A biomechanical comparison of the primary stability of two minimally invasive techniques for repair of ruptured Achilles tendon

Abstract

To compare the primary stability of two minimally invasive procedures of Achilles tendon (AT) repair, namely a modified percutaneous repair of ruptured AT and the Achillon suture configuration. Eighteen (nine matched pairs) frozen ovine ATs were tenotomized 5cm from the calcaneal insertion. In each pair, one tendon was randomly allocated to one of the two techniques: a modified percutaneous repair group and the Achillon device suture configuration. Specimens were tested performing an unidirectional tensile load to failure using a servo-hydraulic testing device (MTS Systems, Eden Prairie, MN, USA), controlled by an electropulse e3000 INSTRON machine (Instron Ltd, Buckinghamshire, UK). The tendons were then loaded to failure at a rate of 10mm/s. Two of the nine pairs of specimens were discarded because one specimen for each of the pair pulled out of the pneumatic clamp during mechanical testing. The remaining seven matched pairs were successfully tested. There were no differences in mean strength, mean maximum load, mean failure elongation, tension, stiffness and mode of failure between the two groups. The Achillon-like configuration and the modified percutaneous repair of ruptured AT provided similar biomechanical performance.