The Fracture Stress of Rat Achilles Tendons

For the determination of the fracture stress of soft tissues both the fracture force and the cross sectional area are required. For short tissues these prerequisites are difficult experimental tasks. The determination of the fracture force necessitates proper gripping without damaging the tissues or altering their properties. In order to meet this challenge the rapid-freezing technique was employed, modified to ensure that the tendon was not frozen. On the other hand an accurate value of the cross sectional area of short soft tissues is difficult to be obtained using conventional techniques. In this context a novel procedure is proposed here based on the histologically-measured cross-sectional area of the dehydrated tendon after the biomechanical testing. Combination of these solutions permitted the performance of tension tests for rat Achilles tendons and calculation of their fracture stress. The values of the Achilles tendon failure stress, as estimated above, exhibited considerably lower scattering compared to those of the fracture forces.