BONE-GROWTH AND MODELING CHANGES INDUCED BY PERIOSTEAL STRIPPING IN THE RAT

In this study, the changes in longitudinal bone growth and metaphyseal modeling induced by middiaphyseal periosteal stripping in the rat fem ur were analysed by means of histomorphometrical techniques. One hundr ed forty-four male 30-day-old Sprague-Dawley albino rats distributed i n 4 groups of 36 were studied: a control group, a sham group, a group with middiaphyseal right femoral periosteal ring wrapped around the st ripped zone. The animals were euthanized at 1, 2, or 4 weeks from the start of the experiment, after double tetracycline labeling. A statist ically significant, albeit small, longitudinal overgrowth of stripped femurs was observed after a latency period of 2 to 4 weeks. The metaph yseal diameters were greater in stripped femurs than nonstripped femur s. This finding was associated with a lower osteoclastic index in the external metaphyseal surface and with a lower bone formation rate in t he internal surface of the metaphyseal cortex. These latter findings h ave not been reported previously in the literature and may support the role of the periosteum in controlling metaphyseal modeling.