Barbed Suture Tenorrhaphy: An Ex Vivo Biomechanical Analysis

BACKGROUND: Using barbed suture for flexor tenorrhaphy could permit knotless repair with tendon-barb adherence along the suture's entire length. The purpose of this study was to evaluate the tensile strength and repair-site profile of a technique of barbed suture tenorrhaphy. METHODS: Thirty-eight cadaveric flexor digitorum profundus tendons were randomized to polypropylene barbed suture repair in a knotless three-strand or six-strand configuration, or to unbarbed four-strand cruciate repair. For each repair, the authors recorded the repair site cross-sectional area before and after tenorrhaphy. Tendons were distracted to failure, and data regarding load at failure and mode of failure were recorded. RESULTS: The mean cross-sectional area ratio of control repairs was 1.5 +/- 0.3, whereas that of three-strand and six-strand barbed repairs was 1.2 +/- 0.2 (p = 0.009) and 1.2 +/- 0.1 (p = 0.005), respectively. Mean load to failure of control repairs was 29 +/- 7 N, whereas that of three-strand and six-strand barbed repairs was 36 +/- 7 N (p = 0.32) and 88 +/- 4 N (p < 0.001), respectively. All cruciate repairs failed by knot rupture or suture pullout, whereas barbed repairs failed by suture breakage in 13 of 14 repairs (p < 0.001). CONCLUSIONS: In an ex vivo model of flexor tenorrhaphy, a three-strand barbed suture technique achieved tensile strength comparable to that of four-strand cruciate repairs and demonstrated significantly less repair-site bunching. A six-strand barbed suture technique demonstrated increased tensile strength compared with four-strand cruciate controls and significantly less repair-site bunching. Barbed suture repair may offer several advantages in flexor tenorrhaphy, and further in vivo testing is warranted.