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 degrees external rotation, 180 degrees external rotation, 270 degrees external rotation and 360 degrees 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 degrees did not decrease the biomechanical properties of the graft.