Flexor tendon repair using a new suture technique: a comparative in vitro biomechanical study.

Background: The purpose of this experimental study was to evaluate the biomechanical characteristics of two new four-strand core suture techniques for flexor tendon repair.

Methods: The two new suture techniques (Marburg 1, Marburg 2) are characterized by four longitudinal stitches which are anchored by a circular or semicircular suture. They were compared with three commonly used core suture techniques (modified Kessler, Tsuge, Bunnell). Fifty porcine flexor tendons were randomly assigned to one of the five core suture techniques. Outcome measures included ultimate tensile strength, maximum of lengthening, mode of failure and 1 mm gap formation force.

Results: The highest ultimate tensile strength was found for the modified Kessler technique (115 N). Both new techniques showed an ultimate load exceeding 50 N (57 N for Marburg 1, 54 N for Marburg 2). The Marburg 1 technique showed the highest gap resistance of all tested suture techniques. The Bunnell and Tsuge core suture techniques produced the poorest mechanical performance.

Conclusions: From these experimental results, the new Marburg 1 core suture technique can be considered for flexor tendon repair in a clinical setting with the use of active motion protocols.