Knot Tying Booklet (Mitek)
This knot tying booklet has been redeveloped for website viewing by ShoulderDoc, with the permission and support of Mitek, UK.
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Terminology:
When sutures are to be tied the ends of the suture are called “limbs”.
The “limb” of the suture that the knot will be tied around is called the “post”. This is typically the limb which is away from the bone and through the soft tissue or the limb on which you want to slide the knot down to re-approximate the tissues.
The other strand is called the “loop”, and is the limb which is tied into a knot around the post strand or looped around the post strand.
The knots are created and pushed down the “post” by the knot pusher which advances the knot, or alternatively, the knot “pusher” is placed on the loop strand ahead of the knot and the knot is “pulled” down the cannula into the joint.
Ten tips for Arthroscopic knot tying:
- Only one pair of sutures at a time should be in a portal at one time. 'Park' other sutures out seperate portals.
- Use a cannula to avoid "catching" tissue in the knot.
- Only if the suture slides freely, through the anchor eyelet, in both directions can a sliding knot be tied.
- The "post" should be the suture limb on the capsular side of the joint for a labral repair and on the cuff side for a rotator cuff repair.
- A haemostat should be clipped onto the end of the post limb to identify it as the “post” and provide a grip.
- The suture should be checked to make sure there are no twists of the suture limbs within the cannula, and that there is no soft tissue entangled around the sutures.
- Use at least 3 additional half-hitches after the sliding knot
- Change both the post and the knot direction with each knot.
- "Past-point" - i.e. push the suture passer past the knot to ensure a tight knot.
- After the knot is tied, it should be cut approximately 3mm from the knot. Use a freehand suture scissors, rather than a sliding scissor.
Sliding Knots
Sliding knots can only be tied when there is easy motion of the suture through the anchor eyelet in both directions. These knots are ideal for arthroscopic knot tying.
Fishermans Knot1.Slide the suture to get one short suture limb and one long suture limb. The short limb is known as the "post" around which you will throw the long suture limb (loop)
2. Throw the long suture (loop) over your thumb - creating a loop.
3. Continue by throwing it over and around both sutures.
4. Throw the long suture three or four times around both sutures (three throws shown in picture)
5 & 6. Pass the free end of the long suture through the loop made by your thumb.
7. Tighten the knot configuration by pulling the loop (long) limb.
8. Compression of the knot while pulling the loop limb will tighten the knot even better.
9. Advance the knot by pulling on the post (short limb). Pushing the knot pusher on the post will help maintaining the tension.
10&11. A series of half hitches on alternating posts (total of 3 or 4) will secure the fisherman's knot.
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Easy KnotClick here for Animation of the technique 1. Make one short limb (the post) and one long limb (the loop)
2. Make a half hitch around the post with the loop.
3 & 4. Repeat the half hitches ...
5 & 6.. ...in the same direction four times, making a total of five half hitches in the same direction.
7. By pushing on the post the knot is tightened.
8. Another half hitch is lowered along the taught loop limb, pulled by the knot pusher which carries along the post limb (thumb).
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Nicks KnotPopularised by Joe DeBeer, South Africa. Named after his son. 1. Make one short limb (the post) and one long limb (the loop).
2 & 3. Make an overhand throw with the loop strand over the post.
4 & 5. Make another overhand throw with the loop over the post.
6. Bring the loop strand over the loop.
7. Pass the loop strand over... 8. ...and under the post.
9. Tighten the knot.
10. By pulling on the post the knot will slide forward. A knot pusher can be used on the post.
11 & 12. Secure the knot with alternating half hitches.
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Roeder's Knot1. Make one short limb (the post) and one long limb (the loop)
2. Throw the loop... 3. ... around the post.
4. Next throw the loop around both limbs.
5. Throw the loop only around the post limb.
6. Pass the tail of the loop limb between the second and third loop.
7. The knot is tensioned and pushed into the joint with a knot pusher on the post limb.
8 & 9. The knot is secured with a series of half hitches, thrown in alternate directions.
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Tennessee Knot1. Make one short limb (the post) and one long limb(the loop).
2. Throw the loop limb around the post.
3. Throw the loop strand around the loop.
4. A second pass around only the post is followed by the end of the loop limb being brought up through the parallel limbs between the first and second loops.
5 & 6. The knot is tensioned and pushed into the joint with the knot pusher on the post.
7 & 8. The knot is secured with several half hitches in alternate directions.
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Non-Sliding Knots
Sometimes, even when the loops supposed to slide in the anchor for some reason the loops do not slide.
In that case a non-sliding knot can be helpful.
Square Knot1. Place an overhand half hitch (passage of the loop over the post) around the post
2. Place a knot pusher on the loop limb and pull the loop into the joint. Pass the knot pusher beyond the area to be opposed (in the picture the thumb is used as the knot pusher). This principle is known as 'past pointing'.
3. Place an underhand half hitch (passage of the loop under the post) around the post and forward the loop into the joint.
4. Tension the knot by moving the knot pusher to the post suture, passing it beyond the knot.
5 & 6. Additional loops can be applied.
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Revo Knot1. Make one short limb (the post) and one long limb (the loop)
2. Throw an underhand (initial loop passage under the post) half hitch around the post.
3. Use a knot pusher to tighten the knot on the tissue
4. Throw another underhand half hitch around the post, while maintaining tension on the post.
5. Push the hitch into the joint until the knot is seated.
6. While maintaining tension on the post throw another half hitch, this time overhand (passage of the loop over the post).
7. Push this third half hitch down into place.
8. This knot is further tightened by past pointing - accomplished by passing the knot pusher (in the picture the thumb) beyond the knot sequence.
9. The loop now will be the new post, the post becoming the new loop. An underhand half hitch is then thrown around the new post ...
10. ... and tensioned.
11 & 12. The original post will become the post again and an overhand hitch is thrown and tensioned with past pointing.
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Acknowledgements
Thanks to W.J. Willems, MD for providing his input into the knot tying booklet
