The accuracy of bony resection and component size planning of total knee arthroplasty assisted with a novel designed patient-specific instrumentation / 中华骨科杂志

ABSTRACT

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.