Arthroscopic Reduction of a Chronic Locked Posterior Shoulder Dislocation.

Posterior shoulder dislocation is a rare condition. It is easily overlooked and often appears in a chronic locked status, which makes the reduction difficult, even through open procedures. Few reports in the literature have described an isolated arthroscopic reduction because it is difficult to elevate the humeral head to the level of the glenoid surface and obtain anterior-posterior soft-tissue balance. On the basis of an analysis of the mechanisms of the locking of the humeral head and the soft-tissue imbalance, we describe a set of arthroscopic shoulder release and reduction techniques, which include mainly the removal of rotator interval tissue; a thorough subscapularis release from the coracoid, the conjoined tendon, and the glenoid; and a 360° capsule-muscle release from the glenoid and the scapula. The described technique is an effective method to obtain a medial-to-lateral humeral head reduction and anterior-to-posterior soft-tissue balance. The introduction of this technique will provide a practical tool for surgeons to realize an arthroscopic shoulder reduction in the case of a chronic locked posterior shoulder dislocation.