The use of Augmented Reality in hip and knee arthroplasty
Mr Charles Rivière, MD,PhD
Consultant Hip & Knee Surgeon,
Augmented reality (AR) is a technological tool that might help at improving total joint replacement (TJR) implants positioning by providing a real-time intra-operative feedback to the surgeon. By enabling intraoperative comparison of the planning and the surgical performing (=implant positioning quality control), AR might help the surgeon to better restore the individual patient’s joint anatomy likely improving patient’s clinical outcomes.
Regarding the total hip replacement procedure, the cup rotational positioning (anteversion and inclination) is mainly dictated by the transverse acetabular ligament (anatomical landmark) and the cup medio-lateral positioning is mainly influenced by the bone quality, that is a bleeding spherical bony acetabular bed. This makes cup positioning not likely to substantially benefit from any assistive tool at the exception of rare cases where a severe spine-hip syndrome make cup positioning adjustment needed. In contrast, the restoration of the proximal femoral anatomy, that is the recreation of the native instantaneous femoral center of rotation by a proper femoral stem positioning (version, height) and selection of its offset, is difficult to achieve and is one of the main factor influencing generation of good patient’s functional outcomes and leg length after hip replacement. By facilitating restoration of the proximal femoral anatomy, AR might improve outcomes of hip replacement and should therefore benefit patients and society.
Regarding the total knee replacement procedure, patient-specific technique for implant positioning (kinematic alignment technique) is being promoted as it shows to improve early to mid-term clinical outcomes of TKA. Femoral implant kinematic positioning with manual generic instrumentation has been demonstrated to be reliable (Riviere et al.) and would therefore not substantially benefit from additional assistive tool. In contrast, the tibial component kinematic positioning is likely to be technically more demanding, frequently necessitate bone recut(s), and would therefore probably be improved by the AR technology.
We are working at the MSK Lab (Imperial College London) on 2 AR projects: 1) Assessing the precision of AR system to restore the native proximal femur anatomy (native instantaneous femoral center of rotation) when performing a kinematically aligned total hip replacement, and 2) Assessing the precision of AR system to restore the native proximal tibia anatomy when performing a kinematically aligned total knee replacement.