Application of 3D printed patient-specific instrumentation in distal tibial tuberosity-high tibial osteotomy

Objective: To observe the clinical efficacy and advantages of 3D printed patient-specific instrumentation (PSI) assisted distal tibial tuberosity - high tibial osteotomy in the treatment of medial compartment knee osteoarthritis. Methods: 75 patients with medial compartment knee osteoarthritis were included in the study performed DTT-HTO in our hospital from August 2017 to August 2019. The patients were divided into the PSI group (n=39) and conventional group (n=36) According to whether PSI was used in surgery. The differences of lateral cortical fracture rate, time of intraoperative X-ray exposure, intraoperative blood loss, operative time, weight bearing line(WBL), Posterior tibial slope(PTS) and Caton–Deschamps index(CDI) were compared between the two groups. Visual analogue scale (VAS) scores and Hospital for Special Surgery (HSS) scores were recorded to evaluate knee pain and function before surgery and after surgery at 3 months and 12 months. Results: All 75 patients were followed up for more than 12 months, the ranged from 12-26 (18.74±6.21) months. Three lateral cortical fractures in the conventional group and no fracture in PSI group. The lateral cortical fracture rate, time of intraoperative X-ray exposure, intraoperative blood loss, operative time in PSI group were lower than those in conventional group(p<0.05). WBL in two groups were significantly improved after surgery(p<0.05), and PTS, CDI were no statistically improved after surgery(p>0.05). While there was no statistically significant difference with WBL, PTS and CDI between two groups (p>0.05). At 1 months, 3 months and 12 months after surgery; VAS and HSS scores in both groups were significantly improved compared with that before surgery(p0.05), and were no statistically significant difference between two groups. Conclusion: 3D printed patient-specific instrumentation assisted DTT-HTO has significant clinical efficacy, and effectively standardized surgical procedures, meanwhile reduced the time of intraoperative X-ray exposure, intraoperative blood loss and risk of lateral cortical fracture.