Fig. 3

Schematic measurements for radiographic parameters in anteroposterior and lateral weight bearing X-rays of the ankle joint. a TAS angle was defined as the angle between the axis of the tibia and the distal articular surface of the tibia; TT angle was defined as the angle between the distal articular surface of the tibia and the upper surface of the talus; TMM angle was defined as the angle between the axis of the tibia and the articular surface of medial malleolus; TC angle was defined as the angle between the axis of the tibia and a line drawn from the apex of medial malleolus to the apex of lateral malleolus. b TLS angle was defined as the angle between the axis of the tibia and the surface of the distal tibia in the lateral view. c The opening-wedge angle was defined as the angle between the upper and lower osteotomy margins after distraction (asterisk), and the wedge height was defined as the distance between the upper and lower osteotomy margins on the medial tibial cortex (red arrow)