To evaluate the influence of a joint effusion on the clinical response to a single injection of Hylan GF-20 for hip osteoarthritis.

We prospectively included patients scheduled for intraarticular Hylan GF-20 injection to treat hip osteoarthritis. Disease severity was assessed based on the Kellgren-Lawrence radiological grade. Ultrasonography was performed to look for a joint effusion. The pain score on a visual analog scale, Lequesne algofunctional index, and WOMAC scores were recorded at baseline and 1, 3, and 6months postinjection. The proportions of patients who met OARSI response criteria and who achieved Patient Acceptable Symptom State (PASS) thresholds were determined in the overall population and in the groups with and without a joint effusion at baseline.

Of 55 included patients, 24 (44%) had an effusion at baseline. The baseline Lequesne index was significantly higher in the group with an effusion (11.9±3.6 versus 8.4±4.5) (p=0.003). The proportions of OARSI responders in the overall population were 31.8%, 39.4%, and 14.8% after 1, 3, and 6months, respectively. The proportions of patients who achieved the PASS for pain and function were 52.4% and 50.0% after 1month, 67.7% and 54.5% after 3months, and 60.0% and 50.0% after 6months, respectively. Presence of an effusion at baseline had no effect on any of the clinical response parameters.

Presence of a joint effusion is associated with worse pain and functional impairment at baseline but has no influence on the clinical response to Hylan GF-20 in patients with hip osteoarthritis.