Associations Between Tissue Donor Variables and Clinically Significant Outcomes, Reoperations, and Failure After Primary Meniscal Allograft Transplantation

Background: Donor-recipient sex mismatch for tissue and organ transplantation has been shown to negatively affect outcomes. Purpose: To analyze the effect of sex mismatching on outcomes after meniscal allograft transplantation (MAT) and to determine if there is an association between the sex of the recipient and the sex of the donor and how this affects clinically significant outcome (CSO), reoperation, and failure rates after primary MAT. Study Design: Case series; Level of evidence, 4. Methods: Between 2003 and 2022, patients who underwent MAT were prospectively followed, with the inclusion criteria of having undergone primary MAT and having a minimum of 2 years’ follow-up. Patient characteristics and clinical data, as well as donor age, donor sex, and graft expiration date, were collected. Reoperation and failure data were also collected, and patients were evaluated for achieving CSOs for the International Knee Documentation Committee (IKDC) score. A reoperation was any surgical intervention involving the transplanted allograft, including second-look arthroscopic surgery in the setting of recurrent symptoms or functional deficits, meniscectomy, and meniscal repair. Failure was defined as revision MAT and unicompartmental or total knee arthroplasty. Survivorship was assessed with a Kaplan-Meier curve. Log-rank testing evaluated survivorship between groups. Results: A total of 245 patients met the inclusion criteria and were followed for a mean of 8.4 ± 4.2 years (range, 2.0-19.1 years). Isolated MAT was performed in 73 of 247 knees (30%). There was a significantly greater prevalence of female knees (89/129 [69%]) than male knees (10/118 [9%]) that received a graft from the opposite sex ( P < .001). On average, graft recipients were younger in the mismatch group than in the nonmismatch group (25.4 ± 8.5 vs 28.6 ± 8.8 years, respectively; P = .004). No donor variables were predictive of achieving CSOs for the IKDC score at 5 years. No difference in rates of survivorship from reoperations or failure was observed. Conclusion: Donor variables, including sex, age, and donor-recipient sex mismatch, did not negatively affect clinical outcomes. These findings suggest that sex matching is not necessary for graft selection, potentially increasing the availability of allografts and facilitating MAT in the setting of limited donor availability.