Hyaluronic acid minimally effective for knee osteoarthritis.

HYALURONIC acid; OSTEOARTHRITIS; KNEE diseases; THERAPEUTICS; META-analysis; CLINICAL trials; PLACEBOS

Presents answers to a question "Is intra-articular hyaluronic acid effective in the treatment of knee osteoarthritis?". Intra-articular hyaluronic acid is minimally, if at all, more effective than placebo in the treatment of knee osteoarthritis. The evidence of publication bias against negative trials in this meta-analysis suggests that any overall positive effect is overestimated. The highest-molecular-weight hyaluronic acid may be more effective than lower-molecular-weight hyaluronic acid. Intra-articular hyaluronic acid for knee osteoarthritis is an expensive therapy that has been widely used since the United States Food and Drug Administration approval in 1997. Two independent researchers performed an extensive search for both English-language and non-English-language studies on MEDLINE and the Cochrane Controlled Trials Register, and in manuscript bibliographies and abstracts from scientific meetings. From a total of 57 initial studies identified, 22 met the inclusion criteria. In almost all the trials, the 95 percent confidence intervals included an effect size of zero, consistent with no effect of the treatment.