Neuroradiology of spine degenerative diseases.
Degenerative disease of the spine is one of the most common clinical entities and affects the intervertebral discs, including opposing vertebral endplates, the intervertebral posterior joints and the ligaments. The most severe primary spinal degenerative changes are found in the lower cervical and lumbar spine regions. The spine contains three different types of joints, each of which presents its own pattern of degenerative disease: (i) cartilaginous joints, represented by the intervertebral disc or, more specifically, the functional unit defined as the 'vertebro-disc connection'; (ii) synovial joints, represented by the posterior intervertebral joints, sacro-iliac and costovertebral joints; (iii) fibrous joints, mainly found in the principal ligaments such as the posterior longitudinal ligament and the yellow ligaments. With regard to radicular pain, root compression alone does not fully account for root pain following disc-root conflict, but it is, nevertheless, considered to be the main cause of pain. We will try to explain that the origin of pain is multi-factorial and that inflammation probably predominates over merely mechanical mechanisms. To conclude, we will consider whether vertebral arthrosis can be construed as the body's decision to favour the spine's static function over its dynamic role when joint 'hypermobility' linked to chronic load in old age could cause severe structural damage to the bony vertebral structures. This hypothesis should also embrace a further concept: ageing of the spine is not merelychronological. Themostaccurate interpretation tha tcan account for similar degenerative phenomena encountered in the young is that of abnormal static and dynamic loading stress.