High-Strength Suture Tapes Are Biomechanically Stronger Than High-Strength Sutures Used in Rotator Cuff Repair

Abstract

PurposeTo assess the mechanical properties, tendon resistance to suture cutout, and knot size of a broad variety of high-strength sutures and tapes available for arthroscopic rotator cuff repair.MethodsNine different types of high-strength sutures and tapes for arthroscopic rotator cuff repair were studied: 6 were tapes (FiberTape, Hi-Fi Tape, Permatape, SutureTape, UltraTape, and XBraid TT), and 3 were sutures (Dynacord, FiberWire, and Ultrabraid). First, mechanical tensile testing of suture loops (n = 6) was performed. Second, the suture material was passed through an intact human cadaveric rotator cuff tendon (supraspinatus or infraspinatus), and cyclic as well as load-to-failure testing was performed, 8 times for each suture or tape. Statistical analysis of groups (tapes vs sutures) and between each suture and each tape was performed.ResultsMaterial testing revealed significant differences with superior mechanical properties of tapes compared with sutures regarding load for 3 mm of displacement (201 N vs 84 N, P < .0001), displacement at 200 N (3.6 mm vs 6.6 mm, P < .0001), stiffness (46 N/mm vs 25 N/mm, P < .0001), and ultimate load to failure (509 N vs 288 N, P < .0001). FiberTape showed the highest ultimate load to failure (805.5 ± 36.1 N), the highest load necessary for 3 mm of displacement (376.2 ± 19.1 N), and the lowest displacement at a 200-N load (2 ± 0.1 mm). Permatape had the highest stiffness (58.5 ± 5.3 N/mm). FiberTape had the highest knot height (9.5 ± 1.3 mm) and knot width (3.8 ± 0.7 mm) of a suture loop with 7 square knots. The typical failure mode in the cadaveric study part was tendon cut through.ConclusionsBiomechanical in vitro testing showed that high-strength suture tapes compared with regular high-strength sutures have significantly better mechanical properties in both dry-laboratory testing and human cadaveric rotator cuff tendon pullout testing. FiberTape outperformed the other tapes and the sutures used in this analysis. Nonetheless, differences in tendon testing appeared to be less substantial than in dry-laboratory testing, and FiberTape had the highest knot height and width.Clinical RelevanceFiberTape revealed the most favorable biomechanical performance in dry-laboratory and rotator cuff tendon testing. It may provide the best repair strength in vivo; however, it also has the largest knot size.