Lumbar Spine Age Changes
Standard descriptions of the lumbar spine refer to the healthy, young, adult spine. There is also variation to what is "normal" for the lumbar spine. With aging you see fairly uniform changes in the lumbar spine, and so normality changes with advancing age. Many changes in the lumbar spine are not associated with symptoms and are therefore not pathological, but rather part of the normal ageing process.
Biochemical Changes
The changes in collagen, proteoglycans, and elastic fibres have major biomechanical effects on the disc. With age they become drier, and with an increase in collagen and reduction of elastin, they become more fibrous and less resilient. The increased collagen and collagen-proteoglycan binding leads the disc to become stiffer (more resistant to deformation), and the decreased water-binding capacity means they are less able to recover from creep deformation. This can lead to a change in mobility.
Area of Change | Biochemical Changes |
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Metabolism | In childhood, the disc adapts to anaerobic metabolism after the regression in infancy of the meagre blood supply to the disc. |
Proteoglycans |
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Collagen |
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Elastic fibres | Reduction in the AP from 13% at age 26 to 8% at age 62 |
Non-collagenous proteins | Increase in concentration, with the appearance of distinctive non-collagenous proteins. Their function is unknown. |
Water content |
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References
Bogduk, Nikolai. Clinical and radiological anatomy of the lumbar spine. Edinburgh: Elsevier/Churchill Livingstone, 2012.