A Comparative Experimental Study of Allograft andPorous Hydroxyapatite as Bone Substitutes / 대한정형외과학회잡지

ABSTRACT

PURPOSE: An experimental animal study was performed to compare the bone fusion capacity of an allograft and porous hydroxyapatite. MATERIALS AND METHODS: Three milliliters of allograft or porous hydroxyapatite particles were inserted between the 4th and 5th lumbar transverse processes of New Zealand white rabbits weighing 3-3.5 kg. The total number of rabbits was 30, which were divided randomly into 2 groups. The bone formation and fusion capacity were evaluated 12 weeks after surgery through the gross findings and manual palpation, as well as radiological, biomechanical, and histological studies. Six rabbits in the allograft group died during breeding but the autopsy finding did not show any evidence suggesting an infection or graft rejection. The allograft was harvested from the iliac crest of the rabbits of the same species aseptically and was preserved at ??80oC for at least 7 days before implantation. RESULTS: The fusion rates were 55.6% (5/9) and 66.7% (10/15) in the allograft and porous hydroxyapatite groups, respectively. The mean values of the tensile strengths were 140.7 N in the allograft group and 189.6 N in the porous hydroxyapatite group. Histological analysis of 2 specimens from each group revealed theporous hydroxyapatite group to show a slightly better osteoconduction capacity. CONCLUSION: The porous hydroxyapatite group showed better bony union capacity even though there was no significant difference between the 2 groups.