The object of this study is to evaluate the use of the bone densitometry as an evaluation method of the bone increment observed when we used bovine BMP in intertransverse arthrodesis of the rabbits' lumbar spine. Since the discovery of the BMP bone inductive properties, countless experimental models have been proposed. This caused the need of setting up evaluation methods to make possible a better understanding of the found results. Twenty female rabbits from New Zealand, divided in two groups, were submitted to the intertransverse arthrodesis of the lumbar column, segment L5/L6, posterior side. In the first group it was used autologous graft and in the second an association of autologous graft with biocompound (bovine BMP, 1.0 mg and hydroxyapatite, 9.0 mg). The animals were maintained in captivity, isolated and after 15 weeks submitted to the execution of bone densitometry by computerized tomography. 268 bone density measures of the normal bone, 134 measures of the newly formed bone by the association of the isolated autologous graft and 134 measures of the newly formed bone by the association autologous graft and BMP were obtained, what demonstrated a significant bone increment after statistical analysis (p=0.034) of the BMP/HAP group, when compared to the control group. We found this same variation of bone density analyzing the normal bone. The bone densitometry accomplished by the computerized tomography is an alternative method to assess the results when the BMP is used in experimental studies. Further studies should be accomplished for better understanding of the bone density variation found when the measures of the normal bone in the two groups are compared.
Bone morphogenetic protein (BMP); Bone transplantation; Durapatite; Bone density; Tomography
