Shoulder Instability

Instability of the shoulder involves painful abnormal translational movement or subluxation and/or recurrent dislocation

Aetiology

Traumatic instability

  • Instability following a traumatic anterior dislocation - patient develops recurrent dislocations and subluxations
  • Age at time of first dislocation predicts the likelihood of further - 80% re‐dislocation rate in under 20s, and 20% re‐dislocation rate in over 30s

Atraumatic instability

  • Patients with generalized ligamentous laxity (idiopathic, Ehlers‐Danlos, Marfan’s) can have pain from recurrent multidirectional (anterior, posterior or inferior) subluxations or dislocations

Clinical presentation

Symptoms

  • Atraumatic laxity/subluxations
  • Not painful

Signs

  • Abnormal shoulder contour
  • Muscle wasting
  • Tenderness
  • Muscle spasm
  • Good ROM
  • Scapular winging/dyskinesia
  • Tests - sulcus sign, anterior and posterior draw tests, anterior apprehension and relocation test, posterior apprehension test, RC strength, general laxity

Management

  • Traumatic instability - Bankart repair (open or arthroscopic) can stabilize the shoulder to prevent recurrent dislocations
    • Reattaches the labrum and capsule to the anterior gleniod which was torn off in the in the first dislocation
  • Treatment for atraumatic instability is difficult as soft tissue procedures may not work