Ultrasound-Guided Injection of High Molecular Weight Hyaluronic Acid versus Corticosteroid in Management of Plantar Fasciitis: A 24-Week Randomized Clinical Trial

Background and Aims: Plantar fasciitis (PF) is the leading cause of heel pain in adults. This study was designed to evaluate the effect of hyaluronic acid (HA) injection in reducing the symptoms of PF, compared with corticosteroid (CS) injection as a conventional treatment. Methods: In this triple-blind, randomized, clinical trial, 75 patients who had the symptoms of PF for at least 3 months were randomly divided into two groups of 38 and 37 individuals. Then, each patient received either a single injection of high molecular weight (>2000 kDa) HA (1 mL HA 20 mg + 1 mL lidocaine 2%) or CS (1 mL methylprednisolone 40 mg + 1 mL lidocaine 2%) under the ultrasonography (US) guidance. Visual analog scale (VAS), foot ankle ability index (FAAI), pressure pain threshold (PPT), functional foot index (FFI), and plantar fascia thickness (PFT) were measured using US at baseline, 6 weeks and 24 weeks after the injection. Eventually, at the end of the treatment period, the patients' satisfaction was measured. Intention to treat analysis was used to assess the results. Results: After 24 weeks of follow-up, results from 60 subjects were fully obtained; however, results of 73 patients included into intention to treat analysis in the sixth-week follow-up. In both groups, VAS, PFT and FFI decreased, while FAAI and PPT increased significantly (P <0.001). At the baseline and at the 24th-week, no significant difference between the two groups was observed in any of the variables. However, a comparison between the baseline and the sixth-week results shows a prominent decrease in PPT and PFT in the CS group compared to the HA group (P = 0.004 and P = 0.011). Finally, there were no statistical differences between the two groups in treatment satisfaction (P = 0.618). Conclusion: Both CS and HA were effective modalities for PF and can improve pain and function with no superiority in 24th-week follow-ups, although CS seems to have a faster trend of improvement in the short term.