Release or transection of superficial medial collateral ligament during open-wedge high tibial osteotomy demonstrated similar clinical outcomes and valgus laxity.

Abstract

To analyse whether valgus laxity and clinical outcomes differ depending on whether the superficial medial collateral ligament (sMCL) is released or transected during medial open-wedge high tibial osteotomy (MOWHTO). Consecutive patients who underwent MOWHTO and subsequent radiological follow-up for at least 2 years were retrospectively evaluated. The patients were divided into release and transection groups, according to the sMCL manipulation technique. Each patient was assessed for the following variables on valgus stress radiographs taken before surgery and at the 12- and 24-month follow-ups: the absolute value of valgus (ABV) and side-to-side difference (SSD) between the affected and normal sides. The differences between preoperative SSD and those at 12 and 24 months were respectively calculated and defined as delta SSD (ΔSSD). The Visual Analogue Scale, Lysholm knee, International Knee Documentation Committee subjective, and Knee Injury and Osteoarthritis Outcome scores were used to evaluate patient-reported outcomes. Eighty-five patients were included in the study. Forty-two patients (49.6%) underwent sMCL release, and the remaining 43 patients (50.4%) underwent sMCL transection. No significant differences were observed in the ABV and SSD of valgus laxity at the different time points between the two groups (n.s.). Furthermore, no significant differences were observed in the ΔSSD at the 12- and 24-month follow-ups between the two groups (n.s.). Significant improvement from preoperative values was observed in all patient-reported outcomes (p < 0.001), with no significant differences between the two groups at any time point (n.s.). Significant improvements in clinical outcomes were observed, regardless of the technique used. Postoperative valgus laxity did not occur with either technique. The transection technique, which can be performed more simply and quickly, demonstrated similar clinical outcomes and valgus laxity to the release technique. Level III.