Summary
Deep MCL reconstruction combined with ACL reconstruction appears to be an effective surgical option for treating chronic Grade II MCL laxity, providing good medial stability and functional outcomes despite a notable rate of residual medial pain.
Abstract
Introduction
Combined injuries of the anterior cruciate ligament (ACL) and medial collateral ligament (MCL) are common in sports and trauma. In chronic Grade II MCL laxity, residual valgus or anteromedial instability may persist despite ACL reconstruction, affecting outcomes. While the superficial MCL has been the main target for repair, recent anatomical and biomechanical studies emphasize the role of the deep MCL (dMCL) in medial and anteromedial stability. This study evaluates whether isolated deep MCL reconstruction (dMCLR), performed alongside ACL reconstruction, effectively corrects persistent medial laxity in chronic Grade II MCL injuries.
Methods
We conducted a retrospective, single-center study of 52 patients treated between July 2020 and January 2023, with a minimum 2-year follow-up. All surgeries were performed by three senior surgeons using uniform techniques. Deep MCL reconstruction was indicated for chronic (>6 weeks) Grade II medial laxity at 20° of flexion without extension laxity. The gracilis tendon was used for dMCLR and the semitendinosus for ACL reconstruction. At follow-up, we assessed complications (re-rupture, infection, contralateral rupture), clinical stability, and functional scores (SKV, ACL-RSI, Lysholm, Tegner, subjective IKDC). A control group of 52 patients undergoing isolated ACL reconstruction (ST4 + ALL), matched for age, BMI, and pre-op Tegner score, was used for comparison.
Results
The mean BMI was 25.1, and the average delay between injury and surgery was 5.1 months. The re-rupture rate was 11%, and reintervention occurred in 12.4% of patients. Mean return-to-sport time was 11.2 months; return to work averaged 3.8 months. Functional outcomes were favorable: Lysholm score 83.4, Tegner 6.9, subjective IKDC 79.7, ACL-RSI 63.8, and SKV 80.5. No infections occurred, and two contralateral ACL ruptures were noted. Seventeen patients (27%) reported medial pain (femoral or tibial). At follow-up, 10 patients (19%) had persistent valgus laxity at 20°, and 34% remained ADER-positive. No significant differences in functional scores were found between the dMCL and control groups.
Discussion
Deep MCL reconstruction associated with ACL reconstruction provides satisfactory stabilization in chronic Grade II MCL injuries. Although a significant number of patients reported residual medial pain, this symptom was not related to mechanical laxity and was not corrected by surgery. The low rate of valgus laxity and absence of extension instability reflect good medial stabilization. The high rate of negative ADER tests supports the effectiveness of the procedure in restoring anteromedial stability.