A Comparison of Patients Receiving a Unicompartmental Knee Replacement With Robotic Assistance or With Conventional Instrumentation

A unicompartmental (partial) knee replacement (UKR) is the removal of one part of the knee joint (a condyle), that has become damaged due to osteoarthritis, and replacing it with an artificial implant. The placement of these artificial implants and how they are aligned with each other is important because they can impact overall knee function and the long-term survival of the implant. A UKR is a highly effective, recognised procedure for patients with end-stage osteoarthritis affecting one compartment of the knee joint. The functional outcomes following UKA are at a minimum of equivalence to total knee arthroplasty procedures, with some recent literature demonstrating improved functional patient reported outcome scores. There have been significant developments in knee replacement surgery over recent years. In particular, the introduction of robotic surgical systems, such as the NAVIO and CORI systems (Smith+Nephew Plc). These systems are hand-held devices which can support the surgeon with the knee replacement procedure, the systems are image-free and do not require the patient to undergo any scans (such as CT scans). Comparisons of robotic systems to conventional instruments have demonstrated that robotic platforms produce fewer positioning errors in total knee replacement. This can result in more precise knee alignment and better outcomes following surgery. With both the NAVIO and CORI Surgical Systems there is a reduction in radiation exposure due to them being image-free. At present, there is some evidence available for the long-term outcomes of knee replacement implanted using robotic assistance (i.e. 2-10 years) however this study is designed to look at the early outcomes following UKR. There is no literature to date to show that robotic-assisted UKR is superior to conventional methods, within the early post-operative period (up to 12 months). This study is designed to show that the NAVIO/CORI surgical systems are better than conventional methods for UKR.