Looking to up your lac repair game? With a simple modification, the old dependable horizontal mattress stitch can be transformed into the notably improved and versatile modified locking horizontal mattress stitch. This stitch provides nice wound eversion, fine approximation, and easier removal. For EM physicians, the technique can also be used for achieving hemostasis during arterial bleeds in lieu of the figure 8 knot.

Here’s how you do it:

Start with your basic horizontal mattress stitch as shown below:
Screen Shot 2016-03-15 at 3.31.11 PM

And now the modification: “the needle driver is brought around the far side and through the
loop created in the previous step (B). The tail is grasped (C), and the needle driver is withdrawn and pulled inferiorly (D) to lay the knot square”

Screen Shot 2016-03-15 at 3.31.19 PM

Source: Olson, J., and D. Berg. “Modified Locking Horizontal Mattress Suture.” Dermatologic Surgery 40, no. 1 (January 2014)