Meniscal Allograft Transplantation Failure Is Associated With Female Sex: A 15-Year Survival Analysis.

BACKGROUND: While short- and midterm outcomes after meniscal allograft transplantation (MAT) are well documented, there is a paucity of data regarding long-term graft survival.

PURPOSE: To assess mid- to long-term graft survivorship and patient-reported outcomes (PROs) after MAT.

METHODS: All patients who underwent MAT with bone block or soft tissue fixation between 1993 and 2020 at a single institution were identified. Individuals with <5 years of follow-up and untreated grade 4 cartilage lesions were excluded. Primary outcomes included graft survivorship and long-term PROs including International Knee Documentation Committee Subjective Knee Form (IKDC SKF) score, Knee injury and Osteoarthritis Outcome Score, and Marx Activity Scale score. Graft failure was defined as the need for meniscal allograft resection or repair, revision MAT, or conversion to total knee arthroplasty. Clinical failure was defined as an IKDC SKF score <56 at the final follow-up. Statistical analyses included chi-square/Fisher exact tests for categorical variables, the Mann Whitney U or t test for continuous variables, and Kaplan-Meier survival analysis with endpoints as graft failure. Statistical significance was defined as a P value <.05.

RESULTS: This study included 160 patients (57% of the screened population; 46% female; median age at surgery, 28 years) with a median follow-up of 15 years (IQR, 10-21 years). A total of 43 graft failures occurred during follow-up, representing an 84% survival rate at 10 years, 76% at 15 years, 69% at 20 years, and 52% at 25 years. On univariable Cox regression, no patient or surgical factors, including age, sex, body mass index, tobacco use, fixation method, cartilage status, or concomitant osteotomy, were significantly associated with both graft and clinical failure (all P > .05). However, after adjusting for age and cartilage grade in the MAT compartment, female sex became a significant predictor for graft failure (P = .04). Clinical failures occurred in 32 patients (40%) and were not associated with graft failures (P = .20). PROs were not significantly different between male and female patients (P > .05).

CONCLUSION: The MAT survival rate was 84% at 10 years, with a gradual decline to 76% at 15 years, 69% at 20 years, and 52% at 25 years. After adjusting for age and presence of cartilage lesion, female sex emerged as a predictor of graft failure. These findings highlight the importance of careful patient selection and counseling regarding long-term expectations after MAT.

STUDY DESIGN: Cohort study; Level of evidence, 3.