Two-hand square knot​

​​By Mathias Mejdahl, MD, PhD and Stephan Bach-Frommer, MD

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• Grab the suture with both hands, holding the end that is pointing away from you with your left hand, and the end pointing towards you with your right hand. In your left hand, you are holding the suture in the palm with your three ulnar fingers, keeping the thumb and index finger free. The right hand holds the suture between the thumb and index finger.

 

• Move your left index finger below the left end of the suture so that it lies on the dorsal and radial side of the index finger.

 

• Move your right hand towards the left index finger, placing the right suture end on the ulnar and palmar side of the left index finger and crossing the left suture end. At the end, use the right middle finger to open the loop slightly.

 

• Close your left index finger and thumb against each other.

 

• Pronate the left hand, moving the thumb through the loop. 

 

• Place the right suture end between your left thumb and index finger and pull the end through the loop by supinating the hand.

 

• Grab the right end with your right hand between your thumb and your index finger.

 

• Tighten the knot, pulling the right suture end away from you and the left suture end towards you. You can use the dorsal side of your three ulnar fingers of the right hand for further tightening. With your left hand, you are tightening with your thumb placed above the suture, placing the suture on the dorsal and radial side of the thumb. In this way, you are also preparing for the second part of the two-hand square knot.

 

• When you have tightened the knot sufficiently, move the right end towards your left thumb. During this movement, grab the right suture end with your left index finger (holding it in a “hook” position”) in a supinating movement of the left hand.

 

• Close your left index finger and thumb against each other, grabbing the right suture end. Now pronate the thumb through the loop moving the right suture end through the loop. Grab the right suture end with your right hand, holding it between your index finger and thumb.

 

• Tighten the knot moving the left end away from you, and the right end towards you.