Page 43 - Arthroscopic Knot Tying: An Instruction Manual

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Arthroscopic Duncan Loop (Hangman's Knot) (Fig. 22)

FIGURE 22. A-F. Arthroscopic Duncan loop.

 Make the post limb half as long as the loop limb.
 Grasp the sutures between the thumb and index finger of the non-dominant hand.
 Create a small circle with the loop strand by passing the loop over the post and hold it between the
thumb and index finger (Fig. 22A ).
 Make four successive loops around both the post and the loop limbs toward the joint (Fig. 22B ).
 Pass the tail of the loop strand through the small circle created by the loop strand that is held
between the thumb and index finger (Fig. 22C ).
 Pull on the loop limb and post limb simultaneously to tighten the knot (Fig. 22D ).
 Advance the knot by pulling on the post limb and simultaneously pushing the knot with the knot
pusher on the post limb (Fig. 22E ).
 Lock the knot with a series of three alternating half hitches with post switching (Fig. 22F ).
o Throw an underhand loop on the original post. Tension with the knot pusher.
o Switch posts.
o Throw an overhand loop over the new post. Tension with the knot pusher.
o Switch posts.
o Throw an underhand loop on the original post again. Tension with the knot pusher.

Although not statistically significant, the Duncan loop was shown to have a higher load to clinical failure
than the Overhand Throw and the Roeder knot but a lower load to failure when compared with the Snyder
knot (26 ). The Duncan loop tied with No. 2 Ethibond was shown to be statistically stronger than the
Overhand Throw, similar in strength to the Tennessee Slider, and inferior in tensile strength to the SMC
knot, Revo knot, Lieurance-Roeder knot, and Savoie-Roeder knot (20 ,23 ). The Duncan loop was also
shown to be inferior to the French knot in tensile strength (22 ).