Research Article
Melrose J
Abstract
The intervertebral disc (IVD) is an intricate collection of connective tissues of disparate structure and function, which collectively act as a weight-bearing cushion between the bony vertebrae of the spine. The outer region of the IVD is the annulus fibrosus (AF), a collagen-rich tissue consisting of successive layers or lamellae which contain the hoop stresses generated in the IVD upon axial compression of the spine, these provide the AF with tensile properties which aid in the dissipation of these compressive loads . The AF encloses the central region of the IVD, the nucleus pulposus (NP) which is a gelatinous tissue (at least in infancy) rich in proteoglycans (aggrecan) that imbibe water and provide hydrodynamic weight bearing properties to the composite IVD.