Evaluation of Mobility in Subjects With Severe Knee Osteoarthritis Who Are to Undergo Total Knee Replacement

Osteoarthritis (OA) is the most common joint disease. It is characterized by a progressive destruction of all the components of the joint, especially the cartilage. This leads to pain, loss of mobility and can be a major handicap for some patients.

Gonarthrosis, or osteoarthritis of the knee, affects 30% of people between the ages of 65 and 75 and is one of the most disabling conditions. In the final stage, the only therapeutic option to relieve patients is to replace the joint with a total knee prosthesis.

Thanks to the contribution of an evaluation technique based on inertial sensors (X-SENS device), our objective is to better evaluate and understand the movement deficit in knee OA subjects.

The hypothesis is that, thanks to the contribution of a technique based on inertial sensors (X-SENS), the investigators can better evaluate the movement deficit of knee OA subjects. The goal is to propose specific, rapid telekinetic biomarkers, allowing a better evaluation of functional improvements following therapeutic interventions, such as a total knee replacement.

Osteoarthritis is the most common joint disease. It is characterized by a progressive destruction of all the components of the joint, especially the cartilage. This leads to pain, loss of mobility and can be a major disability for some patients.

Knee osteoarthritis affects 30% of people between the ages of 65 and 75 and is one of the most disabling conditions. In the final stage, the only therapeutic option to relieve patients is to replace the joint with a total knee prosthesis.

Previous research has shown that self-administered questionnaires to assess the benefits of management in knee osteoarthritis were limited and didn't accurately describe recovery from total knee replacement.

Functional performance tests can objectively capture a patient's mobility, but each test only approaches a small number of parameters involved in movement, which is not representative of the subject's experiences in daily life (walking, going up/down stairs, getting up from a chair).

In knee OA the assessment of pain and function is often based on validated parameters (visual analog scales and/or self-questionnaires) but variable over time (during the day, depending on physical activity or between 2 medical visits).

Given these challenges, there is great interest in using low-cost wearable sensors to develop mobile tools to obtain functional data on patients.

Thanks to the contribution of an evaluation technique based on inertial sensors (X-SENS device), the objective is to better evaluate and understand the movement deficit of of knee OA subjects.

The investigators believe that the combination of clinical, biological, imaging and mobility parameters will allow us to identify prognostic factors for OA.

The hypothesis is that, thanks to the contribution of a technique based on inertial sensors (X-SENS), the investigators can better evaluate the movement deficit of knee OA subjects. The goal is to propose specific, rapid telekinetic biomarkers, allowing a better evaluation of functional improvements following therapeutic interventions, such as a total knee replacement.

Another hypothesis is to better understand the alterations in mobility of the knee OA subject by studying several parameters: contractile function of the quadriceps; changes in body composition and muscle volume; and biological functions of muscle fibers and joint tissue.

Eligibility Criteria:
Inclusion Criteria:

* Patient over 60 years old
* Presence of unilateral knee osteoarthritis (Kellgren and Lawrence radiographic stage ≥ 3) in the femorotibial compartment and/or Iwano stage ≥2 in the femoropatellar compartment);
* Average VAS (Visual Analogic Scale) pain on a reference joint (knee) \> 40/100 during the past month.
* Indication for prosthetic knee surgery (total knee replacement)
* Failure of a well-conducted medical treatment (at least one prior infiltration with corticoids or hyaluronic acid or PRP (Platelet-rich plasma))

Exclusion Criteria:

* Presence of an inflammatory joint disease (rheumatoid arthritis, spondyloarthritis, microcrystalline pathology)
* Presence of a post-traumatic gonarthrosis
* Frontal deformity of the lower limb \> 15
* Preoperative flessum \> 15° or preoperative knee mobility \< 90°
* Neurological pathology
* Spinal pathology that is painful or causes deformity (severe Cobb scoliosis \> 20°)
* History of trauma or surgery of the lower limbs in the last two years,
* Presence of at least one lower limb prosthesis (total hip or ankle prosthesis)
* Subject with a contraindication to MRI examination (pacemaker, neurosensory stimulators, cardiac defibrillator, cochlear implants, ferromagnetic ocular or cerebral foreign bodies...)
* Subjects with a contraindication to DXA examination (coronary stent or metallic cardiac sutures, pacemaker or automatic defibrillator, obesity with a BMI \> 35kg/m2, insulin pump, weight over 200kgs)
* Subject with a legal protection measure (guardianship, curatorship)
* Subject under legal protection
* Subject not affiliated to a social security system or not benefiting from such a system
* Absence of informed written consent