Lumbar Spine Age Changes: Difference between revisions
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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. | 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. | ||
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| Intervertebral disc height ||<ul><li>Intervertebral disc height ''increases'' with age.</li><li>There is an increase in AP diameter by 10% in females, and 2% in males, and a 10% increase in height of most discs. The upper and lower surfaces of the discs increase in convexity.</li><li>Disc height maintenance with age is "normal."</li><li>Any loss of trunk stature is due to decreases in vertebral body height.</li><li>Disc narrowing is due to a process other than ageing.</li></ul> | | Intervertebral disc height ||<ul><li>Intervertebral disc height ''increases'' with age.</li><li>There is an increase in AP diameter by 10% in females, and 2% in males, and a 10% increase in height of most discs. The upper and lower surfaces of the discs increase in convexity.</li><li>Disc height maintenance with age is "normal."</li><li>Any loss of trunk stature is due to decreases in vertebral body height.</li><li>Disc narrowing is due to a process other than ageing.</li></ul> | ||
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==Vertebral Endplate Changes== | ==Vertebral Endplate Changes== | ||
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| Age 20-65 || <ul><li>The endplate becomes thinner</li><li>Cell death in the superficial cartilage layers</li><li>In the subchondral bone of the endplate, vascular channels are gradually occluded leading to a decrease in permeability of the endplate to nutrients for the disc</li><li>Vertebral endplate strength decreases, but this depends on the underlying vertebral body so they should be considered together</li></ul> | | Age 20-65 || <ul><li>The endplate becomes thinner</li><li>Cell death in the superficial cartilage layers</li><li>In the subchondral bone of the endplate, vascular channels are gradually occluded leading to a decrease in permeability of the endplate to nutrients for the disc</li><li>Vertebral endplate strength decreases, but this depends on the underlying vertebral body so they should be considered together</li></ul> | ||
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==Vertebral Body Changes== | ==Vertebral Body Changes== | ||
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| (Schmorl's nodes) || <ul><li>These are more seen in the lower thoracic and thoracolumbar junction, rather than below L2.</li><li>They are due to fractures that are large enough to allow nuclear material to extrude into the vertebral body.</li><li>They are not symptomatic per se. They have highest incidence in adolescence, and don't increase in frequency with age.</li><li>Small protrusions of disc material into the vertebral bodies may be of significance.</li></ul> | | (Schmorl's nodes) || <ul><li>These are more seen in the lower thoracic and thoracolumbar junction, rather than below L2.</li><li>They are due to fractures that are large enough to allow nuclear material to extrude into the vertebral body.</li><li>They are not symptomatic per se. They have highest incidence in adolescence, and don't increase in frequency with age.</li><li>Small protrusions of disc material into the vertebral bodies may be of significance.</li></ul> | ||
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==Facet Joint Changes== | ==Facet Joint Changes== | ||
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| Osteophytes || <ul><li>Development of osteophytes and 'wrap-around bumpers'</li><li>Osteophytes develop along attachment sites of the joint capsule and ligamentum flavum to the superior articular process</li><li>Wrap-around bumpers are extensions of the edges of the articular cartilage curving around the dorsal aspect of the inferior articular process. Repeated stress during rotatory movements causes the cartilage to spread out to cover and protect the edges of the bony articular process</li></ul> | | Osteophytes || <ul><li>Development of osteophytes and 'wrap-around bumpers'</li><li>Osteophytes develop along attachment sites of the joint capsule and ligamentum flavum to the superior articular process</li><li>Wrap-around bumpers are extensions of the edges of the articular cartilage curving around the dorsal aspect of the inferior articular process. Repeated stress during rotatory movements causes the cartilage to spread out to cover and protect the edges of the bony articular process</li></ul> | ||
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==Movement Changes== | ==Movement Changes== | ||
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| Range of motion || <ul><li>Decreased range of motion</li><li>Evident in the entire lumbar spine and individual intervertebral joints</li><li>Young children show the greatest lumbar mobility. They are between 50-300% more mobile than middle-aged people at various segmental levels.</li><li>Decreases considerably by adolescence, and beyond the age of 30 there is then a gradual decline.</li><li><strong>Cause of change:</strong> The reduced mobility is principally due to the increased stiffness in the intervertebral discs with ageing. (proven with release experiments removing the posterior ligaments and facet joints). This is due to disc dehydration and fibrosis</li></ul> | | Range of motion || <ul><li>Decreased range of motion</li><li>Evident in the entire lumbar spine and individual intervertebral joints</li><li>Young children show the greatest lumbar mobility. They are between 50-300% more mobile than middle-aged people at various segmental levels.</li><li>Decreases considerably by adolescence, and beyond the age of 30 there is then a gradual decline.</li><li><strong>Cause of change:</strong> The reduced mobility is principally due to the increased stiffness in the intervertebral discs with ageing. (proven with release experiments removing the posterior ligaments and facet joints). This is due to disc dehydration and fibrosis</li></ul> | ||
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==Spondylosis and Degenerative Joint Disease== | ==Spondylosis and Degenerative Joint Disease== | ||
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The most pivotal reason that all these changes are not diseases, is the fact that they are irregularly associated with pain and disability. There is no correlation between spondylosis and osteoarthrosis in patients with or without symptoms. There is some additional factor that must be the cause of pain. | The most pivotal reason that all these changes are not diseases, is the fact that they are irregularly associated with pain and disability. There is no correlation between spondylosis and osteoarthrosis in patients with or without symptoms. There is some additional factor that must be the cause of pain. | ||
==References== | ==References== | ||
Bogduk, Nikolai. Clinical and radiological anatomy of the lumbar spine. Edinburgh: Elsevier/Churchill Livingstone, 2012. | These are study notes taken from Chapter 13 of: | ||
*Bogduk, Nikolai. Clinical and radiological anatomy of the lumbar spine. Edinburgh: Elsevier/Churchill Livingstone, 2012. | |||
[[Category:Lumbar Spine Anatomy]] | [[Category:Lumbar Spine Anatomy]] |
Revision as of 17:31, 15 April 2021
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 |
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Proteoglycans |
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Collagen |
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Elastic fibres |
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Non-collagenous proteins |
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Water content |
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Structural Changes
Feature | Change |
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Viable cells |
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NP and AF distinction |
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NP changes |
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Collagen lamellae |
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Tensile strength |
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Intervertebral disc height |
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Vertebral Endplate Changes
Age | Changes |
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Newborn |
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Age 10-15 |
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Age 17-20 |
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Age 20-65 |
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Vertebral Body Changes
Feature | Change |
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Bone Density |
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Vertical trabeculae |
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Horizontal trabeculae |
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Cortical bone |
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Microfractures |
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(Schmorl's nodes) |
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Facet Joint Changes
Header text | Header text |
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Subchondral bone |
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Articular cartilage |
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Posterior joint |
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Cell hypertrophy |
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Osteophytes |
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Movement Changes
The biochemical and structure changes that occur have an effect on the mechanical properties and movements of the spine.
Changes | |
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Creep and hysteresis |
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Range of motion |
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Spondylosis and Degenerative Joint Disease
Spondylosis refers to the development of osteophytes along the junction of vertebral bodies and their intervertebral discs. Spondylosis is not a disease but a natural consequence of the stresses applied to the spine throughout life. They are reactive and adaptive changes that are due to compensation of biomechanical aberrations. It is an active and purposeful process, not a degenerative one.
With age, the NP becomes less resilient and stiffer, and the AF bears more of the compressive loads applied to the disc. Adaption occurs with the greater loads. Excessive compression can result in ossification of the terminal ends of the collagen fibres of the AF. This ossification can occur in the anterior and posterior margins of the disc where compressive strains are focused during flexion and extension. Excessive vertical load-bearing can result in the development of osteophytes along the entire margin of the vertebral body. This is the vertebral body trying to expand its articular surface area in order to distribute axial loads over a wider area, and therefore lessening the stress applied to the AF during load. In other words, osteophytosis is a natural response to the altered biomechanics of the lumbar spine that are itself due to biochemical changes in the disc. It is not a disease but rather an expected morphological change with age.
The terms osteoarthrosis and degenerative joint disease refer to changes seen in the facet joints. However again, these are morphological consequences of stresses applied to the facet joints over time. The changes are found in regions of greatest and repeated stresses. These are adaptive changes, the structure remodels to account for the applied stresses. However, with severe or repeated stresses, destructive features may occur.
The most pivotal reason that all these changes are not diseases, is the fact that they are irregularly associated with pain and disability. There is no correlation between spondylosis and osteoarthrosis in patients with or without symptoms. There is some additional factor that must be the cause of pain.
References
These are study notes taken from Chapter 13 of:
- Bogduk, Nikolai. Clinical and radiological anatomy of the lumbar spine. Edinburgh: Elsevier/Churchill Livingstone, 2012.