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: The Efficacy of Viscosupplementation for Early Knee Osteoarthritis

Eligibility criteria:
Inclusion Criteria:

          -  18-70 years

          -  Radiographic evidence of OA in the tibiofemoral compartment (minute or definite
             osteophytes and a measurable joint space)

          -  Pain on walking (Visual Analogue Scale 0-10). Minimum of 4 and maximum of 9.

          -  Oxford knee score (OKS) of above 12 but below 36 (0-48, 48 no problem)

          -  Pain score of 1, 2 or 3 on Q1 (pain) of OKS.

          -  Suitable for viscosupplementation

        Exclusion Criteria:

          -  OKS of below 12 and above 36 (0-48, 48 no problem)

          -  Pain score of 0 or 4 on Q1 (pain) of OKS.

          -  Grade 3 or 4 patellofemoral degeneration (Kellgren-Lawrence classification).

          -  Grade 3 or 4 tibiofemoral degeneration (Kellgren-Lawrence classification).

          -  A clinically apparent tense effusion of the target knee.

          -  Significant valgus/varus deformities.

          -  Ligamentous laxity or meniscal instability.

          -  Viscosupplementation history in any joint in the past 9 months.

          -  Previous surgery at the target knee in the past 6 months.

          -  Concomitant inflammatory disease (rheumatoid arthritis) or other condition that
             affects the joints.

          -  Use of prohibited medication/treatment for chronic pain.

          -  Pregnancy or new mothers who are breastfeeding.

          -  Systemic or intra-articular injection of corticosteroids in any joint within 3 months
             prior to screening.

          -  Obvious cartilage defects producing mechanical symptoms (i.e. locking).

          -  Listed for a knee replacement procedure for osteoarthritis of the knee.

          -  Have a history of failed conservative treatment (exercise therapy, physiotherapy).
No condition on gender to be admitted to the trial.
No healthy subjects accepted to join the trial.
Subject must be at least 18 Years old.
Subject must be at most 70 Years

Eligibility (NLI label): Contradiction