Objective: To observe the clinical effect and mechanism of iontophoresis of Tongluo Zhitong powder articular cavity injection of sodium hyaluronate on the early and medial stages of the knee osteoarthritis. Method: Ninty-eight patients were randomly divided into observation group( n=49) and control group (n=49). Control group were treated with articular cavity injection of sodium hyaluronate

20 mg each time

1 time each week

for 5 weeks. Observation group were treated with iontophoresis of Tongluo Zhitong powder on the basis of control group

2 times each day

for 5 weeks. The symptoms and signs of patients were tested by the Western Ontario and McMaster Universities (WOMAC) scores. The level of hyaluronic aci (HA)

tumor necrosis factor-α (TNF-α) and interleukin-1β(IL-1β) of knee joint synovia in pretherapy and post-treatment were detected. Result: The total effective rate of observation group (97.96%) was superior to control group (81.63%)(P<0.01). The scores of WOMAC which including pain

stiffness

swell and tenderness of observation group were lower than control group (P<0.01). The level of HA in observation group was higher than control group and the level of TNF-α and IL-1β in observation group was lower than control group (P<0.01). Conclusion: The clinical curative effect of iontophoresis of Tongluo Zhitong powder combining with articular cavity injection of sodium hyaluronate on KOA is significant. The mechanism of action may be related with increasing the concentration of HA and decreasing the level of TNF-α and IL-1β.