BACKGROUND: Severe glenoid bone defects can compromise stable baseplate fixation in reverse total shoulder arthroplasty (rTSA). Although structural bone grafts are advocated, reported results are mixed and raise concerns. The purpose of this systematic review was to compare structural bone graft types and glenoid baseplate designs for glenoid reconstruction in primary and revision rTSA to better understand which grafts and designs lead to better outcomes in terms of graft incorporation, glenoid baseplate loosening and reoperation.
METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, PubMed, Embase, and Cochrane Library were queried for all existing articles on structural bone grafting of glenoid defects in rTSA from database inception to January 2025. Articles were screened by two independent reviewers and were included if they reported the use of structural bone graft and either bone graft incorporation and/or baseplate loosening. Statistical analysis was performed to compare graft incorporation rates by graft type as well as baseplate loosening and revision rates by glenoid baseplate design. Outcomes of various combinations of bone graft types and glenoid baseplate designs were compared RESULTS: Thirty-seven studies met the inclusion criteria including 1,382 patients with a mean age of 70.4 ± 9.1 years and mean radiographic follow up of 2.8 ± 2.3 years. After sensitivity analysis was performed, there was no significant difference in the rate of graft incorporation in primary compared to revision rTSA (n=531/552, 96.2% vs n=162/172, 94.2%, p=.26). Furthermore, there was no significant difference in graft incorporation between autograft and allograft when used in primary (Fisher's exact: n=335/342, 98.0% vs n=25/26, 96.2%p=.45) or revision rTSA (Fisher's exact: n=45/50, 90.0% vs n=58/62, 93.5%, p=.51). Rates of baseplate loosening and revision were significantly greater after revision rTSA compared to primary rTSA (Loosening: n=26/226, 11.5% vs n=51/951, 5.4%, p=.001; Revision: n=16/204, 7.8% vs n=26/862, 3.0%, p=.004).
CONCLUSION: Both autograft and allograft incorporate at high rates in primary and revision rTSA. Baseplate design does not seem to influence short-term baseplate integrity when combined with structural bone grafting of glenoid deficits. However, baseplate loosening and revision occur significantly more often after revision rTSA compared to primary rTSA. In primary rTSA, autograft is available and a reliable option to address glenoid bone loss, while in revision settings, allograft provides similarly high incorporation rates. Longer-term follow-up is needed determine if the shorter-term outcomes are durable.
LEVEL OF EVIDENCE: Level IV Systematic Review/Meta-analysis.
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