Higher graft failure rates following primary ACL reconstruction and conservative MCL treatment compared to simultaneous primary ACL and MCL reconstruction: a retrospective cohort study.

BACKGROUND: Combined anterior cruciate ligament (ACL) and medial collateral ligament (MCL) injury is the most common combination of ligamentous knee injury. Many authors support the conservative treatment of MCL tears. This study aimed to compare the outcomes of simultaneous ACL reconstruction (ACL-R) and MCL reconstruction with ACL-R and conservative MCL treatment in cases of combined ACL and grade III MCL injuries. METHODS: In this retrospective cohort study, we evaluated consecutive patients with combined ACL and MCL injuries who underwent surgical treatment over five years in two private hospitals in Tehran, Iran. We compared postoperative knee range of motion (ROM), pain intensity (visual analog scale [VAS]), functional outcomes (Tegner-Lysholm and International Knee Documentation Committee Subjective Knee Form [IKDC] scores), time to and proportion of return to sports, time to return to work, activity level (Marx activity rating scale), and graft failure rate between ACL-R and conservative MCL treatment (ACL-R + conservative MCL group) and ACL-R and MCL reconstruction (ACL-R + MCL-R group). All patients were followed for at least twelve months. RESULTS: Overall, 110 patients, comprising 92 men (83.6%) and 18 women (16.4%), were included, consisting of 67 (60.9%) in the ACL-R + conservative MCL group and 43 (39.1%) in the ACL-R + MCL-R group. The mean age of the patients was 27.5 ± 9.0 years. Age, sex, side, and follow-up period were comparable between the groups (P > 0.05 for all). Graft failure occurred in 6 patients (9.0%) in the ACL-R + conservative MCL group, but in none of the patients in the ACL-R + MCL-R group (P = 0.046). Range of extension and flexion of the knee, VAS, Tegner-Lysholm score, IKDC score, time to return to sports, time to return to work, proportion of return to sports, and activity level did not differ significantly between the groups (P > 0.05 for all). CONCLUSION: ACL-R and MCL reconstruction resulted in similar knee ROM, pain intensity, functional outcomes, time to return to work and sports, and activity level to ACL-R and conservative MCL treatment in patients with combined ACL and MCL injury. However, ACL-R and MCL reconstruction significantly reduced graft failure rates, suggesting the potential benefit of surgical MCL management in conjunction with ACL reconstruction.