Shoulder Instability

= recurrent subluxation / dislocation of humeral head out of the glenoid socket during activities causing symptoms

Stabilizer: inferior glenohumeral ligament-labrum complex = IGHLC (most important); anterior labrum-ligament complex

Lesions after first anterior dislocation:

1. traumatic, unidrectional, Bankart, surgical (TUBS)
   Age:<40 years
   • fall on outstretched hand (FOOSH)
   • capsulolabral avulsion (Bankart lesion / its variants)
   • anterior-inferior instability
2. atraumatic, multidirectional, bilateral, responding to rehabilitation, inferior capsular shift (AMBRI)
   Age:>40 years
   • tear of supraspinatus tendon (33%)
   • fracture of greater tuberosity (33%)
   • subscapularis avulsion from humerus (33%)

Instability lesions:

• detachment of anteroinferior labrum:
  • scapular periosteum disrupted = Bankart lesion:
    • without bone fragment = soft Bankart
    • with bone fragment = osseous Bankart
  • scapular periosteum intact:
    • labrum displaced = ALPSA
    • labrum not displaced = Perthes lesion
  • fractured articular cartilage = GLAD
  • avulsion of humeral detachment of inferior glenohumeral ligament = HAGL
• detachment of posterior labrum