Long-term effects of intra-articular oxygen-ozone therapy versus hyaluronic acid in older people affected by knee osteoarthritis: A randomized single-blind extension study

Abstract

BACKGROUND:

There is little evidence on intra-articular (IA) treatment in knee osteoarthritis (KOA) and there is a lack of long-term follow-up studies.

OBJECTIVE:

To assess the long-term effectiveness and safety of IA oxygen-ozone (O ${}_2$ O ${}_3$ ) and hyaluronic acid (HA) in terms of functioning in KOA patients over a 31-week period.

METHODS:

Patients aged $⩾$ 60 years with KOA were randomly allocated to receive 4 IA knee injections (1/week) of O ${}_2$ O ${}_3$ or HA (T0–T3) and a follow-up visit 4 weeks after the fourth injection (T4). In this extension study we assessed VAS and safety in patients with Visual Analogue Scale (VAS) $⩾$ 4 at the at 6-month follow-up visit (T5), undergoing a second treatment cycle (T5–T8) and 1-month follow-up visit (T9).

RESULTS:

Forty-two patients (aged 70.5 $\pm$ 5.8 years) were randomly allocated to O ${}_2$ O ${}_3$ ( $n=$ 22) or HA group ( $n=$ 20). Twenty-three underwent another IA cycle: 12 (54.6%) in the O ${}_2$ O ${}_3$ group and 11 (55.0%) in the HA group. Both groups showed significant reduction in VAS ( $p<$ 0.013) compared to baseline during both cycles. At follow-up visits (T4 and T9), VAS was significantly lower in the HA group ( $p<$ 0.013). There were no differences in adverse events occurrence between groups.

CONCLUSIONS:

IA O ${}_2$ O ${}_3$ might be comparable to HA in terms of effectiveness and safety in reducing pain in KOA patients, although at both follow-up visits (T4 and T9) VAS was significantly lower in the HA group.