Interdependence of lumbar disc and subdiscal bone properties: a report of the normal and degenerated spine.
A nondestructive mechanical testing technique was used to assess midsagittal plane variations in the mechanical properties of human lumbar vertebral bone adjacent to the intervertebral discs of normal and degenerated spines. Bone mechanical properties were compared with midsagittal plane measurements of intervertebral disc (IVD) physical-chemical properties. In the normal spine a heterogeneous midsagittal plane distribution of subdiscal bone stiffness, IVD hydration and fixed charge density was found. Segments with degenerated discs exhibited a lower amount of midsagittal variation in subdiscal bone and IVD properties. A positive linear correlation between subdiscal bone stiffness and IVD fixed charge density was also found, suggesting that an interdependence of IVD and bone properties exists. These results support previous findings and are hypothesized to be an adaptive response to changes in the stress environment in the IVD.
Department of Mechanical Engineering, University of Vermont, Burlington 05405-0156.
T S
TS
Keller
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I
Ziv
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E
Moeljanto
D M
DM
Spengler
D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D015519:Bone Density; D006801:Humans; D008159:Lumbar Vertebrae / Q000502:physiology* / Q000503:physiopathology*; D008875:Middle Aged; D013122:Spinal Diseases / Q000503:physiopathology*; D013131:Spine / Q000502:physiology*