Radiographic evaluation of ankle alignment using the hip-to-calcaneus view in patients with end-stage ankle arthritis

Background This study aimed to compare various ankle alignment parameters in the hip-to-calcaneus (H-C) view and conventional whole-leg standing radiographs. Methods We retrospectively reviewed 61 patients with end-stage ankle arthritis (Takakura stage 3b/4) who underwent ankle arthrodesis. Preoperative H-C views and conventional radiographs were used to measure the hip-knee-ankle angle, weight-bearing line percentage, talar tilt, and medial distal tibial angle. The percentage of the H-C axis crossing the talus was also analyzed for asymmetry and correlated with the tibiocalcaneal angle, talar tilt, and hip-knee-ankle angle. Results Strong correlations were observed between the H-C view and conventional radiographs for the hip-knee-ankle angle (r = 0.88), weight-bearing line percentage (r = 0.90), and talar tilt (r = 0.87). The H-C axis asymmetry showed a strong correlation with tibiocalcaneal angle (r = -0.96). Conclusions The H-C view is a reliable tool for assessing hindfoot and lower limb alignment in end-stage ankle arthritis.