Osteotomy for malunion of intra-articular ankle fracture assisted by 3D printing relay template / 中华创伤骨科杂志

ABSTRACT

Objective To explore the effectiveness of our self-designed 3D printing relay template in the treatment of malunion of irregular intra-articular ankle fractures.Methods From October 2013 to October 2015,our self-designed 3D printing relay template was used in 14 patients with severe malunion of intra-articular ankle fracture to assist their intra-articular osteotomy.They were 10 males and 4 females,with an average age of 40.5 years (from 34 to 59 years).Thin slice CT scan was preformed preoperatively for all the ankles involved.The computer fictitious tibial and fibular models for location and osteotomy navigation templates were acquired from the data of CT scan after processing,design and reconstruction by software.After the navigation templates which fit the size of solid ankle were printed by a 3D printer,they were sterilized and reserved.The guide plates were used in turn during operation.The irregular malunited bone blocks in the posterior malleolus were completely resected along the osteotomy template.After fracture reduction,the bone blocks were stabilized with internal fixation.Fracture union time was recorded.Scores of visual analogue scale (VAS),American Orthopaedic Foot and Ankle Society (AOFAS) and the short form-36 (SF-36),ankle ROM and complications were also recorded at the final follow-ups.Results The 14 patients obtained an average follow-up of 28.6 months (from 14 to 35 months).Bony union was achieved after an average of 3.7months (from 3 to 6 months).At the final follow-ups,on average,VAS score (2.2 ± O.8),AOFAS ankle and hindfoot score (81.1 ± 6.8),SF-36 score (82.5 ± 5.2),dorsal extension (27.5 ° ± 2.5°),and plantar flexion (24.2° ±6.3°) were significantly improved compared with the preoperative values (6.3 ± 1.8,43.1 ± 12.0,37.6 ± 9.9,14.1° ± 3.8° and 14.4° ± 3.9°,respectively) (P ＜ 0.05).No implant failure,soft tissue complications or post-traumatic arthritis occurred during the follow-up.Conclusion Since our self-designed 3D printing relay templates for osteotomy can accurately position the fracture lines of the distal tibia via limited incision and invasion,they help a lot in precise osteotomy and anatomical reduction of malunited intra-articular ankle fracture,preventing incidence of traumatic arthritis.