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Topographic-quantitative Study of Bone Tissue Formation and 

 Reconstruction in Inert Bones 



G. Marotti, F. Marotti ■'' 

 Istituto di Anatomia Umana, Universita di Bari, Bari, Italia 



A quantitative estimation of the amount of new bone tissue formed in the shafts 

 of bones was carried out on bones rendered mechanically inert for various periods of 

 time. 



The left anterior limbs of young immature and adult dogs were freed of skin and 

 fixed to the thoracic wall in a cutaneous pouch after division of the brachial plexus. 

 The animals were sacrificed from 20 days to several months after the operation; ten 

 days before sacrifice, 20 to 30 mg of Acromycin/Kg of body weight was administered 

 daily for three successive days. 



The area occupied by newly formed acromycin labelled bone (NB) and by 

 unlabelled bone present before (PB) the administration of the antibiotic, was com- 

 puted using an automatic point counter on photomicrographs made with U.V. light 

 (color reversal film). Entire cross-sections taken from various levels of the unloaded 

 and denervated bones, as well as from corresponding levels of the homotypic bones 

 of the opposite mobile leg were examined. The relative amount of bone tissue laid 

 down during acromycin treatment was expressed as "/o NB/(PB-)-NB) and is shown 

 in Figs. 1 to 4. 



=■' Staff member of the Orthopaedic Clinic, University of Padova; Holder of a scholarship of the Italian 

 C.N.R. 



