Total hip replacement rate in a cohort of patients affected by symptomatic hip osteoarthritis following intra-articular sodium hyaluronate (MW 1,500-2,000 kDa) ORTOBRIX study

Hip osteoarthritis is very common and costly. The European League Against Rheumatology Committee agenda asks for research to investigate treatments able to slow down the progression of hip osteoarthritis (OA), to delay joint replacement, and to determine the comparative effectiveness and cost-effectiveness of non-surgical and surgical treatment modalities as well as criteria relating to the indications for and timing of total hip replacement (THR). After publishing the results of a randomized controlled trial and a cohort study on the efficacy of Intra-articular sodium hyaluronate (MW 1,500-2,000 kDa) on symptomatic hip OA, we performed this retrospective study in patients suffering from hip OA treated with ultrasound-guided intra-articular injections of HyalOne (Hyalubrix 60 Italian brand name) involving a group of THR expert orthopedic surgeons to appraise whether or not considered eligible for THR and the frequency and timing of THR. Six orthopedists, not routinely performing hip intra-articular injections, each independently assessed whether 176 patients suffering from hip OA and treated with ultrasound-guided intra-articular injections of sodium hyaluronate (MW 1,500-2,000 kDa) were candidates for THR according to the clinical data (age, body mass index, Pain Visual Analog Scale, Lequesne Algofunctional Index, global patient assessment, global physician assessment, nonsteroidal anti-inflammatory drug intake, and hip X-ray) collected at the first intra-articular sodium hyaluronate injection visit and provided as anonymous electronic data. At 24 months, 159 out of 76 (90 %) patients did not undergo to THR. At 48 months, 82 % (N = 144) of the study population treated with intra-articular hyaluronic acid avoided THR. In the group of 93 patients considered candidates for THR (that is, in which 4, 5, or 6 orthopedic surgeons agreed that the patient was a suitable candidate for THR), only 17 had undergone THR, with survival results of 82 % at 24 months. At 48 months, this percentage reduced to 66 % in this group. In the other groups of patients (in which respectively 3, 2, 1 or no surgeons were in agreement that the patient was a candidate for THR) arthroplasty is not recorded. Sodium hyaluronate (MW 1,500-2,000 kDa) given by ultrasound-guided injection seems to delay THR in the real context of actual overall management of symptomatic hip OA patients. Although further studies are necessary to confirm these data and to identify outcome predictors, hip viscosupplementation should be considered as conservative treatment to perform before proposing patients for THR.