Osteoarthritis occurs when inflammation and injury to a joint cause a breaking down of cartilage tissue. In turn, that breakdown causes pain, swelling, and deformity. Evaluate the effectiveness of viscosupplementation (HA) in hip osteoarthritis (OA) pain, disability, and adverse events.

Randomised controlled trials are comparing HA with any other intra-articular injection. Performed as per the Cochrane/GRADE criteria. Data were extracted and assessed the risk of bias and quality of evidence by two authors. Random-effects meta-analysis was conducted. Protocol registered on PROSPERO under CRD42015017312.

Eight RCTs were obtained (n = 807): among those four had the comparison of HA with placebo (PBO); three studies associated with platelet-rich plasma (PRP), three with placebo and methylprednisolone (MPA), and one study had the comparison of placebo with mepivacaine (MPV). Some RCTs had three arms. There is VERY LOW evidence that HA is not superior to PBO in pain at three months (SMD = - 0.06, p = 0.69), and HIGH evidence that is not superior in adverse events (RR = 1.21, p = 0.38). There is LOW evidence that HA is not superior to PRP for pain at one month. There is VERY LOW evidence that HA is not superior to PRP for pain at 6 and 12 months (mean difference in VAS in cm = -0.05; 1.0; 0.81, respectively). There is HIGH evidence that HA is no different from MPA for pain at one month (SMD = 0.02, p = 0.85). There is LOW evidence HA is no different from MPA for OMERACT-OARSI responders index at one month (RR = 0.44, p = 0.28; There is HIGH evidence HA is no different from MPA for adverse events (RR = 1.2, p = 0.38).

We do not recommend viscosupplementation for hip OA. Compared to placebo, data shows limited evidence of its efficacy up to 3 months and suggests no difference at six months. However, future RCTs could present HA as an alternative to MPA for short-term symptom relief.