title: In Vitro Biomechanical Testing of the Tube Knot.
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.
  
  
  METHODS
  In vitro biomechanical study.
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: College of Veterinary Medicine.
authors.forename: Stephany
authors.initials: S
authors.lastname: Chang
authors.affiliation: Graduate College of Biomedical Sciences.
authors.forename: Fanglong
authors.initials: F
authors.lastname: Dong
authors.affiliation: College of Osteopathic Medicine, Western University of Health Sciences, Pomona, California.
authors.forename: Minette
authors.initials: M
authors.lastname: Lagman
authors.affiliation: College of Veterinary Medicine.
authors.forename: Peggy L
authors.initials: PL
authors.lastname: Schmidt
authors.affiliation: College of Veterinary Medicine.
authors.forename: Kristopher L
authors.initials: KL
authors.lastname: Irizarry
authors.affiliation: Vista Animal Hospital, Boise, Idaho.
authors.forename: David
authors.initials: D
authors.lastname: Schulz
authors.affiliation: College of Veterinary Medicine. mfahie@westernu.edu.
authors.forename: Maria A
authors.initials: MA
authors.lastname: Fahie
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D008422:Materials Testing / Q000662:veterinary*; D013525:Surgical Instruments / Q000662:veterinary*; D013536:Suture Techniques / Q000295:instrumentation / Q000662:veterinary*; D013537:Sutures / Q000662:veterinary*; D013718:Tensile Strength