A novel modified McLaughlin surgery for treating locked chronic posterior shoulder dislocation.

Background: Posterior shoulder dislocation is an uncommon orthopaedics injury and is frequently missed or misdiagnosed, accounting for 2%-4% of all shoulder dislocations, and is associated with the reverse Hill-Sachs lesion. Once posterior shoulder dislocation develops into a chronic disease, it will bring a lot of trouble to the treatment, especially in repairing the humeral defects. Surgical strategies are also developing and innovating to deal with this injury, including transfer of subscapularis tendon or lesser tubercle, humeral rotational osteotomy, autogenous bone graft or allograft. Shoulder replacement seems to be the ultimate and only option when the injury becomes irreparable, although some studies have shown unsatisfactory follow-up results. Considering no gold-standard treatment for locked posterior shoulder dislocation, we described a novel modified McLaughlin procedure for locked chronic posterior shoulder dislocation and evaluated the functional outcomes.

Methods: This study included five locked chronic posterior shoulder dislocation patients with an associated reverse Hill-Sachs lesion, in which the compression surface covered 30-40% of the humeral head. The mean period from injury to receiving surgery was 11.6 weeks (6-24 weeks). All five patients underwent the modified McLaughlin procedure, mainly divided into three steps, including open reduction, transfer of the partial lesser tuberosity and artificial bone to repair the reverse Hill-Sachs defects. The kernel technique was to fix the transferred tuberosity with two lag screws and strengthen it with two Ethibond sutures. The Constant-Murley score (CMS), the range of shoulder motion and the complications were recorded to assess and compare the functional situation of the shoulder postoperatively and postoperatively.

Results: After an average of 19.8 months (12-30) of follow-up, the mean CMS improved to 85.8 ± 4.9 (79-91) compared with 46.0 ± 4.5 (40-52) preoperatively, which showed a significant difference (p = 0.001). In the final follow-up, all five patients showed no symptoms of shoulder instability, and there was no pain or limited activity in daily life, thus all patients were satisfied with the results.

Conclusion: Repairing the reverse Hill-Sachs lesion by transferring the partial lesser tuberosity combined with artificial bone fixed by lag screws and sutures can ensure shoulder stability and provide pain relief and good function in patients with locked chronic posterior shoulder dislocation associated with the humeral head defect.