Comparison between intra-articular ozone and placebo in the treatment of knee osteoarthritis: A randomized, double-blinded, placebo-controlled study

Objective
The aim of the trial was to determine the effectiveness of oxygen-ozone injections on knee osteoarthritis concerning pain reduction, joint functional improvement, and quality of life.
Methods
In this randomized, double-blinded, placebo controlled clinical trial, 98 patients with symptomatic knee osteoarthritis (OA) were randomized into two groups receiving intra-articular 20 μg/ml of ozone (OZ) or placebo (PBO) for 8 weeks. The efficacy outcomes for knee OA were the Visual Analogue Scale (VAS), Lequesne Index, Timed Up and Go Test (TUG Test), SF-36, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Geriatric Pain Measure (GPM).
Results
After 8 weeks of treatment, ozone was more effective than the placebo: VAS [mean difference (MD) = 2.16, p < 0.003 (CI 95% 0.42–3.89)], GPM [MD = 18.94, p < 0.004 (CI 95% 3.43–34.44)], LEQ [MD = 4.05, p < 0.001 (CI 95% 1.10–7.00)], WOMAC (P) [median of diff = 9.999, p = 0.019 (CI 95% 0.000–15.000)], WOMAC (JS) [median of diff = 12.499, p < 0.001 (CI 95% 0.000–12.500)], WOMAC (PF) = [median of diff = 11.760, p = 0.003 (CI 95% 4.409–19.119)], TUG (no statistical difference) and SF-36 (FC) [(MD = -25.82, p < 0.001 (CI 95% 33.65–17.99)], SF-36 (PH) [MD = -40.82, p < 0.001 (CI 95% -54.48–27.17)], SF-36 (GSH) [MD = -3.38, p < 0.001 (CI 95% -4.83–1.93)], SF-36 (SA) [MD = 2.17, p < 0.001 (CI 95% -19.67–8.24), SF-36 (EA) [MD = -35.37, p < 0.001 (CI 95% -48.86–21.89)]. Adverse events occurred in 3 patients (2 in the placebo group and 1 in the ozone group) and included only puncture accidents.
Conclusions
The study confirms the efficacy of ozone concerning pain relief, functional improvement, and quality of life in patients with knee osteoarthritis.
Trial registration
International Standard Randomized Controlled Trial Number Register ISRCTNR55861167