The purpose of this study is to determine the concentration of different adipocytokine (adiponectin, leptin, resistin, visfatin, osteopontin) and an inflammation classic markers as Interleukine 1 beta, tumor necrosis alfa, interleukine 6 and high sensibility reactive c protein in the synovial fluid of knee osteoarthritis patients, and compare with the inflammation detected with ultrasonography evaluation of the joint. In last years, some studies appeared focusing on the role of adipocytokines in osteoarthritis and they correlated adipocytokines with cartilage degradation and x-ray degree; in our study we will focused in the importance of adipocytokines in the inflammatory changes more than in joint destruction.

Inclusion Criteria:

• aged 50 to 81
• primary osteoarthritis of the knee
• synovial effusion in examination
• patient who have the results in our database

Exclusion Criteria:

• any other rheumatic conditions as rheumatoid arthritis or another inflammatory disease
• secondary knee osteoarthritis
• history of knee surgery
• any conditions that at investigator criteria exclude the patient from study procedures

Patient with knee osteoarthritis and synovial effusion who attende to a Rheumatologist unit for this problem. We made the visit and anonimously we kept the results of examination and ultrasonography in our database and we freezed synovial fluid. Now we will determine the adipocytokines and classic inflammatory parameters in this synovial fluid