Surgical Knot Tying Guide

Surgical Knot Tying Guide
from: Davis + Geck Surgical Knot Tying Manual
by: Anderson & Romfh

Introduction
In tying knots, one of the ends of the suture is frequently attached to a needle or ligature reel, so that there is a free end and a fixed end. During practice always put a clamp on one end of the ligature so as to become accustomed to taking the free segment in the proper hand. Otherwise, in the operating room you may grab the free end with the wrong hand, then need to pull the needle, holder, and surgeon through the knot.

Note: It is impolite to pull the surgeon through the knot.

The common knot used in surgery is the square knot. The square knot consists of two mirror-image half hitches, one placed on the other; in contrast to a granny knot, which is made of two identical half hitches. A half hitch is one revolution of one end of a ligature around the other. The revolution is made in two half-revolutions. The first half is made by crossing the ligature segments; the second by putting the free end through the loop made by the crossing. The second half of the revolution is done differently by laymen and surgeons. Laymen poke the
suture through the loop. Surgeons poke a finger or fingers through the loop, then grasp and bring the free end through. Control is thereby maintained by keeping hold of the free end during the manipulation. In proceeding through the following knot-tying maneuvers, stay aware that you are merely revolving the free segment a single turn around the fixed one.

The Two-Handed Square Knot (Tied "Right-Handed")
Note that in the so-called "right-handed" tying, the manipulation is done with the left hand, which holds the fixed segment, and the right hand merely holds, lets go, and regrasps the ligature. Many righthanded surgeons tie left-handed, grasping the free end with the left hand. An advantage of left-handed tying, besides the manipulation being done with the dominant right hand, is that a surgeon tying his own knots during suturing does not need. to change hands with the needle holder to do a two-handed tie. If you desire to learn to tie left-handed, look at the figures in a mirror and reverse the words "right" and "left" in the text.

The two-handed knot has the advantage of the greatest precision in maintaining constant tension on the suture during the tying process.

The Half Hitch
Step 1. Grasping the Ligature Grasp the uncrossed segments so that the ends are toward the little finger aspect of the hands. Hold the free segment between the right index finger and right thumb. Hold the fixed segment by the middle, ring, and little fingers, so as to leave the left thumb and index finger free for subsequent manipulation. Make the segments an optimal length for tying. The half hitch will be formed in the left hand, so the right will need to do its manipulation farther from the wound. Therefore, leave that portion of suture between the point to be tied and the hand, longer on the free than the fixed segment.

Image 3.jpg Step 2. Crossing the Ligature on the Left Index Finger Bring the free segment between the left index and middle fingers and wrap it one half turn around the index finger, thus making a cross on the left index finger.

Image 4.jpg Step 3. Poking the Left Thumb Through the Loop Bring the very tips of the left thumb and index finger together. Then push the thumb through the loop, replacing the index finger. The cross is now on the left thumb.

Image 5a.jpg Image 5b.jpg Step 4. Bringing the Free End Through the Loop Place the free segment between the tips of the left thumb and index finger and rotate the free end through the loop. Let go of the free end with the right hand.

Image 6a.jpg Image 6b.jpg Step 5. Tightening the Half Hitch Take hold of the free seg ment with the right hand and pull down the half hitch.

Image 7.jpg In wrapping one end of a ligature around the other to form a half hitch, the ends finish on opposite sides from where they started. To lay the tie flat, therefore, the segments must be crossed from their original position (Fig. 63). To assure that each segment makes a half turn around the other, exert equal tension on the two segments. Unequal tension would form a slipknot by causing one segment to form a complete revolution around the other straight one. Unequal tension may also stress the tissue being tied. It is important to pull the two segments so that they form a straight angle with one another, not an obtuse angle. A straight angle puts all of the tension in the knot. An obtuse angle puts a vector of unnecessary tension on tissue. When working in a deep wound it is necessary to carry one or the other segments into the wound over an index finger, in order to form the straight angle.

The Mirror-image Half Hitch
Step 1. Grasping the Ligature Continue holding the ligature, as when finishing the first half hitch, with the fixed segment on the palmar surface left index ringer. Bring the tips of the left thumb and index finger together, than rotate the left hand so that the fixed segment enters the palm over the thumb.

Image 8.jpg Step 2. Crossing the Ligature on the Left Thumb Bring the free segment between the left index finger and thumb and wrap it one half turn around the thumb, making a cross on the thumb

Image 9a.jpg Step 3. Poking the Left Index Finger Through Loop Bring the tips of the left thumb and index finger together. Then push the index finger through the loop, replacing the thumb. The cross is now on the index finger.

Image 9b.jpg Image 10.jpg Step 4. Bringing the Free End Through the Loop Place the free segment between the tips of the left index finger and thumb and rotate the free end through the loop.

Image 11a.jpg Image 11b.jpg Step 5. Tightening and Squaring the Knot Take hold of the free end and establish tension with the right hand before the left hand releases. To square the knot, have the segments uncrossed from the starting position.

Image 12.jpg

The One-Handed Knot
The one-handed knot is so named because all of the maneuvering, including releasing and regrasping the free end, is done with one hand. The other hand merely holds the fixed segment taut. One-handed knots have the advantage of allowing more speed in tying, but have less tension control of the segments.

The maneuvering is done with the left hand so that a surgeon tying his own knots during suturing can continue to hold the needle holder in his right hand. The one-handed knot is made by forming a loop around the left middle and ring fingers, putting the free end between these fingers, which then grasp the free end and bring it through the loop.

Step 1. Grasp the free segment between the left thumb and index finger tips 3 in. from the end. Orient the end toward the palm. Depress the thumb-index finger grasp of the ligature toward the little finger side of the palm.

Image 13a.jpg Step 2. Bring the fixed segment between the left ring and little fingers and wrap it one half turn around the middle and ring fingers.

Image 13b.jpg Step 3. Flex the left ring finger so that the dangling free end can be grasped between the left middle and ring fingers.

Image 14.jpg Step 4. Let go of the left thumb-index finger grasp and pull the free end through the loop with the middle and ring fingers.

Image 15a.jpg Step 5. Set the half hitch with hands crossed. An alternate method of forming the first half hitch in one-handed knot tying is the "index finger," or "one-finger," half hitch.

Image 15b.jpg Step 1. Alternate Method
Hold the free segment between the left thumb and middle finger with the segment entering the palm over the radial aspect of the index finger.

Image 16.jpg Step 2. Bring the fixed segment between the index and middle fingers and wrap it one half turn around the index finger, making the loop around, and the cross on, the left index finger.

Image 17a.jpg Step 3. Flex the left index finger to trap the fixed segment of the loop and pull 2 cm additional fixed length into the loop, thereby moving the cross 1 cm away from the index finger.

Image 17b.jpg Step 4. Extend the left index finger in such a way as to trap the free segment between the cross and the thumb-middle finger grip. Pull the trapped segment through the loop.

Image 18.jpg Step 5. Grasp the free segment between the left thumb and index finger as the thumb and middle finger release it. Then set the half hitch with the segments crossed. The fact that this first half hitch of the one-handed knot has an alternate method is a clue that it is hard to do and is less controlled than the second mirror-image half hitch. In tying an interrupted suture, which has two free ends, there is advantage in using only the mirror- image one-handed half hitch, alternating between the left and right hands. The alternating hand method of throwing the easy second or mirror-image half hitch is conducive to the most rapid knot tying.

Image 19a.jpg Image 19b.jpg

The Mirror-image One-Handed Tie
Step 1. Grasp the free segment between the left thumb and index finger as it ends with the first one-handed half hitch or as it ends with the one-finger tie . Make the free end in the palm
between the left ring finger and the little finger.

Image 20.jpg Step 2. Bring the fixed segment between the index and middle fingers, and wrap it one half turn making a loop around the left middle and ring finger with a cross on the palmar surface of the ring finger.

Image 21a.jpg Step 3.Flex the left middle finger and trap the free segment between the middle and ring fingers. Grasp the free end between these fingers and let go of the thumb-index finger grip.

Image 21b.jpg Image 22.jpg Step 4. Pull the free end through the loop with the middle and ring fin gers. Then set the half hitch.