Biomechanical properties after pre-twist of canine patellar tendon

We studied what effect a rotational pre-twist of the patellar tendon had on its mechanical properties. We used the central strip of canine patellar tendons. The length, width and thickness of each specimen were measured and the specimens were mounted in custom-made aluminum pots. Five groups of 10 specimens each were measured with neutral rotation, 90° external rotation, 180° external rotation, 270° external rotation and 360° external rotation. The ultimate stress, ultimate strain, average elastic modulus, and strain energy density were measured. There were no statistically significant differences among the five groups. Twisting the graft up to 360° did not decrease the biomechanical properties of the graft.