Treatment and outcomes of chronic locked posterior shoulder dislocations: a retrospective case series

BACKGROUND: Posterior shoulder dislocations are rare injuries that are often missed on initial presentation. Cases left untreated for more than three weeks are considered chronic, cannot be reduced closely (they become locked) and are usually associated with a significant reverse Hill-Sachs defect. The aim of this study was to evaluate the outcomes of chronic locked posterior shoulder dislocations treated with the McLaughlin procedure (classic or modified). METHODS: This retrospective study included 12 patients with chronic locked posterior shoulder dislocation operated on between 2000 and 2021 by two surgeons in two institutions. Patients received a thorough clinical examination and radiological assessment before and after surgery. Shoulders were repaired with the McLaughlin or modified McLaughlin procedure. Outcomes were assessed by comparing pre- and postoperative values of clinical variables. RESULTS: Most of the dislocations were of traumatic origin. The average delay between dislocation and surgical reduction was 13.5 ± 9.7 weeks. Postoperative clinical outcomes were favourable, with an average subjective shoulder value of 86.4 ± 11.1 and a normalized Constant –Murley score of 90 ± 8.3. None of the patients had a recurrence of shoulder dislocation, but one patient developed avascular necrosis of the humeral head and two patients developed glenohumeral osteoarthritis. CONCLUSIONS: In this group of patients with chronic locked posterior shoulder dislocation, the clinical outcomes of McLaughlin and modified McLaughlin procedures were satisfactory, even when surgery was significantly delayed.