Effects of Repeated Co-Injections of Corticosteroids and Hyaluronic Acid on Knee Osteoarthritis: A Prospective, Double-Blind Randomized Controlled Trial

Background: We compared the effects of repeated co-injections of corticosteroids plus hyaluronic acid (HA) with the effects of HA injections alone in patients with knee osteoarthritis. Methods: A double-blind randomized controlled trial was conducted between October 2016 and July 2017 at a medical center. Patients (n = 57) who fulfilled the clinical and radiographic criteria for knee osteoarthritis established by the American College of Rheumatology with a Kellgren-Lawrence score of 2 or 3 were included. They were assigned to either the HA group (n = 29) or corticosteroids plus HA group (n = 28), and injections were administered under ultrasound guidance once a week for 3 consecutive weeks. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were the primary outcomes. Physical functional performance (10-m fast walking and chair-rising time) and the Knee Injury and Osteoarthritis Outcome Score (KOOS) were secondary outcomes. The assessment was performed prior to injections, 1 week, and 1, 3, and 6 months after injections. Data were analyzed through repeated-measures analysis of covariance. Results: Both groups experienced decreased pain and improved physical function and physical functional performance over time. We found significant group × time interaction effects favoring the corticosteroids plus HA group in WOMAC-pain (P = .005) and physical function (P = .005), chair-rising time (P = .032), and KOOS-pain (P = .001). Conclusions: Repeated co-injections of corticosteroids plus HA more effectively decreased pain and improved physical function and physical functional performance than injections of HA alone from 1 week through 6 months posttreatment.