Five-year Outcomes Following Anterior Cruciate Ligament Reconstruction:  Does Sex Impact Patient-Reported Outcomes and Re-operation Rates?

BACKGROUND: Females have been shown to have a two to eight times higher risk of Anterior Cruciate Ligament (ACL) injury than their male counterparts. Despite the clear difference in risk, sex-based differences in outcomes following ACL reconstruction are less well understood. The purpose of this study was to compare 5-year outcomes between males and females who were under the age of 26 at the time of enrollment in an ACL registry. We hypothesize that male and female patients will have similar patient-reported outcome scores, but females will have a higher incidence of ACL graft re-injury. METHODS: Patients undergoing ACL reconstruction while under the age of 26 were included if they also had completed five-year follow-up questionnaires. Outcomes were compared between males and females, and the outcomes of interest included the International Knee Documentation Committee (IKDC), Knee Injury and Osteoarthritis Score (KOOS), ACL Return to Sport after Injury (ACL-RSI), and reoperation. RESULTS: Of the 159 patients enrolled in the registry, 35 had complete follow-up (22%). The average difference between postoperative and preoperative IKDC scores for males and females was 37.9 ± 21.6 and 33.2 ± 26.6, respectively (p=.600). The average difference between postoperative and preoperative KOOS scores for males and females was 31.6 ± 15.4 and 29.2 ± 23.0, respectively (p=0.731). The average ACL-RSI for males and females was 79.8 ± 47.0 and 56.5 ± 31.1, respectively (p=0.088). The incidence of reoperation and ACL re-tear for the entire cohort was 28.6% and 5.7%, respectively. CONCLUSION: Overall, males and females under the age of 26 who underwent ACLR had similar 5-year outcomes regarding outcomes scores after surgical intervention. The ACL-RSI was lower in women, however, failed to reach significance. The reoperation rate for males and females was not statistically significant. ACL reconstruction is a successful operation in young males and females with improvement in knee outcome scores and ability to return to sport.