Effect of shockwave treatment on tendon injury in rats

Objective To evaluate the effect of extracorporeal shock wave therapy on rats with tendon injury. Methods Forty-three male rats were randomly selected and divided into 3 groups: treatment group (n=20), control group (n=20), blank group (n=3). Rats n blank group did not receive any treatment, and tendon injury models were established with rats in treatment and control groups. Rats from treatment group were given extracorporeal shock wave therapy with the power of 0.16 mJ/mm for 3 000 times, once per day for a week, and then rats were sacrifced after treatment for 1 d, 3 d, 7 d, 14 d, 21 d. The tendon tissue were taken and observed under light microscope. Morphology changes and VEGF levels were detected and evaluated by ELISA. Results In control group, he tissue of tendon showed irregular arrangement, the regenerated tendon fber was unapparent, and scar tissue was formed after njury for 1 d, 3 d, 7 d, 14 d, 21 d. While in treatment group, the tissue of tendon was observed with edema and hyperemia and the collagen fber network was destructed after treatment for 1 d, 3 d, 7 d. The tendon cells were regenerating, the collagen fber network howed regular arrangement, and no apparent scar tissue was observed at 14th d, 21th d after treatment compared with control group. The level of VEGF in control group increased gradually after injury for 1 d, 3 d, 7 d, 14 d, and it achieved its maximum at 21th d. In herapy group, the level of VEGF increased at 1st d, 3rd d, 7th d, 14th d after treatment, and it achieved its maximum at 14th d, while t decreased at 21th d. Conclusion Extracorporeal shock wave therapy can improve the repair of injury tendon effectively.