Effectiveness and Tolerability of Repeated Courses of Viscosupplementation in Symptomatic Hip Osteoarthritis: A Retrospective Observational Cohort Study of High Molecular Weight Medium Molecular Weight Hyaluronic Acid No Viscosupplementation.

Nonsurgical management of symptomatic hip osteoarthritis needs real-world evidence. We evaluated the effectiveness and tolerability of US-guided intra-articular treatment of two hyaluronic acids (HAs) commercially available in Italy and investigated predictors of response. Outpatient records including three cohorts: 122 subjects treated with medium (1,500-3,200 kDa; Hyalubrix) molecular weight (MW) or high (hylan G-F20; Synvisc) MW HAs and 20 controls taking NSAIDs/analgesics on demand were retrospectively analyzed. Pain VAS score, WOMAC, NSAID/analgesic consumption, and causes of suspension were available at 1, 6, 12, and 24 months after first administration. As selection bias usually affects observational retrospective studies, a quasi-randomization process was attained by performing propensity score approach. Propensity score adjustment successfully allowed comparisons among balanced groups of treatments. VAS and WOMAC considerably decreased over time in treated groups independently of the radiological grade (p<0.001). On the other hand, the control group showed only a slight and rather uneven variation in VAS. Mean score changes were comparable in both HA cohorts from the earliest stages (ΔVAS(HA1,500-3,200kDa) = -20%; ΔVAS(hylan G-F20) = -23%/ΔWOMAC(HA1,500-3,200kDa) = -17%; ΔWOMAC(hylan G-F20) = -19%), reaching a further substantial reduction after 12 months (ΔVAS(HA1,500-3,200kDa) = -52%; ΔVAS(hylan G-F20) = -53%/ΔWOMAC(HA1,500-3,200kDa) = -45%; and ΔWOMAC(hylan G-F20) = -47%). Almost 11% (=13/122) of ineffectiveness and few moderate local side effects 3% (=4/122) were detected. Viscosupplementation in a real-life setting seems to provide a sound alternative in pain management in comparison to oral NSAIDs/analgesics, guaranteeing a reduced intake of pain killer medications. Analgesic effectiveness, functional recovery, and reduced joint stiffness extend and improve over 12 and 24 months, suggesting that repeated administrations achieve an additive effect.