What donor-recipient matching variables impact outcomes for osteochondral allograft transplantation? A systematic review.

Abstract

Current donor-recipient matching for osteochondral allograft transplantation (OCAT) emphasizes anatomic factors, but other variables may also influence outcomes. Evidence regarding demographic, immunologic, and morphometric matching remains inconsistent, and guidelines are lacking. To synthesize and evaluate the literature on donor-recipient matching and its effect on OCAT outcomes. Systematic review; Level of evidence, 2. PubMed and Embase were searched from inception to February 2025 for clinical observational studies comparing OCAT outcomes between matched and mismatched cohorts across at least one variable. Eligible studies required ≥2 years of follow-up and standardized outcome reporting. Risk of bias was assessed using the ROBINS-I V2 tool. Nine studies met inclusion, evaluating demographic (n = 3), immunologic (n = 3), and morphometric (n = 3) variables. All studies carried at least moderate risk of bias due to confounding and missing data. Age- and sex-based demographic matching showed no consistent association with outcomes. Immunologically, ABO and Rh mismatches did not impact graft survival, but anti-HLA antibody responses correlated with larger graft size and adverse imaging findings. Among morphometric factors, major sagittal plane curvature mismatch predicted inferior function. Current protocols prioritizing anatomic dimensions and laterality without considering blood type, age, or sex appear safe and effective. However, radius of curvature and HLA characteristics may warrant further consideration for select indications. Future studies should refine matching protocols to improve outcomes while optimizing donor tissue availability and integration.