Functional Brain MRI to Understand Pain Phenotypes in Knee Osteoarthritis

Some people with knee osteoarthritis (gonarthrosis) experience pain differently. In some, the pain is described as "nociceptive" (directly related to the joint), while in others it has "neuropathic" characteristics (related to nerve function). The goal of this multicenter, cross-sectional and comparative study is to compare resting brain activity in a brain region called the anterior insula among female patients with painful knee osteoarthritis who experience nociceptive pain compared to those with neuropathic pain. Researchers will compare brain activity at rest between these two types of pain in women over 40 with painful knee osteoarthritis. A better understanding could help improve pain management in the future. Participants will be asked to : * complete questionnaires during the inclusion visit and on the day of the scan, * undergo a clinical examination and a blood test at the inclusion visit, * undergo a functional MRI (fMRI), an imaging test that allows observation of brain activity at rest. Paticipants in the study does not involve any additional treatment. the fMRI scan is non-invasive and does not require any injections.