Bilateral neglected posterior dislocation of the shoulder treated by reverse arthroplasty and contralateral osteochondral autograft. A case report.

Bilateral posterior dislocation of the glenohumeral joint is an uncommon event, that can be missed at the initial presentation. We report the case of a 76-year old woman, who suffered a traumatic bilateral posterior dislocation, that was diagnosed three months later. She underwent surgical treatment on both shoulders in a single stage. Since the right shoulder showed a defect of the articular surface >50%, a reverse shoulder arthroplasty was performed on this side. The resected portion of the humeral head was retrieved and used as osteochondral graft to fill the reverse Hill-Sachs lesion of the left shoulder. At 18-month follow up, the patient was pain-free and had recovered excellent shoulder function on both sides: Constant score was 79 for the right shoulder and 88 for the left one. X-rays showed a grade 1 scapular notch of the right reverse prosthesis and good incorporation of the graft in the left shoulder, with no evidence of degenerative joint changes. Neglected posterior dislocations of the shoulder can be surgically treated by replacement or reconstruction. In case of bilateral injuries, the surgeon should carefully evaluate the pathoanatomy of both glenohumeral joints in order to choose and plan the most suitable procedure. If shoulder replacement is required on one side, the resected portion of the humeral head can be used as osteochondral autograft for a reconstruction procedure in the opposite side. The choice is influenced by several variables and decision-making might be challenging.