High tibial osteotomy assisted by a 3D printed composite template for genu varum / 中华创伤骨科杂志

ABSTRACT

Objective:To explore the efficacy of a 3D printed personalized composite template in the high tibial osteotomy for genu varum.Methods:A retrospective analysis was conducted of the 12 patients with genu varum who had been treated by high tibial osteotomy assisted by a 3D printed composite template at Department of Orthopaedics, The Third Hospital of Changsha between May 2016 and March 2019. They mere 2 men and 10 women, with a mean age of 55.1 years(range, from 46 to 65 years). Before operation, 3D printing technology was used to design and print a personalized composite osteotomy template for each patient. All patients underwent knee arthroscopy before osteotomy. The personalized 3D printed composite template was used to assist the high tibial osteotomy. The therapeutic outcomes were evaluated by comparison of posterior tibial slope angle (PTS), patellar height (Insall-Salvatti index), femorotibial angle, weight-bearing line (WBL) and medial proximal tibial angle (MPTA) on X-ray radiographs, American Hospital for Special Surgery (HSS) knee score and visual analogy scale (VAS) between pre-operation and 12 months after operation.Results:The 12 patients were followed up for 15 to 36 months after operation, with an average of 14.7 months. All wounds healed at the first stage after operation with no complications like infection, nerve injury, deep vein thrombosis at lower limbs, delayed fracture union or nonunion. Follow-ups revealed no such complications as plate breakage or internal fixation loosening. The values of femorotibial angle (181.09°±3.94°), WBL (19.11%±17.61%), MPTA (81.20°±1.15°), HSS (87.6±7.1) and VAS[0(0, 1)] at 12 months after operation were significantly improved compared with those before operation[171.79°±2.77°, 61.71%±2.14%, 88.06°±1.44°, 64.6±12.9 and 4 (3,5) , respectively] (all P<0.05). There was no significant difference in PTS or Insall-Salvatti index between pre-operation and 12 months post-operation ( P>0.05). According to the HSS scores at the last follow-up, the efficacy was excellent in 10 knees, good in one and fair in one. Conclusion:A 3D printed composite osteotomy template can lead to precise correction of alignment of lower limbs in the high tibial osteotomy for genu varum, resulting in good short-term outcomes.