Shoulder Dislocation: Understanding Anterior Dislocations

The shoulder is the most frequently dislocated major joint, and anterior dislocation accounts for 95-97% of cases. The humeral head displaces anteriorly and inferiorly out of the glenoid fossa.

Mechanism of Injury

• Typically: forced abduction, external rotation, and extension (e.g., falling on outstretched hand, throwing motion, direct blow to posterior shoulder).
• Humeral head leverages off the anterior glenoid rim, often causing a Bankart lesion (labral detachment) and/or Hill-Sachs lesion (posterolateral humeral head impaction fracture).

Clinical Presentation

• Arm held in slight abduction and external rotation (cannot adduct/rotate internally).
• Squared-off shoulder contour (loss of deltoid roundness).
• Prominent humeral head palpable anteriorly.
• Severe pain, inability to move arm.
• Neurovascular check: axillary nerve (deltoid sensation), brachial plexus, distal pulses.

Management

1. Urgent reduction: Multiple techniques (Hippocratic, Stimson, Milch, FARES, traction-countertraction). Procedural sedation preferred.
2. Post-reduction: Immobilization (sling/swathe) 1-3 weeks; earlier motion for >40yo to prevent stiffness.
3. Imaging: Pre-reduction X-rays (AP, scapular Y, axillary); post-reduction to confirm alignment and detect fractures.
4. Rehabilitation: Rotator cuff/periscapular strengthening; gradual return to sport.

Recurrence Risk

• Age <20: 70-90% recurrence.
• Age 20-30: 50-60%.
• Age >40: <10% (but higher rotator cuff tear risk).
• Recurrent instability may require surgical stabilization (Bankart repair, Latarjet).

Always seek professional medical care for shoulder dislocation. Self-reduction risks fracture, nerve injury, and malreduction.