Orthopedic Applications of Carbon Fiber Composites

Abstract

Carbon fiber (CF) composite materials have unique advantages for use in orthopedic surgery, because of their excellent fatigue characteristics, radiolucency, and high strength: weight ratios. The materials can be easily manipulated into complex composite designs, to take advantage of each material's biomechanical and biocompatible properties, and minimize their weaknesses in the overall composite design. By allowing individual material properties, mechanical properties, and geometrical design considerations to blend into an overall composite design, composite materials of CF exhibit remarkable versatility for orthopedic applications. This versatility is enhanced by the ability of complex designs or shapes to be manufactured by injection- or compression-molding techniques, to modify the biologic and/or biomechanical composite properties. Surface topography and coatings can be easily applied to permanent CF-thermoplastic composites for use as implant devices, to modify interface conditions with host tissue. The ability to vary stiffness within the composite material allows for matching the biomechanical requirements necessary for long-term periprosthetic implantation, as well as fracture fixation with short-term devices, such as external fixators and plates. Orthopedic radiographic imaging techniques are enhanced because of the relative radiolucency of the CF composites, which also allows for in vitro and in vivo implant imaging analysis, to monitor the structural integrity of the device itself. To enhance their clinical utility, the CF composites can be sterilized by standard techniques; customized to size, shape, and appearance; adjusted to weight requirements; and maintained at reasonable shelf lives. In this chapter the versatility of CF composites is illustrated in a joint reconstructive femoral hip implant and acetabular component, as well as in a unique external fixator device for use in orthopedic trauma fracture care.