Isokinetic muscle strength in patients with osteoarthritis before and after hyaluronic acid therapy

Aim: In the study we evaluted the effectiveness of intraarticular injected hyaluronic acid (Hyalart(R)) with regard to the changes in the parameters m aximal isokinetic muscle strength, total work, pain at rest, and pain under toad. Method: We examined 43 patients with osteoarthritis in both knee joi nts (Kellgren II or II according to X-ray) in right/left comparison. We use d the isokinetic system Cybex 600 for measuring the maximal isokinetic musc le strength and the total work. We used the visual analog scale for the pal n. The evaluated parameters were measured before and after a 5-week treatme nt phase with 5 intraarticular injections (one injection per week with 20 m g hyaluronic acid). Results: In knees treated with hyaluronic acid the mean peak torque of the knee extensor was 57 +/- 26.15/32 +/- 19.63 Nm vs. 77.1 7 +/- 32.54/47.83 +/- 21.43 Nm after (p<0.01), the mean peak torque of the knee flexor was 40.44<plus/minus>21.58/22.89 +/- 16.64 Nm vs. 53.55 +/- 24. 26/34.05 +/- 17.37 Nm after treatment (p<0.01) at the angular velocities of 60<degrees>/s and 180 degrees /s. Significant differences (p>0.01) between treated and untreated knee were found for total work of the extensor and f lexor of the knee. The pain at rest decreased from 3.83 +/-1.72 cm to 1.36 +/-1.42 cm and the pain under load decreased from 7.57 +/-1.34cm to 3.75 +/ -1.32 cm in the treated knee group (p<0,01). Conclusion: The intraarticular injection of hyaluronic acid is effective and safe in the treatment of pat ients with gonarthrosis. The treatment resulted in a functional improvement of the knee joint and had a good pain lowering effect in patients sufferin g from gonarthrosis.