Instrumentation with 3D printed patient-specific guides versus conventional techniques in supramalleolar osteotomy for varus ankle osteoarthritis

Objective To compare instrumentation with 3D-printed patient-specific guides versus conventional techniques in supramalleolar osteotomy for varus ankle osteoarthritis. Methods A retrospective analysis was done of the 21 patients with varus ankle osteoarthritis who had been treated at Department of Orthopaedics, Shanghai JiaoTong University Affiliated Sixth People's Hospital from January 2017 to December 2018. They were divided into 2 groups by their treatment methods. In the 9 patients treated by instrumentation with 3D-printed patient-specific guides, there were 6 males and 3 females with an age of 54.6±8.6 years, 4 left and 5 right sides involved, and one case of Takakura stage 1, 3 cases of Takakura stage 2 and 5 cases of Takakura stage 3a. In the 12 patients treated by conventional techniques, there were 7 males and 5 females with an age of 53.0±6.5 years, 7 left and 5 right sides involved, and one case of Takakura stage 1, 5 cases of Takakura stage 2 and 6 cases of Takakura stage 3a. The 3D printed guide group and the conventional group were compared in terms of operation time, intraoperative blood loss and frequency of intraoperative fluoroscopy, tibial anterior surface angle (TAS), talar tilt angle (TT), and tibial lateral surface angle (TLS). The differences in TAS, TT and TLS between pre- and post-operation in the 3D printed guide group were also evaluated. Results There were no significant differences in the preoperative general data between the 2 groups (P>0.05), indicating they were comparable. All the patients were available for follow-up for an average of 7.8 months (from 3 to 15 months). The 3D printed guide group incurred significantly shorter operation time (106.2±10.6 min), less intraoperative blood loss (207.2±16.0 mL) and lower fluoroscopy frequency (2±0) than the conventional osteotomy group (all P 0.05). Conclusions Compared with conventional techniques, instrumentation with 3D-printed patient-specific guides can shorten operation time and reduce intraoperative blood loss and fluoroscopy frequency. The 3D printed patient-specific guides in osteotomy can facilitate accurate correction of varus deformity, leading to similar efficacy compared with conventional osteotomy. Key words: Ankle joint; Ostearthritis; Osteotomy; 3D printing; Patient-specific guide; Supramalleolar osteotomy