Reflections on the nucleus pulposus

The intervertebral disc is usually divided into two parts, the anulus fibrosus and the nucleus pulposus. However, they are not considered two separate anatomic parts since one is essentially part of the other and this should be borne in mind to understand the process of ageing. The intervertebral disc should therefore be thought of as a dynamically evolving anatomo-functional unit. The dynamics of this process were investigated by studying the histobiochemistry of the acellular matrix of the joint cartilage in general and that of the intervertebral disc in particular to understand the effects of this arrangement on the stuctural changes to the disc induced by biomechanical stress: especially during ageing. Lastly, we focussed on the disc's nutritional mechanisms in order to examine "disc degeneration" as a sign of metabolic impairment of the nucleus pulposus and "disc regeneration" This concept was unknown until recently and is currently monitored in percutaneous controls following treatment for disc disease.