Reconstruction of a Chronic Posterior Dislocation of the Shoulder using a Limited Posterior Deltoid-splitting Approach: A Case Report

INTRODUCTION: Chronic posterior dislocation is a very rare injury. Various methods have been described for its treatment. This report describes a rare case of post-traumatic chronic posterior dislocation of the shoulder. Posterior bone block procedure performed through a limited posterior deltoid splitting approach was used with good surgical outcomes. The bone block procedure for chronic posterior dislocation is rarely described in the literature. CASE REPORT: A 30-year-old male presented with complaints of pain on movement of the left shoulder and inability to lift the arm overhead for the past 5 months, following a fall from a moving train on his left shoulder. He had been treated conservatively with no improvement in symptoms. On clinical examination, there was a loss of deltoid contour with painful and restricted abduction and external rotation. The shoulder joint could be reduced by bringing the arm in 90o of abduction in the scapular plane. The anteroposterior radiograph showed a positive light bulb sign and a malunited fracture greater tuberosity. Magnetic resonance imaging revealed a reverse Hill-Sachs lesion with intact rotator cuff. Unlike a classical chronically dislocated joint, the shoulder joint was not stiff in this position. The reduction of the joint was possible but was not maintained in the resting position of the limb. Hence, the joint could be reduced intraoperatively, and reduction maintained with a posterior bone block procedure, without any need for further soft-tissue releases. A tricortical iliac crest bone graft was used as the bone block. CONCLUSION: Chronic posterior dislocation of the shoulder is a rarely reported entity, which can be easily missed in clinical examination. The limited deltoid splitting approach is a safe approach with excellent exposure of posterior glenoid rim. Posterior bone block procedure is a viable reconstructive option in treating cases of chronic posterior dislocation.