Rotational alignment of femoral components in total knee arthroplasty: nonimage-based navigation system versus conventional technique.

A randomized prospective study was undertaken to compare the accuracy of rotational alignment of the femoral component in total knee arthroplasty using a nonimage-based navigation system and a conventional method. The authors randomly used two methods and implants in 55 patients and measured the angles between posterior condylar lines and transepicondylar axes on computed tomography images before and after surgery. Analysis showed no significant differences between the two techniques in mean errors (P>.05), but the navigation system showed higher accuracy than the 3 degrees external rotation method by reducing outliers.