Anatomic Reconstruction of Acute Posterior Shoulder Instability With Reverse Hill-Sachs Lesions: A Report of Two Cases.

Posterior shoulder dislocation associated with a reverse Hill-Sachs lesion is an uncommon injury that may result in persistent instability when the humeral head defect is engaged. Management depends on lesion size, engagement, chronicity, and reconstructibility; both non-anatomic procedures and anatomic reconstruction strategies have been described for acute lesions within the joint-preserving range. We present two cases of acute posterior shoulder instability with engaging reverse Hill-Sachs lesions treated with a combined arthroscopic-open approach. In both patients, arthroscopic posterior labral repair was followed by open disimpaction and graft-supported anatomic reconstruction of the humeral head through a deltopectoral approach with partial superior subscapularis tenotomy. In the first case, supplemental cannulated screw fixation (Raynham, MA: DePuy Synthes) was used because of a deeper defect, whereas in the second case graft support alone was sufficient after stable reduction was achieved. Immediate post-operative imaging demonstrated concentric reduction of the glenohumeral joint and restoration of humeral head contour in both patients. At a final follow-up of 24 months, neither patient had sustained recurrent instability or other symptoms, and neither required reoperation or other intervention. Active forward elevation was 160° in both patients, with external rotation at the side of 90° and 70° and internal rotation to T7 and T9, respectively. American Shoulder and Elbow Surgeons scores were 90 and 88, Single Assessment Numeric Evaluation scores 95 and 93, and visual analog scale pain scores 0 of 10 in both patients. This report highlights a practical combined arthroscopic-open, joint-preserving strategy that addresses both the posterior capsulolabral lesion and the humeral head defect while allowing direct visualization of the impacted articular surface and fixation tailored to lesion morphology. In selected acute, engaging, and reconstructible reverse Hill-Sachs lesions, this approach may be technically feasible as a joint-preserving anatomic option; comparative studies are required before it can be positioned as an alternative to established non-anatomic procedures.