Chapter 4: Table of Contents
Simple throws are the basis of the square knot, granny knot and half-hitch knot. Each of these three knots consists of two simple throws, but in different configurations.
A square knot is the most frequently used knot when placing ligatures and sutures. It is the most secure knot and is least likely to unravel. A square knot consists of two simple throws, with the second simple throw in the reverse direction of the first. Both throws must begin with the needle driver between both strands of suture. Even horizontal tension must be maintained between the two suture ends while the knot is being tightened, otherwise it will become a half-hitch knot.
A surgeon’s knot is often used in high-tension tissues that cannot be properly apposed using a square knot. The surgeon’s knot differs from the square knot due to an extra pass through the loop of the first throw. This extra twist in the first throw provides more friction to maintain its position until the second throw is placed.
A granny knot is most often created by incorrect knotting technique and is more likely to slip when compared to a square knot. A granny knot consists of two simple throws, with one throw beginning with the instrument between each strand of suture and the other beginning with the instrument outside of the strand of suture. Even tension must be maintained between the two suture ends while the knot is being tightened, otherwise it will become a half-hitch knot.
A half-hitch knot is most often created by incorrect knotting technique, and results in a knot that readily slips. Periodically this knot can be used by the surgeon to overcome tension by using it as a slipknot, and must be followed by several square knots to prevent further slippage. A half-hitch knot can be the result of uneven tension applied to the two suture ends while tightening the knot (either granny or square), when the suture is pulled upward while tightening (a frequent mistake) or when the second simple throw is placed in the same direction as the first (without crossing over to create a square knot).