Efficacy of a single intra-articular injection of ultra-high molecular weight hyaluronic acid for hip osteoarthritis: a randomized controlled study.

Abstract

Viscosupplementation with hyaluronic acid (HA) is increasingly used for the treatment of hip osteoarthritis (OA). The purpose of this study was to compare the efficacy of intra-articular injections of an ultra-high molecular weight viscosupplement (UHMW-HA, Fermathron S) with a medium molecular weight hyaluronan (MMW-HA, Hyalubrix 60) in hip OA. Fifty-four patients with hip OA grade 3 on the Kellgren/Lawrence scale were randomized. All infiltrations were performed under ultrasound guidance. Evaluation was performed preoperatively and at 1, 3, 6 and 12 months after infiltration. Patients were clinically evaluated using Lequesne index, VAS and WOMAC score. Fifty patients, including 27 in the MMW-HA group and 23 in the UHMW-HA group, completed the follow-up. No significant difference was found between the two groups in terms of VAS, WOMAC or Lequesne index preoperatively or at 1, 3, 6 and 12 months after viscosupplementation. A stratified analysis was performed to study the development over time of Lequesne index of patients aged ≤ 55 years, > 55 and, ≤ 70 years and > 70 years and Lequesne index was different between the three age-stratified subgroups only in the MMW-HA group. The subgroup of older patients showed a higher Lequesne index than the subgroups of younger patients (p < 0.05). UHMW-HA is a safe and effective treatment for hip osteoarthritis. A single dose of UHMW-HA was as effective as two doses of MMW-HA resulting in similar reductions of pain and disability. Multicenter, independent, prospective, randomized controlled trial with level of evidence 1.