Navigation involves the use of computer software to enhance implant positioning. Historically, surgeons have used a variety of handheld jigs to estimate the bone cuts made during surgery. The introduction of computer navigation has significantly improved the accuracy and precision of these bone cuts. Essentially, the computer software is used to calculate the center of the hip, knee, and ankle during surgery.
Once these points are registered, the mechanical axes of the femur and tibia are determined by the software, and the bone cuts are planned using these data. Multiple studies have now demonstrated that computer navigation improves both implant position and patient-reported outcomes in total knee replacement.
Robotic-assisted knee replacement expands upon the previous forms of computer navigation by using a haptic robotic arm, which is brought onto the surgical field to assist with the bone resections. The surgeon registers multiple anatomic checkpoints into the computer, creating a 3-dimensional map of the patient's knee which is matched to a preoperative CT scan. A virtual surgery is trialed on the computer, creating a plan which accurately reconstructs the mechanical axis of the limb while ensuring proper gap balancing. The robotic arm is then brought onto the sterile field and executes the surgical plan.