Intra-articular injections of oxygen-ozone versus hyaluronic acid for the treatment of knee osteoarthritis: A randomized controlled trial

Objective The purpose of this paper was to evaluate the efficacy of intra-articular (AI) injections of Hyaluronic Acid (HA) versus Oxygen-Ozone (O 2 O 3 ) in relieving pain and reducing disability in patients affected by knee osteoarthritis (KOA). Methods People with painful KOA for at least three months were randomly allocated to receive three IA injections, once a week, of HA (Group A) vs O 2 O 3 (Group B). They were evaluated at baseline (T0), at 1 (T1), 3 (T2), 6 (T3), and 12 months (T4) after the treatment, using as outcomes: WOMAC pain score, WOMAC LK 3.1, Numeric Rating Scale (NRS), and KOOS. Results Of the 122 patients assessed for eligibility, 112 participants were enrolled. Both groups A and B showed significant improvements in all outcomes measures from 1 month after the treatment (HA Group: 6.77 ± 2.53 vs 3.66 ± 2.57; O2O3 Group: 6.50 ± 2.24 vs 3.45 ± 2.30). In contrast, at T2 and T3, the HA-treated group showed significant pain and functional improvement compared to O 2 O 3 group. Conclusion Both HA and O 2 O 3 might be considered safe and potential effective treatments for KOA, due to their anti-inflammatory effects. O 2 O 3 seems to have a faster effect; rather, HA showed superior efficacy at 3 months onwards from the end of the treatment.