The Weston slip knot was initially described in the obstetric and gynecology literature and is also used in arthroscopic surgery.The advantage of this knot is that it is relatively easy to tie outside, can then slip easily into place and be tightly secured. The post strand does not move throughout the knot; the loop strand is the longer strand which is moved to make the knot. The advantage of the Weston knot is that it locks readily and is not bulky.