Treatment of Cartilage Lesions in Flanders Today

Inclusion criteria

• Symptomatic single cartilage lesions of the femur condyles
• Size of the lesion, determined by MRI:

between 1-2 cm² for the group who will receive conservative treatment between 2-5 cm² for the group who will have surgery

• Mechanical joint pain, assessed by a 100 mm Visual Analogue Scale: > 40 mm for the conservative group, > 60 mm for the operative group

• Agree to stop using analgetics and NSAID's 2 weeks before the First respond of the surveys, and 2 weeks before the second respond of the surveys. Only paracetamol (4g/day) is allowed.
• men and women, women have to use contraceptive to avoid pregnancies.
• age between 18 - 50 years

Exclusion criteria

• participation in concurrent trials
• participation in previous trials within 3 months
• subjects with HIV, hepatitis, syphilis
• malignancy
• alcohol and drug abuse
• poor general health condition as judged by the investigator
• osteochondritis dissecans
• advanced osteoarthritis (kellgren 2-4)
• known allergy to penicillins and gentamicin or presence of multiple severe allergies
• complex ligamentous instability of the knee
• lateral meniscus lesion or more than 50% resection of medial meniscus
• Varus or valgus misalignment exceeding 3° (kissing lesions out)
• Mosaicplasty (OATS)
• Microfracture performed less than 1 year before baseline
• Received hyaluronic acid intra-articular injections into the afflicted knee within the last six months of baseline
• Taking specific OA drugs, such as chondroitin sulphate, diacerein, capsaicin within two weeks of the baseline visit
• Corticosteroid therapy by systemic or intra-articular route within the last month of baseline or intramuscular or oral corticosteroids within the last two weeks of baseline
• Chronic use of anticoagulants
• Uncontrolled diabetes
• Any concomitant painful or disabling disease of the spine, hips or lower limbs that would interfere with evaluation of the afflicted knee
• Any clinically significant or symptomatic vascular or neurologic disorder of the lower extremities
• Any evidence of the following disease in the target joint: septic arthritis, inflammatory joint disease, hematochrosis, collagen gene mutations
• Current diagnosis of osteomyelitis
• A blood result showing liver enzymes more than two times the upper limit of normal or any other result that in the clinical investigator's mind is important clinically
• CRP level greater than 10g/l
• Unwilling to participate in post-operative rehabilitation protocol