MANUAL MINORS
Anterior shoulder dislocation is the most common type of shoulder dislocation, accounting for about 95% of all shoulder dislocation cases. It occurs when the humeral head is displaced forward, out of the glenoid cavity of the scapula.
This injury is typically caused by a fall onto an outstretched arm, a direct blow, or a forced abduction, extension, and external rotation of the arm. Anterior dislocations can damage nearby structures, including the axillary nerve, the glenoid labrum (Bankart lesion), or the humeral head (Hill-Sachs lesion).
Diagnosis
Diagnosis is based on a history of trauma, followed by acute pain, visible shoulder deformity (loss of the rounded contour of the shoulder), and difficulty or inability to move the arm.
In anterior dislocation, the arm is often slightly abducted and externally rotated. The physical exam includes a neurovascular assessment, with special attention to the axillary nerve, which may be injured. Anteroposterior and axillary X-rays of the shoulder are necessary to confirm the dislocation and rule out associated fractures.
Differential Diagnosis
Pathology | Characteristics |
|---|---|
Posterior shoulder dislocation | Pain and deformity, but the arm is internally rotated; less common |
Humeral neck fracture | Shoulder deformity, but without complete joint dislocation |
Rotator cuff tear | Shoulder weakness and pain, without visible deformity |
Acromioclavicular dislocation | Deformity at the top of the shoulder, without humeral displacement |
Shoulder contusion | Pain and mild limitation, but no significant displacement or deformity |
Emergency Management
Immediate management includes closed reduction of the dislocation to restore anatomical alignment. Techniques such as Kocher, Hippocrates, or Stimson can be used, depending on the clinician’s experience, with sedation or local anaesthesia.
It is essential to assess neurovascular function before and after reduction. Once the shoulder is reduced, it should be immobilised with a sling or splint for 2 to 4 weeks. Post-reduction X-rays are necessary to confirm proper alignment and rule out fractures.
Definitive Treatment
Definitive treatment depends on the presence of associated injuries and the stability of the joint. In uncomplicated anterior dislocations, conservative management with immobilisation and physiotherapy is sufficient. Early rehabilitation focuses on restoring range of motion and muscle strength.
However, in young patients or athletes with recurrent instability, or if there are associated injuries such as a Bankart lesion (labrum tear) or Hill-Sachs lesion (compression fracture of the humeral head), surgical intervention may be required to repair and stabilise the joint. The most common surgery is arthroscopic labrum repair or capsular reconstruction.
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