Institutional members access full text with Ovid®

Share this article on:

Comparison of Tensile Strength of Slip Knots With That of 3-1-1 Knots Using 10-0 Nylon Sutures

Lutchman, Carla R. MD, FRCSC; Leung, Linus H. BASc, MASc; Moineddin, Rahim PhD; Chew, Hall F. MD, FRCSC

doi: 10.1097/ICO.0000000000000063
Basic Investigation

Purpose: The aim of this study was to compare the tensile strength of slip knots with that of 3-1-1 knots using 10-0 nylon sutures.

Methods: In vitro, destructive materials testing was used. By adhering to the American Standard for Testing and Materials standards for testing of suture materials, slip knots were compared with 3-1-1 knots using 10-0 nylon suture material. Tensile testing was performed on each knot type using the Instron Microtester (Model 5848 Norwood, MA). Scanning electron microscopy was used to analyze all sutures tested to failure. The main outcome measure was the maximum load (newtons) or ultimate tensile strength before which each knot failed by breakage or by unraveling.

Results: The mean force resulting in failure by breakage of the 3-1-1 knot and slip knot was 0.71 and 0.64 N, respectively (P = 0.048). The mean force resulting in failure by the unraveling of the 3-1-1 knot and slip knot was 0.48 and 0.37 N, respectively (P = 0.022).

Conclusions: In 10-0 nylon sutures, the 3-1-1 knot has a statistically significant greater tensile strength than the slip knot has in conditions wherein they fail by either breakage or unraveling.

Departments of *Ophthalmology and Vision Sciences;

Mechanical and Industrial Engineering; and

Family and Community Medicine, University of Toronto, Toronto, Canada.

Reprints: Hall F. Chew, Department of Ophthalmology and Vision Sciences, University of Toronto, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto ON M4N 3M5, Canada (e-mail:

Presented at the American Academy of Ophthalmology Annual Meeting, October 2011.

The authors have no funding or conflicts of interest to disclose.

Received September 16, 2013

Accepted December 04, 2013

Copyright © 2014 Wolters Kluwer Health, Inc. All rights reserved.