Computer-Assisted and Robotic Unicompartmental Knee Arthroplasties

Computer-assisted and robotic unicompartmental knee arthroplasties (UKA) have improved positioning and reproducibility and are a rare surgical procedure in France. Navigation can be performed by navigating tibial resection alone or by navigating tibial and femoral resection. Navigation is used to place a UKA with navigation on the tibial plateau and femoral condyle. Preoperative preparation requires radiographic measurement of two elements, and a semicircular frame is fixed under navigation control to the femoral reference screw. The Navio® system from Smith & Nephew and the MAKO® system from Stryker can be used to implant a medial UKA with isolated navigation on the tibial plateau. The NAVIO® system does not require preoperative imaging and is based on kinematic preoperative image acquisitions and acquisition of points of interest. Dynamic acquisition of the hip, ankle and knee axis of flexion is essential for effective dynamic planning. Points of interest are acquired on the femur and tibia, and the desired position is determined in three spatial planes. The femoral component should be as close as possible to the intercondylar notch to improve contact points between the femoral and tibial implants. The tibial and femoral components should be positioned in varus/valgus, tibial slope, rotation and mediolateral positioning. The MAKO® system (Stryker) consists of four components: an infrared camera, a screen for the surgeon, a control console for the engineer, and a robotic arm. It is used to plan the positioning of the implants and assess mobility of the knee. Positioning of femoral and tibial sensors percutaneously, acquisition of points of interest, ligament balance, preoperative planning, bone cuts, tests, and results are similar to the NAVIO® system. Robotic UKA has a significant advantage in terms of aberrant values, restitution of the joint space, and faster procedure times due to preoperative planning and the robotic arm. It also reduces the risk of complications in the tibial implant.