HYADD 4 versus methylprednisolone acetate in symptomatic knee osteoarthritis: a single-centre single blind prospective randomised controlled clinical study with 1-year follow-up

The aim of the present study was to compare the clinical results and the quality of life in patients with symptomatic knee osteoarthritis randomised to either a new HA (HYADD 4) or corticosteroid (CS). A separate rationale was to evaluate the safety profile of HYADD 4.

All the patients presenting for unilateral symptomatic primary knee osteoarthritis were prospectively randomly assigned to receive 2 injections of either HYADD 4 or CS, and were evaluated before the injections and at 6, 12, 26 and 52 weeks. Primary end point was WOMAC score at 26 weeks; secondary end points were WOMAC score, VAS for pain, and SF-36 score at any time point.

There were 53 females and 22 males in the HYADD 4 group (mean age 71.5±10.6 years), and 50 females and 25 males in the CS group (mean age 68.6±9.9 years). The observed sided effects were mild and their incidence was similar in the two groups. Patients in the HYADD 4 group reported significantly better WOMAC scores at 26 weeks. The patients improved in all considered outcomes after the injections, with a peak of therapeutic effect between 6 and 12 weeks. Patients in the HYADD 4 group obtained significantly better scores than the CS group up to 26 weeks. At the 1-year follow-up no statistically significant differences between treatments were detected.

HYADD 4 did not have significantly higher side effects when compared to CS injections and provided better short-term (but not long-term) control of symptoms in patients with mild to moderate knee osteoarthritis. Patients with less pain and dysfunction at baseline may be the best candidates for HYADD 4 injections.