Total Knee Arthroplasty and Augmented Reality-based Navigation System

Does an Augmented Reality-based Navigation System in Total Knee Arthroplasty Allow a Better Alignment of the Lower Limb and Does it Improve Functional Results ? An Equivalence, Monocentric, Prospective and Randomized Study

The purpose of Total Knee Replacement (TKR) is to remove worn cartilage surfaces and replace them with artificial parts of the same shape. TKR can be used in cases of osteoarthritis, inflammatory rheumatism, bone necrosis of the knee or following malformative or traumatic sequelae.

Implant alignment is paramount in TKR and the last years have seen a proliferation of alignment techniques following the introduction of computer and robotic-assisted surgery. Among Computer-assisted surgery, the augmented reality-based navigation system can be an option to improve accuracy in orthopaedic surgery.

The hypothesis of this study is: the use of augmented reality-based navigation system allows a prosthesis alignment and positioning that is at least as good as with the traditional mechanically aligned technique, and therefore improves knee functional results. This study also aims at assessing the cost-effectiveness of this new technology.

In this randomised study, TKR will be performed either with the traditional mechanically aligned technique or with an augmented reality-based navigation system using Knee+ technology.

Knee+ is a Class Im software medical device (European classification, Directive 93/42/EEC, Annex IX) and obtained CE Mark 0459 in May 2020.

This technology is used in total knee replacement procedures, and offers the orthopedic surgeon intraoperative assistance in positioning the implants with the help of a pair of augmented reality glasses. The cutting planes are oriented with respect to the mechanical axes calculated according to anatomical landmarks acquired with a pointer. The connected glasses calculate precisely the 3D coordinates of the instruments thanks to the analysis of their specific markers (QR-Code), filmed by the integrated camera. The navigation information is displayed in the surgeon's field of vision, who interacts with the application thanks to the glasses' accelerometers.

Inclusion Criteria:

1. Gonarthrosis on a varum knee requiring a Total Knee Replacement
2. Female or male, 18 years of age or older
3. Affiliation to a social security scheme
4. Patient has been informed of the study and has signed an informed consent form

Exclusion Criteria:

1. Osteonecrosis,
2. Post traumatic osteoarthritis with femoral or tibial callus,
3. History of tibial or femoral osteotomy,
4. Valgum knee,
5. Isolated patellofemoral osteoarthritis,
6. Significant hip dysplasia or other excessive pelvic deformity,
7. Patient already equipped with medical devices that may conflict with the instrumentation required for augmented reality navigation,
8. Pregnant or breastfeeding women,
9. Patients under legal protection.