Paper number 598

PERFORMANCE OF A PROSTHETIC INTERVERTEBRAL DISC

R. G. Hudgins¹ and J.D. Muzzy²

1Engineering Science and Mechanics Department.
2Composites Manufacturing Research Program, School of Chemical Engineering
Georgia Institute of Technology, Atlanta, Georgia 30332-0100, USA

Summary

Various flexible composite materials were investigated for replacement of the intervertebral disc, the cartilage in the spine between the vertebrae. Four prototype designs were considered. The prototypes consisted of a thermoplastic polyurethane matrix reinforced with aramid or polyethylene fibers. The laminated and the unidirectional composites were strength sensitive to the wet, simulated physiological environment. These two prototypes failed in shear by debonding between the fiber and matrix. The biaxially and triaxially braided designs maintained most of their mechanical properties in the simulated physiological environment, and their strength was shown to be independent of the presence of an interfacial bond between the braided fibers and the elastomeric matrix.

Keywords

prosthetic disc, polyurethane elastomer, aramid fiber, polyethylene fiber, braided composite.