Changes in Hindfoot Alignment After High or Low Tibial Osteotomy

Background: We aimed to determine the change in hindfoot alignment after high (HTO) or low tibial osteotomy (LTO), which is commonly performed to prevent the progression of arthritis of the knee or ankle. Methods: We retrospectively reviewed the radiographic findings of patients who underwent HTO or LTO for arthritis with varus deformity of the knee or ankle joint. The hindfoot alignment view angle (HAVA), hindfoot alignment ratio (HAR), and hindfoot moment arm (HMA) were measured using the hindfoot alignment radiographs. All radiographic parameters were measured at 3, 6, and 12 months postoperatively to assess serial changes. Results: In the HTO group, the HAVA and HMA were significantly increased at 12 months postoperatively compared to preoperatively (P = .03 and .001, respectively). Similarly, the HAR increased from 0.23 preoperatively to 0.44 at 12 months postoperatively, which was a statistically significant change (P = .001). In the LTO group, the 12-month postoperative HAVA, HAR, and HMA were significantly decreased (P = .001 for each), which represented a hindfoot alignment change to the valgus position. Conclusions: After HTO, preoperative hindfoot valgus deviation was significantly decreased at 12 months and approached normal values, while the preoperative mild hindfoot varus alignment was changed to valgus deviation after LTO. Level of Evidence: Level III, comparative series.