In Vitro Biomechanical Testing of the Tube Knot

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Vet Surg. 2016 Oct;45(7):962-967. doi: 10.1111/vsu.12529. Epub 2016 Aug 23. In Vitro Biomechanical Testing of the Tube Knot. Chang S1, Dong F2, Lagman M3, Schmidt PL1, Irizarry KL1, Schulz D4, Fahie MA5. Author information Abstract OBJECTIVE: To compare in vitro biomechanical properties of the tube knot (TB) to a crimp clamp (CC) system, and square knot (SQ) using 3 monofilament materials. STUDY DESIGN: In vitro biomechanical study. SAMPLE POPULATION: Suture loops (n=20 per material/knot construct). METHODS: Monotonic tensile loading (300 mm/min single pull to failure) was performed on knots tied using 3 knots (TB, 5-throw SQ, and CC system) with each of 3 materials (40# Securos® nylon, #2 polypropylene, and #2 nylon). Ultimate tensile strength, elongation, and stiffness were measured and compared by sequential 1- and 2-way ANOVA. RESULTS: Ultimate tensile strength was greatest with 40# nylon CC (mean ± SD, 293.6 ± 26.2 N), followed by TB (289.8 ± 9.2 N) and SQ (252.2 ± 8.5 N) with no significant difference between CC and TB. TB with #2 polypropylene (158.1 ± 7.4 N) and #2 nylon (126.3 ± 5.5 N) had significantly greater tensile strength than SQ with #2 polypropylene (143.6 ± 5.3 N) and #2 nylon (110.7 ± 6.2 N). Elongation at failure was significantly greater in 40# nylon TB (25.3 ± 3.2 mm) and SQ (10.8 ± 1.6 mm) compared to CC (5.3 ± 1.0 mm). Both material and knotting method had an effect on ultimate tensile strength, elongation at failure, and stiffness, based on 2-way ANOVA. CONCLUSION: Ultimate tensile strength of TB was equivalent to that of CC; however, elongation at failure was greatest for TB, which may be of concern for clinical applications. © Copyright 2016 by The American College of Veterinary Surgeons.

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Why is it important?

This knot has potential application for any surgical procedure where you need a secure knot that can be adjusted to proper tightness before it is locked (for example, an arytenoid cartilage lateralization to the right level of abduction, or a lateral suture stabilization for cruciate disease to allow for stifle range of motion)

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