ABSTRACT
The vast majority of spinal surgery is performed for lumbar disc prolapse. The incidence of lumbar disc degeneration is so high as to consider it a normal part of the ageing process. Often it will be asymptomatic, even when prolapse has occurred. In post-mortem studies of asymptomatic individuals, the rate of prolapse is 15%. MRI scans cannot therefore be relied on to make a diagnosis of symptomatic anatomical abnormality, and much trouble ensues if the patient is made aware of normal degenerative changes without being made aware of their lack of clinical significance. Disc disease may present with either or both of low back pain or radicular symptoms. The former is due to the direct damage to the disc, whereas the latter to the effects of the disc protrusion itself. Low back pain is discussed elsewhere but suffice it to mention it may arise from sources other than the disc, such as the muscles, ligaments, facet joints or the dural tube itself – this is not an exhaustive list.
