Femoral component rotation during total knee arthroplasty

One-hundred consecutive posterior cruciate retaining total knee arthroplast ies were performed by one surgeon in 81 patients with an average age of 69 years. Diagnoses included osteoarthritis in 93 knees and rheumatoid arthrit is in seven. The femoral alignment necessary to create a rectangular flexio n gap was determined and compared with Whiteside's line, the transepicondyl ar axis, and a line in 3 degrees external rotation relative to the posterio r condyles of the femur. The transepicondylar axis most consistently recrea ted a balanced flexion space whereas 3 degrees external rotation off the po sterior condyles was least consistent especially in knees in valgus.