Bilateral irreducible inferior shoulder dislocation: A case report

INTRODUCTION: Bilateral inferior shoulder dislocation is rare; but the dislocation is almost always reducible by closed means. We present a unique case of irreducible bilateral inferior shoulder dislocation. PRESENTATION OF CASE: A 35-year old male fell down from height. Direct axial loading while both shoulders were fully abducted resulted in bilateral inferior shoulder dislocation. All attempts of closed reduction failed. Open reduction revealed that the cause of irreducibility was the entrapment of the humeral head in a button-hole through the inferior joint capsule and the surrounding soft tissue envelope. At 6 months, there was almost full range of motion and no pain. DISCUSSION: The direct axial loading resulted in a narrow defect in the inferior joint capsule/soft tissue envelope; and this may have led to button-hole entrapment of the dislocated humeral head and irreducibility. Open reduction required widening of the button-hole while protecting the axillary neurovascular bundle. CONCLUSION: We present a rare case of bilateral irreducible inferior shoulder dislocation. We highlight the pathomechanics of irreducibility: button-hole entrapment of the humeral head. We emphasize technical tips during open reduction such as widening of the button-hole and protection of the axillary neurovascular bundle. The outcome is good although some limitation of shoulder abduction is to be expected.