SAN FRANCISCO – Intra-articular ozone injections were effective in reducing pain, improving function, and improving quality of life in patients with knee osteoarthritis in the first randomized study to evaluate this approach.
Patients treated with a series of ozone injections achieved significant improvements on all measures, except for the Timed Up and Go Test, compared with patients given placebo, according to study results presented at the annual meeting of the American College of Rheumatology.
“After 8 weeks of treatment, ozone can give patients with knee osteoarthritis [OA] better quality of life with less pain and more independence in performing daily activities. More studies are needed to validate this option in patients with OA. Intra-articular ozone injections are safe with similar complications to placebo. In elderly people with comorbidities requiring chronic medication, this approach is a good option because it doesn’t interact with medications. The only restriction is anticoagulant therapy, as there may be bleeding at the injection site,” said Dr. Virginia Trevisani, professor at the Federal University of São Paulo.
Alice Goodman/Frontline Medical News
Dr. Virginia Trevisani
The next series of studies Dr. Trevisani and her coauthors are planning will incorporate MRI imaging to assess the effect of the ozone injections on structural progression in knee OA.
Ozone is thought to have anti-inflammatory effects by reducing oxidative stress. Ozone is being used for medical purposes in countries such as Russia, Germany, and Spain, but it is not currently used clinically in the United States. “You can’t perform these injections in patients without experience. The only requirement is a machine to make ozone that costs about $1,000 USD,” she said.
Before this study, evidence in support of ozone injections in knee OA was anecdotal and from observational studies. The present study is the first randomized trial to evaluate intra-articular ozone injections in patients with knee OA.
The study enrolled 98 patients with documented knee OA between the ages of 60 and 85 years; 63 patients were randomized to intra-articular injections of ozone in the knee with the most pain (one injection per week for 8 consecutive weeks), and 35 were randomized to placebo injections of a small amount of air.
Patients were evaluated at baseline, after 4 and 8 injections, and 8 weeks following the last injection. Two patients in the ozone group withdrew from the study. The only adverse events were three puncture-site wounds – two in the ozone group and one in the placebo group.
Significant improvement was observed on all measures, except for the Timed Up and Go Test (getting up from a chair), at every time point for the ozone injections. Dr. Trevisani said that the ability to get up from a chair without help depends on balance and muscle strength, which may explain why the results were not significant.
Measures of pain on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the visual analog scale improved significantly with ozone, compared with placebo, and by week 16, the P value was .000 for both measures. WOMAC joint stiffness intensity was significantly improved by ozone (P = .075 at week 4; P = .002 at week 8). Quality of life on the Short Form–36 for pain and functional capacity were significantly improved by ozone, compared with placebo (P = .000 at week 16 for both measures).
Dr. Trevisani said ozone injections may be able to delay the need for total joint replacement surgery, and that they are cost effective, compared with surgery and other pharmacologic treatments.
Dr. Trevisani had no relevant financial disclosures.