Influence of bone staple design on interfragmentary compression.

Abstract

Staple fixation, most commonly thought of as static, has been studied with regard to effecting dynamic compression. Features of staple design that relate to the creation of interfragmentary compression have been analyzed, and a simple manipulative technique to effect compression is illustrated. Compressive forces of bone fixation staples were measured using pressure-sensitive film. Thirteen staple designs were tested in a wood-block model and in cadaveric bone. Staples with legs splayed outward produced higher compressive forces than standard staple designs. Internal beveling of the staple leg tips also produced high compressive forces, while external beveling produced distraction. Staples with legs tapered over their entire length produced compression, but caused splitting in the wood-block model. Our results show that outward splaying of the staple legs is a simple method to increase compression in any staple design.