pulposuksesta

The nucleus pulposus is the gel-like inner core of an intervertebral disc, situated between adjacent vertebral bodies and surrounded by the annulus fibrosus. It functions as a cushion and allows the disc to distribute and absorb compressive loads during movement and weight-bearing.

The nucleus pulposus is rich in water and proteoglycans, particularly aggrecan, with a supporting matrix of type II collagen. In early life, notochordal cells contribute to its cellular population, which gradually shifts to chondrocyte-like cells with maturation. The tissue is avascular and relies on diffusion from the adjacent vertebral endplates for nutrients and waste removal, a factor that influences its capacity for self-repair after injury.

With aging and repetitive mechanical stress, the nucleus pulposus undergoes dehydration and a reduction in proteoglycan content. These changes decrease its water-holding ability, reduce disc height, and alter the mechanical properties of the disc. Degenerative processes can lead to fissures in the surrounding annulus fibrosus and may predispose to disc herniation.

Clinically, disruption of the nucleus pulposus can result in disc herniation or extrusion, where material protrudes through a damaged annulus and may compress adjacent nerve roots, causing radicular pain or sciatica. Magnetic resonance imaging often shows high water content in a healthy nucleus pulposus on T2-weighted sequences, while degenerative discs display reduced signal intensity and structural changes.

Management ranges from conservative approaches—physical therapy, analgesia, and activity modification—to surgical interventions in select cases. Research continues into regenerative strategies aimed at restoring nucleus pulposus structure and function.