Suture material for flexor tendon repair: 3–0 V-Loc versus 3–0 Stratafix in a biomechanical comparison ex vivo

BACKGROUND Barbed suture material offers the possibility of knotless flexor tendon repair, as suggested in an increasing number of biomechanical studies. There are currently two different absorbable barbed suture products available, V-Loc and Stratafix, and both have not been compared to each other with regard to flexor tendon repair. The purpose of this study was to evaluate both suture materials for primary stability under static and cyclic loading in a biomechanical ex vivo model. METHODS Forty fresh porcine flexor digitorum profundus tendons were randomized in two groups. A four-strand modified Kessler suture technique was used to repair the tendon either with a 3-0 V-Loc or 3-0 Stratafix without a knot. Parameters of interest were mode of failure, 2-mm gap formation force, displacement, stiffness and maximum load under static and cyclic testing. RESULTS The maximum load was 42.3 ± 7.2 for the Stratafix group and 50.7 ± 8.8 N for the V-Loc group. Thus, the ultimate tensile strength was significantly higher for V-Loc (p < 0.05). The 2-mm gap occurred at 24.8 ± 2.04 N in the Stratafix group in comparison to 26.5 ± 2.12 N in the V-Loc group (n.s.). Displacement was 2.65 ± 0.56 mm in the V-Loc group and 2.71 ± 0.59 mm in the Stratafix group (n.s.). Stiffness was 4.24 ± 0.68 (N/mm) in the V-Loc group and 3.85 ± 0.55 (N/mm) the Stratafix group (n.s.). Those measured differences were not significant. CONCLUSION V-Loc demonstrates a higher maximum load in tendon reconstruction. The differences in 2-mm gap formation force, displacement and stiffness were not significant. Hereby, the V-Loc™ has an advantage when used as unidirectional barbed suture for knotless flexor tendon repair.