Changes in tendon strength after partial cut and effects of running peripheral sutures

We performed a study to evaluate the tensile properties of partial tendon lacerations and the effects of peripheral sutures on the tendon strength. Seventy-two fresh pig flexor digitorum profundus tendons were divided equally into eight groups. Tendons in four of the groups were subjected to partial lacerations (60%, 70%, 80%, and 90%) and were not repaired. In the other four similar groups partial lacerations were repaired with running peripheral sutures. The tendons were subjected to load-to-failure tests in an Instron tensile machine to determine the initial, 1mm, 2mm gap formation forces and the ultimate strength. The tendons with lacerations of 80% and 90% had a remarkably lower tensile strength than those 60% and 70% lacerations. Running peripheral sutures increased the gap formation forces and the ultimate strength of all the tendons, though particularly those with 80% and 90% lacerations.