Computed tomographic measurement of cortical bone geometry

Sumner, Dale R.; Olson, Chad; Freeman, P. M.; Lobick, John J.; Andriacchi, T.P.

doi:10.1016/0021-9290(89)90015-8

Cited by 28 publications

(8 citation statements)

References 13 publications

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“…Thus, our data were not directly obtained from cadaver dissection, but from multiplanar CT-reformation. In addition, CT-based measurements of thin compact structures are known to be affected by the CT resolution and choice of HU thresholding (Sumner et al, 1989;Aamodt et al, 1999). The exactness of the multiplanar reconstructions used in our study relies on the resolution of the cross-sectional CT slices, which is influenced by the size of the image matrix and the reconstruction mode.…”

Section: Discussionmentioning

confidence: 99%

The femoral calcar: A computed tomography anatomical study

et al. 2011

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The femoral calcar is a dense internal septum reaching from the femoral neck to the distal part of the lesser trochanter. Our study aimed at providing an exhaustive radio-anatomical description of this structure. One hundred pelvic computed tomography examinations were retrospectively selected to bilaterally evaluate the shape, dimensions, and density of the femoral calcar. Then, its relation to the femoral cavity was assessed by recording the dimensions of the medullary canal at the level of the greatest length of the spur. The femoral calcar exhibited a variable shape classified as ridge-type 17% (34/200), spur-type 66.5% (133/200), and septum-type 16.5% (33/200). Its mean dimensions were: height = 33.03 mm (20-46), length = 9.94 mm (5-16), and thickness = 2.71 mm (1-4). These dimensions were positively correlated to the height and weight of the individuals (P < 0.001) and were higher in males (P < 0.001). Its mean density was 788.5 Hounsfield units (530-1,200). The longest oblique and anteroposterior diameters of the femoral cavity were respectively 38.74 mm (28-51) and 22.04 mm (17-27). The femoral cavity dimensions were positively correlated to the height and weight of the individuals (P < 0.001), to the femoral calcar dimensions (P < 0.001) and were higher in males (P < 0.001). The femoral calcar was constantly identified as a vertical plate of compact bone exhibiting a consistent anatomical pattern, which suggests a significant mechanical function within the upper femur. Our results may lead to a greater understanding of the hip fracture patterns and to alternative designs for hip arthroplasties.

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Section: Discussionmentioning

confidence: 99%

The femoral calcar: A computed tomography anatomical study

et al. 2011

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“…These measurements are affected by beam-hardening, partial volume effect, CT resolution, and choice of HU thresholding (Sumner et al 1989, Aamodt et al 1999. CT-based measurements of the internal femoral canal have an accuracy of 0.8-1.1 mm (Rubin et al 1992, Laine et al 1997.…”

Section: Discussionmentioning

confidence: 99%

The internal calcar septum and its contact with the virtual stem in THRA computer tomographic evaluation

Decking¹,

Decking²,

Schoellner³

et al. 2003

Acta Orthopaedica Scandinavica

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“…The threshold computed tomographic numbers used for edge detection of bone were chosen by the method described by Sumner et al (37). To maximize geometric accuracy, the threshold level was changed to accommodate different bone densities.…”

Section: Finite Element Modelsmentioning

confidence: 99%

Femoral prosthesis implantation induces changes in bone stress that depend on the extent of porous coating

Skinner

Kim

Keyak

et al. 1994

Journal Orthopaedic Research

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The objective of this study was to evaluate the effect of implantation of porous-coated anatomic medullary fitting prostheses on stress in the proximal femur. Three-dimensional finite element models of a cadaveric femur before and after implantation were used to evaluate the resulting changes in stress in the bone. Models of the femur were generated automatically from computed tomographic scan data with use of an innovative mesh-generation technique. The models were analyzed for three levels of porous coating (proximal, 5/8, and full), with the assumption of ideal ingrowth (perfect bonding) over porous areas and a frictionless, tension-free surface on smooth areas. All models were loaded and restrained to represent conditions of normal gait. The stresses predicted in the implanted femur are consistent with clinical observations of proximal cortical atrophy (normal stress reduced to 6-9% of normal at the calcar and 50-55% at mid-prosthesis) and of hypertrophy at the porous coating junctions (normal stress at the 5/8-coating junction, 123% of stress proximal to the junction) and hypertrophy near the distal tip of the prosthesis (anterior and posterior normal stresses 200-800% of normal). The fully coated prosthesis induced stresses in the bone near the tip of the prosthesis that were most like stresses in the normal femur (medial and lateral normal stress 105 and 102% of the stress in the normal femur). Below the collar, the normal stress associated with the proximally coated prosthesis was 6% greater than that produced with the other two levels of coating but still was only 2% of normal. The 5/8-coated prosthesis appeared to combine the worst features of the fully coated and proximally coated prostheses--greater stress-shielding at the calcar and higher stress near the tip of the prosthesis.

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Computed tomographic measurement of cortical bone geometry

Cited by 28 publications

References 13 publications

The femoral calcar: A computed tomography anatomical study

The femoral calcar: A computed tomography anatomical study

The internal calcar septum and its contact with the virtual stem in THRA computer tomographic evaluation

Femoral prosthesis implantation induces changes in bone stress that depend on the extent of porous coating

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