Failed arthroscopic repair of a large reverse Hill-Sachs lesion using bone allograft and cannulated screws: a case report.

Anterior impression fractures of the humeral head (reverse Hill-Sachs lesions) are typical concomitant bony injuries of posterior shoulder dislocations. When more than 20% of the humeral articulating surface is affected, surgical treatment is required, typically necessitating open surgery. Recently, cases of successful arthroscopic treatment of small reverse Hill-Sachs lesions involving less than 30% of the articulating surface have been reported. This article presents a case of a large reverse Hill-Sachs lesion affecting over 40% of the articulating surface that was treated arthroscopically by retrograde elevation, bone allografting, and cannulated screw insertion. The postoperative radiographic images showed a successful reduction of the impacted articulating surface of the humeral head. However, at 6 months' follow-up, the patient presented with pain and symptoms of a frozen shoulder. Cross-sectional imaging showed necrosis, partial absorption, and loss of reduction of the formerly elevated segment requiring humeral head replacement. This case report shows that even though the arthroscopic retrograde elevation of large reverse Hill-Sachs lesions is technically achievable, the outcome can be unsatisfactory because of the limitations in biologic healing response associated with large lesions of the humeral articulating surface.