ScholarWorks@동국대학교

초록

Osteoarthritis knee can be restored by total knee arthroplasty (TKA). Imageless TKA requires a few anatomical points to construct a reference coordinate system to measure bone resections and implant placement. Inaccuracies in the definition of the coordinate system lead to malalignment and failure of the implant. The surgical transepicondylar axis (sTEA) is a reliable anatomical axis to define the lateromedial axis for the femoral coordinate system (FCS), however the presence of the collateral ligaments and deterioration of medial sulcus (MS) make the registration of sTEA a challenging task. In this work, sTEA is assigned using the articular surfaces of the femoral condyles, independent of lateral epicondyle (LE) and MS. A single 3D arc is marked on each condyle which is transformed into a 2D arc to get the best-fit curve according to the profile of condyles. The turning point of each best-fit curve, when transformed back to 3D, defines an axis parallel to sTEA. The condyles-based sTEA is measured experimentally on a 3D-printed bone using an Optitrack tracking setup. As per the proposed method, the angle between aTEA, sTEA, and Whiteside's line was 3.77°, 0.55°, and 92.72°, respectively. Apart from the ease in registration of sTEA, the proposed method provides the same level of accuracy and improves the surgery time, as there is no need to register the LE and MS.