Background: Anterior cruciate ligament (ACL) graft tears and contralateral ACL tears are both relatively common after primary ACL reconstruction (ACLR). There is little prior work comparing the outcomes of reconstruction after these injuries. Hypothesis: The authors hypothesize that patient-reported outcome measures (PROMs) and activity level are lower after revision ACLR than after primary contralateral ACLR. Study Design: Cohort study; Level of evidence, 3. Methods: From a cohort of 2333 patients who underwent primary unilateral ACLR, 267 were identified who underwent subsequent revision ACLR or primary contralateral ACLR within 5 years of primary ACLR. After exclusion of 11 patients who had both injuries, 256 were eligible for the study, including 124 who underwent revision ACLR and 132 who underwent primary contralateral ACLR. Patients were contacted for follow-up at 6 years after the primary ACLR, and PROMs were collected, including subjective International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score for pain (KOOS-Pain) and knee-related quality of life (KOOS-QOL), and Marx activity level. Patient demographics, surgical factors, and PROMs were compared between groups. Beta regression models with identity link were used to determine whether side of subsequent surgery (revision vs primary contralateral ACLR) was a significant predictor of outcome. Results: Of 256 patients, 223 (87%) were contacted and completed PROMs at 6 years after the primary ACLR. At baseline, there were no significant differences between groups except that the subsequent revision group had a lower incidence of partial lateral meniscectomy and a higher incidence of lateral meniscal repair and was more likely to have received allograft for the primary ACLR than the subsequent contralateral reconstruction group. The median time from primary ACLR to second ACL surgery was lower in the revision group (1.3 years) than the contralateral group (2.0 years; P < .001). When controlling for demographics, surgical factors, and baseline PROMS, the revision ACL group demonstrated a 7.8-point lower International Knee Documentation Committee score ( P < .001), a 3.2-point lower KOOS-Pain score ( P = .012), a 10.4-point lower KOOS-QOL score ( P < .001), and 2.0-point lower Marx score ( P = .002) than the contralateral ACLR group. Conclusion: Patients who undergo revision ACLR within 5 years of primary ACLR demonstrate poorer PROMs and lower activity levels than those who undergo primary contralateral ACLR during this period. These 2 groups of patients should not be pooled to study outcomes of ACLR.
Magnussen et al. (Mon,) studied this question.