To determine the effect of intra-articular hyaluronic acid (HA) on gait velocity, pain, and function, in older knee osteoarthritis (OA) patients.
Thirty knee OA patients (Kellgren-Lawrence II-III) [72.44 (± 6.11) years old] were randomized, using the 'RANDBETWEEN' function in Microsoft Excel, to receive three weekly injections of HA (2 ml of 20 mg/ml HA), or placebo (P) (1.2 ml of 0.001 mg/ml HA), with fifteen participants per group. Patients and assessors were blind to treatment. Self-selected and fast gait velocities were measured with the GAITRite system. Knee pain, stiffness, and physical function were measured with the Western Ontario McMaster Osteoarthritis OA index (WOMAC OA index). Data from 1 week, 3 and 6 months post-treatment were analyzed using repeated measures ANOVA.
The HA group significantly improved self-selected and fast gait velocity, while the P group only significantly improved self-selected gait velocity. Mean improvements in self-selected gait velocity [Mean (SD); 95% CI] [1.25 (52.4)cm/s; -18.38; 20.88] and fast gait velocity [7.16 (71.75)cm/s; -19.72; 34.04] were not significantly different between groups. Improvements in WOMAC pain scores were significantly greater in the HA group than the P group [-2.47 (6.39); -4.86; -0.08], while improvements in stiffness [-0.87 (2.42); -1.77; 0.04] and physical function [-7.23 (19.77); -14.63; 0.16] scores were not.
The overall effect of HA on gait velocity in older knee OA patients was not significant compared to placebo. The preliminary results of improved fast gait velocity following HA treatment should be investigated further, along with the incidence of falls, in a larger sample of older knee OA patients.ClinicalTrials.gov ID: NCT00778076.