In Vitro Evaluation of the Aberdeen Knot for Continuous Suture Patterns with Large Gauge Suture

Abstract

Objective: To evaluate the strength, size, and holding capacity of the Aberdeen knot compared to surgeon's and square knots using large gauge suture.

Study design: In vitro mechanical study.

Study population: Knotted suture.

Methods: Aberdeen, 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. Mode of failure and knot holding capacity (KHC) were recorded and relative knot security (RKS) was calculated as a percentage of KHC. Knot volume and weight were quantified by a digital micrometer and balance, respectively. Strength between number of throws, suture, suture size, and knot type were compared by ANOVA and post hoc testing. P≤.05 was considered significant.

Results: Aberdeen knots had higher KHC and RKS than surgeon's or square knots for all suture types and number of throws (P<.001). For all suture materials, none of the Aberdeen knots unraveled, but a portion of square and surgeon's knots with <7 throws did unravel (P=.101). Aberdeen knots had a smaller volume and weight than both surgeon's and square knots with equal numbers of throws (P<.001). The knot with the combined highest RKS and smallest size and weight was an Aberdeen knot with 4 throws using 3 USP polyglactin 910.

Conclusion: The Aberdeen knots were stronger, more secure, and smaller than surgeon's and square knots for ending a continuous suture pattern. Clinically, the Aberdeen knot may be a useful alternative for completion of continuous patterns using large gauge suture, without sacrificing knot integrity.