ABSTRACT
Objective:To compare minimally invasive treatment with versus without a 3D printed guide plate for Sanders type Ⅱ calcaneal fractures.Methods:A retrospective analysis was done of the 74 patients with Sanders type Ⅱ displaced intra-articular calcaneal fracture who had been treated at Foot and Ankle Surgery Center, Beijing Tongren Hospital Affiliated to Capital Medical University from January 2018 to January 2020. They were divided into 2 groups according to whether a 3D printed guide plate was used or not. In the 3D printing group of 38 patients treated by minimally invasive surgery assisted by a 3D printed guide plate, there were 22 males and 16 females with an age of (41.5±3.5) years; in the control group of 36 patients treated by traditional minimally invasive surgery, there were 24 males and 12 females with an age of (40.3±7.2) years. The 2 groups were compared in terms of operation time, intraoperative fluoroscopy, American Orthopaedic Foot and Ankle Society (AOFAS) score, visual analog scale (VAS), Short Form 36 (SF-36), B?hler angle, Gissane angle, calcaneal length, width and height and postoperative complications.Results:There was no significant difference in the preoperative demographic data between the 2 groups, indicating comparability between groups ( P>0.05). All patients were available for a follow-up of (12.6±3.6) months (from 6 to 24 months) after surgery. The operation time [(55.3±7.1) min] and intraoperative fluoroscopy [(8.1±2.6) times] in the 3D printing group were significantly less than those in the control group [(71.2±8.7) min and (21.2±8.7) times] ( P<0.01) while the AOFAS score in the former group (81.4±6.3) was significantly higher than that in the latter (77.9±6.2) ( P<0.01). There were no statistically significant differences between the 2 groups in VAS, SF-36, B?hler angle, Gissane angle, calcaneal length, calcaneal width or calcaneus height ( P>0.05). In the control group, 4 screws were found to be too long with possible impingement on the medial structures of the foot, and 3 screws to penetrate the subtalar joint; in the 3D printing group, there were no too long or off-target screws in the sustentaculum tali. Conclusion:The minimally invasive treatment of Sanders type Ⅱ calcaneal fractures assisted by a 3D printing guide plate can reduce operation time, intraoperative fluoroscopy and potential complications, improving the clinical efficacy.