DEVELOPMENTAL STUDY OF CARTILAGE CANAL IN TIBIA OF ALBINO RAT

Abstract

Carti Iage canals are channels of loose, vascularized mesenchyme that traverse the hyaline cartilage of the epiphysis before ossification. _The canals contain blood vessels which eventually become incorporated into the developing ossific center and connective tissue cells which are generally described as polymorphic mesenchymal cells. The aim of this work was to study the cartilage canals developmentally as regard to their structure, function and fate. A total number of 45 albino rats were used in this study. The animals were divided into 9 groups, 5 animals in each group. The animals were sacrificed and the knee joints were dissected, fixed in 10% formaline and decalcified in neutral E.D.T.A. After the routine histological processing, the specimens wered embedded in paraffin. Serial longitudinal sections were cut at a thickness of 1 OJ.! and were stained with'Haematoxylin and Eosin for studying the cells and matrix of the canals. Also, VanGieson stain was used for studying collagen fibers of the canals and perichondrium. The results of this study were divided into 4 stages. First stage (Precanal stage) is represented in the present study by the ages 19th,20th day prenataly and newborn. The epiphysis is formed of highly cellular hyaline catiilage. No canals were appeared at this stage. Second stage "Formation stage" is represented by the ages 4 & 7 days postnatally. The canals appeared at the age of four days and reached its full maturation at the age of seven days age postnatally. Third stage "Ossification center stage" is represented by the ages 8 & 10 days postnatally. During this stage the ossification center appeared and reached its full development.