Efficacy of an Intra-articular Ozone Injection for Chronic Knee Pain Due to Osteoarthritis

Context . Osteoarthritis (OA) is the most common form of arthritis, affecting an estimated 302-million people worldwide, and it's a leading cause of disability among older adults. Current treatments for OA are largely unsatisfactory. Ozone is an inexpensive, accessible, and easily applicable treatment for OA. Objective . The study aimed to retrospectively evaluate the effects of a short-term, three-month OA treatment using an intra-articular ozone injection, on pain and physical function in patients with stage 2-3 knee OA. Design . The research team designed the study as a retrospective review of files from a hospital's archive as well as the results of a follow-up questionnaire about pain that patients completed at a related clinic. Setting . The study took place at the Algology Clinic at Ankara University in Ankara, Turkey. Participants . Participants were 94 patients, aged between 28 and 75 years, with stage 2-3 OA who had applied to the clinic between January 1, 2018 and January 1, 2020 and had received an intra-articular ozone injection. Intervention . Participants received intra-articular ozone treatments at a dose of 10 ml at 15 mcg/ml for 4 weeks, once a week. Outcome Measures . Participants completed a visual analogue score (VAS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), measuring pain at baseline and at one month and at 3 months postintervention. The study also determined if the treatment had an effect on analgesic drug use and measured patient satisfaction. Results . The decreases in participants' pain scores on both scales were statistically significant at one month and at 3 months postintervention (P =.000). The need for analgesic medication had decreased for 56 participants (61.5%) at one month postintervention and for 50 (54.9%) at 3 months postintervention. Of the 94 participants, 66 (70.2%) were satisfied and 28 (29.8) weren't. Conclusions . The intra-articular injection of ozone, applied once a week for 4 weeks, resulted in a reduction in pain in stage 2-3 knee OA, without any side effects. However, further studies are needed to resolve the uncertainties in dosage, number of sessions, and intervals for intra-articular ozone injections. The current study's results need support from further prospective studies that can evaluate the efficacy of ozone treatment for a longer period of time.