Can the epicondylar axis be defined accurately in total knee arthroplasty?

Only 75% of knees would have been within 3° of the true epicondylar axis using the epicondyles to control rotation. The error range was large (range 6° ER to 11° IR). Our conclusion is that even in experienced hands clinical estimation of the epicondylar axis is inaccurate and should not be relied upon as the sole determinant of femoral rotation.