Objective: The purpose of this randomized clinical trial was to compare the pain and knee function between a single-dose (Sodium hyaluronate 3%, 2 ml, 60 mg) versus two-weekly (Sodium hyaluronate 1.6%, 2 ml, 32 mg) intraarticular hyaluronic acid (HA) injections in mild to moderate symptomatic knee osteoarthritis (OA).
Materials and Methods: Sixty patients with clinically and radiographically confirmed knee OA were randomly divided into two groups for two HA injection regimens. The first group received a single-dose 60 mg HA, while the second group received two-weekly 32 mg HA injections. Pain and knee function were evaluated with the Visual Analogue Scale (VAS) and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) before injection and first, third, and sixth months after injections.
Results: There was no significant difference in baseline characteristics, including age, sex, body mass index, and OA grade, between the two groups (p:n.s. for all variables). Our analysis showed that total WOMAC and VAS mean scores improved compared to the baseline measurements (p<0.001 for both scores). However, regarding the minimal important change (MIC) values for both VAS and WOMAC, there was no significant difference between the groups at the final follow-up (p=0.217 and p=0.500, respectively). An adequate pain reduction could not be achieved in more than half of the patients (56.6%), and almost half (45%) did not have a clinically significant increase in knee function at the final follow-up according to MIC values. No major complications were seen.
Conclusion: This study failed to show a significant benefit or clinically important change after viscosupplementation regardless of the tested dosing regimens.