目的:通过对比术中截取骨片的厚度、术中使用假体型号与术前三维规划的差异，以初步探讨新型改良3D打印个体化导向器辅助人工全膝关节置换术的手术精准度。方法:回顾性收集2018年3月至2019年4月采用新型改良3D打印个体化导向器辅助人工全膝关节置换术35例（38膝），其中男10例（11膝），女25例（27膝），年龄（67.7±6.9）岁（范围49~81岁）。对比术中截取骨片的厚度与术前三维规划的截骨厚度的差异；对比术中使用的假体型号与术前三维规划的假体型号的差异；以评价其手术截骨厚度、角度和对假体型号预测的精度。结果:截骨后采用游标卡尺测量截取骨片厚度与三维术前规划的差异为：股骨远端内侧（-0.1±1.6）mm、股骨远端外侧（-0.5±1.6）mm，股骨后内髁（0.8±1.7）mm，股骨后外髁（0.0±1.7）mm，股骨前髁（0.0±1.4）mm，胫骨平台内侧（-0.3±1.4）mm，胫骨平台外侧（0.3±1.5）mm；截取骨片厚度与三维术前规划的差异<2 mm与<3 mm的比例分别为：股骨远端内侧78.3%、96.88%，股骨远端外侧87.8%、93.94%，股骨后内髁71.3%、85.71%，股骨后外髁77.14%、91.43%，股骨前髁88.46%、100%，胫骨平台内侧85.29%、97.06%，胫骨平台外侧83.78%、94.59%。手术中使用股骨型号与术前规划一致为34例（89.47%），与术前规划相差0.5号为4例（10.53%），无相差大于0.5号以上的病例；手术中使用胫骨型号与术前规划一致为14例（36.84%），与术前规划相差0.5号为23例（60.53%），与术前规划相差1号为1例（2.63%），无相差大于1号以上的病例。结论:新型改良3D打印个体化导向器辅助人工全膝关节置换术的截骨量较为精确，假体型号规划准确，采用该技术简化手术步骤、提高手术精度。“,”Objective:To investigate the accuracy of bony resection and component size planning of total knee arthroplasty (TKA) assisted with a novel designed patient-specific instrumentation (PSI).Methods:Thirty-eight TKAs assisted with a novel designed PSI of thirty-five patients from March 2018 to April 2019 were retrospectively analyzed. There were 11 males (10 knees) and 27 females (25 knees), aged 67.7±6.9 years (range 49-81 years). Intraoperative bone resection thicknesses at medial distal femur (MDF), lateral distal femur (LDF), medial posterior femur (MPF), lateral posterior femur (LPF), anterior femur (AF), medial tibial (MT), lateral tibial (LT) were measured with vernier caliper and compared with the preoperative planned bone resections as a primary outcome. The femur and tribal component sizes used intraoperatively were recorded and compared the preoperative planning.Results:The difference of thickness was -0.1±1.6 mm at MDF, -0.5±1.6 mm at LDF, 0.8±1.7 mm at MPF, 0.0±1.7 mm at LPF, 0.0±1.4 mm at AF, -0.3±1.4 mm at MT and 0.3±1.5 mm at LT. The ratio of differences <2 mm and <3mm were 87.8% and 93.94% at MDF, 87.8% and 93.94% at LDF, 71.3% and 85.71% at MPF, 77.14% and 91.43% at LPF, 88.46% and 100% at AF, 85.29% and 97.06% at MT, 83.78% and 94.59% at LT. 89.47% of femoral components were the same size with preoperative planning, 10.53% femoral components were within 0.5 size compared to the preoperative planning, no femoral components were over 0.5 size compared to the preoperative planning; 36.84% of tibial components were the same size with preoperative planning, 60.53% tibial components were within 0.5 size compared to the preoperative planning, 2.63% tibial components were within 1 size compared to the preoperative planning, notibial components were over 1 size compared to the preoperative planning.Conclusion:TKA assisted with a novel designed PSI shows good accuracy with bone resection and component size planning. The procedure of TKA could be simplified with this technique.