Histomorphometric evaluation of bone healing in rabbit fibular osteotomy model without fixation

BACKGROUND: Animal models of fracture consolidation are fundamental for the understanding of the biological process of bone repair in humans, but histological studies are rare and provide only qualitative results. The objective of this article is to present the histomorphometric study of the bone healing process using an experimental model of osteotomy in rabbit fibula without interference of synthesis material. METHODS: Fifteen rabbits were submitted to fibular osteotomy without any fixation device. Groups of five animals were submitted to pharmacological euthanasia during a period of one (group A), two (group B) and four weeks (group C) after osteotomy. Histomorphometric evaluation was performed in the histological sections. RESULTS: During week one there was intense cellularity (67/field), a large amount of woven bone (75.7%) and a small amount of lamellar bone (7.65%). At two weeks there was a decrease in woven bone (41.59%) and an increase in lamellar bone (15.16%). At four weeks there was a decrease of cellularity (19.17/field) and lamellar bone (55.56%) exceeded the quantity of woven bone (31.68%). CONCLUSION: Histomorphometric (quantitative) evaluation of the present study was shown to be compatible with bone healing achieved in qualitative experimental models that have been commended in the literature.