This study sought to use a systematic review to ascertain the efficacy and safety of hyaluronic acid (HA) in the treatment of hip osteoarthritis (OA).
A protocolized search was made of a number of electronic databases, including Medline, EMBASE, Cochrane Library and Health Technology Assessment (HTA) among others. Two independent reviewers applied a series of inclusion and exclusion criteria to the studies located in the search, and selected only those that included more than 20 patients; had a follow-up period of more than 1 week; and exclusively assessed the efficacy and/or effectiveness of HA in patients with confirmed hip OA.
A total of eight studies, comprising clinical trials and one review, met the inclusion criteria, and had study populations ranging from 22 to 104 patients. Only two of the trials were controlled: one compared two HAs of different molecular weights; and the other compared HA with corticoids and a placebo. Relief of pain was estimated to be around 40-50% by most studies, though the duration of this post-treatment effect was not known.
Based on available evidence, HA treatment should only be used under careful supervision by the clinician and just in those cases where other treatments have failed in hip OA. There are methodologic limitations displayed in the literature, which were mainly the absence of a control group in most of the studies, overly short follow-up periods, and different ways of measuring outcomes.