From the Guidelines
The management of a posterior shoulder dislocation begins with prompt reduction, typically using the modified Stimson technique or scapular manipulation under adequate sedation and muscle relaxation, as this approach is crucial for minimizing morbidity and improving quality of life. The initial treatment includes immobilization in neutral rotation or slight external rotation using a sling for 3-4 weeks, followed by a progressive rehabilitation program 1. Pain management consists of NSAIDs like ibuprofen (400-600mg every 6-8 hours) or naproxen (500mg twice daily), with short-term opioids such as hydrocodone/acetaminophen 5/325mg every 6 hours for severe pain.
Key Considerations
- Physical therapy should focus on gradual range of motion exercises, followed by strengthening of the rotator cuff and periscapular muscles, typically starting 1-2 weeks after immobilization.
- For recurrent dislocations or cases with significant bone defects (reverse Hill-Sachs lesions >25% of the humeral head), surgical intervention may be necessary, ranging from arthroscopic posterior labral repair to bone grafting or arthroplasty for severe cases.
- Posterior dislocations are often missed on initial evaluation due to their rarity (2-4% of all shoulder dislocations), so careful clinical examination and proper radiographic views (such as an axillary lateral view or a scapular Y view, as recommended for trauma cases 1) are essential for accurate diagnosis and appropriate treatment planning.
Radiographic Evaluation
- Radiography is a useful initial screening modality for acute shoulder pain of all causes, including posterior shoulder dislocation 1.
- The shoulder trauma protocol should have ≥3 views, of which 2 are orthogonal, and may include a Grashey projection to profile the glenohumeral joint, which is AP to the scapula, by turning the patient into a 30° posterior oblique profile 1.
- An axillary lateral view or scapular Y view is advisable if there is a question of instability or dislocation, but care should be taken if the shoulder has just been reduced because this positioning may lead to redislocation 1.
From the Research
Management and Treatment of Posterior Shoulder Dislocation
The management and treatment of posterior shoulder dislocation involve several steps, including:
- Early recognition and diagnosis of the condition to prevent delayed treatment and associated morbidity 2, 3
- Use of conventional X-ray as the standard to diagnose a posterior shoulder dislocation, with a CT scan performed if symptoms persist 2
- Careful physical examination with comparison to the unaffected arm, paying attention to subtle posterior fullness and anterior flatness of the shoulder, along with a lack of external rotation and abduction 3
- Radiographic trauma series made in the scapular plane to rule out posterior dislocation 3
Treatment Approaches
Different treatment approaches may be used, including:
- Assisted self-reduction technique, which has been shown to be effective and simple to perform for acute anterior shoulder dislocation, but its efficacy for posterior shoulder dislocation is not well-studied 4
- Traction-countertraction method, which is a well-known and widely used technique, but may require sedation or general anesthesia in some cases 5, 4
- Stepped care approach to reduction, which involves a series of steps and manipulation methods to address the pathological deforming forces in a dislocated shoulder, and may be adapted for posterior shoulder dislocation 6
Importance of Early Recognition
Early recognition and diagnosis of posterior shoulder dislocation are crucial to prevent delayed treatment and associated morbidity, as highlighted in several studies 2, 3. A high index of suspicion is necessary, particularly in patients with a history of seizures, electroshock, or a fall onto a flexed, adducted arm 3.