关键词: 踝关节, 斜形截骨, 计算机辅助技术, 3D打印

Abstract: Objective To explore the digital analysis of the angle of the medial malleolus oblique osteotomy relative to the long axis of the tibia and the clinical application of the 3D printed personalized osteotomy guide.Methods From March 2015 to March 2016, 40 patients were selected with PACS system for anteroposterior ankle joint and coronal CT data. The angle of the bisector of the angle between the articular surface of the distal tibia and the articular surface of the medial malleolus was measured. The angle of the osteotomy plane with respect to the long axis of the tibia was measured. Preoperative digital osteotomy guide plates were designed in 6 patients and the postoperative Results were compared with preoperative design Results. Results Relative to the distal tibial articular surface, the average angle of the bisection angle on the X-ray film was （57.4 ± 1.8）°. The median angle of the anterior ,middle and rear articular surface on CT was （58.7 ± 1.5）°, （56.1 ± 1.4）°, and （58.6 ± 1.7）°. The mean angle was （57.8 ± 1.9）°. The angle of the osteotomy line with respect to the long axis of the tibia is （31.0 ± 2.1）°.The use of individualized 3D printed osteotomy guide plate in the postoperative X-ray examination of the ankle joints and the position of the screws were satisfactory. No local traumatic arthritis occurred after 2 years of follow-up. Conclusions A medial malleolar osteotomy directed at a mean 31° relative to the tibial axis to the tibial cartilage, and will result in a congruent joint surface. The use of individualized 3D printed osteotomy guide plates assisted the operation with reliable stability.

Key words: ankle joint, osteotomy, computer-aided design, 3D printing