• OBJECTIVE
    • To assess the efficacy of viscosupplementation (hyaluronic acid [HA]) on the pain and disability caused by hip osteoarthritis, and to determine the occurrence of adverse events.
  • DATA SOURCES
    • PubMed, EMBASE, Cochrane Library, ClinicalTrials.gov database, and specific journals up to March 2017.
  • STUDY SELECTION
    • Randomized controlled trials (RCTs) comparing HA with any other intra-articular injection.
  • DATA EXTRACTION
    • Performed according to Cochrane/Grades of Recommendation, Assessment, Development, and Evaluation criteria. Two authors extracted data and assessed the risk of bias and quality of evidence. A random-effects meta-analysis was conducted.
  • DATA SYNTHESIS
    • Eight RCTs were retrieved (n=807): 4 comparing HA to placebo; 3 to platelet-rich plasma (PRP); 3 to methylprednisolone; and 1 to mepivacaine. Some RCTs had 3 arms. There is very low evidence that HA is not superior to placebo for pain at 3 months (standardized mean difference [SMD]=-.06; 95% CI, -.38 to .25; P=.69), and high evidence that it is not superior in adverse events (risk ratio [RR]=1.21; 95% CI, .79-1.86; P=.38). There is low evidence that HA is not superior to PRP for pain at 1 month. There is very low evidence that HA is not superior to PRP for pain at 6 and 12 months (mean difference in visual analog scale [in cm]: -.05 [95% CI, -.81 to .71], 1.0 [95% CI, -1.5 to 3.50], and .81 [95% CI, -1.11 to 2.73], respectively). There is high evidence that HA is no different from methylprednisolone for pain at 1 month (SMD=.02; 95% CI, -.18 to .22; P=.85). There is low evidence that HA is no different from methylprednisolone for Outcome Measures in Rheumatoid Arthritis Clinical Trials-Osteoarthritis Research Society International Responders Index at 1 month (RR=.44; 95% CI, .10-1.95; P=.28). There is high evidence that HA is no different from methylprednisolone for adverse events (RR=1.21; 95% CI, .79-1.87; P=.38).
  • CONCLUSIONS
    • We do not recommend viscosupplementation for hip osteoarthritis. Compared with placebo, data show scarce evidence of its efficacy up to 3 months, and suggest no difference at 6 months. However, future RCTs could present HA as an alternative to methylprednisolone for short-term symptom relief.