Determining the clinical utility of the NextAR navigation system in providing soft tissue balance pattern data during total knee replacement surgery, to enable prosthesis implants to resemble more native knee alignment and thereby improve patient outcomes.

The Total Knee Replacement (TKR) procedure is a standard of care intervention to treat severe degenerative knee joint disease conditions (such as osteoarthritis). All patients being considered for enrollment in this trial will be undergoing TKR as per usual treatment management plans provided by their referring clinician. Surgery will take place in accredited public hospital surgical theatre by qualified orthopaedic surgeons. As part of the TKR procedure, the patients will be implanted with a TGA Approved artificial knee joint prosthesis. The prosthesis will be fitted to the patient using custom 3D printed Patient-Specific Guides (PSGs) that are placed on the bone to guide the surgeon to make accurate bone resections in order to accommodate the knee prosthesis. The custom 3D printed PSGs are used routinely and are a well-accepted method of performing TKR surgery in Australia. For this trial, one group of patients will undergo routine TKR surgery with the custom 3D printed PSGs, another group of patients will undergo TKR surgery using the 3D printed PSGs and additionally their collateral ligaments will be assessed intra-operatively using a Computer-Aided Surgery (CAS) Navigation system (NEXT-AR). The NEXT-AR Navigation system comprises of infrared cameras that are able to track the movement of the knee joint throughout surgery and can provide the surgeon with data about the state of the collateral ligaments of that patient. This ligament data can inform the surgeon about the optimal positioning of the knee prosthesis to potentially improve the patient satisfaction and knee kinematics post-operatively. This trial will assess if there are any differences in patient satisfaction or knee kinematics between the two patient groups.