A Functional Comparison of Two TKR Designs

Total knee replacement (TKR) is an established treatment for knee osteoarthritis and leads to a satisfactory outcome in over 75% of patients. However, up to 25% of patients are not entirely satisfied with their TKR. Patient dissatisfaction has been associated with inadequate functional outcome, especially during negotiation of stairs and slopes. This phenomenon, known as mid-flexion instability, is believed to be caused by excessive anterior-posterior motion of the implant during activities of daily living. This is characterised as a perception that the replaced knee is unsteady during certain tasks. This study will compare the functional outcome of two implants that have been designed to provide patients with a functionally stable knee throughout its range of motion. The different design roles in preventing implant-related mid-flexion instability remain unknown. The functional outcome and stability of these implants will be tested non-invasively with 3D motion capture technology.