Immediate and Late Effect of Sutures in Extrasynovial Tendons: Biomechanical Study in Rats.

OBJECTIVE The aim of this study was to evaluate the effects on the mechanical properties of rats' calcaneus tendons, of repair arrangements using suture material in the absence of any healing process. METHOD Twelve male Wistar rats were used. They were subjected to placement of a modified Kessler suture stitch in the calcaneus tendon. The sacrifices were performed immediately after and six weeks after the operation. The mechanical properties studied were maximum load, tension in the maximum load and module of elasticity. The contralateral tendon was used as a control. RESULTS The statistical analysis showed that for the times studied, the values for mechanical properties did not present any significant differences. In relation to the control, i.e. the contralateral tendon without a suture, the results demonstrated that, six weeks after the operation, the values for the modulus of elasticity were lower, whereas there were no significant variations in maximum load or tension at maximum load. CONCLUSION Placement of suture material on an extrasynovial tendon without lesions decreased the modulus of elasticity, but it did not interfere with the maximum load or tension at maximum load, six weeks after the operation.