Sex-based differences in physical and psychological recovery, and return to sport, following anterior cruciate ligament reconstruction

Objectives: Despite the increasing rate of anterior cruciate ligament (ACL) tears and surgical reconstruction (ACLR), little is known about the post-operative recovery in males versus females. Sex-based recovery differences after ACLR are yet to be examined, and identifying any differences is the first step to then understanding why they exist, subsequently permitting more tailored patient education on pre- and post-operative expectations, as well as permitting more targeted management. This study sought to investigate sex-based differences in the physical and psychological recovery, as well as return to sport (RTS), after ACLR. Methods: This study prospectively recruited 104 patients (49 females, 55 males) that underwent ACLR with a hamstrings tendon autograft. Patients were assessed pre-operatively and at 6-, 12- and 24-months post-surgery, via patient-reported outcome measures (PROMs) including the International Knee Documentation Committee (IKDC) form, the Tegner Activity Scale (TAS) and the Anterior Cruciate Ligament Return to Sport after Injury (ACL-RSI) score. All patients completed a 4-hop test battery consisting of the 6-meter timed hop (6MTH) and the single (SHD), triple (THD) and triple crossover (TCHD) hop tests for distance, as well as assessment of peak isokinetic knee extensor (PKET) and flexor (PKFT) strength. Repeated measures analysis of variance was employed to statistically analyze absolute measures and limb symmetry indices (LSIs) over time and between sexes, while Pearson’s correlations assessed any association between ACL-RSI scores and performance LSIs. The percentage of males (versus females) that had returned to pivoting sports within the first 24 months was assessed. Results: All PROMs significantly improved (p<0.05), though females reported significantly lower ACL-RSI (p=0.002) and IKDC (p=0.007) scores. All performance measure LSIs improved significantly (p<0.05) and, while no sex-based differences (p>0.05) were observed in hop test LSIs, males demonstrated significantly higher mean LSIs for PKET at 6 (p=0.037) and 24 (0.047) months, and PKFT at 6 (p=0.007) and 12 (p=0.002) months. Several physical performance measure LSIs, and operated limb absolute scores, were significantly correlated with ACL-RSI scores. At 24-months, a significantly greater (p=0.030) percentage of males (60%) versus females (41%) had returned to pivoting sports. Conclusion: This study demonstrates the disparity between sexes in physical and psychological recovery, as well as RTS status, in community-level patients undergoing ACLR. The development and implementation of enhanced post-operative patient-centered care may be warranted tailored to sex, encompassing rehabilitation, education, and counseling after ACLR to promote increased engagement in rehabilitation, expedited physical recovery, and improved RTS outcomes.