Key Words: bone development, fracture repair, osteotomy, intramembranous bone, endochondral bone, mesenchymal osteoblasts, surface osteoblasts, distraction osteogenesis

Publication date: April 1st 2008

Abstract: Bone development occurs by two mechanisms: intramembranous bone formation and endochondral bone formation. Bone tissue forms by eventual differentiation of osteoprogenitor cells into either mesenchymal osteoblasts (MOBL), which synthesize woven bone in random orientation, or surface osteoblasts (SOBL), which synthesize bone on surfaces in a well oriented lamellar array. Bone repair uses the same formation patterns as bone development but the specific mechanism of repair is determined by the biomechanical environment provided. Bone synthesis and maintenance are highly dependent on the blood supply of bone and on cell-cell communication via the lacunar-canalicular system. Recent investigations highlight the molecular cascades leading to cell differentiation, the components of the structural proteins such as the various collagens, and tissue vascularization. The patterning of bone matrix from an initial woven to an eventual lamellar orientation is essential for bone to develop its maximum strength. This review demonstrates the repetitive nature of woven to lamellar bone formation as mediated by MOBLs and SOBLs in both normal vertebrate bones and bone repair. Repair, using endochondral, primary, direct and distraction osteogenesis mechanisms, is reviewed along with the associated molecular, vascular, and biophysical features.

Article download: Pages 53-76 (PDF file)

Acrobat Reader:

To read this article you will need to install Adobe Acrobat Reader on your computer. Should you experience any difficulty in reading the PDF file we suggest that you save the file to your computer BEFORE opening it from Adobe Acrobat.

Last modified October 21, 2011

Publisher: AO Foundation, Davos, Switzerland