HISTOMORPHOMETRIC ANALYSIS OF THE REPAIR OF A SEGMENTAL DIAPHYSEAL DEFECT WITH CERAMIC AND TITANIUM FIBERMETAL IMPLANTS - EFFECTS OF BONE-MARROW

We used a rat femoral diaphyseal defect/implant model to quantify the ingrowth of bone, cartilage, and fibrous connective tissue in a compar ative study of woven sintered titanium fibermetal and porous hydroxyap atite/tricalcium phosphate ceramic implanted with and without the addi tion of syngeneic bone marrow cells. The patterns of tissue growth int o the implants were analyzed with respect to time, type of implant, an d the presence or absence of syngeneic marrow. Significantly more bone was found in ceramic implants than in fibermetal implants, with the a ddition of syngeneic marrow than without it, and at 4 months than at 2 months. Significantly more bone was found at both time periods in cer amic implants with bone marrow than in any other combination studied. We hypothesize that these findings resulted from interactions between the implanted material and its surroundings, specifically its ability to serve as a substratum for cell attachment, and cells in and around the defect, whether surgically implanted or arising from the soft-tiss ue bed.