Fig. 1

(a) X-ray films of standard ankle acupoints were projected by c-arm machine to locate the insertion point of screw channel; (b) Use a 2.5 mm Kirschner pin as the drill bit to drill the screw channel. After the position of the channel is confirmed by fluoroscopy, measure the length of the screw channel and tap; (c) Screw the screw into the channel for fixation (the channel direction is roughly parallel to the direction of the lower tibiofibular notch in the anteroposterior position, while in the lateral X-ray film, it should be consistent with the posterior inclination of the ankle joint); (d) Image of screw on CT cross section