Combining the Sulcus Line and Posterior Condylar Axis Reduces Femoral Malrotation in Total Knee Arthroplasty

Objectives:Femoral component malrotation is a common cause of patient dissatisfaction after total knee arthroplasty. The Sulcus Line (SL) is formed from multiple points along the floor of the trochlear groove, and has been shown to be more accurate than Whiteside Line. A trochlear alignment guide (TAG) is required to maintain the accuracy of the SL and allow intraoperative comparison of the SL and the posterior condylar axis (PCA). The hypothesis is that averaging these two landmarks will lead to less femoral malrotation.Methods:Surgery was performed in 50 patients using the TAG. The component was inserted at a position between the SL and PCA. An intraoperative photograph was taken of the distal cut surface of the femur showing the pin-holes representing the SL, the PCA and the final component position. These were compared to the component position achieved relative to the surgical epicondylar axis (SEA) on a postoperative CT scan. Comparison was made between the final component position and the position ...