THE RESPONSE OF CANCELLOUS AND CORTICAL CANINE BONE TO HYDROXYLAPATITE-COATED AND UNCOATED TITANIUM RODS

Because of the recent trend in total hip arthroplasty to achieve direc t contact of the endoprosthesis with cortical bone, comparison of bone apposition from cortical bone and cancellous bone was performed. The response of cortical and cancellous bone to hydroxylapatite was also c ompared. Implants in cortical bone demonstrated a higher interface she ar strength and more bone apposition than those in cancellous bone ove r all time periods tested, Hydroxylapatite coating increased the inter facial shear and bone apposition in cortical bone at all time periods and in both the 3- and 6-week cancellous bone models. The potential ef fect of stress shielding (and subsequent bone resorption) by femoral s tems ingrown with cortical bone is discussed. (C) 1995 John Wiley & So ns, Inc.