Because of technical problems (researcher moved to different city).

The purpose of this study is to determine whether an intraarticular injection of Ozone into the knee joint is an effective therapy for pain control in patients with osteoarthritis of the knee.

Ozone, as a gas made of three atoms of oxygen with a cyclic structure, has been used as a medical therapy from the mid ninetieth century. Today, this therapy is a recognized modality in many European and Latin American nations for orthopedic problems, infections, ischemic diseases, and skin problems. However, despite of this wide use internationally, there is minimal mention of this treatment modality in the Anglo-American literature.

The present is the first of a series of studies planned to scientifically test the effectiveness of ozone as a main-stream therapy, introducing it to the Anglo-American literature. In this first study we will check whether intraarticular injections of Ozone into the knee joint are effective as a therapy for pain control in patients with osteoarthritis of the knee.

Inclusion Criteria:

- Osteoarthritis of knee

Exclusion Criteria:

• Positive rheumatologic serologic tests
• Cognitive impairment
• Adjacent osteomyelitis
• Bacteremia
• Hemarthrosis
• Impending (scheduled within days) joint replacement surgery
• Infectious arthritis
• Joint prosthesis
• Osteochondral fracture
• Periarticular cellulitis
• Poorly controlled diabetes mellitus
• Uncontrolled bleeding disorder or coagulopathy.