Biomechanical comparison of suture materials across a bone tunnel edge.

INTRODUCTION: Wrist reconstructive procedures commonly use synthetic materials passed through transosseous tunnels to stabilize the carpus. This experimental study compared the tensile mechanical properties of common sutures and synthetic tapes across a bone tunnel edge. We hypothesized that failure would primarily occur at the cortical bone edge owing to abrasion at the suture-bone interface and that increasing strand number would increase construct stiffness and decrease failure.

METHODS: Five suture materials (SutureTape, LabralTape, FiberTape, Ethibond, and Mersilene) were tested in one-, two- and four-strand configurations, with 12 constructs per group. Constructs were passed through a 2.5 mm transverse tibial bone tunnel and secured to a servohydraulic testing apparatus with knotless fixation. Testing simulated physiologic scapholunate ligament loading with 1000 cycles from 0 to 100 N at 1.5 Hz followed by ramp loading to 300 N. One-way ANOVA with Tukey post hoc analysis (α = 0.05) evaluated load at failure and percentage elongation.

RESULTS: Single-strand SutureTape, Mersilene and Ethibond demonstrated greater elongation at 100 N than single-strand LabralTape and FiberTape (p < 0.001). Mersilene and Ethibond elongated significantly more than SutureTape. Increasing strand number decreased elongation, although not proportionally to the number of strands. Single-strand Ethibond and Mersilene had the highest failure rates and lowest failure loads. No single- or double-strand LabralTape or FiberTape constructs failed at the bone tunnel edge.

CONCLUSION: Synthetic suture and tape constructs demonstrated differing mechanical properties and failure modes across a bone tunnel edge. Material selection and strand configuration may influence construct stiffness, elongation, and failure risk for ligament reconstruction.