Tensile strength of a surgeon's or a square knot.
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.
Muffly
Tyler M
TM
Center of Urogynecology and Pelvic Floor Disorders, Obstetrics, Gynecology & Women's Health Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA. mufflyt@ccf.org
Boyce
Jamie
J
Kieweg
Sarah L
SL
Bonham
Aaron J
AJ
D002398:Catgut; D020099:Coated Materials, Biocompatible; D047011:Silk; D013536:Suture Techniques; D013537:Sutures; D013718:Tensile Strength
D020099:Coated Materials, Biocompatible; D047011:Silk
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