Clinical and Functional Outcomes Following MOWHTO for Combined Tibial and Femoral Deformities in Varus Knees: A Retrospective Cohort Study.

OBJECTIVES

Varus knee deformities involving both the tibia and femur can be addressed using proximal tibial osteotomy alone or in combination with femoral osteotomy; however, the outcomes have been inconsistent. Medial opening wedge high tibial osteotomy (MOWHTO) presents a viable alternative for correction. This study aims to evaluate the clinical and functional outcomes of MOWHTO in patients with combined tibial and femoral deformities.

METHODS

We retrospectively analyzed 30 patients who underwent MOWHTO at Shafa Yahyaiyan Hospital, Iran University of Medical Sciences, between 2015 and 2021. In all cases, the procedure aimed to overcorrect the medial proximal tibial angle (MPTA) to 90 degrees, without addressing the femoral varus deformity. Preoperative and postoperative standing radiographs were used to measure the joint line obliquity angle (JLOA), joint line convergence angle (JLCA), hip-knee-ankle angle (HKA), MPTA, and mechanical lateral distal femoral angle (mLDFA). Functional outcomes were assessed using the Knee Society Score (KSS), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Visual Analog Scale (VAS).

RESULTS

The mean age of patients was 32.19 ± 11.63 years, with a mean follow-up duration of 39.38 months. MPTA increased significantly (90.53 ± 1.80 vs. 82.47 ± 3.66; p = 0.001), while the HKA and JLCA decreased significantly (p < 0.05). Functional outcomes, assessed by the KSS, KOOS, and VAS, showed significant improvement (p < 0.05). Although the JLOA increased by approximately 3 degrees postoperatively, this change was not clinically significant.

CONCLUSION

MOWHTO, with overcorrection of the MPTA to 90 degrees, demonstrated excellent short- to mid-term clinical and radiological outcomes. Although the follow-up duration was limited, the findings support the efficacy of MOWHTO in managing combined tibial and femoral deformities in patients with varus knee alignment.