The Bisector of the Trochlear Groove as a New Axis for Kinematic Alignment of Total Knee Arthroplasty: A Radio-Graphic Study

Background: There is a growing interest in TKA components alignment, especially around the kinematic technique, which aims at reestablishing the alignment of the native knee. However, the practical application of this technique has some limitations; (2) Methods: A series of consecutive full weight-bearing lower limbs radiographs performed in our Hospital without signs of osteoarthritis, post-traumatic deformities, and any previous surgical procedure (e.g. any joint replacement , osteotomy, anterior cruciate ligament reconstruction) were included. Several radiological parameters as the bisector line were measured by three members of our orthopedic unit and were then used to assess the inter-observer reliability.; (3) Results: 110 radiographic images belonging to 59 patients (both legs for 51 patients and one leg for 8 patients) were finally included in the present analysis. The bisector of the trochelar groove was perpendicular to the femoral joint line (mean 89.4°).; (4) Conclusions: The main finding of the current study was that the new anatomic landmark investigated, the bisector of the trochlear groove, was perpendicular to the femoral joint line viewed in the AP weight-bearing radiograph of the entire lower limbs of the healthy knee and therefore could potentially simplify the achievement of the kinematic alignment during a TKA procedure.