Association between distal tibial rotation and clinical outcomes of medial open-wedge high tibial osteotomy.

Background: The purpose of this study was to evaluate the association between changes in knee joint geometry after medial open-wedge high tibial osteotomy (MOWHTO) and clinical outcomes.

Methods: This was a retrospective study of patients who underwent MOWHTO (101 knees) at our hospital between January 2015 and February 2022 and who were followed up for > 2 years. Radiological and functional outcomes were compared between those who were satisfied with surgery (satisfaction group) and patients who were dissatisfied with surgery (dissatisfaction group). Multiple regression analysis was performed to analyze factors affecting the radiological parameters that significantly differed between the two groups.

Results: The average follow up period was 38.0 ± 15.4 months. There were no significant differences regarding demographic characteristics and preoperative radiological parameters between the satisfaction and dissatisfaction groups. There was a significant intergroup difference with respect to postoperative distal tibial rotation and change in distal tibial rotation (13.5 ± 4.8° and 9.5 ± 4.3°, respectively; P < 0.001). The difference in tibial rotation before and after surgery was 4.3 ± 2.3° and 1.7 ± 1.8° in the dissatisfaction and satisfaction groups (P < 0.001) Multiple regression analysis showed that the correction angle affected the distal tibial rotation in MOWHTO (R = 0.079, ß = 0.165, P = 0.038).

Conclusions: In MOWHTO, an increase in distal tibial rotation was associated with patient dissatisfaction. Because the increase in distal tibial rotation is associated with a large correction angle, excessive distal tibial rotation should be avoided when MOWHTO requires a large correction angle.