Here at SurgiReal, we believe perfect practice leads to the best outcomes for medical students and their patients. Our RealSkills® series tackles fundamental clinical tasks to support medical instructors and their students as they build competence and confidence in these essential skills. Today’s skill: How to Tie a Square Knot. Let’s dive in!
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Any student training to practice medicine knows that knot-tying is a fundamental skill to closing wounds. The ability to tie secure and consistent knots can make a significant—sometimes life-changing—difference in a patient’s outcome. It’s no surprise, then, that surgical knots are an essential skill taught in today’s PA and NP curricula. As they master knot-tying, students seek to improve their dexterity, precision, and hand-eye coordination—and their confidence in delivering excellent care to their patients.
What is a Surgical Knot?
A surgical knot is any of a variety of knots used in tying ligatures or surgical stitches. Without a stable surgical knot, wounds will not heal as expected, and other complications can occur. Sutures must stay in place, and the two sides must be closed, strong, secure, and flat to finish the procedure.
Today, we’re highlighting the most common surgical knot: the square knot. A square knot, also known as a reef knot, is made by tying two simple knots in alternating directions (right over left, then left over right) to create a secure, flat knot. Let’s unpack the steps to make sure your surgical sutures never slip.
Square Knot-Tying Techniques
Two-Handed Tie
The two-handed tie is the basic starting point for surgical knot tying. Using both hands to tie a surgical knot helps you learn and understand how to tie a strong square. Important features to pay attention to: lay the first throw all the way down to the tissue before starting the next throw, holding equal tension on both strands, and pass the free strand through each loop in alternating directions with each successive throw.
One-Handed Tie
The one-handed tie is a more advanced way of tying knots, and it can also be more efficient. One hand will constantly hold one strand, while the other hand will be used to form all of the alternating loops and throws.
Instrument Tie
When suturing, you’ll often use an instrument, leading to our third way to tie a knot: the instrument tie. You will hold one strand with your non-instrumented hand, loop the strand around your held instrument, and then grab the free strand with your instrument before pulling both strands tight. Remember to alternate directions with each throw to make square knots (see below).
How to Practice a Square Knot on a Surgical Knot Board
To prepare for your first throw, hold the suture ends in each hand. Cross the right end over the left end, then tuck the right end under the left and pull tight. For the second throw, cross the left end over the right end, then tuck the left end under the right and pull tight. Do a final check, and ensure the knot is square and lies flat. The two ends should come out evenly, and the knot should be secure. Once the knot is secure, trim the excess suture material, leaving a small tail if required. Ensure the knot is tight and that it won’t come undone. It should be neat and flat. A square knot done well will only require four (alternating) throws to achieve optimal tightness.
Improving Your Technique
If you want to improve your technique ahead of your clinical exams or just brush up on your skills, here are a few tips to throw the perfect knot:
- Hold each strand with equal tension, but don’t overpull.
- Tight knots don’t unravel. The more friction between the strands, the higher the security.
- Lay the knot down as close to the tissue as possible. A smooth, untwisted loop is a strong loop.
- Adjust the knot board to mimic different scenarios like tying knots in confined spaces or with different suture materials.
- Go slow. Speed will come with repetition. Make sure your technique is strong before trying to go faster.
They say practice makes perfect, so persistence will lead to confidence and confidence. Practicing with a knot board (like our SurgiReal Knot Tying Board) can help you build muscle memory, improve precision, and seek feedback from your instructors. The SurgiReal knot board was created by surgeon educators, so you can rest assured that you will learn the skill the right way the first time.
What is a Surgical Knot Board?
A surgical knot board stimulates a real surgical environment, and you can develop your knot-tying skills to take into an actual procedure room. Our SurgiReal Knot Tying Board has a rubber back to keep the board in place, a spot for deep closure tying, opposing tubes, and an open hook for easy learning. You’ll be throwing the perfect knot in no time. We’ve found that when students practice on inadequate materials, they can develop bad habits, and that affects how they take care of patients. Our goal is to make sure you never learn bad habits in the first place.
Strong knots enable strong healing. By mastering this foundational skill, you can be confident that your knots will prevent complications, ensure healing, and improve your patient’s outcome. With the edges of a wound aligned, a proper knot keeps the stitches secure so everything can heal as intended. By using a surgical knot-tying board, you can master the skill needed to tie secure and effective knots in a controlled environment, preparing you for real-world surgical situations. As you sharpen your knot-tying skill, you’ll also be improving your dexterity and hand-eye coordination, which will come in handy when giving injections and handling delicate instruments. In surgery, minor details can matter the most. Master a strong and stable knot, and you will provide excellent care to your patients.
Want to learn more about the art of knot tying? Check out this post.
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