Comparative Study of Tensile Strength in Vicryl™ vs. Prolene™ 5-0 Knots: Impact of Throw Type and Count

Abstract Background Knots are the weakest point of sutures, making their security and tensile strength critical. While suture material and the number of throws substantially affect knot strength, surgeon’s knots and suture size appear less influential. To our knowledge, however, there has been no study investigating the effect of multiple consecutive surgeon’s knots on tensile strength. Aims To determine whether the use of multiple throws of double overhand (surgeon’s) knots or single overhand knots affects the knot's tensile strength and the elongation of the suture’s loop with Vicryl™ and Prolene™ sutures. Methods Vicryl™ and Prolene™ 5-0 sutures were tied in knots of three, four, and five throws, across twelve 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 three-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 three-throw series for both Prolene™ and Vicryl™ sutures. For both sutures, a three-throw surgeon’s knot showed the same tensile strength as a five-throw simple knot. Loop elongation depended on the number of throws and surgeon’s knots. Conclusion The use of surgeon’s knots alone increased knot’s breaking resistance without needing additional throws of simple knots. A three-throw surgeon’s knot provides breaking resistance equivalent to a knot with more throws. If reduced loop elongation is desired, the choices would be four surgeon’s throws for Vicryl™ and five simple throws for Prolene™.