Functional Brain MRI to Understand Pain Phenotypes in Knee Osteoarthritis

Inclusion Criteria: * Women aged 40 or older (only women will be included to ensure consistency in the analyses, given the higher prevalence of osteoarthritis in women and the influence of sex/gender on the experience of pain) * Diagnosis of femorotibial osteoarthritis of the knee according to the 1986 American College of Rheumatology criteria * Presence of knee pain with an intensity of ≥ 4/10 on a numerical rating scale (NRS) * Chronic knee pain, i.e., lasting at least 6 months with at least 15 days of pain in the past 30 days * Completion of the PainDETECT questionnaire, which will allow the patient to be assigned to one of two groups prior to the enrollment visit (those with nociceptive pain \[score ≤ 12\] and those with neuropathic pain \[score \> 13\]) * Patients have read and understood the information letter * Patients have signed the informed consent form * Patients are enrolled in a social security program Exclusion Criteria: * Other joint diseases affecting the knees (gout, chondrocalcinosis, rheumatoid arthritis, spondyloarthritis, psoriatic arthritis) * Conditions that, in the investigator's opinion, interfere with the assessment of osteoarthritic pain, such as conditions causing neuropathic pain in the lower extremities (e.g., peripheral neuropathy, chronic radiculopathy) or fibromyalgia * Kellgren-Lawrence radiographic stage IV in one or both knees * Patients with one or more knee prostheses * Claustrophobia making MRI impossible * Contraindication to MRI * …