Medial opening wedge high tibial osteotomy (MOWHTO) is an effective treatment for varus osteoarthritic knee. Alteration ofknee alignment after MOWHTO may affect ankle biomechanics.
To evaluate the coronal alignment change of the ankle after MOWHTO.
Thirty-five patients who underwent 40 MOWHTO procedures were retrospectively reviewed. Pre-operative and 6 to 12 month postoperative standing hip-to-ankle films were assessed. Differences in the anatomical femorotibial angle (FTA) and the talar tilt angle (TTA) were measured and the correlations were analyzed.
The mean differences in FTA and TTA were 14.06 ± 4.89 degrees and 0.48 +1.27 degrees, respectively. Increased FTA difference was found to correlate with increased TTA (p < 0.001). According to ROC analysis, an FTA correction of more than 14 degrees results in a 50% chance of altering ankle coronal alignment.
An FTA correction of more than 14 degrees may alter ankle coronal alignment. Other factors may affect talar tilt; therefore, further study is required.