Does static precede dynamic osteogenesis in endochondral ossification as occurs in intramembranous ossification?
Article first published online: 9 OCT 2006
Copyright © 2006 Wiley-Liss, Inc.
The Anatomical Record Part A: Discoveries in Molecular, Cellular, and Evolutionary Biology
Volume 288A, Issue 11, pages 1158–1162, November 2006
How to Cite
Ferretti, M., Palumbo, C., Bertoni, L., Cavani, F. and Marotti, G. (2006), Does static precede dynamic osteogenesis in endochondral ossification as occurs in intramembranous ossification?. Anat. Rec., 288A: 1158–1162. doi: 10.1002/ar.a.20386
- Issue published online: 17 OCT 2006
- Article first published online: 9 OCT 2006
- Manuscript Accepted: 26 JUL 2006
- Manuscript Received: 6 MAR 2006
- 2004 MURST Cofinancing. Grant Number: 2004067411_001
- endochondral ossification;
- intramembranous ossification;
- static osteogenesis;
- dynamic osteogenesis
Endochondral ossification takes place with calcified cartilage cores providing a rigid scaffold for new bone formation. Intramembranous ossification begins in connective tissue and new bone formed by a process of static ossification (SO) followed by dynamic ossification (DO) as previously described. The aim of the present study was to determine if the process of endochondral ossification is similar to that of intramembranous ossification with both a static and a dynamic phase of osteogenesis. Endochondral ossification centers of the tibiae and humeri of newborn and young growing rabbits were studied by light and transmission electron microscopy. The observations clearly showed that in endochondral ossification, the calcified trabeculae appeared to be lined first by osteoclasts. The osteoclasts were then replaced by flattened cells (likely cells of the reversal phase) and finally by irregularly arranged osteoblastic laminae, typical of DO. This cellular sequence did not include osteoblasts seen in the phase of SO. These findings clearly support our working hypothesis that SO only forms in soft tissues to provide a rigid framework for DO, and that DO requires a rigid mineralized surface. The presence of osteocytes in contact with the calcified cartilage also suggests the existence of stationary osteoblasts in endochondral ossification. Stationary osteoblasts did not appear to be a unique feature of SO. The presence of stationary osteoblasts may appear to provide the initial osteocytes during osteogenesis that may function as mechanosensors throughout the bone tissue. If this is the case, then bone would be capable of sensing mechanical strains from its inception. Anat Rec Part A, 288A:1158–1162,2006. © 2006 Wiley-Liss, Inc.