Objective evidence for optimum knot configuration

The knot configurations used in clinical practice often are based on tradition and previous training. This study was designed to test the hypothesis that knot quality improves with the addition of a single throw in two-throw and three-throw knots. We tested this hypothesis by using commonly used knot configurations and suture materials.

Three suture materials, SURGIPRO, BIOSYN and POLYSORB, of 3-0 caliber were used. The break force and integrated force of each material, a single-hitch throw on each material, and 2160 knots of six configurations were measured by using tensiometry. The knot quality scores (KQS) of the different knot configurations were compared by using nonparametric tests.

A single-hitch throw on the suture material reduced the break force by up to 40%. The addition of an extra throw improved KQS in 2 x 1 x 1, 2 x 2, and 2 x 2 x 1 knots. The four-throw knot configurations resulted in high KQS and low slippage rates. The 2 x 2 knots were most likely to slip and had the lowest KQS.

If a double-hitch throw is used in the first throw, two to three further throws are recommended. The four-throw knot configurations have the best knot qualities and should generally be used.