Biomechanical comparison of suture materials across a bone tunnel edge

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.

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.

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.

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.