Auxiliary medial small locking plate fixation enhances bone healing and minimizes delayed union in inverted V-shaped high tibial osteotomy: A comparative study of 154 knees.

PURPOSE: To determine whether auxiliary fixation with a T-shaped small locking plate (SLP) placed on the medial tibial cortex can enhance bone healing and reduce delayed union compared with the conventional inverted V-shaped high tibial osteotomy (iVHTO) fixed with a locking compression plate (LCP). METHODS: This retrospective cohort study included 154 knees (135 patients) that underwent iVHTO. The knees were allocated to Group S (n = 72), treated with conventional single LCP fixation, and Group D (n = 82), treated with auxiliary medial SLP fixation in addition to the conventional procedure. Radiological and clinical evaluations were performed with a minimum follow-up of 2 years. Bone healing was assessed using radiographs and computed tomography scans, and the time to complete union was quantitatively evaluated with an established scoring system. RESULTS: The time to union was significantly shorter in Group D than in Group S (median, 8 vs. 12 weeks; p < 0.001; 95% confidence interval [CI] for the difference, 0.0-4.0 weeks). The incidences of delayed union and non-union were both significantly lower in Group D than in Group S (2.4% vs. 20.8% and 0% vs. 5.6%, respectively; p < 0.001 and p = 0.046; 95% CIs, 8.6%-29.3% and 0.0%-13.4%). The rate of other complications, including transient anterior compartment syndrome and superficial infection, did not differ significantly between the groups (4.9% vs. 4.2%; p = 0.98; 95% CI, -7.2% to 8.2%). The Lysholm score was slightly but significantly higher in Group D than in Group S (p = 0.043; 95% CI, 0.0-5.0), whereas no significant differences were observed in the other clinical scores. CONCLUSION: Auxiliary medial fixation using an SLP enhanced bone healing and minimized the incidence of delayed union or non-union following conventional iVHTO with single lateral LCP fixation, without increasing other complications or compromising clinical outcomes. LEVEL OF EVIDENCE: Level III, prospective cohort study.