[PECULIARITIES OF BONE TISSUE MORPHOGENESIS DURING SHIN LENGTHENING USING THE METHOD OF TRANSOSSEOUS DISTRACTION OSTEOSYNTHESIS WITH THE INCREASED DAILY RATE].

ABSTRACT

Histogenesis of bone tissue was studied in 25 adult mongrel dogs under conditions of automatic shin lengthening by the technique of transosseous distraction osteosynthesis with the daily rate of 3 mm in 120 repeats using the methods of light, scanning electron microscopy, electron probe microanalysis, immunohistochemistry and morphometry. During the distraction period, cellular heteromorphism and proliferative activity of the cells of connective tissue interlayer and periosteum were clearly detected in the interfragmental diastasis. In the post-distraction period, the reduction of cellular heteromorphism and the increase of the biosynthetic activity of the osteoblastic cells were observed while the provisional endosteal bone regenerate of normotrophic type with the signs of organotypic reorganization was formed. Intramembranous osteogenesis was noted at all the stages of the experiment. The organ-specific nature of the newly formed bone occured by 30 days after the apparatus removal. Bone tissue plasticity and the conditions of high-fractional distraction allow to increase the daily rate of leg lengthening up to 3 mm, as well as to provide the formation of weight-bearing bone part during 45 days, thereby reducing by 31% the duration of the period of fixator use for shin lengthening in comparison with that one adopted in classic technique with the daily rate not exceeding 1 mm.