Differences in Strength, Patient-Reported Outcomes, and Return-to-Play Rates Between Athletes With Primary Versus Revision ACL Reconstruction at 9 Months After Surgery.

Background: Patient-reported outcomes and return-to-play (RTP) rates are inferior after revision anterior cruciate ligament reconstruction (ACLR) compared with primary ACLR. Physical properties such as maximal, explosive, and reactive strength influence reinjury and RTP rates after ACLR. No study has compared these outcomes between revision and primary ACLR. Purpose: To compare maximal, explosive, and reactive strength of the ACLR limb, as well as patient-reported outcomes and RTP rates between primary and revision ACLR at 9 months after surgery. Study Design: Cohort study; Level of evidence, 2. Methods: A comparative study was performed at 9 months after surgery for 344 male athletes who had undergone ACLR (298 primary, 46 revision). Maximal strength of the ACLR limb was measured by means of isokinetic dynamometry. Explosive strength was measured by use of single-leg countermovement jump height, and reactive strength was measured by single-leg drop jump. Patient-reported outcomes and responses to RTP questionnaires were recorded for both groups. Results: The primary ACLR group had higher scores than the revision ACLR group for single-leg countermovement jump height (P= .02) and single-leg drop jump reactive strength index (P= .01) on the ACLR limb. No significant difference was observed between groups on maximal strength of the quadriceps or hamstring, and no significant difference in limb symmetry index was observed between groups on any strength or jump test. The primary ACLR group demonstrated higher scores on the Marx Activity Rating Scale (P= .03) and the Anterior Cruciate Ligament-Return to Sport after Injury scale (P< .001). Athletes in the primary ACLR group were more likely to have returned to sport (P< .001). Conclusion: At 9 months after surgery, athletes who had undergone revision ACLR achieved maximal strength similar to that of athletes who had undergone primary ACLR. However, athletes who had revision ACLR demonstrated lower scores on explosive and reactive strength tests. Athletes who underwent revision ACLR had lower RTP rates at 9 months after surgery, potentially due to explosive and reactive strength deficits and lower perceived readiness for RTP.