Deleterious effect of sex mismatch between donor and recipient after meniscus allograft transplantation

Purpose: The purpose of this study was to investigate the effect of meniscal allograft freezing-time, demographical characteristics of the donor and the effect of mismatch of those parameters between donor and recipient on the survivorship of meniscal allograft transplantation (MAT). Methods: This study consist of a retrospective analysis of 375 consecutive MAT procedures Inclusion criteria were complete demographic data for both the donor and recipient, minimum 2 years of follow-up (FU) and age >18 years old; exclusion criteria were incomplete data, FU time of less than 2 years, body mass index (BMI) over 40 and age <18 years old. Failure was defined as the need for graft removal for any reason. Statistical analysis was performed to compare the graft survivorship based on sex mismatch and blood group mismatch between patients and donors. A receiver operating curve (ROC) was performed to evaluate the association and the difference between the demographical parameters between donors and recipients with MAT failure. Results: A total of 360 procedures fulfilled the inclusion criteria, mean age at surgery was 39.6 ± 11.4 years and mean FU time was 8.8 ± 3.6 years. Female patients who received MAT from a male donor had a failure rate of 39%, which was significantly higher when compared with the other groups. The failure rate in both the female-to-male and male-to-male groups was 7%, while in the female-to-female group was 9%. No association with failure was found for graft freezing time, age, sex, BMI of the donor, difference in age, BMI and blood group. Conclusion: Mismatch between donor and recipient sex had a negative effect on MAT survival only when a meniscus from a male donor was transplanted in a female patient. Other parameters investigated like age and BMI of the patients, as well as blood group mismatch, did not affect the outcomes. Level of evidence: Level IV, retrospective comparative study.