Abstract:

BACKGROUND: Ultrasound has been clinically used to treat acute and chronic soft tissue injury, but the ultrasonic treatment for tendon contracture has been rarely reported.
OBJECTIVE: To observe the effect of ultrasonic treatment on level of interleukin 1β (IL-1β) in Achilles of stress-shielded rats．
METHODS: Twenty-four SD rats were randomly divided into three groups: normal group, model group, and ultrasound treatment group. The left hind limbs of all rats of the later two groups were modeled using Achilles tendon cerclage combined with sciatic nerve cut method. At 3 weeks after surgical operation, the treatment group was subjected to ultrasound treatment, strength 1W/cm2, frequency 1MHz, inflation ratio 20%, 5 days per week, once per day, 10 minutes once, for a total of 3 weeks. At 6 weeks post-surgery, the left hind limb Achilles tendon tissue was detected by transmission electron microscopy and the level of IL-1β was detected by enzyme-labeled immunosorbent assay. 
RESULTS AND CONCLUSION: After 3 weeks of ultrasound treatment, collagen fibers arranged neater than in the model, small fibers decreased, closed to the control group. The level of IL-1β in the model group was significantly higher than the normal group. After ultrasound treatment, the level of IL-1β was dramatically decreased. The results suggested that ultrasound treatment played an effective role in the treatment of Achilles tendon contracture, which might reduce the level of IL-1β in the Achilles tendon.