I went to a local doctor for a consult and he mentioned that he uses a 2-3 bladed knife with the Haber spreader to insure that no transection occurs. He said that there is less transection with that than with the single bladed knife, when used properly. According to him, with the single blade, you must go down 2-3 times as deep to cut past the follicles, and if you are not right on target there will be some transection. Does this sound correct – does using a Haber spreader with a 2-3 bladed knife sound right?
More than 2 blades with depth may cause hair transection. The use of spreading instruments such as the Haber spreader or a Kelly clamp will also work to minimize transection. If a two-bladed knife is used, it should have a built-in angle to minimize transection. A three (or greater)-bladed knife causes more transection and loss of hair from the donor area.
One vs two blades (with built-in knife angles for the 2-bladed instrument) are about equal to minimize hair loss from the harvest. I use a specially designed (by me) two-bladed knife that has a 30 degree angle built into the holder to minimize transection. Two-bladed knives like the one I use precisely control the width of the strip, so I prefer that to a single-bladed knife.