Biomechanical analysis of dorsal plate fixation in proximal phalangeal fractures

The biomechanical properties of three minifragment plate and screw systems were compared to determine whether plate systems primarily designed for maxillofacial reconstruction are biomechanically sound for use in proximal phalangeal fracture fixation. A middiaphyseal transverse osteotomy was created in each of 30 fresh-frozen human proximal phalanges to simulate an unstable fracture. Each osteotomy was then fixed with four 2.0ml screws through one of three different four-hole minifragment plates in a middorsal position. Plating systems tested included a vitallium plate with self-tapping screws (Luhr), a stainless steel plate with tapped screws (Synthes), and a titanium plate with tapped screws (Synthes). Testing was performed to failure in an apex volar three-point bending mode. The titanium-plated phalanges were the stiffest construct and required the greatest load and total energy absorbed to failure. However, only the load to failure for titanium versus stainless steel was significantly different. Therefore, there is no biomechanical disadvantage to using the titanium or vitallium plate and screw systems in the setting of unstable proximal phalangeal fractures.