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Geometry of the intervertebral volume and vertebral endplates of the human spine.

van der Houwen EB, Baron P, Veldhuizen AG, Burgerhof JG, van Ooijen PM, Verkerke GJ - Ann Biomed Eng (2009)

Bottom Line: Ten adjacent points on both sides of the vertebrae (S1-superior to T12-inferior) and sagittal and transverse diameters were measured to describe the shape of the caudal and cranial vertebral planes of the vertebrae.It was found that the largest endplate depth is located in the middle or posterior regions of the vertebra, that there is a linear relationship between all inferior endplate depths and the endplate location (p < 0.0001) within the spinal column, and that the superior endplate depth increases with age by about 0.01 mm per year (p < 0.02).The results allow for improvement of the fit of intervertebral disc-prostheses to the vertebrae and optimized force transmission through the vertebral column.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, University Medical Center Groningen, University of Groningen, A. Deusinglaan 1, 9713AV, Groningen, The Netherlands. vdhouwen@gmail.com

ABSTRACT
Replacement of a degenerated vertebral disc with an artificial intervertebral disc (AID) is currently possible, but poses problems, mainly in the force distribution through the vertebral column. Data on the intervertebral disc space geometry will provide a better fit of the prosthesis to the vertebrae, but current literature on vertebral disc geometry is very scarce or not suitable. In this study, existing CT-scans of 77 patients were analyzed to measure the intervertebral disc and vertebral endplate geometry of the lumbar spine. Ten adjacent points on both sides of the vertebrae (S1-superior to T12-inferior) and sagittal and transverse diameters were measured to describe the shape of the caudal and cranial vertebral planes of the vertebrae. It was found that the largest endplate depth is located in the middle or posterior regions of the vertebra, that there is a linear relationship between all inferior endplate depths and the endplate location (p < 0.0001) within the spinal column, and that the superior endplate depth increases with age by about 0.01 mm per year (p < 0.02). The wedge angle increases from T12-L1 to L5-S1. The results allow for improvement of the fit of intervertebral disc-prostheses to the vertebrae and optimized force transmission through the vertebral column.

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Related in: MedlinePlus

Depth profiles (exact depth per point printed on the x-axis for clarity), endplate sizes and disc contour from the sagittal and frontal plane (all values in mm). Standard deviations depicted by error bars
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Fig2: Depth profiles (exact depth per point printed on the x-axis for clarity), endplate sizes and disc contour from the sagittal and frontal plane (all values in mm). Standard deviations depicted by error bars

Mentions: Figure 2 (left column) lists all vertebrae and their relative depths. The smallest depth is generally located on the anterior side, followed by the lateral (left and right) locations. The middle or posterior locations generally show the maximum depth. For T12inf and L1inf the maximum is located on the posterior side. For L3inf, L4inf, and L5inf the maximum is in the middle. The average left and right depths are similar. There was no significant difference between the endplate depths on point [8] or [3] (Fig. 1). There is an increase in inferior endplate depth (in mm) from L1inf to L5inf for all locations. T12inf does not follow this trend and tends to have larger values. A linear relationship between the depth and the endplate location within the spinal column was found for all measured points at the inferior sides only (p < 0.0001). For measurement point [4] a relationship between age and depth was also found. The following equations can be used to calculate endplate depths (in mm) for different locations in the spinal column:Point on endplateDepth as a function of spinal locationRight [7]Depth = 2.46 − 0.10*locationMiddle [8]Depth = 3.06 − 0.14*locationLeft [9]Depth = 2.36 − 0.08*locationAnterior [4]Depth = 1.56 − 0.09*location + 0.008*ageMiddle [3]Depth = 3.17 − 0.15*locationPosterior [2]Depth = 2.75 − 0.09*locationFigure 2


Geometry of the intervertebral volume and vertebral endplates of the human spine.

van der Houwen EB, Baron P, Veldhuizen AG, Burgerhof JG, van Ooijen PM, Verkerke GJ - Ann Biomed Eng (2009)

Depth profiles (exact depth per point printed on the x-axis for clarity), endplate sizes and disc contour from the sagittal and frontal plane (all values in mm). Standard deviations depicted by error bars
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2803258&req=5

Fig2: Depth profiles (exact depth per point printed on the x-axis for clarity), endplate sizes and disc contour from the sagittal and frontal plane (all values in mm). Standard deviations depicted by error bars
Mentions: Figure 2 (left column) lists all vertebrae and their relative depths. The smallest depth is generally located on the anterior side, followed by the lateral (left and right) locations. The middle or posterior locations generally show the maximum depth. For T12inf and L1inf the maximum is located on the posterior side. For L3inf, L4inf, and L5inf the maximum is in the middle. The average left and right depths are similar. There was no significant difference between the endplate depths on point [8] or [3] (Fig. 1). There is an increase in inferior endplate depth (in mm) from L1inf to L5inf for all locations. T12inf does not follow this trend and tends to have larger values. A linear relationship between the depth and the endplate location within the spinal column was found for all measured points at the inferior sides only (p < 0.0001). For measurement point [4] a relationship between age and depth was also found. The following equations can be used to calculate endplate depths (in mm) for different locations in the spinal column:Point on endplateDepth as a function of spinal locationRight [7]Depth = 2.46 − 0.10*locationMiddle [8]Depth = 3.06 − 0.14*locationLeft [9]Depth = 2.36 − 0.08*locationAnterior [4]Depth = 1.56 − 0.09*location + 0.008*ageMiddle [3]Depth = 3.17 − 0.15*locationPosterior [2]Depth = 2.75 − 0.09*locationFigure 2

Bottom Line: Ten adjacent points on both sides of the vertebrae (S1-superior to T12-inferior) and sagittal and transverse diameters were measured to describe the shape of the caudal and cranial vertebral planes of the vertebrae.It was found that the largest endplate depth is located in the middle or posterior regions of the vertebra, that there is a linear relationship between all inferior endplate depths and the endplate location (p < 0.0001) within the spinal column, and that the superior endplate depth increases with age by about 0.01 mm per year (p < 0.02).The results allow for improvement of the fit of intervertebral disc-prostheses to the vertebrae and optimized force transmission through the vertebral column.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, University Medical Center Groningen, University of Groningen, A. Deusinglaan 1, 9713AV, Groningen, The Netherlands. vdhouwen@gmail.com

ABSTRACT
Replacement of a degenerated vertebral disc with an artificial intervertebral disc (AID) is currently possible, but poses problems, mainly in the force distribution through the vertebral column. Data on the intervertebral disc space geometry will provide a better fit of the prosthesis to the vertebrae, but current literature on vertebral disc geometry is very scarce or not suitable. In this study, existing CT-scans of 77 patients were analyzed to measure the intervertebral disc and vertebral endplate geometry of the lumbar spine. Ten adjacent points on both sides of the vertebrae (S1-superior to T12-inferior) and sagittal and transverse diameters were measured to describe the shape of the caudal and cranial vertebral planes of the vertebrae. It was found that the largest endplate depth is located in the middle or posterior regions of the vertebra, that there is a linear relationship between all inferior endplate depths and the endplate location (p < 0.0001) within the spinal column, and that the superior endplate depth increases with age by about 0.01 mm per year (p < 0.02). The wedge angle increases from T12-L1 to L5-S1. The results allow for improvement of the fit of intervertebral disc-prostheses to the vertebrae and optimized force transmission through the vertebral column.

Show MeSH
Related in: MedlinePlus