Glenoid structural bone grafting in reverse total shoulder arthroplasty: clinical and radiographic outcomes

Abstract

IntroductionCurrent options for reconstruction of large glenoid defects in reverse total shoulder arthroplasty (RTSA) include structural bone grafting, utilization of augmented components, or 3D printed custom implants. Given the paucity in the literature on structural bone grafts in RTSA, this study reflects our experience on clinical and radiographic outcomes of structural bone grafts utilized for glenoid defects in RTSA. MethodsWe identified 33 consecutive patients who underwent RTSA utilizing structural bone grafts for glenoid bone loss between 2008 and 2019. Twenty-six patients with mean clinical follow-up of 4.4 ± 3.9 years and mean radiographic follow-up of 2.7 ± 3.2 years were included. Patient demographic data, peri-operative functional outcomes, radiographic outcomes, complications, and re-operation rates were determined. ResultsBetween 2008 and 2019, 26 RTSAs were performed utilizing structural autograft or allograft for glenoid defects. There were 20 females (77%) and 6 males (23%), with mean presenting age of 68 years (range 41-86), mean BMI of 29 (range 21-44) and mean Charlson Comorbidity Index of 3 (range 0-8). There were 19 cases of central glenoid defects, and 7 were combined central and peripheral defects. Structural grafts included humeral head autograft (7), proximal humerus autograft (7), iliac crest autograft (7), distal clavicle autograft (2), and femoral head allograft (3). All eighteen revision RTSA cases had simultaneous humeral-sided revision. There was significant postoperative improvement in ASES scores (27.0 ± 12.6 preop vs. 59.8 ± 24.1 postop; p<0.001) and VAS scores (8.1 ± 3.6 preop vs. 3.0 ± 3.2 postop; p<0.001). Range of motion improved significantly for active forward elevation (63 ± 36º preop vs. 104 ± 36º postop; p<0.001) and external rotation (21 ± 20º preop vs. 32 ± 23º postop, p=0.036). Eighty-eight percent (23/26) of cases had successful reconstruction of the glenoid, defined as no visible radiolucent lines nor glenoid component migration at final follow-up. Re-operation rate was 19% (5/26) Postoperative complications included 2 cases of acromial stress fractures that were treated non-operatively, for a total complication rate (including re-operation) of 27% (7/26 cases). ConclusionsThe use of structural bone autografts and allografts in RTSA was associated with improved outcome scores and range of motion. A reoperation rate of 19% and total complication rate of 27% were reported for these challenging cases. However, 86% of these complications were not related to structural glenoid reconstruction failure. Structural grafts are a reasonable option for glenoid reconstruction in RTSA cases with glenoid bone loss.