Purpose: This study evaluated the tensile strength properties (maximum tensile load or ultimate tensile strength, and gapping at the repair site, and the pattern of failure) of flexor tendon repaired with barbed sutures.

Introduction: According to Strickland an ideal tendon repair should permit easy placement of sutures in the tendon, would allow smooth gliding, have secure suture knots with a smooth junction of tendon ends without gapping at the repair site, create minimal interference with tendon vascular, and have sufficient strength throughout healing to permit early motion of the tendon. The difficulty in satisfying all these criteria by any repair technique is probably reflected in the multitude of repairs described and currently utilized by practioners. There are many variations in the suture technique of placing core sutures. The described technique includes the Bunnell, Tsuge, Tajima, Strickland, Kessler, modified Kessler, Savage, Becker, modified Becker (MGH repair), and Indianapolis repair. Tendon repair ruptures usually occur at the suture knots. Adhesion formation remains the most common complication after flexor tendon repair, despite the widespread use of early-motion protocols. With these factors related to tendon repair failure considered, our department performed a pilot study using barbed sutures to repair lacerated flexor digitorum tendons. Barbed sutures (self-anchoring) have been developed by Quill Medical,in which bidirectional barbs are introduced into a suture that eliminates the need for tying a knot to obtain suture closure. The barbs are designed to grip tissue and obviate the need for tying a knot during tissue approximation. They can pass easily through tissue in one direction, but can not be reversed, therefore providing knot security.

Material & Methods: 160 cadaveric and porcine flexor tendons were harvested and cut. Repairs were performed using 0 or 2-0 barbed Nylons and same sizes standard Nylon. Modified Bunnell and Modified Kessler techniques were used.All repairs have been done without epitendonous suture. The repaired tendons were then tested for Maximum Load, Gap Strength, and Initial Gap, using a Tensiometer.

Result: Overall mean Maximum Load for barbed sutures was 41.12 N. Mean Maximum Load for 0 barbed Nylon was 55.90 N. Mean Maximum Load for 2-0 barbed Nylon was 37.46 N, and mean Maximum Load for 2-0 Nylon was 53.76. Mean Maximum Load for conventional 3-0 Ethibond was 31.25 N. These data are fairly consistent with what has been seen previously in the literature.

Summary: Overall, barbed sutures gave a stronger repair, especially when 0 barbed Nylons were used. Conventional 0 barbed Nylons would be clinically unfeasible, as the knots would be far too bulky. The ability to use this size of suture without the need for knot tying gives hand surgeons this option in repair of flexor tendon injuries.