Sex-related differences after ACL reconstruction differ between early functional recovery and 5-year outcomes

To compare early functional recovery and 5-year clinical, sports and psychological outcomes after anterior cruciate ligament reconstruction (ACLR) according to sex.

This retrospective cohort study included consecutive patients who underwent primary ACLR between January 2017 and December 2019, with standardized 6-month functional and psychological assessment and available 5-year follow-up. Patients were analyzed according to sex. Baseline characteristics, 6-month quadriceps strength and hop-test performance, and 5-year patient-reported and sports outcomes were compared between groups. The primary outcome was recovery of preinjury activity level at 5 years, defined as a post-operative Tegner score greater than or equal to the preoperative Tegner score. Multivariable logistic regression was used to identify factors independently associated with the primary outcome.

A total of 479 patients were included, comprising 173 women (36.1%) and 306 men (63.9%). At 6 months, men demonstrated higher quadriceps limb symmetry and lower hop-test deficits than women, whereas anterior cruciate ligament return to sport after injury (ACL-RSI) did not differ significantly between groups. At 5 years, overall return-to-sport rates were similar between sexes (187 [61.2%] men vs. 103 [59.5%] women, p = 0.85), but men had higher post-operative Tegner (6 [5-7] vs. 5 [4-7], p < 0.001), IKDC (82.5 [75.7-87.3] vs. 79.5 [72.8-86.3], p = 0.02) and ACL-RSI scores (77.5 [55.8-92.5] vs. 69.2 [53.3-85.8], p = 0.02) and were more likely to recover their preinjury activity level (137 [45.1%] vs. 48 [28.1%], p < 0.001). In the baseline-adjusted multivariable model, male sex was independently associated with recovery of preinjury activity level (odds ratio [OR] = 2.16, 95% confidence interval [CI] = 1.40-3.39; p < 0.001). This association persisted after inclusion of 6-month recovery variables (OR = 1.93, 95% CI = 1.20-3.15; p = 0.007), while lower single-hop deficit was also independently associated with the outcome.

Men and women did not demonstrate the same recovery profile after ACLR. Early differences were mainly functional, whereas 5-year differences involved recovery of preinjury activity level, subjective knee function and psychological readiness, despite similar overall return-to-sport rates. These findings suggest that return to sport should not be interpreted as equivalent recovery quality after ACLR.

Level III.