Knee is the most common site of osteoarthritis. Treatment of knee osteoarthritis starts with a full course of medical therapy, followed by surgery to replace the knee with a prosthesis if this strategy fails, or in advanced cases. However, the new recommendations of the French rheumatology society, which evaluate the various treatments and position them in the treatment plan, are not well known, and the definition of a complete treatment remains unclear. The vast majority of patients are therefore referred to a surgeon after having tried a small part of the therapeutic arsenal (generally analgesics and corticosteroid or hyaluronic acid infiltrations). The goal of this study is to to select patients most likely to gain from surgery and to develop strategies that avoid the need for major surgery.

Knee is the most common site of osteoarthritis. Treatment of knee osteoarthritis starts with a full course of medical therapy, followed by surgery to replace the knee with a prosthesis if this strategy fails, or in advanced cases.

However, the new recommendations of the French rheumatology society, which evaluate the various treatments and position them in the treatment plan, are not well known, and the definition of a complete treatment remains unclear. The vast majority of patients are therefore referred to a surgeon after having tried a small part of the therapeutic arsenal (generally analgesics and corticosteroid or hyaluronic acid infiltrations).

Yet medical treatment has proved effective, suggesting that it could prevent a significant number of total knee arthroplasties. In addition, osteoarthritis of the knee is associated with various co-morbidities (diabetes, cardiovascular) that medical treatment can minimize (diet, physical activity).

The effectiveness of knee prostheses has been demonstrated, but up to 20% of patients continue to experience pain, and surgical procedures induce rare but serious events. Prostheses can also be revised, and are expensive.

This research is designed for patients suffering from femoro-tibial osteoarthritis who have been proposed total knee replacement by a surgeon, and aims to develop strategies to avoid the need for major surgery until the medical treatment arsenal adapted to the patient's situation has been tried.

In the treatment of osteoarthritis, the impact of shared decision-making between rheumatologists, orthopaedic surgeons and the patient in the event of incomplete medical treatment has been shown to be important, as the decision is often modified after discussion.

The main objective of this prospective, randomized, pragmatic, non-blinded, multicenter study is to investigate whether shared decision-making coupled with multimodal medical strategies delays surgery by at least 2 years in most patients, with non-inferiority on pain and function, lower cost and fewer serious adverse events compared with total knee arthroplasty from the outset.

Inclusion Criteria:

• Age 18-90 years old
• Femoro-tibial osteoarthritis Kellgren stage stage≥ 2 without laxity in extension;
• A proposal of total knee replacement by a surgeon;
• No corticosteroid joint injection within 3 months;
• Visual analogic score pain (VAS) >40/100 but <90/100 or Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index function sub scale >40/100 at inclusion;
• Wish to discuss medical care;
• Able to consent and having signed a consent form.

Exclusion Criteria:

• Contraindication or no indication to surgery or medical care (severe infection for example)
• Inflammatory arthritis
• Lack of social insurance
• Symptomatic (VAS pain >40) contralateral knee or hip osteoarthritis (with or without replacement)
• Pregnant or breastfeeding woman
• Patient under court protection, guardianship, curatorship
• Patient deprived of liberty

All collected data that underlie results in a publication

Data will be available beginning five years and ending fifteen years following the final study report completion

Data access request will be reviewed by the internal committee of Brest UH. Requestors will be required to sign and complete a data access agreement.