An additional reference axis for determining rotational alignment of the femoral component in total knee arthroplasty.

No studies have examined the trochlear line connecting the most anterior projections of the lateral and medial femoral condyles in relation to the surgical epicondylar axis. To determine if the trochlear line is more consistent relative to the transepicondylar axis than the posterior condylar axis and the Whiteside's line, the angles between the surgical epicondylar axis and each of the 3 axes in 50 knees of cadavers were measured using computed tomography scans. The results showed that the variability in the trochlear line for referencing the transepicondylar axis was comparable to those of the Whiteside line and the posterior condylar axis. The trochlear line may be considered as an additional reference axis for determining the rotational alignment of the femoral component in total knee arthroplasty.