Computer-assisted total knee arthroplasty: impact of the surgeon's experience on the component placement

Accuracy of implant positioning in total knee arthroplasty (TKA) has a major impact on postoperative outcomes. We investigate the accuracy of positioning of multiples values simultaneously in TKA navigated, even among novice users. The "novice" group included the first 91 knees operated on by 10 operators new to navigation and the "experienced" group 174 knees by an experienced navigator. Deviations from the preoperative planning were graded as optimal (a parts per thousand currency sign3A degrees), acceptable (4A degrees aEuro"5A degrees) or non-acceptable (a parts per thousand yen5A degrees). Moreover, the percentage of the three values fulfilling simultaneously the objective was calculated. No significant difference in the number of non-acceptable results was found. The common objective for these three values was achieved within 5A degrees in 96 % in the novice group and 98 % in the experienced one. The satisfactory HKA alignment was not the result of reversed errors between the tibia and the femur, since it correlated the successful simultaneous results of alpha and beta angles.