Abstract: A Comparison of Epitendinous Repair Techniques for Flexor Tenorraphy

Abstract

INTRODUCTION: The purpose of the epitendinous component of flexor tendon repairs was originally thought to just “tidy-up” the repair site but it is now recognized that it has a structural role and contributes approximately 20% to the strength of the repair. Polypropylene (Prolene™) has been the most popular material for epitendinous repairs yet little research has been carried out on other materials. We hypothesized that a polyester (Ethibond™) epitendinous suture would significantly increase the overall tensile strength of flexor repairs compared to a traditional polypropylene suture in an ex-vivo porcine model. METHODS: Eighty porcine tendons were transected and randomly assigned to one of four repair groups; Group 1: 3-0 polyester core and 5-0 polyester epitendinous; Group 2: 3-0 polyester core and 5-0 polypropylene epitendinous; Group 3: 3-0 polypropylene core and 5-0 polyester epitendinous; and Group 4: 3-0 polypropylene core and 5-0 polypropylene epitendinous. A cross-locked cruciate technique was used for all core sutures. A simple continuous suture was utilized for the epitendinous repair in all groups. Biomechanical testing was carried out with a tensiometer and the ultimate strength, 2mm gap-formation force and method of failure were recorded. RESULTS: Group 1 (96.3 ± 15.77N) with 3-0 polyester core and 5-0 polyester epitendinous repairs had significantly greater tensile strengths and 2mm gap forces than the Groups 2,3 and 4 (70.12 ± 11.4N, 62.9 ± 8.52N and 46.27 ± 9.18N respectively). The addition of a running 5-0 polyester epitendinous repair significantly improved the tensile strengths of both Groups 2 and 3. CONCLUSION: This study has demonstrated that a running polyester epitendinous suture significantly augments the strength of flexor repairs when compared to a traditional epitendinous polypropylene suture. Further study is certainly warranted in animal models looking at different types of epitendinous repair techniques. The authors feel that a 5-0 polyester suture should be considered for the epitendinous component of flexor tenorraphy as we have demonstrated that it produces a stronger repair with less gapping than traditional techniques in a porcine model.