduce the symptoms (TABLE 1^5,6). Complications of PSS include pulmonary embolism, postthrombotic syndrome (pain, heaviness, and swelling), and recurrent thrombosis.⁷

Contrast venography best shows the extent of thrombosis

Duplex ultrasound, with its high sensitivity and specificity, is the initial, noninvasive test of choice (TABLE 2^4,8-11). However, duplex ultrasound has a false-negative rate of 30% because it is highly technician-dependent and can be complicated by acoustic shadows from the clavicle or sternum.⁸

The most direct and definitive means to confirm the diagnosis of PSS is catheter-directed contrast venography.⁹ This method provides complete anatomic information regarding the site and extent of thrombosis, allows definitive evaluation of the collateral venous pathways, and is a necessary step toward the use of thrombolytic therapy. Contrast load, however, contraindicates the procedure in patients with renal failure and in those who are pregnant.

Contrast-enhanced computed tomography (CT) and magnetic resonance angiography (MRA) are also highly sensitive for detecting focal stenosis at the level of the first rib, the presence or absence of enlarged collateral veins, and the chronicity of any thrombus present. However, the usefulness of CT and magnetic resonance venography in initial screening is unclear, due to a lack of randomized controlled trials.

Treatment involves anticoagulants, thrombolytics, and possibly surgery

Prompt use of anticoagulation is indicated in PSS. Initial anticoagulation with low molecular weight unfractionated heparin or a direct thrombin inhibitor followed by warfarin for a minimum of 3 to 6 months is recommended.¹²

Patients treated with anticoagulation alone have a higher incidence of long-term residual symptoms, disability, and recurrent thrombosis.⁷ As a result, a more aggressive approach with the use of thrombolytic therapy is indicated, especially in young, active patients, to minimize long-term consequences. Alteplase or reteplase are used for this purpose. Thrombolysis is less likely to be beneficial if the thrombus is more than 2 weeks old or if there are inflammatory changes in the vein. The use of catheter-directed thrombolysis minimizes the risk of systemic adverse effects and achieves higher clot resolution rates.¹³

Because PSS is caused by compression of the vein, rather than a disorder of blood clotting, there is still a 50% to 70% risk of recurrent thrombosis despite thrombolysis and anticoagulation.¹⁴ Therefore, the most definitive management approach remains surgical treatment. Patients with recent thrombosis who are within the first several weeks of undergoing successful thrombolytic therapy are excellent candidates for surgery. Operative treatment for PSS includes first rib resection, scalene muscle removal, or subclavius muscle removal, along with removal of constricting scar tissue from around the vein.⁷

THE TAKEAWAY

PSS is characterized by upper-extremity DVT resulting from repetitive trauma to the subclavian-axillary vein. Early diagnosis of PSS with contrast venography and prompt use of anticoagulation can effectively restore venous patency, reduce the risk of rethrombosis, and return the patient to normal function. Primary care physicians should be aware of this condition, because delayed recognition in a high-functioning person can be potentially disabling.

Our patient had a first rib resection, partial division of the scalenus anterior and medius muscles, and lysis of the cervical band. Follow-up venography confirmed resolution of thrombosis without any complications. The patient was continued on anticoagulation with warfarin for 3 months.

THE CASE

A 16-year-old boy presented to the emergency room (ER) with pain, redness, and swelling of his right upper arm that had been bothering him for 2 days. He was the quarterback of his high school football team, a sport that he’d been playing since he was 8 years old. He indicated that his football training—which involved repetitive throwing with his right arm—had intensified over the previous 2 months.

Prior to the ER visit, the patient was healthy and active with no significant medical history. He’d had no shoulder trauma and there was no family history of any coagulopathies, venous thrombosis, or pulmonary embolism. He denied chest pain, shortness of breath, palpitations, and fever, and said that he did not smoke cigarettes or drink alcohol.

On physical examination, his blood pressure was 118/70 mm Hg and his heart rate was 74 beats per minute. He had nonpitting edema and erythema of his right upper arm. His radial and brachial pulses were strong and equal in both arms. Assessment of neurologic and vascular integrity produced positive Wright’s and Adson’s tests, but a negative Halstead’s test. (For more on these tests, see: Wright’s test, Adson’s test, and Halstead’s test.) The circumference of the patient’s right upper arm was 2.5 cm greater than the left upper arm. The remainder of the physical exam was normal.

THE DIAGNOSIS

A duplex ultrasound of the right upper arm revealed an acute occlusive thrombus in the axillary vein. We started the patient on intravenous heparin. A venogram confirmed thrombosis of the axillary-subclavian vein (FIGURE 1A). Based on the patient’s clinical presentation and the results of the venogram, we diagnosed Paget-Schroetter syndrome. The venogram was followed by thrombolysis with alteplase (FIGURE 1B) and a balloon angioplasty (FIGURE 1C). One week later, a repeat venogram demonstrated partial removal of the thrombus and an area of compression on the inferior aspect of the subclavian vein due to a cervical band (FIGURE 1D).

DISCUSSION

Paget-Schroetter syndrome (PSS), or effort thrombosis of the upper extremities, is defined as spontaneous thrombus in the axillary and subclavian veins that occurs as a consequence of strenuous upper-extremity activity. It is a rare condition with an incidence of one to 2 cases per 100,000 people per year, and represents 1% to 4% of all cases of deep vein thrombosis (DVT).¹

Spontaneous thrombosis of the upper extremities typically presents in young, otherwise healthy individuals. It has been described in athletes who are involved in ball games, games with rackets or clubs, aquatic sports, combatant sports, and in violin players.² The repetitive movements used in these activities can lead to compression of the axillary and subclavian veins by hypertrophied muscles. Repetitive trauma causes intimal damage and thrombogenesis.³

PSS is characterized by the abrupt, spontaneous swelling of the entire arm, cyanosis, and pain that occurs with use or overhead positioning. Enlarged subcutaneous veins are present in the upper arm, around the shoulder, or in the upper anterior chest wall (Urschel’s sign). The classic presentation is acute onset of upper extremity pain and swelling in the dominant arm following a particularly strenuous activity.⁴ A low-grade fever, superficial thrombophlebitis, or neurologic symptoms may coexist. Certain provocative maneuvers can help reproduce the symptoms (TABLE 1^5,6). Complications of PSS include pulmonary embolism, postthrombotic syndrome (pain, heaviness, and swelling), and recurrent thrombosis.⁷

Contrast venography best shows the extent of thrombosis

Duplex ultrasound, with its high sensitivity and specificity, is the initial, noninvasive test of choice (TABLE 2^4,8-11). However, duplex ultrasound has a false-negative rate of 30% because it is highly technician-dependent and can be complicated by acoustic shadows from the clavicle or sternum.⁸

The most direct and definitive means to confirm the diagnosis of PSS is catheter-directed contrast venography.⁹ This method provides complete anatomic information regarding the site and extent of thrombosis, allows definitive evaluation of the collateral venous pathways, and is a necessary step toward the use of thrombolytic therapy. Contrast load, however, contraindicates the procedure in patients with renal failure and in those who are pregnant.

Contrast-enhanced computed tomography (CT) and magnetic resonance angiography (MRA) are also highly sensitive for detecting focal stenosis at the level of the first rib, the presence or absence of enlarged collateral veins, and the chronicity of any thrombus present. However, the usefulness of CT and magnetic resonance venography in initial screening is unclear, due to a lack of randomized controlled trials.

Treatment involves anticoagulants, thrombolytics, and possibly surgery

Prompt use of anticoagulation is indicated in PSS. Initial anticoagulation with low molecular weight unfractionated heparin or a direct thrombin inhibitor followed by warfarin for a minimum of 3 to 6 months is recommended.¹²

Patients treated with anticoagulation alone have a higher incidence of long-term residual symptoms, disability, and recurrent thrombosis.⁷ As a result, a more aggressive approach with the use of thrombolytic therapy is indicated, especially in young, active patients, to minimize long-term consequences. Alteplase or reteplase are used for this purpose. Thrombolysis is less likely to be beneficial if the thrombus is more than 2 weeks old or if there are inflammatory changes in the vein. The use of catheter-directed thrombolysis minimizes the risk of systemic adverse effects and achieves higher clot resolution rates.¹³

Because PSS is caused by compression of the vein, rather than a disorder of blood clotting, there is still a 50% to 70% risk of recurrent thrombosis despite thrombolysis and anticoagulation.¹⁴ Therefore, the most definitive management approach remains surgical treatment. Patients with recent thrombosis who are within the first several weeks of undergoing successful thrombolytic therapy are excellent candidates for surgery. Operative treatment for PSS includes first rib resection, scalene muscle removal, or subclavius muscle removal, along with removal of constricting scar tissue from around the vein.⁷

THE TAKEAWAY

PSS is characterized by upper-extremity DVT resulting from repetitive trauma to the subclavian-axillary vein. Early diagnosis of PSS with contrast venography and prompt use of anticoagulation can effectively restore venous patency, reduce the risk of rethrombosis, and return the patient to normal function. Primary care physicians should be aware of this condition, because delayed recognition in a high-functioning person can be potentially disabling.

Our patient had a first rib resection, partial division of the scalenus anterior and medius muscles, and lysis of the cervical band. Follow-up venography confirmed resolution of thrombosis without any complications. The patient was continued on anticoagulation with warfarin for 3 months.

THE CASE

A 16-year-old boy presented to the emergency room (ER) with pain, redness, and swelling of his right upper arm that had been bothering him for 2 days. He was the quarterback of his high school football team, a sport that he’d been playing since he was 8 years old. He indicated that his football training—which involved repetitive throwing with his right arm—had intensified over the previous 2 months.

Prior to the ER visit, the patient was healthy and active with no significant medical history. He’d had no shoulder trauma and there was no family history of any coagulopathies, venous thrombosis, or pulmonary embolism. He denied chest pain, shortness of breath, palpitations, and fever, and said that he did not smoke cigarettes or drink alcohol.

On physical examination, his blood pressure was 118/70 mm Hg and his heart rate was 74 beats per minute. He had nonpitting edema and erythema of his right upper arm. His radial and brachial pulses were strong and equal in both arms. Assessment of neurologic and vascular integrity produced positive Wright’s and Adson’s tests, but a negative Halstead’s test. (For more on these tests, see: Wright’s test, Adson’s test, and Halstead’s test.) The circumference of the patient’s right upper arm was 2.5 cm greater than the left upper arm. The remainder of the physical exam was normal.

THE DIAGNOSIS

A duplex ultrasound of the right upper arm revealed an acute occlusive thrombus in the axillary vein. We started the patient on intravenous heparin. A venogram confirmed thrombosis of the axillary-subclavian vein (FIGURE 1A). Based on the patient’s clinical presentation and the results of the venogram, we diagnosed Paget-Schroetter syndrome. The venogram was followed by thrombolysis with alteplase (FIGURE 1B) and a balloon angioplasty (FIGURE 1C). One week later, a repeat venogram demonstrated partial removal of the thrombus and an area of compression on the inferior aspect of the subclavian vein due to a cervical band (FIGURE 1D).

DISCUSSION

Paget-Schroetter syndrome (PSS), or effort thrombosis of the upper extremities, is defined as spontaneous thrombus in the axillary and subclavian veins that occurs as a consequence of strenuous upper-extremity activity. It is a rare condition with an incidence of one to 2 cases per 100,000 people per year, and represents 1% to 4% of all cases of deep vein thrombosis (DVT).¹

Spontaneous thrombosis of the upper extremities typically presents in young, otherwise healthy individuals. It has been described in athletes who are involved in ball games, games with rackets or clubs, aquatic sports, combatant sports, and in violin players.² The repetitive movements used in these activities can lead to compression of the axillary and subclavian veins by hypertrophied muscles. Repetitive trauma causes intimal damage and thrombogenesis.³

PSS is characterized by the abrupt, spontaneous swelling of the entire arm, cyanosis, and pain that occurs with use or overhead positioning. Enlarged subcutaneous veins are present in the upper arm, around the shoulder, or in the upper anterior chest wall (Urschel’s sign). The classic presentation is acute onset of upper extremity pain and swelling in the dominant arm following a particularly strenuous activity.⁴ A low-grade fever, superficial thrombophlebitis, or neurologic symptoms may coexist. Certain provocative maneuvers can help reproduce the symptoms (TABLE 1^5,6). Complications of PSS include pulmonary embolism, postthrombotic syndrome (pain, heaviness, and swelling), and recurrent thrombosis.⁷

Contrast venography best shows the extent of thrombosis

Duplex ultrasound, with its high sensitivity and specificity, is the initial, noninvasive test of choice (TABLE 2^4,8-11). However, duplex ultrasound has a false-negative rate of 30% because it is highly technician-dependent and can be complicated by acoustic shadows from the clavicle or sternum.⁸

The most direct and definitive means to confirm the diagnosis of PSS is catheter-directed contrast venography.⁹ This method provides complete anatomic information regarding the site and extent of thrombosis, allows definitive evaluation of the collateral venous pathways, and is a necessary step toward the use of thrombolytic therapy. Contrast load, however, contraindicates the procedure in patients with renal failure and in those who are pregnant.

Contrast-enhanced computed tomography (CT) and magnetic resonance angiography (MRA) are also highly sensitive for detecting focal stenosis at the level of the first rib, the presence or absence of enlarged collateral veins, and the chronicity of any thrombus present. However, the usefulness of CT and magnetic resonance venography in initial screening is unclear, due to a lack of randomized controlled trials.

Treatment involves anticoagulants, thrombolytics, and possibly surgery

Prompt use of anticoagulation is indicated in PSS. Initial anticoagulation with low molecular weight unfractionated heparin or a direct thrombin inhibitor followed by warfarin for a minimum of 3 to 6 months is recommended.¹²

Patients treated with anticoagulation alone have a higher incidence of long-term residual symptoms, disability, and recurrent thrombosis.⁷ As a result, a more aggressive approach with the use of thrombolytic therapy is indicated, especially in young, active patients, to minimize long-term consequences. Alteplase or reteplase are used for this purpose. Thrombolysis is less likely to be beneficial if the thrombus is more than 2 weeks old or if there are inflammatory changes in the vein. The use of catheter-directed thrombolysis minimizes the risk of systemic adverse effects and achieves higher clot resolution rates.¹³

Because PSS is caused by compression of the vein, rather than a disorder of blood clotting, there is still a 50% to 70% risk of recurrent thrombosis despite thrombolysis and anticoagulation.¹⁴ Therefore, the most definitive management approach remains surgical treatment. Patients with recent thrombosis who are within the first several weeks of undergoing successful thrombolytic therapy are excellent candidates for surgery. Operative treatment for PSS includes first rib resection, scalene muscle removal, or subclavius muscle removal, along with removal of constricting scar tissue from around the vein.⁷

THE TAKEAWAY

PSS is characterized by upper-extremity DVT resulting from repetitive trauma to the subclavian-axillary vein. Early diagnosis of PSS with contrast venography and prompt use of anticoagulation can effectively restore venous patency, reduce the risk of rethrombosis, and return the patient to normal function. Primary care physicians should be aware of this condition, because delayed recognition in a high-functioning person can be potentially disabling.

Our patient had a first rib resection, partial division of the scalenus anterior and medius muscles, and lysis of the cervical band. Follow-up venography confirmed resolution of thrombosis without any complications. The patient was continued on anticoagulation with warfarin for 3 months.

Case Reports

A platoon of 24 US Marines participated in a 1-week outdoor training exercise (February 4–8) at the Marine Corps Training Area Bellows in Oahu, Hawaii. During the last 3 days of training, 15 (62.5%) marines presented to the same primary care provider with what appeared to be diffuse scattered lesions on the face, neck, and dorsal aspect of the hands. All 15 patients reported that they noticed the lesions upon waking up the morning after their second night at the training area. The patients were unable to recollect specific direct arthropod interactions, but they reported the presence of “bugs” in the training area and denied use of any insect repellents, insect nets, or sunscreen. Sleeping arrangements varied from covered vehicles and cots to sleeping bags on the ground, which were laundered independently by each marine and thereby were ruled out as a commonality. The patients denied working with any chemicals or cleansers while in the field. Further questioning of all 15 patients revealed a history of extended contact with live foliage as branches were broken off to build camouflaged sites.

The following week, a second platoon of 20 marines occupied a separate undisturbed portion of the same training area for a similar 1-week training evolution. Manifestation of similar symptoms among members of the second group, who had no contact with the initial 15 patients, supported the likely environmental etiology of the eruptions.

Figure 1. Numerous well-circumscribed, discrete, pink-red papules diffusely scattered across the face.

Figure 2. Papules with classic anemic halos.

Referral

Two patients from the first group were evaluated at the dermatology clinic at Tripler Army Medical Center (Honolulu, Hawaii) on day 10 of the initial outbreak. Cutaneous examination revealed numerous discrete, pink-red, well-circumscribed, 2- to 4-mm, dome-shaped papules exclusive to exposed areas on the face, neck, and dorsal aspect of the hands (Figures 1 and 2). Anemic halos surrounding the hand papules were noted (Figure 2). A punch biopsy in both patients revealed spongiotic dermatitis with superficial perivascular and interstitial lymphohistiocytic inflammation with eosinophils, suggestive of an arthropod bite (Figure 3). No retained arthropod parts wereidentified. Both patients were treated with triamcinolone ointment twice daily for 7 days with total resolution of the lesions.

Site Survey Results

Five days following the initial presentation of the first outbreak, a daytime site survey of the training area was conducted by a medical entomologist, an environmental health scientist, and a wildlife biologist. Records indicated that prior to the current utilization, the training area had not been used for 9 months. Approximately half of the training area was covered with mixed scrub vegetation and the remainder was clear pavement or sand (clear of vegetation). Feral hogs (Sus scrofa), cats (Felis domesticus), and mongooses (Herpestes javanicus) were observed at the site. Patient interviews and site survey ruled out a number of potential environmental irritants, including contact with fresh or salt water and chemical contaminants in the air or soil.

Because biting insects were suspected as the cause of the eruptions, an overnight entomological survey was conducted 3 weeks after the first outbreak under similar weather conditions and was centered in the area of an Australian pine (Casuarina equisetifolia) forest where most of the marines had slept during training. Mosquitoes (Aedes albopictus and Culex quinquefasciatus) were observed in the area, with an estimated biting rate of 1 to 2 bites per hour. Centipedes (Scolopendra subspinipes) were commonly observed after dark. There was no sign of heavy bird roosting or nesting, which would be a possible source of biting ectoparasites. Other than the Australian pine, notable vegetation present included Christmasberry (Schinus terebinthifolius), koa haole (Leucaena leucocephala), and Chinese banyan (Ficus microcarpa). A survey of the vegetation uncovered no notable insects, and no damage to the leaves of the Chinese banyans, which is typical of thrip infestation, was noted.

Figure 3. Superficial and deep perivascular and interstitial dermatitis (A)(H&E, original magnification ×10) with lymphocytic predominance (B)(H&E, original magnification ×40).

After completion of a resource-intensive investigation that included site survey, literature review, detailed patient history including thrips-associated skin manifestations, and thorough consultation with local dermatologists and entomologists, the findings seemingly pointed to thrips as the most likely etiology of the eruption seen in our patients and a diagnosis of Thysanoptera dermatitis was made.

Comment

Thrips are small winged insects in the order Thysanoptera, which comprises more than 5000 identified species ranging in size from 0.5 to 15 mm, though most are approximately 1 mm.¹ The insects typically are phytophagous (feeding on plants) and are attracted to humidity and seemingly the sweat of animals and humans.² Although largely a phytophagous organism, a few published cases of thrips exposure reported papular skin eruptions known as Thysanoptera dermatitis.^3-8 Several species of thrips across the globe have been associated with incidental attacks on humans to include “Heliothrips indicus Bagnall, a cotton pest of the Sudan; Thrips imagines Bagnall, reported in Australia; Limothrips cerealium (Haliday), in Germany; Gynaitkothrips uzeli Zimmerman, in Algeria; and other species.”⁷ In Hawaii, Gynaikothrips ficorum (Cuban laurel thrips) is a common pest of the Chinese banyan tree (F microcarpa) tree.⁹

A case series reported by Goldstein and Skipworth⁵ in the late 1960s of military personnel stationed in Oahu described exposure to similar environmental conditions with resultant lesions that were nearly identical to those seen in our patients. The final conclusion of the investigation was that Cuban laurel thrips were the likely etiology, though mites also were considered.⁵ In a subsequent commentary in 1968, Waisman¹⁰ reported similar eruptions in hospitalized patients with further comment regarding the nocturnal occurrence of the bites. Additionally, the eruptions were reported to be short lasting and devoid of discomfort, similar to our patient population.¹⁰

Following suit, Aeling⁶ published a case series in 1974 depicting several service members who presented with symptoms that were nearly identical to the symptoms experienced by our patients as well as those of Goldstein and Skipworth.⁵ The investigator coined the term hypoanesthetic halos in Hawaii to describe the findings and further reported that Hawaiian dermatologists were familiar with the symptoms and clinical presentation of the disease. Patients in this outbreak had observed small flying insects, similar to the reports from our patients, and postulated that the symptoms occurred secondary to insect bites.⁶

Since the report by Goldstein and Skipworth⁵ in 1968, the majority of the literature regarding Thysanoptera dermatitis has largely been in case reports. In 1987, Fishman⁷ reported the case of a 43-year-old woman who presented with a palm-sized area of grouped red puncta on the lateral neck with the subsequent entrapment and identification of a flower thrips from the patient’s clothing. In 2005, Leigheb et al² reported the case of a 30-year-old man with an erythematous papular cutaneous eruption on the anterior chest. In this case, the causative etiology was unequivocally confirmed upon identification of the presence of thrips on biopsy.² In 2006, Guarneri et al¹ reported the case of a 59-year-old farmer who had tentatively been diagnosed with delusional parasitosis until persistent presentation to a dermatologist for evaluation enabled the capture and identification of grain thrips. More recently, another case of likely Thysanoptera dermatitis was published in 2012 after a man presented with a slide-mounted thrip from his skin for evaluation as to a potential cause of a recurrent rash he had been experiencing.¹¹ In all of these cases, it was fortunate that a specific organism could be identified for 2 reasons: (1) members of the order Thysanoptera have a biological cycle of only 11 to 36 days, and (2) thrips may go virtually unnoticed by humans, as they are often difficult to see due to their small size.^2,12 Perhaps the most extensive report, however, comes from Childers et al⁸ in a descriptive case series published in 2005. In this report, the investigators provided a thorough detailing of multiple encounters dating back to 1883 through which patients were inadvertently exposed to various species of thrips and subsequently presented with arthropod bites.

Conclusion

The rapid and clustered manner of patient presentation in this case series makes it unique and highlights the need for further consideration of Thysanoptera dermatitis as a potential etiology for an outbreak of a papular eruption. Further reporting may help to better contextualize the true epidemiology of the condition and subsequently may trigger its greater inclusion in the differential diagnosis for a pruritic papular eruption.

Acknowledgments

We would like to extend our appreciation to Amy Spizuoco, DO (New York, New York), for her assistance with the initial diagnosis; Steve Montgomery, PhD (Honolulu, Hawaii), for his assistance with further entomological discussion of potential etiologies; and John R. Gilstad, MD (Honolulu, Hawaii), for contributing his thoughts on the differential diagnosis of the presenting symptoms.

Case Reports

A platoon of 24 US Marines participated in a 1-week outdoor training exercise (February 4–8) at the Marine Corps Training Area Bellows in Oahu, Hawaii. During the last 3 days of training, 15 (62.5%) marines presented to the same primary care provider with what appeared to be diffuse scattered lesions on the face, neck, and dorsal aspect of the hands. All 15 patients reported that they noticed the lesions upon waking up the morning after their second night at the training area. The patients were unable to recollect specific direct arthropod interactions, but they reported the presence of “bugs” in the training area and denied use of any insect repellents, insect nets, or sunscreen. Sleeping arrangements varied from covered vehicles and cots to sleeping bags on the ground, which were laundered independently by each marine and thereby were ruled out as a commonality. The patients denied working with any chemicals or cleansers while in the field. Further questioning of all 15 patients revealed a history of extended contact with live foliage as branches were broken off to build camouflaged sites.

The following week, a second platoon of 20 marines occupied a separate undisturbed portion of the same training area for a similar 1-week training evolution. Manifestation of similar symptoms among members of the second group, who had no contact with the initial 15 patients, supported the likely environmental etiology of the eruptions.

Figure 1. Numerous well-circumscribed, discrete, pink-red papules diffusely scattered across the face.

Figure 2. Papules with classic anemic halos.

Referral

Two patients from the first group were evaluated at the dermatology clinic at Tripler Army Medical Center (Honolulu, Hawaii) on day 10 of the initial outbreak. Cutaneous examination revealed numerous discrete, pink-red, well-circumscribed, 2- to 4-mm, dome-shaped papules exclusive to exposed areas on the face, neck, and dorsal aspect of the hands (Figures 1 and 2). Anemic halos surrounding the hand papules were noted (Figure 2). A punch biopsy in both patients revealed spongiotic dermatitis with superficial perivascular and interstitial lymphohistiocytic inflammation with eosinophils, suggestive of an arthropod bite (Figure 3). No retained arthropod parts wereidentified. Both patients were treated with triamcinolone ointment twice daily for 7 days with total resolution of the lesions.

Site Survey Results

Five days following the initial presentation of the first outbreak, a daytime site survey of the training area was conducted by a medical entomologist, an environmental health scientist, and a wildlife biologist. Records indicated that prior to the current utilization, the training area had not been used for 9 months. Approximately half of the training area was covered with mixed scrub vegetation and the remainder was clear pavement or sand (clear of vegetation). Feral hogs (Sus scrofa), cats (Felis domesticus), and mongooses (Herpestes javanicus) were observed at the site. Patient interviews and site survey ruled out a number of potential environmental irritants, including contact with fresh or salt water and chemical contaminants in the air or soil.

Because biting insects were suspected as the cause of the eruptions, an overnight entomological survey was conducted 3 weeks after the first outbreak under similar weather conditions and was centered in the area of an Australian pine (Casuarina equisetifolia) forest where most of the marines had slept during training. Mosquitoes (Aedes albopictus and Culex quinquefasciatus) were observed in the area, with an estimated biting rate of 1 to 2 bites per hour. Centipedes (Scolopendra subspinipes) were commonly observed after dark. There was no sign of heavy bird roosting or nesting, which would be a possible source of biting ectoparasites. Other than the Australian pine, notable vegetation present included Christmasberry (Schinus terebinthifolius), koa haole (Leucaena leucocephala), and Chinese banyan (Ficus microcarpa). A survey of the vegetation uncovered no notable insects, and no damage to the leaves of the Chinese banyans, which is typical of thrip infestation, was noted.

Figure 3. Superficial and deep perivascular and interstitial dermatitis (A)(H&E, original magnification ×10) with lymphocytic predominance (B)(H&E, original magnification ×40).

After completion of a resource-intensive investigation that included site survey, literature review, detailed patient history including thrips-associated skin manifestations, and thorough consultation with local dermatologists and entomologists, the findings seemingly pointed to thrips as the most likely etiology of the eruption seen in our patients and a diagnosis of Thysanoptera dermatitis was made.

Comment

Thrips are small winged insects in the order Thysanoptera, which comprises more than 5000 identified species ranging in size from 0.5 to 15 mm, though most are approximately 1 mm.¹ The insects typically are phytophagous (feeding on plants) and are attracted to humidity and seemingly the sweat of animals and humans.² Although largely a phytophagous organism, a few published cases of thrips exposure reported papular skin eruptions known as Thysanoptera dermatitis.^3-8 Several species of thrips across the globe have been associated with incidental attacks on humans to include “Heliothrips indicus Bagnall, a cotton pest of the Sudan; Thrips imagines Bagnall, reported in Australia; Limothrips cerealium (Haliday), in Germany; Gynaitkothrips uzeli Zimmerman, in Algeria; and other species.”⁷ In Hawaii, Gynaikothrips ficorum (Cuban laurel thrips) is a common pest of the Chinese banyan tree (F microcarpa) tree.⁹

A case series reported by Goldstein and Skipworth⁵ in the late 1960s of military personnel stationed in Oahu described exposure to similar environmental conditions with resultant lesions that were nearly identical to those seen in our patients. The final conclusion of the investigation was that Cuban laurel thrips were the likely etiology, though mites also were considered.⁵ In a subsequent commentary in 1968, Waisman¹⁰ reported similar eruptions in hospitalized patients with further comment regarding the nocturnal occurrence of the bites. Additionally, the eruptions were reported to be short lasting and devoid of discomfort, similar to our patient population.¹⁰

Following suit, Aeling⁶ published a case series in 1974 depicting several service members who presented with symptoms that were nearly identical to the symptoms experienced by our patients as well as those of Goldstein and Skipworth.⁵ The investigator coined the term hypoanesthetic halos in Hawaii to describe the findings and further reported that Hawaiian dermatologists were familiar with the symptoms and clinical presentation of the disease. Patients in this outbreak had observed small flying insects, similar to the reports from our patients, and postulated that the symptoms occurred secondary to insect bites.⁶

Since the report by Goldstein and Skipworth⁵ in 1968, the majority of the literature regarding Thysanoptera dermatitis has largely been in case reports. In 1987, Fishman⁷ reported the case of a 43-year-old woman who presented with a palm-sized area of grouped red puncta on the lateral neck with the subsequent entrapment and identification of a flower thrips from the patient’s clothing. In 2005, Leigheb et al² reported the case of a 30-year-old man with an erythematous papular cutaneous eruption on the anterior chest. In this case, the causative etiology was unequivocally confirmed upon identification of the presence of thrips on biopsy.² In 2006, Guarneri et al¹ reported the case of a 59-year-old farmer who had tentatively been diagnosed with delusional parasitosis until persistent presentation to a dermatologist for evaluation enabled the capture and identification of grain thrips. More recently, another case of likely Thysanoptera dermatitis was published in 2012 after a man presented with a slide-mounted thrip from his skin for evaluation as to a potential cause of a recurrent rash he had been experiencing.¹¹ In all of these cases, it was fortunate that a specific organism could be identified for 2 reasons: (1) members of the order Thysanoptera have a biological cycle of only 11 to 36 days, and (2) thrips may go virtually unnoticed by humans, as they are often difficult to see due to their small size.^2,12 Perhaps the most extensive report, however, comes from Childers et al⁸ in a descriptive case series published in 2005. In this report, the investigators provided a thorough detailing of multiple encounters dating back to 1883 through which patients were inadvertently exposed to various species of thrips and subsequently presented with arthropod bites.

Conclusion

The rapid and clustered manner of patient presentation in this case series makes it unique and highlights the need for further consideration of Thysanoptera dermatitis as a potential etiology for an outbreak of a papular eruption. Further reporting may help to better contextualize the true epidemiology of the condition and subsequently may trigger its greater inclusion in the differential diagnosis for a pruritic papular eruption.

Acknowledgments

We would like to extend our appreciation to Amy Spizuoco, DO (New York, New York), for her assistance with the initial diagnosis; Steve Montgomery, PhD (Honolulu, Hawaii), for his assistance with further entomological discussion of potential etiologies; and John R. Gilstad, MD (Honolulu, Hawaii), for contributing his thoughts on the differential diagnosis of the presenting symptoms.

Case Reports

A platoon of 24 US Marines participated in a 1-week outdoor training exercise (February 4–8) at the Marine Corps Training Area Bellows in Oahu, Hawaii. During the last 3 days of training, 15 (62.5%) marines presented to the same primary care provider with what appeared to be diffuse scattered lesions on the face, neck, and dorsal aspect of the hands. All 15 patients reported that they noticed the lesions upon waking up the morning after their second night at the training area. The patients were unable to recollect specific direct arthropod interactions, but they reported the presence of “bugs” in the training area and denied use of any insect repellents, insect nets, or sunscreen. Sleeping arrangements varied from covered vehicles and cots to sleeping bags on the ground, which were laundered independently by each marine and thereby were ruled out as a commonality. The patients denied working with any chemicals or cleansers while in the field. Further questioning of all 15 patients revealed a history of extended contact with live foliage as branches were broken off to build camouflaged sites.

The following week, a second platoon of 20 marines occupied a separate undisturbed portion of the same training area for a similar 1-week training evolution. Manifestation of similar symptoms among members of the second group, who had no contact with the initial 15 patients, supported the likely environmental etiology of the eruptions.

Figure 1. Numerous well-circumscribed, discrete, pink-red papules diffusely scattered across the face.

Figure 2. Papules with classic anemic halos.

Referral

Two patients from the first group were evaluated at the dermatology clinic at Tripler Army Medical Center (Honolulu, Hawaii) on day 10 of the initial outbreak. Cutaneous examination revealed numerous discrete, pink-red, well-circumscribed, 2- to 4-mm, dome-shaped papules exclusive to exposed areas on the face, neck, and dorsal aspect of the hands (Figures 1 and 2). Anemic halos surrounding the hand papules were noted (Figure 2). A punch biopsy in both patients revealed spongiotic dermatitis with superficial perivascular and interstitial lymphohistiocytic inflammation with eosinophils, suggestive of an arthropod bite (Figure 3). No retained arthropod parts wereidentified. Both patients were treated with triamcinolone ointment twice daily for 7 days with total resolution of the lesions.

Site Survey Results

Five days following the initial presentation of the first outbreak, a daytime site survey of the training area was conducted by a medical entomologist, an environmental health scientist, and a wildlife biologist. Records indicated that prior to the current utilization, the training area had not been used for 9 months. Approximately half of the training area was covered with mixed scrub vegetation and the remainder was clear pavement or sand (clear of vegetation). Feral hogs (Sus scrofa), cats (Felis domesticus), and mongooses (Herpestes javanicus) were observed at the site. Patient interviews and site survey ruled out a number of potential environmental irritants, including contact with fresh or salt water and chemical contaminants in the air or soil.

Because biting insects were suspected as the cause of the eruptions, an overnight entomological survey was conducted 3 weeks after the first outbreak under similar weather conditions and was centered in the area of an Australian pine (Casuarina equisetifolia) forest where most of the marines had slept during training. Mosquitoes (Aedes albopictus and Culex quinquefasciatus) were observed in the area, with an estimated biting rate of 1 to 2 bites per hour. Centipedes (Scolopendra subspinipes) were commonly observed after dark. There was no sign of heavy bird roosting or nesting, which would be a possible source of biting ectoparasites. Other than the Australian pine, notable vegetation present included Christmasberry (Schinus terebinthifolius), koa haole (Leucaena leucocephala), and Chinese banyan (Ficus microcarpa). A survey of the vegetation uncovered no notable insects, and no damage to the leaves of the Chinese banyans, which is typical of thrip infestation, was noted.

Figure 3. Superficial and deep perivascular and interstitial dermatitis (A)(H&E, original magnification ×10) with lymphocytic predominance (B)(H&E, original magnification ×40).

After completion of a resource-intensive investigation that included site survey, literature review, detailed patient history including thrips-associated skin manifestations, and thorough consultation with local dermatologists and entomologists, the findings seemingly pointed to thrips as the most likely etiology of the eruption seen in our patients and a diagnosis of Thysanoptera dermatitis was made.

Comment

Thrips are small winged insects in the order Thysanoptera, which comprises more than 5000 identified species ranging in size from 0.5 to 15 mm, though most are approximately 1 mm.¹ The insects typically are phytophagous (feeding on plants) and are attracted to humidity and seemingly the sweat of animals and humans.² Although largely a phytophagous organism, a few published cases of thrips exposure reported papular skin eruptions known as Thysanoptera dermatitis.^3-8 Several species of thrips across the globe have been associated with incidental attacks on humans to include “Heliothrips indicus Bagnall, a cotton pest of the Sudan; Thrips imagines Bagnall, reported in Australia; Limothrips cerealium (Haliday), in Germany; Gynaitkothrips uzeli Zimmerman, in Algeria; and other species.”⁷ In Hawaii, Gynaikothrips ficorum (Cuban laurel thrips) is a common pest of the Chinese banyan tree (F microcarpa) tree.⁹

A case series reported by Goldstein and Skipworth⁵ in the late 1960s of military personnel stationed in Oahu described exposure to similar environmental conditions with resultant lesions that were nearly identical to those seen in our patients. The final conclusion of the investigation was that Cuban laurel thrips were the likely etiology, though mites also were considered.⁵ In a subsequent commentary in 1968, Waisman¹⁰ reported similar eruptions in hospitalized patients with further comment regarding the nocturnal occurrence of the bites. Additionally, the eruptions were reported to be short lasting and devoid of discomfort, similar to our patient population.¹⁰

Following suit, Aeling⁶ published a case series in 1974 depicting several service members who presented with symptoms that were nearly identical to the symptoms experienced by our patients as well as those of Goldstein and Skipworth.⁵ The investigator coined the term hypoanesthetic halos in Hawaii to describe the findings and further reported that Hawaiian dermatologists were familiar with the symptoms and clinical presentation of the disease. Patients in this outbreak had observed small flying insects, similar to the reports from our patients, and postulated that the symptoms occurred secondary to insect bites.⁶

Since the report by Goldstein and Skipworth⁵ in 1968, the majority of the literature regarding Thysanoptera dermatitis has largely been in case reports. In 1987, Fishman⁷ reported the case of a 43-year-old woman who presented with a palm-sized area of grouped red puncta on the lateral neck with the subsequent entrapment and identification of a flower thrips from the patient’s clothing. In 2005, Leigheb et al² reported the case of a 30-year-old man with an erythematous papular cutaneous eruption on the anterior chest. In this case, the causative etiology was unequivocally confirmed upon identification of the presence of thrips on biopsy.² In 2006, Guarneri et al¹ reported the case of a 59-year-old farmer who had tentatively been diagnosed with delusional parasitosis until persistent presentation to a dermatologist for evaluation enabled the capture and identification of grain thrips. More recently, another case of likely Thysanoptera dermatitis was published in 2012 after a man presented with a slide-mounted thrip from his skin for evaluation as to a potential cause of a recurrent rash he had been experiencing.¹¹ In all of these cases, it was fortunate that a specific organism could be identified for 2 reasons: (1) members of the order Thysanoptera have a biological cycle of only 11 to 36 days, and (2) thrips may go virtually unnoticed by humans, as they are often difficult to see due to their small size.^2,12 Perhaps the most extensive report, however, comes from Childers et al⁸ in a descriptive case series published in 2005. In this report, the investigators provided a thorough detailing of multiple encounters dating back to 1883 through which patients were inadvertently exposed to various species of thrips and subsequently presented with arthropod bites.

Conclusion

The rapid and clustered manner of patient presentation in this case series makes it unique and highlights the need for further consideration of Thysanoptera dermatitis as a potential etiology for an outbreak of a papular eruption. Further reporting may help to better contextualize the true epidemiology of the condition and subsequently may trigger its greater inclusion in the differential diagnosis for a pruritic papular eruption.

Acknowledgments

We would like to extend our appreciation to Amy Spizuoco, DO (New York, New York), for her assistance with the initial diagnosis; Steve Montgomery, PhD (Honolulu, Hawaii), for his assistance with further entomological discussion of potential etiologies; and John R. Gilstad, MD (Honolulu, Hawaii), for contributing his thoughts on the differential diagnosis of the presenting symptoms.

Systemic cobalt toxicity has been reported in the literature after hip arthroplasty revisions for failed ceramic components secondary to third-body abrasive wear of cobalt-chrome (CoCr) components, as well as with metal-on-metal (MOM) hip arthroplasty designs. There have been several cases of systemic cobalt toxicity after revision for fractured ceramic components.^1,2 Of these 7 reported cases, all patients had neurologic complaints and 4 patients developed cardiomyopathy secondary to toxic cobalt levels, with 1 case being fatal.¹ MOM hip prostheses have also been associated with local and systemic problems secondary to metal debris. Adverse local tissue reactions have been reported to occur in up to 59% of patients, and, in some registries, the failure rate of MOM arthroplasty caused by these soft-tissue reactions is 2 to 3 times that of conventional metal-on-polyethylene design failures.^3,4 The occurrence of systemic complications from MOM total hip arthroplasty (THA) wear debris is much less common. There have been 6 cases of systemic cobalt toxicity reported in the literature resulting from MOM total hip prosthesis design.^1,2

We present a case of biopsy-confirmed cardiomyopathy secondary to cobalt toxicity from a MOM THA design with subsequent requirement for left ventricular assist device (LVAD) implantation despite prosthesis removal. To our knowledge, this is the first report in the literature of this specific implant design causing systemic cobalt toxicity. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

The patient was a healthy nondiabetic man age 54 years who presented to our clinic 6 years after undergoing left THA and 5 years after undergoing right THA with the Biomet M2a-Magnum MOM prosthesis at an outside facility. The left-side components placed at the index procedure were a size 50 cup, 44 magnum head, 10 Taperloc stem (Biomet), and +9 neck. The right-side components were a size 52 cup, 46 magnum head, 10 Taperloc stem, and +3 neck. The patient emphasized that he was very happy with his hip prostheses and denied groin or thigh pain. His medical history was significant for exogenous obesity, and he denied any history of alcohol, tobacco, steroid, or recreational drug use.

The patient’s review of systems suggested that, approximately 11 months prior to presentation at our facility, he began having difficulty with his activities of daily living secondary to chest pressure with exertion, fatigue, and associated diaphoresis. He complained of decreased sensation in his feet bilaterally but denied any hearing loss, tinnitus, or vision changes. He underwent evaluation of the new-onset chest discomfort with a cardiac stress test that suggested no active cardiac ischemia. An echocardiogram revealed mitral regurgitation, stage II diastolic dysfunction with a left ventricular ejection fraction of 55%. Additionally, during this time period, the patient was being followed by his local orthopedic surgeon for an elevated cobalt level of 120 ppb and a chromium level of 109 ppb. The patient was referred to our clinic for recommendations regarding the elevated metal-ion levels. Upon initial evaluation, the patient denied any hip or groin pain. His physical examination revealed a nonantalgic gait with full range of motion and no signs of instability, tenderness, or masses. The patient was also noted to have no vibratory sensation in his feet bilaterally. The plain radiographs indicated bilateral MOM THA with acetabular inclination levels of 55º on the right and left sides. No cystic changes or other worrisome signs that would suggest implant loosening or failure were present (Figure 1). The serum metal levels were repeated and showed a cobalt level of 189 ppb and a chromium level of 71 ppb. Whole venous blood samples were drawn at our request using trace element tubes and were sent to Medtox Laboratories Inc. for analysis. Other pertinent laboratory values, including hematocrit and thyroid levels, were within normal limits. Because of concerns of systemic toxicity from significantly elevated cobalt and chromium levels, the patient elected to proceed with revision of the MOM components.

During the preoperative medical evaluation, the patient’s cardiac status was a concern, and the etiology of the cardiac dysfunction was unclear. Cardiac magnetic resonance imaging (MRI), which was performed to evaluate the extent and etiology of cardiac dysfunction, showed biventricular dysfunction. To evaluate the underlying myocardial tissue characteristics, delayed contrast imaging was performed and showed diffuse myocardial hyperenhancement of the anterior, lateral, and apical walls, with sparing of the base and midseptum. This type of extensive hyperenhancement is commonly seen with cardiac amyloidosis; however, the blood-pool kinetics during contrast administration is unusual for amyloidosis, as well as the diffuse edema noted on T2-weighted MRI. Importantly, cardiac MRI is very specific in excluding alternative diagnoses, such as postinfarct, infiltrative, acquired, viral, or alcoholic/drugs of abuse etiologies. In the absence of amyloidosis, the only other pattern that would be consistent with symptoms was diffuse, fulminant myocarditis of toxic origin lacking clinical evidence for an infectious origin. The patient’s prior exposure to cobalt was noted. Thus, the hyperenhancement and edema could be strong supportive evidence of cobalt infiltration, despite no reported cases in the literature of cobalt cardiomyopathy found on cardiac MRI.

Additional workup was initiated, and cardiac catheterization showed that the patient continued to decompensate, with worsening global left ventricular dysfunction with an ejection fraction of 30% without evidence of coronary artery disease. Also, he was noted to have mild renal impairment with a blood urea nitrogen level of 31 mg/dL and a creatinine level of 1.7 mg/dL. The etiology of the renal impairment was unknown and had not been established, according to the patient and his wife. The renal impairment was not thought to be caused by the elevated metal ions levels but likely resulted from prerenal azotemia secondary to decreased cardiac output. During catheterization, an endomyocardial biopsy was performed and the tissue sent to the Mayo Clinic pathology department for analysis. The sample showed myocyte hypertrophy and interstitial fibrosis with scattered myofibers containing large cytoplasmic vacuoles. Also present was karyomegaly consistent with myocyte hypertrophy (Figures 2A, 2B). Trichrome stain confirmed replacement of myofibers by collagen (Figure 2C). Electron microscopy performed on a paraffin block showed reduced contractile elements, vacuolar spaces, and increased lipofuscin. The findings were very consistent with, but not specific for, cardiomyopathy from cobalt toxicity. No evidence of an inflammatory infiltrate was identified. The diagnosis was cobalt cardiomyopathy based on biopsy, presentation, cobalt levels, and intraoperative findings.

The patient was admitted to the cardiac intensive care unit preoperatively and optimized with inotropic agents. A multidisciplinary consultation with the cardiology and anesthesia departments was obtained. Both recommended cardiac anesthesia with intraoperative Swan-Ganz catheter and transesophageal echo monitoring. Assuming that the patient remained hemodynamically stable with limited blood loss and the first hip was timely performed, the cardiology department recommended a single surgery, because fewer risks and complications could be expected than from a staged procedure. Subsequently, surgery was performed on the left hip via a conservative anterior approach on the fracture table. The patient remained stable with limited blood loss. During the same operating room time, revision of the right hip was performed using an anterior approach. The intraoperative findings showed evidence of pseudotumors in the adjacent soft tissues and abundant brown, creamy fluid upon entering the joint capsule, consistent with a metallic appearance. Both hips showed similar prosthetic findings. There was no significant visible wear of the large diameter metal heads or gross abnormality of the acetabular components. The trunnion area on both femoral implants was abnormal, revealing a black coating suggestive of marked corrosion. The components were all well fixed, without visible damage, and, because of his fragile cardiac status, the patient’s acetabular components were not revised. The trunnions were cleaned and the femoral heads were revised to active articulation dual-mobility metal-on-polyethylene constructs using 28-mm Biolox Option ceramic (CeramTec). The tissue specimens from the operation showed chronic inflammation with areas of fibroconnective tissue and bland fibrinoid necrosis with extensive brown pigment-laden macrophage reaction. The intraoperative cultures were negative.

The patient tolerated the surgery without complication, and his postoperative period was without incident. Nine months after surgery, the patient’s cobalt and chromium levels had declined to 16 ppb and 32 ppb, respectively (normal, <1 ppb). However, his cardiac status continued to worsen with significant shortness of breath and bilateral lower extremity edema despite diuresis. Follow-up cardiac MRI indicated progressive left and right dysfunction with ejection fractions of 23% and 25%, respectively. After progressive heart-failure symptoms, the patient was admitted to the hospital for severe congestive heart failure and underwent implantation of a HeartWare LVAD with tricuspid valve repair using an Edwards annuloplasty ring. He has since had a cardiac transplant and is doing well.

Discussion

To our knowledge, this is the first reported case of cardiomyopathy in a patient with elevated cobalt ion levels and a Biomet M2a-Magnum hip prosthesis. This is also the first reported case of cardiac MRI–defined cobalt cardiomyopathy. The cobalt levels seen in this patient were similar to those of other cases with systemic cobalt toxicity from a MOM hip construct. Mao and colleagues⁵ reported 2 cases of systemic cobalt toxicity in 2 patients with articular surface replacement hip prostheses.One patient presented with mild groin pain, neurologic symptoms, and a cobalt level of 410 ppb 5 years after her index procedure. The other patient presented with cardiac and neurologic symptoms but no hip complaints. The patient’s cobalt levels ranged from 185 ppb to 210 ppb. Both patients improved after their revision surgery, and their cobalt levels decreased. The 2 patients in Tower’s report⁶ were 49-year-old men who had articular surface replacement implants (DePuy). One patient who presented with progressive hip pain 11 months postoperatively developed neurologic symptoms and cardiomyopathy, with cobalt levels of 83 ppb before revision surgery 43 months after his index procedure. The other patient presented with hip pain and vertigo, headaches, fatigue, and dyspnea. He underwent hip revision 40 months postoperatively and required closed reduction under sedation for dislocation. Finally, and most recently, Allen and colleagues² reported a 59-year-old woman with a cobalt level of 287 ppb whose symptoms did not resolve after implantation of an LVAD or cardiac transplantation but only after removal of her bilateral hip prosthesis. Our case is most similar to this report but significantly adds to the literature in 2 distinct manners: (1) Biomet M2a-Magnum has not been implicated in cobalt toxicity; and (2) this is the first reported use of dedicated cardiac MRI to noninvasively define underlying cardiac pathology.

The cardiac manifestations secondary to systemic cobalt toxicity in this patient represent a frightening consequence of MOM prosthetic wear. The effects of cobalt toxicity on cardiac tissues were first described in a series of alcoholic patients from Manchester in 1900;⁷ however, it was not until 1967, in a series of patients in Quebec, that cobalt was found to be the inciting factor. In the modern era, hip arthroplasty techniques resulting in excessive cobalt and chromium wear have demonstrated the same findings of myocyte hypertrophy, interstitial fibrosis, and scattered myofibers containing large cytoplasmic inclusions.^8,9 The patient presented here has pathologic findings consistent with previous cases of cobalt cardiomyopathy; however, in the other cases of cardiomyopathy due to MOM total hip components, the patients’ cardiac conditions improved after the prostheses were revised and the cobalt levels began to diminish.^5,6In our case, the patient has sustained permanent damage to his myocardium and a progressive decline in his cardiac status, which is a deviation from reported cases as of 2014.

While there is no guideline to unequivocally diagnose cobalt cardiomyopathy, the constellation of findings, including pathologic, biologic, blood levels, imaging, and surgical, all uniformly indicate a unifying diagnosis. The lack of improvement after prosthetic device removal supports a diagnosis of permanent myocardial damage, which is consistent with cardiomyopathy of advanced toxic etiology.

Conclusion

This case presents a patient with bilateral MOM THAs, acetabular cup inclinations of greater than 55º, renal impairment, and cobalt levels greater than 60 ppb, with occult cardiac failure leading to LVAD implantation as a prelude to cardiac transplantation in order to avoid certain death. These factors have been shown, in prior case reports, to be associated with cardiac damage that may be reversible.⁶ However; it is important for orthopedic surgeons to recognize that certain hip prostheses can be associated or lead to irreversible cardiac damage.

Systemic cobalt toxicity has been reported in the literature after hip arthroplasty revisions for failed ceramic components secondary to third-body abrasive wear of cobalt-chrome (CoCr) components, as well as with metal-on-metal (MOM) hip arthroplasty designs. There have been several cases of systemic cobalt toxicity after revision for fractured ceramic components.^1,2 Of these 7 reported cases, all patients had neurologic complaints and 4 patients developed cardiomyopathy secondary to toxic cobalt levels, with 1 case being fatal.¹ MOM hip prostheses have also been associated with local and systemic problems secondary to metal debris. Adverse local tissue reactions have been reported to occur in up to 59% of patients, and, in some registries, the failure rate of MOM arthroplasty caused by these soft-tissue reactions is 2 to 3 times that of conventional metal-on-polyethylene design failures.^3,4 The occurrence of systemic complications from MOM total hip arthroplasty (THA) wear debris is much less common. There have been 6 cases of systemic cobalt toxicity reported in the literature resulting from MOM total hip prosthesis design.^1,2

We present a case of biopsy-confirmed cardiomyopathy secondary to cobalt toxicity from a MOM THA design with subsequent requirement for left ventricular assist device (LVAD) implantation despite prosthesis removal. To our knowledge, this is the first report in the literature of this specific implant design causing systemic cobalt toxicity. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

The patient was a healthy nondiabetic man age 54 years who presented to our clinic 6 years after undergoing left THA and 5 years after undergoing right THA with the Biomet M2a-Magnum MOM prosthesis at an outside facility. The left-side components placed at the index procedure were a size 50 cup, 44 magnum head, 10 Taperloc stem (Biomet), and +9 neck. The right-side components were a size 52 cup, 46 magnum head, 10 Taperloc stem, and +3 neck. The patient emphasized that he was very happy with his hip prostheses and denied groin or thigh pain. His medical history was significant for exogenous obesity, and he denied any history of alcohol, tobacco, steroid, or recreational drug use.

The patient’s review of systems suggested that, approximately 11 months prior to presentation at our facility, he began having difficulty with his activities of daily living secondary to chest pressure with exertion, fatigue, and associated diaphoresis. He complained of decreased sensation in his feet bilaterally but denied any hearing loss, tinnitus, or vision changes. He underwent evaluation of the new-onset chest discomfort with a cardiac stress test that suggested no active cardiac ischemia. An echocardiogram revealed mitral regurgitation, stage II diastolic dysfunction with a left ventricular ejection fraction of 55%. Additionally, during this time period, the patient was being followed by his local orthopedic surgeon for an elevated cobalt level of 120 ppb and a chromium level of 109 ppb. The patient was referred to our clinic for recommendations regarding the elevated metal-ion levels. Upon initial evaluation, the patient denied any hip or groin pain. His physical examination revealed a nonantalgic gait with full range of motion and no signs of instability, tenderness, or masses. The patient was also noted to have no vibratory sensation in his feet bilaterally. The plain radiographs indicated bilateral MOM THA with acetabular inclination levels of 55º on the right and left sides. No cystic changes or other worrisome signs that would suggest implant loosening or failure were present (Figure 1). The serum metal levels were repeated and showed a cobalt level of 189 ppb and a chromium level of 71 ppb. Whole venous blood samples were drawn at our request using trace element tubes and were sent to Medtox Laboratories Inc. for analysis. Other pertinent laboratory values, including hematocrit and thyroid levels, were within normal limits. Because of concerns of systemic toxicity from significantly elevated cobalt and chromium levels, the patient elected to proceed with revision of the MOM components.

During the preoperative medical evaluation, the patient’s cardiac status was a concern, and the etiology of the cardiac dysfunction was unclear. Cardiac magnetic resonance imaging (MRI), which was performed to evaluate the extent and etiology of cardiac dysfunction, showed biventricular dysfunction. To evaluate the underlying myocardial tissue characteristics, delayed contrast imaging was performed and showed diffuse myocardial hyperenhancement of the anterior, lateral, and apical walls, with sparing of the base and midseptum. This type of extensive hyperenhancement is commonly seen with cardiac amyloidosis; however, the blood-pool kinetics during contrast administration is unusual for amyloidosis, as well as the diffuse edema noted on T2-weighted MRI. Importantly, cardiac MRI is very specific in excluding alternative diagnoses, such as postinfarct, infiltrative, acquired, viral, or alcoholic/drugs of abuse etiologies. In the absence of amyloidosis, the only other pattern that would be consistent with symptoms was diffuse, fulminant myocarditis of toxic origin lacking clinical evidence for an infectious origin. The patient’s prior exposure to cobalt was noted. Thus, the hyperenhancement and edema could be strong supportive evidence of cobalt infiltration, despite no reported cases in the literature of cobalt cardiomyopathy found on cardiac MRI.

Additional workup was initiated, and cardiac catheterization showed that the patient continued to decompensate, with worsening global left ventricular dysfunction with an ejection fraction of 30% without evidence of coronary artery disease. Also, he was noted to have mild renal impairment with a blood urea nitrogen level of 31 mg/dL and a creatinine level of 1.7 mg/dL. The etiology of the renal impairment was unknown and had not been established, according to the patient and his wife. The renal impairment was not thought to be caused by the elevated metal ions levels but likely resulted from prerenal azotemia secondary to decreased cardiac output. During catheterization, an endomyocardial biopsy was performed and the tissue sent to the Mayo Clinic pathology department for analysis. The sample showed myocyte hypertrophy and interstitial fibrosis with scattered myofibers containing large cytoplasmic vacuoles. Also present was karyomegaly consistent with myocyte hypertrophy (Figures 2A, 2B). Trichrome stain confirmed replacement of myofibers by collagen (Figure 2C). Electron microscopy performed on a paraffin block showed reduced contractile elements, vacuolar spaces, and increased lipofuscin. The findings were very consistent with, but not specific for, cardiomyopathy from cobalt toxicity. No evidence of an inflammatory infiltrate was identified. The diagnosis was cobalt cardiomyopathy based on biopsy, presentation, cobalt levels, and intraoperative findings.

The patient was admitted to the cardiac intensive care unit preoperatively and optimized with inotropic agents. A multidisciplinary consultation with the cardiology and anesthesia departments was obtained. Both recommended cardiac anesthesia with intraoperative Swan-Ganz catheter and transesophageal echo monitoring. Assuming that the patient remained hemodynamically stable with limited blood loss and the first hip was timely performed, the cardiology department recommended a single surgery, because fewer risks and complications could be expected than from a staged procedure. Subsequently, surgery was performed on the left hip via a conservative anterior approach on the fracture table. The patient remained stable with limited blood loss. During the same operating room time, revision of the right hip was performed using an anterior approach. The intraoperative findings showed evidence of pseudotumors in the adjacent soft tissues and abundant brown, creamy fluid upon entering the joint capsule, consistent with a metallic appearance. Both hips showed similar prosthetic findings. There was no significant visible wear of the large diameter metal heads or gross abnormality of the acetabular components. The trunnion area on both femoral implants was abnormal, revealing a black coating suggestive of marked corrosion. The components were all well fixed, without visible damage, and, because of his fragile cardiac status, the patient’s acetabular components were not revised. The trunnions were cleaned and the femoral heads were revised to active articulation dual-mobility metal-on-polyethylene constructs using 28-mm Biolox Option ceramic (CeramTec). The tissue specimens from the operation showed chronic inflammation with areas of fibroconnective tissue and bland fibrinoid necrosis with extensive brown pigment-laden macrophage reaction. The intraoperative cultures were negative.

The patient tolerated the surgery without complication, and his postoperative period was without incident. Nine months after surgery, the patient’s cobalt and chromium levels had declined to 16 ppb and 32 ppb, respectively (normal, <1 ppb). However, his cardiac status continued to worsen with significant shortness of breath and bilateral lower extremity edema despite diuresis. Follow-up cardiac MRI indicated progressive left and right dysfunction with ejection fractions of 23% and 25%, respectively. After progressive heart-failure symptoms, the patient was admitted to the hospital for severe congestive heart failure and underwent implantation of a HeartWare LVAD with tricuspid valve repair using an Edwards annuloplasty ring. He has since had a cardiac transplant and is doing well.

Discussion

To our knowledge, this is the first reported case of cardiomyopathy in a patient with elevated cobalt ion levels and a Biomet M2a-Magnum hip prosthesis. This is also the first reported case of cardiac MRI–defined cobalt cardiomyopathy. The cobalt levels seen in this patient were similar to those of other cases with systemic cobalt toxicity from a MOM hip construct. Mao and colleagues⁵ reported 2 cases of systemic cobalt toxicity in 2 patients with articular surface replacement hip prostheses.One patient presented with mild groin pain, neurologic symptoms, and a cobalt level of 410 ppb 5 years after her index procedure. The other patient presented with cardiac and neurologic symptoms but no hip complaints. The patient’s cobalt levels ranged from 185 ppb to 210 ppb. Both patients improved after their revision surgery, and their cobalt levels decreased. The 2 patients in Tower’s report⁶ were 49-year-old men who had articular surface replacement implants (DePuy). One patient who presented with progressive hip pain 11 months postoperatively developed neurologic symptoms and cardiomyopathy, with cobalt levels of 83 ppb before revision surgery 43 months after his index procedure. The other patient presented with hip pain and vertigo, headaches, fatigue, and dyspnea. He underwent hip revision 40 months postoperatively and required closed reduction under sedation for dislocation. Finally, and most recently, Allen and colleagues² reported a 59-year-old woman with a cobalt level of 287 ppb whose symptoms did not resolve after implantation of an LVAD or cardiac transplantation but only after removal of her bilateral hip prosthesis. Our case is most similar to this report but significantly adds to the literature in 2 distinct manners: (1) Biomet M2a-Magnum has not been implicated in cobalt toxicity; and (2) this is the first reported use of dedicated cardiac MRI to noninvasively define underlying cardiac pathology.

The cardiac manifestations secondary to systemic cobalt toxicity in this patient represent a frightening consequence of MOM prosthetic wear. The effects of cobalt toxicity on cardiac tissues were first described in a series of alcoholic patients from Manchester in 1900;⁷ however, it was not until 1967, in a series of patients in Quebec, that cobalt was found to be the inciting factor. In the modern era, hip arthroplasty techniques resulting in excessive cobalt and chromium wear have demonstrated the same findings of myocyte hypertrophy, interstitial fibrosis, and scattered myofibers containing large cytoplasmic inclusions.^8,9 The patient presented here has pathologic findings consistent with previous cases of cobalt cardiomyopathy; however, in the other cases of cardiomyopathy due to MOM total hip components, the patients’ cardiac conditions improved after the prostheses were revised and the cobalt levels began to diminish.^5,6In our case, the patient has sustained permanent damage to his myocardium and a progressive decline in his cardiac status, which is a deviation from reported cases as of 2014.

While there is no guideline to unequivocally diagnose cobalt cardiomyopathy, the constellation of findings, including pathologic, biologic, blood levels, imaging, and surgical, all uniformly indicate a unifying diagnosis. The lack of improvement after prosthetic device removal supports a diagnosis of permanent myocardial damage, which is consistent with cardiomyopathy of advanced toxic etiology.

Conclusion

This case presents a patient with bilateral MOM THAs, acetabular cup inclinations of greater than 55º, renal impairment, and cobalt levels greater than 60 ppb, with occult cardiac failure leading to LVAD implantation as a prelude to cardiac transplantation in order to avoid certain death. These factors have been shown, in prior case reports, to be associated with cardiac damage that may be reversible.⁶ However; it is important for orthopedic surgeons to recognize that certain hip prostheses can be associated or lead to irreversible cardiac damage.

Systemic cobalt toxicity has been reported in the literature after hip arthroplasty revisions for failed ceramic components secondary to third-body abrasive wear of cobalt-chrome (CoCr) components, as well as with metal-on-metal (MOM) hip arthroplasty designs. There have been several cases of systemic cobalt toxicity after revision for fractured ceramic components.^1,2 Of these 7 reported cases, all patients had neurologic complaints and 4 patients developed cardiomyopathy secondary to toxic cobalt levels, with 1 case being fatal.¹ MOM hip prostheses have also been associated with local and systemic problems secondary to metal debris. Adverse local tissue reactions have been reported to occur in up to 59% of patients, and, in some registries, the failure rate of MOM arthroplasty caused by these soft-tissue reactions is 2 to 3 times that of conventional metal-on-polyethylene design failures.^3,4 The occurrence of systemic complications from MOM total hip arthroplasty (THA) wear debris is much less common. There have been 6 cases of systemic cobalt toxicity reported in the literature resulting from MOM total hip prosthesis design.^1,2

We present a case of biopsy-confirmed cardiomyopathy secondary to cobalt toxicity from a MOM THA design with subsequent requirement for left ventricular assist device (LVAD) implantation despite prosthesis removal. To our knowledge, this is the first report in the literature of this specific implant design causing systemic cobalt toxicity. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

The patient was a healthy nondiabetic man age 54 years who presented to our clinic 6 years after undergoing left THA and 5 years after undergoing right THA with the Biomet M2a-Magnum MOM prosthesis at an outside facility. The left-side components placed at the index procedure were a size 50 cup, 44 magnum head, 10 Taperloc stem (Biomet), and +9 neck. The right-side components were a size 52 cup, 46 magnum head, 10 Taperloc stem, and +3 neck. The patient emphasized that he was very happy with his hip prostheses and denied groin or thigh pain. His medical history was significant for exogenous obesity, and he denied any history of alcohol, tobacco, steroid, or recreational drug use.

The patient’s review of systems suggested that, approximately 11 months prior to presentation at our facility, he began having difficulty with his activities of daily living secondary to chest pressure with exertion, fatigue, and associated diaphoresis. He complained of decreased sensation in his feet bilaterally but denied any hearing loss, tinnitus, or vision changes. He underwent evaluation of the new-onset chest discomfort with a cardiac stress test that suggested no active cardiac ischemia. An echocardiogram revealed mitral regurgitation, stage II diastolic dysfunction with a left ventricular ejection fraction of 55%. Additionally, during this time period, the patient was being followed by his local orthopedic surgeon for an elevated cobalt level of 120 ppb and a chromium level of 109 ppb. The patient was referred to our clinic for recommendations regarding the elevated metal-ion levels. Upon initial evaluation, the patient denied any hip or groin pain. His physical examination revealed a nonantalgic gait with full range of motion and no signs of instability, tenderness, or masses. The patient was also noted to have no vibratory sensation in his feet bilaterally. The plain radiographs indicated bilateral MOM THA with acetabular inclination levels of 55º on the right and left sides. No cystic changes or other worrisome signs that would suggest implant loosening or failure were present (Figure 1). The serum metal levels were repeated and showed a cobalt level of 189 ppb and a chromium level of 71 ppb. Whole venous blood samples were drawn at our request using trace element tubes and were sent to Medtox Laboratories Inc. for analysis. Other pertinent laboratory values, including hematocrit and thyroid levels, were within normal limits. Because of concerns of systemic toxicity from significantly elevated cobalt and chromium levels, the patient elected to proceed with revision of the MOM components.

During the preoperative medical evaluation, the patient’s cardiac status was a concern, and the etiology of the cardiac dysfunction was unclear. Cardiac magnetic resonance imaging (MRI), which was performed to evaluate the extent and etiology of cardiac dysfunction, showed biventricular dysfunction. To evaluate the underlying myocardial tissue characteristics, delayed contrast imaging was performed and showed diffuse myocardial hyperenhancement of the anterior, lateral, and apical walls, with sparing of the base and midseptum. This type of extensive hyperenhancement is commonly seen with cardiac amyloidosis; however, the blood-pool kinetics during contrast administration is unusual for amyloidosis, as well as the diffuse edema noted on T2-weighted MRI. Importantly, cardiac MRI is very specific in excluding alternative diagnoses, such as postinfarct, infiltrative, acquired, viral, or alcoholic/drugs of abuse etiologies. In the absence of amyloidosis, the only other pattern that would be consistent with symptoms was diffuse, fulminant myocarditis of toxic origin lacking clinical evidence for an infectious origin. The patient’s prior exposure to cobalt was noted. Thus, the hyperenhancement and edema could be strong supportive evidence of cobalt infiltration, despite no reported cases in the literature of cobalt cardiomyopathy found on cardiac MRI.

Additional workup was initiated, and cardiac catheterization showed that the patient continued to decompensate, with worsening global left ventricular dysfunction with an ejection fraction of 30% without evidence of coronary artery disease. Also, he was noted to have mild renal impairment with a blood urea nitrogen level of 31 mg/dL and a creatinine level of 1.7 mg/dL. The etiology of the renal impairment was unknown and had not been established, according to the patient and his wife. The renal impairment was not thought to be caused by the elevated metal ions levels but likely resulted from prerenal azotemia secondary to decreased cardiac output. During catheterization, an endomyocardial biopsy was performed and the tissue sent to the Mayo Clinic pathology department for analysis. The sample showed myocyte hypertrophy and interstitial fibrosis with scattered myofibers containing large cytoplasmic vacuoles. Also present was karyomegaly consistent with myocyte hypertrophy (Figures 2A, 2B). Trichrome stain confirmed replacement of myofibers by collagen (Figure 2C). Electron microscopy performed on a paraffin block showed reduced contractile elements, vacuolar spaces, and increased lipofuscin. The findings were very consistent with, but not specific for, cardiomyopathy from cobalt toxicity. No evidence of an inflammatory infiltrate was identified. The diagnosis was cobalt cardiomyopathy based on biopsy, presentation, cobalt levels, and intraoperative findings.

The patient was admitted to the cardiac intensive care unit preoperatively and optimized with inotropic agents. A multidisciplinary consultation with the cardiology and anesthesia departments was obtained. Both recommended cardiac anesthesia with intraoperative Swan-Ganz catheter and transesophageal echo monitoring. Assuming that the patient remained hemodynamically stable with limited blood loss and the first hip was timely performed, the cardiology department recommended a single surgery, because fewer risks and complications could be expected than from a staged procedure. Subsequently, surgery was performed on the left hip via a conservative anterior approach on the fracture table. The patient remained stable with limited blood loss. During the same operating room time, revision of the right hip was performed using an anterior approach. The intraoperative findings showed evidence of pseudotumors in the adjacent soft tissues and abundant brown, creamy fluid upon entering the joint capsule, consistent with a metallic appearance. Both hips showed similar prosthetic findings. There was no significant visible wear of the large diameter metal heads or gross abnormality of the acetabular components. The trunnion area on both femoral implants was abnormal, revealing a black coating suggestive of marked corrosion. The components were all well fixed, without visible damage, and, because of his fragile cardiac status, the patient’s acetabular components were not revised. The trunnions were cleaned and the femoral heads were revised to active articulation dual-mobility metal-on-polyethylene constructs using 28-mm Biolox Option ceramic (CeramTec). The tissue specimens from the operation showed chronic inflammation with areas of fibroconnective tissue and bland fibrinoid necrosis with extensive brown pigment-laden macrophage reaction. The intraoperative cultures were negative.

The patient tolerated the surgery without complication, and his postoperative period was without incident. Nine months after surgery, the patient’s cobalt and chromium levels had declined to 16 ppb and 32 ppb, respectively (normal, <1 ppb). However, his cardiac status continued to worsen with significant shortness of breath and bilateral lower extremity edema despite diuresis. Follow-up cardiac MRI indicated progressive left and right dysfunction with ejection fractions of 23% and 25%, respectively. After progressive heart-failure symptoms, the patient was admitted to the hospital for severe congestive heart failure and underwent implantation of a HeartWare LVAD with tricuspid valve repair using an Edwards annuloplasty ring. He has since had a cardiac transplant and is doing well.

Discussion

To our knowledge, this is the first reported case of cardiomyopathy in a patient with elevated cobalt ion levels and a Biomet M2a-Magnum hip prosthesis. This is also the first reported case of cardiac MRI–defined cobalt cardiomyopathy. The cobalt levels seen in this patient were similar to those of other cases with systemic cobalt toxicity from a MOM hip construct. Mao and colleagues⁵ reported 2 cases of systemic cobalt toxicity in 2 patients with articular surface replacement hip prostheses.One patient presented with mild groin pain, neurologic symptoms, and a cobalt level of 410 ppb 5 years after her index procedure. The other patient presented with cardiac and neurologic symptoms but no hip complaints. The patient’s cobalt levels ranged from 185 ppb to 210 ppb. Both patients improved after their revision surgery, and their cobalt levels decreased. The 2 patients in Tower’s report⁶ were 49-year-old men who had articular surface replacement implants (DePuy). One patient who presented with progressive hip pain 11 months postoperatively developed neurologic symptoms and cardiomyopathy, with cobalt levels of 83 ppb before revision surgery 43 months after his index procedure. The other patient presented with hip pain and vertigo, headaches, fatigue, and dyspnea. He underwent hip revision 40 months postoperatively and required closed reduction under sedation for dislocation. Finally, and most recently, Allen and colleagues² reported a 59-year-old woman with a cobalt level of 287 ppb whose symptoms did not resolve after implantation of an LVAD or cardiac transplantation but only after removal of her bilateral hip prosthesis. Our case is most similar to this report but significantly adds to the literature in 2 distinct manners: (1) Biomet M2a-Magnum has not been implicated in cobalt toxicity; and (2) this is the first reported use of dedicated cardiac MRI to noninvasively define underlying cardiac pathology.

The cardiac manifestations secondary to systemic cobalt toxicity in this patient represent a frightening consequence of MOM prosthetic wear. The effects of cobalt toxicity on cardiac tissues were first described in a series of alcoholic patients from Manchester in 1900;⁷ however, it was not until 1967, in a series of patients in Quebec, that cobalt was found to be the inciting factor. In the modern era, hip arthroplasty techniques resulting in excessive cobalt and chromium wear have demonstrated the same findings of myocyte hypertrophy, interstitial fibrosis, and scattered myofibers containing large cytoplasmic inclusions.^8,9 The patient presented here has pathologic findings consistent with previous cases of cobalt cardiomyopathy; however, in the other cases of cardiomyopathy due to MOM total hip components, the patients’ cardiac conditions improved after the prostheses were revised and the cobalt levels began to diminish.^5,6In our case, the patient has sustained permanent damage to his myocardium and a progressive decline in his cardiac status, which is a deviation from reported cases as of 2014.

While there is no guideline to unequivocally diagnose cobalt cardiomyopathy, the constellation of findings, including pathologic, biologic, blood levels, imaging, and surgical, all uniformly indicate a unifying diagnosis. The lack of improvement after prosthetic device removal supports a diagnosis of permanent myocardial damage, which is consistent with cardiomyopathy of advanced toxic etiology.

Conclusion

This case presents a patient with bilateral MOM THAs, acetabular cup inclinations of greater than 55º, renal impairment, and cobalt levels greater than 60 ppb, with occult cardiac failure leading to LVAD implantation as a prelude to cardiac transplantation in order to avoid certain death. These factors have been shown, in prior case reports, to be associated with cardiac damage that may be reversible.⁶ However; it is important for orthopedic surgeons to recognize that certain hip prostheses can be associated or lead to irreversible cardiac damage.