Intra-articular hyaluronic acid injections for hip osteoarthritis.

Although viscosupplementation has been used in the past few years both for knee and hip osteoarthritis (OA), the number of intra-articular injections and the interval between doses still remains an undetermined subject. The aim of this open retrospective study was to evaluate the clinical and functional outcome in patients with mild-moderate hip OA treated with a course of 1, 2 or 3 Hyaluronic Acid (HA) intra-articular injections. Ninety-six patients were included: 19 patients received only one injection, 24 received two injections, and 44 received three injections. Age, sex, VAS for pain and WOMAC score before each intra-articular injection, number of intra-articular injections, reasons for interrupting the treatment, adverse events, time between HA injections, and number of patients who had a total hip replacement were retrieved from the medical records of each patient. VAS and WOMAC scores were obtained from all patients also at a mean follow-up of 7 months after the last hip injection. All patients who received 1, 2 or 3 hip injections improved in VAS and WOMAC score. Three intra-articular injections provided a better outcome in terms of pain reduction compared to 1 or 2 injections. Intrarticular injections for mild-moderate hip OA were demonstrated to be effective in reducing pain and improving function. A full course of three injections provided the best result in pain control.