Patient case (clinical description): A 47-year-old woman comes to the office complaining of pain in the calf and knee when she bends down. The pain limits her activity. Her medical history is significant for osteoarthritis, for which she uses nonsteroidal anti-inflammatory drugs (NSAIDs) for the past two years. She is living with her husband and has 3 children. She doesn't smoke but drinks alcohol occasionally. Her vital signs are normal. On physical examination, there is a small effusion in the right knee. The effusion grew a little larger and she developed a tender swelling in the popliteal fossa and calf. Both the pain and swelling worsened as she bent and straightened her knee.

Patient's own account: I'm a 47-year-old woman, married with 3 kids. I don't smoke and I drink occasionally. I went to the doctor because of pain in my calf and knee when I was bending down. This has been limiting my daily activities. I have been diagnosed with osteoarthritis for which I have taken anti-inflammatory drugs for the past 2 years. The doctor saw a small fluid buildup in my right knee. This buildup became a bit bigger and I have a swollen calf. The pain is worse when I bend and straighten my knee.

Clinical trial: Evaluation of the Prognostic Value of Biological Markers, Coll2-1 and Coll2-1NO2 in Patients With Symptomatic Knee Osteoarthritis

Eligibility criteria:
Inclusion Criteria:

          -  Male or female, aged 45 to 80 years with a BMI ≤ 40

          -  With an uni- or bilateral femorotibial knee osteoarthritis associated or not with a
             femoro-patellar knee osteoarthritis

          -  Responding to clinical and radiological criteria of the ACR

          -  Symptomatic for more than 6 months (for the most painful knee)

          -  K&L radiological grade of Felson II or III

          -  With a cartilage lesion identified during MRI and either at least 1 out of 4 MRI
             severity criteria:

               -  bone oedema

               -  meniscal lesion in the central region of the medial compartment

               -  effusion without answer to corticosteroids

               -  zone without cartilage

          -  or at least 1 out of 3 clinical severity criteria:

               -  genu varum>3°

               -  previous meniscal surgery

               -  known polyarthritis

               -  effusion on the target knee

          -  Sign an informed consent after being informed

          -  Able to follow the instructions of the study

          -  With an agreement from the physicians having established the diagnosis of
             osteoarthritis (if any) to give relevant information to the investigator

          -  With health insurance (for France).

        Exclusion Criteria:

        For osteoarthritis:

          -  Isolated patellofemoral arthritis

          -  Chondromatosis or villo-nodular synovioma of the knee

          -  Recent trauma-induced knee pain

          -  Joint disease due to joint dysplasia, aseptic osteonecrosis, acromegaly, Paget's
             disease, hemophilia, hemochromatosis, …

          -  inflammatory pathologies as rheumatoid polyarthritis, gout arthritis, infectious
             arthritis

          -  Diseases that may interfere with the evaluation of osteoarthritis (radiculalgia of
             lower limbs, arteritis, …)

          -  Genu valgum (degree considered as pathological by the physician)

        For previous treatments:

        • Treatment with strontium ranelate, bisphosphonates, SERM and PTH

        For known associated diseases:

          -  Serious associated diseases: severe liver or renal failure, uncontrolled
             cardiovascular disease, HIV, hepatitis B or C

          -  Knee tumor

        For patients:

          -  Patient who participated to a therapeutic clinical trial 3 months before the T0
             inclusion visit

          -  Patient who are the subject of a judicial protection measure or under guardianship

          -  Pregnant woman

        For MRI contraindications:

          -  Patient with a pacemaker, an implantable defibrillator, neurosurgical clips, a
             neurostimulator, cochlear implant, a stent, an insulin pump

          -  Patient with a ferromagnetic splinter in the body, or having wire sutures

          -  Serious mobility problem (Parkinson, tremors)
No condition on gender to be admitted to the trial.
No healthy subjects accepted to join the trial.
Subject must be at least 45 Years old.
Subject must be at most 80 Years

Eligibility (NLI label): Entailment