13/07/2015
Los osteofitos son una respuesta del cartilago, hueso subcondral y articulacion ante la enfermedad.
Osteophyte Formation
One of the most remarkable and consistent features of joints affected with osteoarthritis, whether naturally occurring or experimentally induced, is the development of
prominent osteochondral nodules known as osteophytes, osteochondrophytes, and chondro-osteophytes.
Indeed, the presence of chondro-osteophytes in a joint, more than any other pathological feature, distinguishes osteoarthritis from other arthritides.
Mechanical and humoral factors are involve in stimulating the formation of osteophytes, though the exact functional significance of osteophyte growth remains unclear.
There is, however, direct evidence that osteophytes help stabilize osteoarthritic joints Notwithstanding uncertainties of how and why they form, osteophytes are an example of new cartilage and bone development in osteoarthritic joints, which are ultimately characterized by articular cartilage degeneration. Close examination of the biosynthetic activity of developing chondro-osteophyte in the Pond-Nuki dog model of osteoarthritis revealed that the cells arise from tissue associated with the chondro-synovial junction, indicating that there is a population of pluripotential cells in the periosteum that is responsive to the mechanical and humoral sequelae of joint injury.
The formation of chondro-osteophytes in OA joints is a unique example of adult neochondrogenesis that bears some similarities to growth plate elongation and fracture callus formation. Studies using in situ hybridization histochemistry to define the molecular phenotype of cells in active chondro-osteophytes have been performed in a dog model of early OA.
Chondro-osteophytes are composed of fibrocytes and osteoblasts that express type I procollagen mRNA, mesenchymal prechondrocytes that express type IIA procollagen mRNA, and maturing chondrocytes that express type IIB procollagen mRNA. Based on the spatial pattern of gene expression and cytomorphology, the neochondrogenesis associated with chondro-osteophyte formation closely resembles that of the healing fracture callus and recapitulates events of endochondral bone formation.
The fact that BMP-2 is a morphogenetic factor stimulated by pro-inflammatory cytokines, strongly suggests that this factor could stimulate differentiation in multipotent cells into osteophyte in the joint tissues
