Surgeon's Knot

A commonly used suture tension knot.

The Surgeon's Knot is the recommended knot for tying many synthetic sutures (i.e. nylon, polypropylene, polyester). In the diagrams below, adapted from the Ethicon guide, one "half" of the suture has been colored purple to make the instructions more clear -- a good way to practice is with a shoelace that you've colored to match this. It's a little confusing, but once you get the hang of it, it's like riding a bike and becomes almost reflex:

1. White half placed over index finger of left hand and held in palm. Purple half held between thumb and index finger of right hand.

2. Purple half crossed over white half by moving right hand away from you at an angle to the left. Thumb and index finger of left hand form a loop in the white half over the index finger.

3. Left hand is rotated inward, and loop of white half is slipped onto left thumb. The purple strand is grasped between the thumb and index finger of the left hand. Right hand is released.

4. Left hand is rotated, extending the left index finger to pass the purple half through loop. Regrasp the purple half with your right hand.

5. The loop is slid onto the thumb of the left hand by rotating the pinched thumb and index finger of left hand beneath the loop.

6. Purple half is drawn left with the right hand and again grasped between the thumb and index finger of your left hand.

7. Left hand is rotated, extending left index finger to again pass purple strand through forming a double loop.

8. Horizontal tension is applied by moving your left hand toward you, and your right hand away from you. This double loop must be placed in precise position for the final knot.

9. With your thumb swung under white half, the purple half is grasped between your thumb and index finger of your left hand and held over the white half with your right hand.

10. Release the purple half. Rotate your left hand to regrasp the purple half with your index finger beneath the loop of the white half.

11. Rotate the purple half under the white half by rotating your thumb and index finger of your left hand to pull the purple half through the loop. Regrasp the purple half with your right hand to complete the second throw square.

12. Apply horizontal tension by moving your left hand away from you and your right hand toward you. The final tension on the final throw should be as horizontal as possible.

You can find video of the knot being tied at the UPENN surgery site and web searches should find you numerous other reference sites.