Femoral component rotation and Laurin angle after total knee arthroplasty.

One of the main problems after total knee arthroplasty is pain in the patellofemoral joint, which in some cases leads to revision surgery. Rotation of the femoral component has a significant influence on the path followed by the patella within the patellofemoral joint. We examined the influence of rotation of the femoral component after total knee arthroplasty on patellar tilt. We retrospectively analysed the radiographs of 48 patients who underwent primary LCS total knee arthroplasty without patella resurfacing and without lateral release. Rotation of the femoral component was determined using Kanekasu's technique and patellar tilt assessment according to Laurin on Merchant's views. This radiographic study confirmed a highly significant correlation between external rotation of the femoral component and a decrease in patellar tilt following TKA. Furthermore, we found a highly significant correlation between pre- and postoperative patellar tilt angle.