Shoulder Dislocation

  • Most common joint dislocation, because the head of the humerus is substantially larger than the gleniod fossa

AETIOLOGY + PATHOPHYSIOLOGY

  • Most common in younger patients (teenage - 30 years)
  • Sporty
  • Mostly traumatic - fall, traction injury

Anterior (95%)

  • Humeral head anterior to the glenoid
  • Most common - traumatic, sports
  • Fall with shoulder in external rotation
  • Can result in axillary artery compromise
  • Needs regimental badge area sensory assessment to assess axillary nerve

Posterior

  • Humeral head posterior to the glenoid
  • Fall with shoulder in anterior location
  • Direct blow to anterior shoulder
  • Usually associated with seizures - epileptic fit, electrocution

Inferior

  • Humeral head inferior to glenoid
  • Rare
  • Shoulder forced into hyperabduction
  • Needs prompt neurovascular assessment and reduction due to proximity of brachial plexus

CLINICAL PRESENTATION

  • Severe shoulder pain
  • Inability to move the shoulder
  • Empty glenoid fossa (dent) may be visible

INVESTIGATIONS

  • X-ray - AP shoulder and Garth views (apical oblique)
    • When the humerus dislocates posteriorly, the lack of displacement makes it difficult to appreciate on an AP x-ray
    • Should always obtain an oblique view which will show abnormal humeral displacement posterior to the articular surface of the glenoid
  • MR anthrogram

MANAGEMENT

Anterior shoulder dislocation in ED

  • Analgesia and sedation IV
  • O2
  • Reduction by manipulation (closed reduction under sedation or open reduction)
    • Kocher method
    • Hippocratic method
    • Stimson method

Post reduction treatment

  • Analgesia
  • Stabilisation - 2-3 weeks
  • Rehabilitation - gradually early mobilisation, physio
  • Recurrent instability risk is related to age, risk of recurrence decreases with age