Clinical and Radiographic Outcomes and Graft Incorporation Rate Assessed by CT Scan After Reverse Shoulder Arthroplasty With Glenoid Structural Bone Graft Reconstruction.

Introduction: Reverse total shoulder arthroplasty (RTSA) with structural bone graft has been described as a technique in addressing glenoid bony defects. Studies have demonstrated acceptable outcomes with structural autograft or allograft. However, most of these studies are relatively small and rarely evaluate bone graft incorporation with CT scan. The aim of this study was to assess clinical and radiographic outcomes and report graft incorporation assessed on CT scan after RTSA where structural bone autograft or allograft was used to reconstruct the glenoid.

Methods: From May 2011 through June 2016, 38 patients underwent RTSA with structural bone graft. Of these, 35 were available for a minimum 2-year follow-up and retrospectively enrolled. From July 2016 through February 2019, 32 patients undergoing RTSA with structural bone graft were prospectively enrolled. Preoperative and postoperative American Shoulder and Elbow Surgeons and visual analog scale (for pain) scores and radiographs were obtained. CT scan was obtained at least 1 year postoperatively.

Results: Thirty-five patients were enrolled retrospectively (52.2%) and 32 prospectively (47.8%). Autograft was used in 46 cases (68.7%) and allograft in 21 cases. The mean American Shoulder and Elbow Surgeons score improved from 33.1 (SD 18.5) to 78.2 (SD 22.4), with P < 0.0001. On postoperative radiographs, 63 cases (94.0%) showed stable RTSA constructs while four cases (6.0%) developed glenoid baseplate subsidence. Postoperative CT scan demonstrated complete graft incorporation in 45 cases (90.0%) while partial incorporation was noted in 4 cases (8.0%), and in 1 case (2.0%), there was no graft incorporation. No correlation was observed between baseplate subsidence and graft type (autograft versus allograft) or primary versus revision surgery.

Discussion: Reverse shoulder arthroplasty with structural bone autograft and allograft is reliable for glenoid augmentation in patients undergoing RTSA in both primary and revision settings. Bony incorporation of autograft and allograft as evaluated on CT scan is predictably high.