scholarly journals Correlation between the Computed Tomography Values of the Screw Path and Pedicle Screw Pullout Strength: An Experimental Study in Porcine Vertebrae

2020 ◽  
Vol 14 (3) ◽  
pp. 265-272
Author(s):  
Atsushi Ikeura ◽  
Taketoshi Kushida ◽  
Kenichi Oe ◽  
Yoshihisa Kotani ◽  
Muneharu Ando ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Bone Mineral Density ◽  
Pedicle Screw ◽  
Bone Mineral ◽  
Lumbar Vertebrae ◽  
Pedicle Screws ◽  
Mineral Density ◽  
Screw Insertion ◽  
Pull Out ◽  
Pull Out Strength

Study Design: Biomechanical study.Purpose: To assess the correlation between the computed tomography (CT) values of the pedicle screw path and screw pull-out strength.Overview of Literature: The correlation between pedicle screw pull-out strength and bone mineral density has been well established. In addition, several reports have demonstrated a correlation between bone mineral density and CT values. However, no previous biomechanical studies investigated the correlation between CT values and pedicle screw pull-out strength.Methods: Sixty fresh-frozen lumbar vertebrae from 6-month-old pigs were used. Before screw insertion, the CT values of the screw path were obtained for each sample. Specimens were then randomly divided into three equal groups. Each group had one of three pedicle screws inserted: 4.0-mm LEGACY (4.0-LEG), 4.5-mm LEGACY (4.5-LEG), or 4.5-mm SOLERA (4.5-SOL) (all from Medtronic Sofamor Danek Inc., Memphis, TN, USA). Each screw had a consistent 30-mm thread length. Axial pull-out testing was performed at a rate of 1.0 mm/min. Correlations between the CT values and pedicle screw pull-out strength were evaluated using Pearson’s correlation coefficient analysis.Results: The correlation coefficients between the CT values of the screw path and pedicle screw pull-out strength for the 4.0-LEG, 4.5-LEG, and 4.5-SOL groups were 0.836 (<i>p</i> <0.001), 0.780 (<i>p</i> <0.001), and 0.873 (<i>p</i> <0.001), respectively. Greater CT values were associated with greater screw pull-out strength.Conclusions: The CT values of the screw path were strongly positively correlated with pedicle screw pull-out strength, regardless of the screw type and diameter, suggesting that the CT values could be clinically useful for predicting pedicle screw pull-out strength.

Quantitative dual-energy CT for phantomless evaluation of cancellous bone mineral density of the vertebral pedicle: correlation with pedicle screw pull-out strength

2014 ◽  
Vol 25 (6) ◽  
pp. 1714-1720 ◽  
Author(s):  
Julian L. Wichmann ◽  
Christian Booz ◽  
Stefan Wesarg ◽  
Ralf W. Bauer ◽  
J. Matthias Kerl ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Pedicle Screw ◽  
Bone Mineral ◽  
Cancellous Bone ◽  
Dual Energy ◽  
Dual Energy Ct ◽  
Mineral Density ◽  
Pull Out ◽  
Pull Out Strength

scholarly journals AGE AND SEX-RELATED STRUCTURAL AND FUNCTIONAL CHANGES OF BONE REMODELING DURING SIMULTATE ABDOMEN CT-SCANNING

2020 ◽  
Vol 73 (1) ◽  
pp. 91-94
Author(s):  
Nazar M. Kostyshyn ◽  
Liubov P. Kostyshyn ◽  
Mechyslav R. Gzhegotskyi
Keyword(s):  
Computed Tomography ◽  
Bone Mineral Density ◽  
Bone Mass ◽  
Old Age ◽  
Bone Mineral ◽  
Lumbar Vertebrae ◽  
Middle Adulthood ◽  
Mineral Density ◽  
Functional Changes ◽  
Early Old Age

The aim of investigation was to study the structural and functional conditions of cortical and trabecular layers of lumbar vertebrae L1-L5 in different age groups. Materials and methods: In order to assess BMD of the lumbar vertebrae 102 people18 to 75 years old was examined. Study of bone mineral density cortical and trabecular layer of lumbar vertebrae (L1-L5) performed by computed tomography in Hounsfield Units (HU) in terms of standard deviation (SD). Results: The results of computed tomography showed a direct relationship of bone mineral density of lumbar vertebrae with age of examined persons. Osteoporosis and osteopenia was registered in 15% of men and 30% women in middle adulthood, in late adulthood – 35% and 50% respectively. During early old age osteopenia and osteoporosis are observed in 37,5% and 25% of men and 26% and 64% women. Osteoporosis in the middle old age has been reported in 50% of men and 75% of women Conclusions: Results of the study showed a direct link between mineral density, age and gender. The middle adulthood age period was characterized by the highest mineral mass compared with the other age periods. Then there is a loss of bone mass throughout life, and with the onset of aging osteopenia and osteoporosis are recorded. It was investigated that in the early old age, loss of bone mass is mainly observed in female.

Anchor Design and Bone Mineral Density Affect the Pull-Out Strength of Suture Anchors in Rotator Cuff Repair

2004 ◽  
Vol 32 (6) ◽  
pp. 1466-1473 ◽  
Author(s):  
Markus J. Tingart ◽  
Maria Apreleva ◽  
Janne Lehtinen ◽  
David Zurakowski ◽  
Jon J. P. Warner
Keyword(s):  
Bone Mineral Density ◽  
Rotator Cuff ◽  
Bone Mineral ◽  
Rotator Cuff Repair ◽  
Suture Anchors ◽  
Mineral Density ◽  
Pull Out ◽  
Anchor Design ◽  
Cuff Repair ◽  
Pull Out Strength

scholarly journals Phantomless assessment of volumetric bone mineral density using virtual non-contrast images from spectral detector computed tomography

2020 ◽  
Vol 93 (1109) ◽  
pp. 20190992 ◽  
Author(s):  
David Zopfs ◽  
Simon Lennartz ◽  
Charlotte Zaeske ◽  
Martin Merkt ◽  
Kai Roman Laukamp ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Bone Mineral Density ◽  
Contrast Enhancement ◽  
Bone Mineral ◽  
Lumbar Vertebrae ◽  
Volumetric Bone Mineral Density ◽  
Mineral Density ◽  
Phase Images ◽  
Spectral Detector Ct ◽  
Venous Phase

Objective: To evaluate phantomless assessment of volumetric bone mineral density (vBMD) based on virtual non-contrast images of arterial (VNCa) and venous phase (VNCv) derived from spectral detector CT in comparison to true non-contrast (TNC) images and adjusted venous phase conventional images (CIV(adjusted)). Methods: 104 consecutive patients who underwent triphasic spectral detector CT between January 2018 and April 2019 were retrospectively included. TNC, VNCa, VNCv and venous phase images (CIV) were reconstructed. vBMD was obtained by two radiologists using an FDA/CE-cleared software. Average vBMD of the first three lumbar vertebrae was determined in each reconstruction; vBMD of CIV was adjusted for contrast enhancement as suggested earlier. Results: vBMD values obtained from CIV(adjusted) are comparable to vBMD values derived from TNC images (91.79 ± 36.52 vs 90.16 ± 41.71 mg/cm3, p = 1.00); however, vBMD values derived from VNCa and VNCv (42.20 ± 22.50 and 41.98 ± 23.3 mg/cm3 respectively) were significantly lower as compared to vBMD values from TNC and CIV(adjusted) (all p ≤ 0.01). Conclusion: Spectral detector CT-derived virtual non-contrast images systematically underestimate vBMD and therefore should not be used without appropriate adjustments. Adjusted venous phase images provide reliable results and may be utilized for an opportunistic BMD screening in CT examinations. Advances in knowledge: Adjustments of venous phase images facilitate opportunistic assessment of vBMD, while spectral detector CT-derived VNC images systematically underestimate vBMD.

Assessment of the bone mineral density in the lumbar vertebrae of newborns by quantitative computed tomography

1996 ◽  
Vol 25 (8) ◽  
pp. 711-715 ◽  
Author(s):  
P. M. Braillon ◽  
A. Lapillonne ◽  
P. S. Ho ◽  
R. Bouvier ◽  
M. Bochu ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Bone Mineral Density ◽  
Bone Mineral ◽  
Quantitative Computed Tomography ◽  
Lumbar Vertebrae ◽  
Mineral Density
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