Do Outcomes of Osteochondral Allograft Transplantation Differ Based on Patient Sex: A Comparative Matched Group Analysis of Male and Female Patients

OBJECTIVES: Osteochondral allograft transplantation (OAT) is being performed with increasing frequency, though to date, the impact of patient sex on outcomes and failure rates has not been assessed. The purpose of this study was to determine clinical outcomes for male versus female patients undergoing OAT. METHODS: A retrospective review of prospectively collected data of patients who underwent OAT by a single surgeon with a minimum follow-up of 2 years was conducted. Males who underwent OAT were compared to a matched group of females who underwent OAT (age ± 3 years, gender, BMI ± 5 kg/m(2), the presence of previous ipsilateral knee surgeries, and the presence of meniscal transplantation). The reoperation rate, failure rate, timing of reoperation, procedures performed, findings at surgery, and patient reported outcome scores were reviewed. Failure was defined by revision OAT, conversion to knee arthroplasty, or gross appearance of graft failure at 2(nd) look arthroscopy. Descriptive statistics, fisher’s exact or chi-square testing, and Mann-Whitney U testing were performed, with P<0.05 set as significant. RESULTS: A total of 98 patients (average age 32.1±9.9 years, 49 males, 49 females) who underwent OAT with an average follow-up of 4.7±2.33 years (range, 2.1-12.1) were included. These patients underwent an average of 2.6±1.8 prior surgical procedures on the ipsilateral knee prior to OAT. A total of 33 patients underwent reoperation at an average 2.4±2.4 years, with 27% (9/33) undergoing additional reoperations (range, 1-2 additional reoperations). Male patients did not have significantly different reoperation rates (42% vs. 27%), time to reoperation (2.50±2.12 vs. 2.29±1.71 years) or failure rates (20% vs. 8%) compared to female patients (P>0.05 for all). Both male and female patients showed significant improvement in Lysholm, IKCD, KOOS, WOMAC, and SF-12 physical subscale as compared to preoperative values (P>0.05 for all for both groups). The SF-12 mental subscale was not significantly improved at final follow-up for either group (P>0.05). There were no significant differences in patient reported outcomes scores at most recent follow-up when comparing males and females. Males demonstrated significantly larger defect areas compared to females (371.65±168.89 vs. 310.63±117.15 mm(2), P=0.037), though the defect:condyle ratio was not significantly different (male: 0.19 vs. female: 0.20, P>0.05). CONCLUSION: Males and females have similar clinical outcomes at 5 years following OAT, though males trended toward increased reoperation rates and increased failure rates. This data implies that overall, similar favorable outcomes may be expected for patients regardless of sex, with an 86% graft survival rate at 5 years. This information can be used to counsel patients when being offered OAT as part of a knee joint preservation strategy.