Biomechanical analysis in the early period of flexor tendon healing after decimeter wave therapy / 中华物理医学与康复杂志

ABSTRACT

Objective To investigate the biomechanicai characteristics of flexor profundus tendons repaired after decimeter wave therapy, and to observe the effect of decimeter wave therapy on early active mobilization. Methods A total of 56 Leghorn chickens were randomly divided into a therapy group and a control group with 28 chickens in each. The 3rd and 4th toes of their left feet were employed for the establishment of a tendon injury model. The flexor profundus tendons were cut and repaired. Gypsum support was applied and fixed with an adhesive plaster after the operation. The operated sites on toes Ⅲ and Ⅳ were exposed. The external fixation was removed 3 weeks later and the chickens were left free to move. Decimeter wave therapy ( frequency 915 MHz, power 8 Watts) was ap-plied for 10 minutes once daily on the left foot of each chicken in the therapy group from day 1 until 3 weeks after the operation. Sham decimeter wave therapy was applied to chickens in the control group. Four chickens from each group were randomly selected at the 1st, 7th, 10th, 14th, 18th, 21st and 28th days for biomechanical analysis. Biome-chanical parameters including tensile strength of rupture (Pmax), elongation ratio at rupture (δimax) and the tensile adhesion strength of the rupture zone (W0>) were observed at each time point. Results At the 7th, 10th, 14th, 18th, 21st and 28th day after the operation, the differences in Pmax, δmax and W0 between the therapy and control groups were statistically significant. The results of the therapy group were better than those of the control group. Conclusions Local decimeter wave therapy after flexor tendon repair can promote intrinsic healing and reduce ex-trinsic healing. The speed and quality of healing are improved. The elasticity and tenacity of the injured tendons are enhanced. Therefore decimeter wave therapy is helpful for early active mobilization training.