Oral administration of polymer hyaluronic acid alleviates symptoms of knee osteoarthritis: a double-blind, placebo-controlled study over a 12-month period

Tashiro T, Seino S, Sato T, et al. · The Scientific World Journal

Across the 38 analysed, the total JKOM score fell in both arms and did not differ between them at any of the four time points, nor did the pain-and-stiffness, daily-life or general-activity subscales; only the four-item 'health conditions' subscale was lower on HA at every visit. In the 21 subjects aged 70 or under the total score was lower on HA at 2 and 4 months but not at 6 or 12; in the 17 aged 71 or older nothing separated. Kellgren-Lawrence grade did not change in either arm over the year, and use of NSAIDs and of intra-articular HA did not differ.

Population

Japanese adults aged 50 or older (mean 69) with symptomatic Kellgren-Lawrence grade 2 or 3 knee osteoarthritis; 60 randomised, 38 analysed

Intervention

High-molecular-weight oral hyaluronic acid 200 mg/day for 12 months, plus daily quadriceps exercises in both groups

Comparator

Placebo (plus the same exercises)

Limitations

Authors from Kewpie Corporation (product manufacturer); 22 of 60 excluded from analysis for withdrawal, possible side effects or poor adherence; a daily quadriceps-exercise co-intervention in both arms, and intra-articular HA injection allowed during the trial. The headline benefit is a subgroup result at two of four time points in a 60-person trial, and the pain subscale never separated from placebo.