Background: Surgical knot security is essential to preventing complications such as knot failure or tissue tearing. The number of throws and the use of surgeon's knots influence knot strength; thus, this study aimed to evaluate the impact of throws and surgeon's knots on the tensile strength and loop elongation of Vicryl and Prolene 5-0 sutures.

Methods: Vicryl and Prolene 5-0 sutures were tied in knots of 3, 4, and 5 throws, across 12 different knot sequences: single knots only, surgeon's knots only, and an increasing number of surgeon's knots. Samples were tested using a tensiometer applying a constant force until knot failure or slippage.

Results: The tensile strength of the knots increased significantly with the number of throws and the presence of surgeon's knots (P < 0.005). Five-throw knots were stronger than 3-throw knots regardless of the number of surgeon's knots for both types of sutures. The use of surgeon's knots only significantly increased strength in the 3-throw series for both Prolene and Vicryl sutures. For both sutures, a 3-throw surgeon's knot showed the same tensile strength as a 5-throw simple knot. Loop elongation depended on the number of throws and surgeon's knots.

Conclusions: The use of surgeon's knots alone increased a knot's breaking resistance without the need for additional simple throws. A 3-throw surgeon's knot provides breaking resistance equivalent to a knot with more throws. If reduced loop elongation is desired, the choices would be 4 surgeon's throws for Vicryl and 5 simple throws for Prolene.