Molecular biology of degenerative disc disease

THE INTERVERTEBRAL DISC is a complex anatomic and biochemical structure. It is composed primarily of fibrocytes and chondrocytes that are anatomically segregated in an elaborate avascular macromolecular matrix of collagen and proteoglycans. Degenerative processes associated with aging and trauma res ult in morphological and molecular changes to the disc. Morphological chang es are observed as dehydration, fissuring, and tearing of the nucleus, annu lus, and endplates. On the molecular level, degenerative changes include de creased diffusion, decreased cell viability, decreased proteoglycan synthes is, and alteration in collagen distribution. The role of inflammatory media tors in these processes, and the potential use of growth factors to delay o r reverse the degenerative cascade, is poorly understood. However, these ar eas are under active investigation, the results of which may soon contribut e significantly to our understanding of degenerative disc disease.