Skeletal dysplasias caused by a disruption of skeletal patterning and
endochondral ossification.
CED results from disturbance of intramembranous ossification (Fig.(1)) affecting the long bones, calvaria, mandible and facial bones.(11,16) There are a few reported cases of involvement of the skull base (a site of
endochondral ossification), but these occur in advanced stages.(3,11,17,18)
RXR binds to bone morphogenetic proteins (BMP) which substantially affect the process of complete maturation and hypertrophy of chondrocytes in the
endochondral ossification pathway (Enomoto-Iwamoto et al., 1998; Volk and Leboy, 1999).
Dysplasia of
endochondral ossification, affecting secondary spongiosa, are characterized by errors in resorption or remodeling of secondary spongiosa, which results in focal densities and/or striations within the trabecular bone (3).
The results were compared with two samples of bone (one
endochondral, one dermal) from a modern animal.
Several cellular mechanisms have been proposed to be affected by PEMF including an increased mineralization, collagen production,
endochondral ossiication and decreased osteoclastogenesis (7).
Acceleration of experimental
endochondral ossification by biophysical stimulation of the progenitor cell pool.
Ueno T, Kagawa T, Mizukawa N, Nakamura H, Sugahara T , Yamamoto T 2001 Cellular origin of
endochondral ossification from grafted periosteum Anatomical Record 264 348-357
Impaired fracture healing in the absence of TNF-alpha signaling: the role of TNF-alpha in
endochondral cartilage resorption.
Failure of
endochondral ossification of the skull base, vertebral bodies and long bones results in rhizomelic limb shortening (short proximal segments), macrocephaly, frontal bossing and midface hypoplasia (5).
Mice lacking tartrate-resistant acid phosphatase (Acp 5) have disrupted
endochondral ossification and mild osteopetrosis.