A biomechanical study of flexor tendon repair in zone II: comparing a combined grasping and locking core suture technique to its grasping and locking components.

INTRODUCTION: All previous experimental and clinical repairs of flexor tendons in zone II have used either a grasping or a locking technique. In this article, a combined (grasping and locking) repair was compared biomechanically to its grasping and locking components.
METHODS: Using fresh flexor profundus adult sheep tendons, three techniques of tendon repair were tested biomechanically: the 'three figure-of-eight sutures' (a six-strand grasping technique), the 'locked cruciate repair' (a four-strand locked technique) and the 'combined technique' (a 10-strand repair using both the figure-of-eight and cruciate sutures). All repairs were tested to single-cycle tensile failure using a computerised tensometer. For each repair, the 2-mm gap force and the ultimate breaking (failure) force were recorded.
RESULTS: Biomechanically, the combined repair was found to be the strongest regarding both gap and failure (P<0.025; two-tailed by the Mann-Whitney test).
CONCLUSION: The combined 10-strand repair is stronger biomechanically than its grasping and locking components.