title: Minimum number of throws needed for knot security.
abstract: OBJECTIVE
  The purpose of the study was to determine the optimal number of throws to ensure knot security.
  
  
  METHODS
  Knots were tied with 3, 4, 5, or 6 square throws with 0-gauge coated polyester, polydioxanone, polypropylene, and polyglactin 910. The suture was soaked in 0.9% sodium chloride and subsequently transferred to a tensiometer and broken.
  
  
  RESULTS
  A total of 225 knots were tied. Regardless of the suture type, tension at failure for knots with 4 throws, 5 throws, and 6 throws was higher than tension at failure of knots with only 3 throws (p < 0.05 for each). We found no difference in the tensile strength between knots with 4, 5, or 6 throws (p > 0.05 for each). Knots with 4 throws were significantly more likely to come untied than knots with 5 or 6 throws (p < 0.01).
  
  
  CONCLUSIONS
  Under laboratory conditions, the ideal knot has 5 throws to maximize tensile strength and rate of untying. This finding does not seem to vary by type of suture material.
authors.affiliation: Center for Urogynecology and Reconstructive Pelvic Surgery, Obstetrics, Gynecology and Women's Health Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA. tylermuffly@hotmail.com
authors.forename: Tyler M
authors.initials: TM
authors.lastname: Muffly
authors.forename: Nathan
authors.initials: N
authors.lastname: Kow
authors.forename: Imran
authors.initials: I
authors.lastname: Iqbal
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Barber
mesh_terms: D006801:Humans; D008422:Materials Testing; D017751:Safety Management; D012680:Sensitivity and Specificity; D013529:Surgical Wound Dehiscence / Q000517:prevention & control*; D013536:Suture Techniques / Q000009:adverse effects / Q000592:standards*; D013537:Sutures / Q000009:adverse effects / Q000592:standards*; D013718:Tensile Strength