Biomechanical comparison of three methods for distal Achilles tendon reconstruction.

Abstract

To compare the load at failure and stiffness associated with three surgical techniques for distal Achilles tendon reconstruction (AT). Nine matched pairs of fresh-frozen human cadaveric ATs were divided into three groups. Distal AT reconstruction was performed using suture anchors or one of two lengths of tendon overlap (10 or 5 mm). Each tendon was loaded to failure. The load at failure (N), stiffness (N/mm), and mode of failure were recorded. Differences in load at failure and stiffness were analysed. Mean load at failure was significantly higher in the 10-mm group than in the 5-mm group (p < 0.05) or the suture-anchor group (p < 0.05). Load at failure did not differ significantly between the suture-anchor and 5-mm group, and stiffness did not differ significantly between any two groups. In the 10- and 5-mm groups, failure was caused by the grafts pulling out through the substance of the AT. Modes of failure varied in the suture-anchor group. The load at failure was higher in the 10-mm group than in the 5-mm and suture-anchor groups. Although all three surgical techniques provide sufficient primary load-bearing ability, the 10-mm tendon-overlap technique may be more conducive to early post-operative rehabilitation.