Applied Evidence

Step-by-step evaluation and treatment of shoulder dislocation

Author and Disclosure Information

Tailor management decisions by taking into account the patient’s age, the direction of instability, functional demands, risk of recurrence, and associated injuries.

PRACTICE RECOMMENDATIONS

› Refer first-time dislocation in patients younger than 20 years or who have a displaced fracture to an orthopedic surgeon. A

› Order magnetic resonance imaging (MRI) for all patients with a suspected rotator cuff tear. A

› Send patients with weakness of the rotator cuff—but no tear on MRI—for evaluation by electromyography and nerve-conduction studies. A

Strength of recommendation (SOR)

A Good-quality patient-oriented evidence
B Inconsistent or limited-quality patient-oriented evidence
C Consensus, usual practice, opinion, disease-oriented evidence, case series


 

References

The architecture of the glenohumeral joint makes it the most common large joint to become dislocated, accounting for approximately 45% of all dislocations. Anterior dislocation constitutes more than 95% of glenohumeral joint dislocations; posterior dislocation, only 2% to 5%.1,2

For the family physician, determining appropriate follow-up after emergent reduction depends on several distinct variables, which we review here; subsequent treatment might involve, as we outline, physical therapy, immobilization, surgical intervention, or a combination of several modalities. Treatment decisions can make the difference between successful rehabilitation and potential disability, particularly in typically young and active patients.

Numerous mechanisms of injury

Anterior shoulder dislocations typically occur with the affected shoulder in a position of abduction and external rotation; 90% of patients are 21 to 30 years of age, and men are affected 3 times more often than women.2 Unsurprisingly, athletes are affected most frequently, with the common sports-related mechanism of injury being either sudden pressure exerted on the abducted and externally rotated arm or a fall onto an outstretched hand with the arm elevated. Repetitive microtrauma from such sports as swimming, baseball, and volleyball can also lead to instability.

Bankart lesion. This tear of the anterior or inferior section of the labrum is the most characteristic lesion noted in anterior dislocations, found in 73% of first-time dislocations and 100% of recurrent dislocations.3,4

Hills-Sachs lesion is often associated with a Bankart lesion. The Hills-Sachs lesion is an impaction fracture of the posterolateral aspect of the humeral head resulting from its displacement over the anterior lip of the glenoid. Hill-Sachs lesions are seen in 71% of first-time and recurrent dislocations.3

Less common concomitant injuries during anterior shoulder dislocation include rupture of the rotator-cuff tendons (particularly in patients older than 40 years), glenoid and proximal humerus fractures, a tear of the superior labrum (known as a “SLAP lesion”), cartilage injury, and neurovascular injury.

Posterior instability typically occurs as a result of a strong muscle contraction, as seen in electrocution or seizure; however, it can be caused by athletic trauma, particularly in football.5 Repetitive forces exerted on the forward-flexed and internally rotated shoulder position during blocking puts football players at increased risk of posterior instability.5

Continue to: Multidirectional instability

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