COMPOSITION, CONSTITUTION, AND INTERACTION OF BONE WITH HYDROXYAPATITE COATINGS DETERMINED BY FT RAMAN MICROSCOPY

An optimized FT Raman microscope (inverted microscope with high throug hput of radiation) was developed that allows minimal sample preparatio n and Raman spectroscopy without fluorescence. A quantitative determin ation of the mineralization of bone tissue and hydroxyapatite (HA) coa tings of hip and knee prostheses was performed. The lateral resolution reached down to 10 mu m. The distribution of the I-IA content in the coatings investigated was found to be similar all the time. This resul t was independent of the composition of the coatings and the history o f the whole prosthesis. In the immediate vicinity of the prosthesis a large HA content could be observed that decreased to a minimum towards the periphery of the coating and increased at the site of the ongrown bone. For the interface between bone and HA coating a transitional zo ne was observed at a lateral distance of 30-40 mu m to the implant. (C ) 1998 John Wiley & Sons, Inc.