Knee version associated with anterior knee pain

Version of the knee in the presence and absence of anterior knee pain was evaluated by computed tomography in this study. Version of the knee is defined as the static rotation of the tibia with respect to the femur in full knee extension. Fourteen patients in whom conservative management for anterior knee pain failed were compared with 14 volunteers with no symptoms. Computed tomography images of the femoral condyles and tibial plateau were obtained with the knee extended. The angle between the bicondylar and posterior tibial axes was measured. This angle, representing external rotation of the tibia relative to the femur, was increased significantly in patients with symptoms (7 degrees) compared with volunteers with no symptoms (1 degree). This increased knee version identifies a unique morphologic characteristic of the knee with anterior pain.