The purpose of this study was to evaluate the effect of intra-articular hyaluronic acid (HA) injections after arthroscopic debridement on pain and functional parameters in patients with mild-to-moderate knee osteoarthritis.
Sixty-seven patients (21 men, 46 women; mean age 56 years; range 40 to 65 years) who underwent standard arthroscopic debridement for primary knee osteoarthritis of Kellgren-Lawrence grade II-III were randomly assigned to HA injections (n=33) or to only follow-up as controls (n=34). Intra-articular sodium hyaluronate injections (Orthovisc) were started three weeks after arthroscopic debridement, totaling three injections interspersed with a week. The two groups were evaluated with the pain and physical function subscales of the WOMAC osteoarthritis index before and after 6, 12, and 24 weeks of arthroscopic debridement.
Improvement in pain scores at 6 weeks did not differ between the two groups (HA 21%, control 16%; p=0.478), whereas improvement in function scores was significantly higher in the HA group (23% vs 9.2%; p=0.018). The rates of improvement in pain and function scores increased in subsequent evaluations, but these did not differ significantly between the two groups. The percentages of patients who exhibited at least 30% and 40% improvement from baseline function scores were significantly greater in the HA group only at six weeks (p=0.025 and p=0.038, respectively).
Intra-articular HA injections after arthroscopic debridement provide additional short-term benefits, but this combination therapy should be justified by further controlled studies with longer follow-up and larger patient groups.