A Biomechanical Comparison of Tendon Repair with a Knotless Barbed Suture and a Conventional Monofilament Suture Material: An ex-vivo Animal Experiment

Objective: Our aim is to compare the ultimate tensile strength and stiffness of a 2/0 barbed suture and a 3/0 polypropylene monofilament suture in a porcine tendon repair model. Methods: Sixteen porcine Achilles tendons were transected and separated into two groups. In group I tendons were repaired with a modified knotless four-strand Kessler technique using a 2/0 V-Loc barbed suture. In group II tendons were repaired with a four-strand Kessler technique using a 3/0 monofilament conventional suture and knots were tied. All specimens were biomechanically tested for ultimate tensile strength (UTS) and stiffness. Mode of failure was also noted. Results: Five specimens in group I failed by stripping of the suture from the tendon tissue, three failed due to suture breakage. In group II two out of eight tendons failed by stripping of the suture and remaining six failed by suture breakage. Median UTS value was found to be 85.96 N (range: 63.24) in group I and 64.29 N (range: 56.84) in group II. Median stiffness value of the samples in group I was found to be 5.67 N/mm (range: 4.32) and in group II it was found to be 4.53 N/mm (range: 6.23). The statistical analysis of UTS and stiffness values revealed no significant difference between the groups (p=0.17 and p=0.56 respectively). Conclusion: A knotless Kessler tendon repair made with a 2/0 barbed suture is biomechanically equivalent to a knotted Kessler tendon repair made with a 3/0 conventional polypropylene suture in ex-vivo conditions.