Page 29 - Arthroscopic Knot Tying: An Instruction Manual

P.22

Post Switching Technique (Fig. 15)

FIGURE 15. A-C. Post switching technique.

 Hold the post in the nondominant hand and the loop in the dominant hand (Fig. 15A ).
 Move the original post forward and ahead of the half hitch.
 Apply parallel traction on the post and loop simultaneously converting the half hitch to a flat knot
(Fig. 15B ).
 Apply axial traction to the loop limb converting it into the new post limb and the half hitch is
reversed (Fig. 15C ).

Arthroscopic Knot-Tying Techniques

It is important to determine if the suture slides through the tissue and suture anchor prior to knot
tying. If the suture does not readily slide, a sliding or locking knot should not be used and a nonsliding
knot should be chosen.
Only one pair of sutures should be within the working cannula during arthroscopic knot tying. If more
than one pair of sutures are within the working cannula during tying, there is a high likelihood that the
sutures will become twisted and knot tying will become quite tedious if not impossible. Additional
sutures should be shuttled via a monofilament suture (less tissue abrasion) or by an arthroscopic
grasper to an accessory portal.
Transparent cannulas are recommended for arthroscopic knot tying. These cannulas allow the surgeon
to see if there is any twisting of the suture strands prior to knot tying.
The arthroscopic surgeon should ensure that there is no redundant soft tissue around the tissue being
apposed or in the path of the suture limbs because this will impede knot tying and increase the
likelihood of knot failure.
When tying half hitches with a standard single-hole knot pusher, the first throw commonly slips when
the knot pusher is removed in preparation for the second throw. When the second throw is advanced,
there is a chance that the hitches will lock prior to complete apposition of the tissue. To prevent this,
the surgeon can throw the first two hitches in the same direction (overhand hitch followed by an
overhand hitch or an underhand hitch followed by an underhand hitch), allowing the hitches to slide
down the post to appose the tissue. In this sense, the two identical half hitches on the same post act
as a sliding knot. Another method of preventing initial loop loosening is to use a double-diameter knot-
pushing device, such as the Arthrex 6th Finger (Arthrex, Naples, FL) to maintain tension on the initial
hitch while throwing the second hitch.