The clinical use of plastic plates for osteosynthesis in human fractures

Abstract

After a fractured bone has passed the phase of bone union, the remodelling of the bone begins, the periosteal and endosteal callus being resorbed according to Wolff's law. In this later stage the stress protecting effect of rigid metal plates has an adverse effect on cortical bone and gives rise to osteopenia with reduced strength of the plated bone. From many experiments it is clear that the most important single factor that determines the degree of stress protection is the stiffness of the plate relative to that of the bone. We have used semirigid plates made of polyethersulphone reinforced with carbon fibres for internal fixation of bone shaft fractures in men (two humeral, 10 forearm and 5 lower leg fractures). The mean time for bony union was 12 weeks; meantime of plate removal was eight months. Histology of the capsules surrounding the plates showed no adverse reactions. The results give support to the concept that semirigid fixation is not only desirable theoretically but also works in practice.