The purpose of this study is to evaluate the efficacy and safety of PRGF infiltrations in the treatment of knee osteoarthritis.

Several studies have shown the positive effects of the autologous "Preparation Rich in Growth Factors" (PRGF) in different clinical situations involving connective tissues and also in OA synovial cells. PRGF is a biological delivery system of a complex mixture of bioactive proteins essential to natural repair including anabolic factors for cartilage such as transforming growth factor-β1 (TGF-β1), platelet-derived growth factor (PDGF) and insulin-like growth factor (IGF-I). The potential of PRGF to enhance the limited capacity of cartilage to repair itself encouraged the idea of treating degenerative joint conditions with this autologous preparation.

The present study was undertaken to assess the efficacy and safety of the intra-articular injection of PRGF and to obtain useful information about the clinical effects. Since pain is the most pressing problem facing people with OA, a significant improvement in pain would indicate the potential of the proposed treatment. We will also evaluate functionality and quality of life. In addition we will examine changes in novel serum and synovial fluid biomarkers and their correlation with MRI-based parameters in a subgroup of patients.

Inclusion Criteria:

• Patients of both sexes and aged between 40 and 72 years.
• Diagnosed with osteoarthritis of the knee by radiological image.
• Pain in the joint equal to or greater than 2.5 points in EAV.
• Radiological severity:Value in the Ahlback score 3 or less.
• Body mass index between 20 and 30.
• Possibility for observation during follow-up period.

Exclusion Criteria:

• Bilateral Gonarthrosis requiring infiltration in both knees.
• Body mass index greater than 30.
• Diagnosed polyarticular disease.
• Severe mechanical deformation.
• Previous arthroscopy in the past year.
• Intraarticular infiltration of hyaluronic acid in the last 6 months.
• Rheumatic autoimmune systemic disease.
• Poorly controlled diabetes mellitus.
• Blood alterations.
• Immunosuppressive treatments and/or coumarinics.
• Treatment with steroids for 3 months prior to its inclusion in the study.
• Treatment with nonsteroidal anti-inflammatory drugs for 15 days prior to its inclusion in the study.