Histologic analysis of distraction osteogenesis in the femoral shaft of the immature rabbit

Abstract

A study of the distraction callus in the femur of the growing rabbit was performed. Thirty animals separated into 10 groups were used. Distraction between both ends of a femoral osteotomy induced the formation of a connective callus which subsequently ossified. This callus disappeared between the fourth and the eighth week after the lengthening was completed. The osteogenesis model was of a mixed type, intramembranous and endochondral, with a predominance of the former. The bone healing and the initial signs of remodeling in the newly formed bony tissue were seen at the end of the first week of distraction. The original cortex was resorbed during the lengthening and was progressively substituted by a new cortex, whose formation and remodeling was not finished 24 weeks after the completion of the distraction. Experimental conditions could explain some of the findings.