Changes in Tibiofemoral Joint Space Following Total Knee Arthroplasty During Weight-Bearing Knee Motion

Increasing the range of knee flexion following total knee arthroplasty (TKA) remains an important objective for design of new implants and advancement of surgical techniques. With the excellent long term (10–15 year) outcome of TKA, surgeons are more confident about performing the procedure on younger, more active patients demanding increased range of knee flexion [1–3]. Numerous factors have been linked to limited flexion (<120°) following TKA, including patient factors such as preoperative range of motion, intraoperative factors such as component malposition, and implant design [1–3]. Extensor mechanism overstretching due to overstuffing of the knee joint is hypothesized to be a contributing factor limiting knee flexion [1–4]. However, no study to date has investigated the changes in tibiofemoral joint space following TKA. The aim of this study was to examine pre- and post-operative tibiofemoral joint space in a group of TKA patients during weight-bearing knee flexion and to compare it to that in the normal/healthy knee. This could help determine if changes in the proximal-distal distance between the femur and the tibia (tibiofemoral joint space) could lead to extensor mechanism overstretching and consequently limited range of flexion.