Related Experiment Video
Updated: Mar 8, 2026
A Training and Testing System for Performing Vascular Reconstruction In Vitro
Published on: October 26, 2019
In vitro evaluation of square and surgeon's knots in large gauge suture
Alex M Gillen1, Amelia S Munsterman1, Ramsis Farag2,3
1Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, Auburn, Alabama.
Objective:
To investigate the strength and size of surgeon's and square knots for starting and ending continuous suture lines using large gauge suture.
Study Design:
In vitro mechanical study.
Study Population:
Knotted suture.
Methods:
Surgeon's and square knots were tested using 2 and 3 USP polyglactin 910 and 2 USP polydioxanone under linear tension on a universal testing machine. Failure mode and knot holding capacity (KHC) were recorded, and relative knot security (RKS) was calculated as a percentage of KHC. Comparisons were made between number of throws, suture size, suture type, and knot types. Knot volume and weight were assessed by a digital micrometer and balance, respectively.
Results:
There were no significant differences in KHC (P = .295), RKS (P = .307), volume (P = .128), or weight (P = .310) between square and surgeon's knots at the start or end of suture lines with the same number of throws and suture type. A minimum of 6 throws were required for start knots and 7 throws at end knots to prevent unraveling. Knots tied with 3 polyglactin 910 were strongest (P < .001) and 2 polyglactin 910 produced knots with higher KHC and RKS than 2 polydioxanone (P < .001).
Conclusion:
No consistent differences were detected between knots types tied with the same suture material; however, number of throws affected KHC and RKS up to 6 throws in start or 7 throws in end knots. The configuration of square and surgeon's knots performed at the end of a continuous line alters their KHC, supporting the use of additional throws for knot security.
