Fig. 1

Measurement of HKA and ankle parameters based on full-leg standing anteroposterior radiographs. TTA was defined as the medial angle between “e” and “f.” TAS was defined as the medial angle between “e” and “d.” LDTA was defined as the lateral angle between “c” and “d.” TT was defined as the angle between “d” and “f.” GT was defined as the angles between “f” and “h.” GP was defined as the angle between “d” and “h.” PP was defined as the angles between “b” and “d.” TC was defined as the medial angles between “e” and “g.” Line a was the line from the center of the femoral head to the center of the knee. Line b was the joint surface of the tibial plateau. Line c was the line from the center of the tibial plateau to the center of ankle. Line d was the distal tibial plafond. Line e was the anatomical axis of the tibia. Line f was the upper joint surface of the talus. Line g was the line from medial malleolus to lateral malleolus. Line h was the ground surface