Normal Aging of the Spine
Degeneration of the spinal column and its associated constituents is part of the normal aging of the spine. Some research has shown that the intervertebral discs even begin to degenerate in the second decade of life1.
The reason for this early degeneration relates to the relative poor vascularisation of the discs, but there are many other contributing factors.
The natural history of the aging spine has been divided up into three stages:
- Initial stage is dehydration due to loss of the proteoglycan content of the nucleus.
- Typically occurring between 15-45 years.
Early degenerative changes are characterised by circumferential or radial tears to the annulus. Can be associated with synovitis of the facet joints.
- Typically occurring between 35-70 years.
- There is disruption of the disc, re-absorption and subsequent loss of height.
The facet joints degenerate and this is associated with capsular laxity and subluxation.
Progressive development of hypertrophic bone around the discs and facet joints leaded to relative stability of the intervertebral discs.
Horner HA, Urban JPG, Effects of Nutrient Supply on the Viability of Cells from the Nucleus Pulposus of the Intervertebral Disc: 2001 Volvo Award in Basic Science. Spine 2001; 26(23): 2543-2549