title: Tensile strength of a surgeon's or a square knot.
abstract: OBJECTIVE
  To test the integrity of surgeon's knots and flat square knots using 4 different suture materials.
  
  
  METHODS
  Chromic catgut, polyglactin 910, silk, and polydioxanone sutures were tied in the 2 types of knot configurations. For all sutures, a 0-gauge United States Pharmacopeia suture was used. Knots were tied by a single investigator (J.B.). The suture was soaked in 0.9% sodium chloride for 60 s and subsequently transferred to a tensiometer where the tails were cut to 3-mm length. We compared the knots, measuring knot strength with a tensiometer until the sutures broke or untied.
  
  
  RESULTS
  A total of 119 throws were tied. We found no difference in mean tension at failure between a surgeon's knot (79.7 N) and a flat square knot (82.9 N). Using a chi(2) test, we did not find a statistically significant difference in the likelihood of knots coming untied between surgeon's knots (29%) and flat square knots (38%).
  
  
  CONCLUSIONS
  Under laboratory conditions, surgeon's knots and flat square knots did not differ in tension at failure or in likelihood of untying.
authors.affiliation: Center of Urogynecology and Pelvic Floor Disorders, Obstetrics, Gynecology & Women's Health Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA. mufflyt@ccf.org
authors.forename: Tyler M
authors.initials: TM
authors.lastname: Muffly
authors.forename: Jamie
authors.initials: J
authors.lastname: Boyce
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Kieweg
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Bonham
mesh_terms: D002398:Catgut; D020099:Coated Materials, Biocompatible; D047011:Silk; D013536:Suture Techniques; D013537:Sutures; D013718:Tensile Strength
chemical_list: D020099:Coated Materials, Biocompatible; D047011:Silk
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