LIGHT-MICROSCOPIC IDENTIFICATION OF SUBMICRON POLYETHYLENE WEAR DEBRIS

A simple, yet specific, means to identify submicron polyethylene (PE) particles in routine histologic sections would be practically useful. We have previously reported a very fine, diffuse, birefringence (when viewed under polarized light) in the cytoplasm of phagocytic cells fro m around total hip replacements (THRs) with a PE acetabular bearing an d proposed that this finding was caused by multiple submicron PE parti cles. In order to determine the specificity of this light microscopic finding, we have analyzed a wide range of specimens (N = 27), characte rized by a foreign-body inflammatory response to both biologic and pro sthetic material, that do not contain PE. In no case was there any sug gestion of the diffuse cytoplasmic birefringence that is characteristi c of specimens from THRs with a PE acetabular bearing surface. This st udy indicates that, within the range of orthopedic implant materials a nd designs currently in use, this diffuse birefringence is a specific finding and it represents a simple, practical, and useful method for l ight microscopic identification of submicron PE. (C) 1993 John Wiley & Sons, Inc.