Abstract
BACKGROUND: Although numerous studies have reported the clinical outcomes of meniscal allograft transplantation (MAT), no systematic review has clearly clarified its overall efficacy or the factors influencing clinical results. PURPOSE: To systematically evaluate clinical outcomes and graft survival across different follow-up periods following MAT and analyze potential factors that may influence postoperative outcomes. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: A systematic review was conducted via PubMed, Embase, and the Cochrane Central Register of Controlled Trials to identify studies on MAT published between 2015 and 2025. Only studies involving meniscal transplantation for meniscal defects were included. The methodological quality of the included studies was assessed via the methodological index for non-randomized studies scale. The primary outcomes were the Lysholm score, visual analog scale score, Tegner activity score, Knee injury and Osteoarthritis Outcome Score, and International Knee Documentation Committee score. Data on graft survival rates and return-to-sport rates were also extracted. Additionally, exploratory subgroup analyses were conducted on the basis of follow-up duration, graft laterality (medial vs lateral), rehabilitation protocol, and fixation technique, with the Lysholm score used as the primary outcome measure for subgroup comparisons. RESULTS: A total of 24 studies comprising 3251 patients were included. Significant improvements were observed across all reported clinical outcome scores following MAT (P < .001), but all had high heterogeneity (I (2) > 90%). Both the clinical and the surgical graft survival rates decreased with increasing follow-up duration. Among the subgroup analyses, only follow-up duration had a statistically significant effect on postoperative improvement in the Lysholm score, with longer follow-up times associated with a smaller degree of improvement. No significant differences were found in the other subgroup comparisons. Metaregression revealed that body mass index, the lateral-medial ratio, and follow-up time constituted the major sources of heterogeneity. CONCLUSION: MAT is an effective treatment for patients with symptoms following meniscectomy. It results in significant improvements in knee function, pain relief, and quality of life. Lack of standardized patient selection, surgical technique, and rehabilitation limit the ability to identify factors that may influence outcomes. While it presents a promising alternative to meniscectomy, its long-term efficacy and broader applicability require further investigation. REGISTRATION: CDR420251001961 (PROSPERO database).