Knee Surgery, Sports Traumatology, Arthroscopy June 2019, Volume 27, Issue 6, pp 1992–2002

Single intra-articular injection of lightly cross-linked hyaluronic acid reduces knee pain in symptomatic knee osteoarthritis: a multicenter, double-blind, randomized, placebo-controlled trial

Petterson, S.C. & Plancher, K.D.


The primary objective was to demonstrate the safety and effectiveness of Monovisc™ in the relief of joint pain in patients with idiopathic knee OA compared to saline injection. It was hypothesized that patient success, defined as ≥ 50% improvement from baseline and ≥ 20 mm absolute improvement from baseline in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) visual analog scale (VAS) pain score, would be greater in the Monovisc™ group compared to the Saline control group.



In this multicenter, double-blind, randomized, placebo-controlled trial, patients with idiopathic, symptomatic, knee OA were randomized to either 4 ml single injection of Monovisc™ or 4 ml injection of 0.9% saline. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was used to assess patient outcomes at 2, 4, 8, 12, 20, and 26 weeks post-injection. The primary effectiveness endpoint was a 50% improvement and ≥ 20 mm improvement from baseline in the WOMAC pain through 26 weeks. Secondary outcome measures included a ≥ 20 mm improvement from baseline on the WOMAC physical function, patient global assessment, evaluator global assessment, and knee range of motion.



369 patients (154 male, 215 female) were randomized to either Monovisc™ or saline. The Monovisc™ group had a significantly greater rate of patient success (e.g. ≥ 50% improvement and ≥ 20 mm absolute improvement from baseline in the WOMAC pain through Week 26) compared to saline (p = 0.043).



Monovisc™, a single-injection intra-articular HA device, is a safe and effective treatment for providing a clinically meaningful reduction in knee pain within 2 weeks. The results of this study support the use of a single injection of hyaluronic acid (Monovisc™) for patients with symptomatic knee OA in patients older than 45 years, as a safe and effective alternative for patients who may want an alternative treatment modality or may not be candidates for partial or total knee replacement.


Level of evidence

I, multicenter, double-blind, randomized, placebo-controlled trial.

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