Vertebral Body Compressive Strength Evaluated by Dual-Energy X-Ray Absorptiometry and Hounsfield Units In Vitro

Abstract Working Hypothesis: Mutations in the CYP2R1 gene, highly expressed in the testis and encoding vitamin D 25-hydroxylase, result in a vitamin D deficiency and a defective calcium homeostasis leading to rickets. Objective: Our aim was to investigate CYP2R1 expression in pathological testis samples and relate this to vitamin D metabolism in testiculopathic patients. Design, Patients, Setting: Testis samples for in vitro study and 98 young men were transversally evaluated at Padova's Center for Male Gamete Cryopreservation. Methods: CYP2R1 mRNA expression and protein production were evaluated by quantitative RT-PCR, Western blot analysis, and immunofluorescence. Hormonal and bone-marker levels, and bone densitometry by dual-energy x-ray absorptiometry, were determined in patients with Sertoli-cell-only syndrome and severe hypospermatogenesis. Results: We found a lower gene and protein expression of CYP2R1 in samples with hypospermatogenesis and Sertoli-cell-only syndrome (P < 0.05) and a colocalization with INSL-3, a Leydig cell marker, at immunofluorescence. In all testiculopathic patients 25-hydroxyvitamin D levels were significantly lower and PTH levels higher compared to controls (P < 0.05). Furthermore, testiculopathic patients showed osteopenia and osteoporosis despite normal testosterone levels compared with controls both with increased bone-marker levels and altered dual-energy x-ray absorptiometry in the femoral neck and lumbar spine (for all parameters, P < 0.05). Conclusions: Our data show an association between testiculopathy and alteration of the bone status, despite unvaried androgen and estrogen levels and no other evident cause of vitamin D reduction. Further studies in larger cohorts are needed to confirm our results.

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Dual-Energy X-Ray Absorptiometry Measurements of Body Composition: Effects of Depth and Tissue Thickness, Including Comparisons with Direct Analysis

Clinical Science ◽

10.1042/cs0880319 ◽

1995 ◽

Vol 88 (3) ◽

pp. 319-324 ◽

Cited By ~ 51

Author(s):

Susan A. Jebb ◽

Gail R. Goldberg ◽

Graham Jennings ◽

Marinos Elia

Keyword(s):

Body Composition ◽

Fat Mass ◽

Research Work ◽

Experimental System ◽

Direct Analysis ◽

Dual Energy ◽

Tissue Thickness ◽

X Ray ◽

Few Data

1. There are few data regarding the accuracy of Hologic QDR-1000W dual-energy X-ray absorptiometry for the measurement of body composition. In two studies, one in an in vitro experimental system using oil and water mixtures and the other in samples of pork meat, the effect of depth and tissue thickness on the measured composition was assessed. In the latter study the measured fat mass was compared with that measured by direct analysis. 2. All data indicated a trend in the measured fat mass with depth, such that more fat was measured at extremes of depth (<10 cm and >25 cm) than at intermediate depths. 3. In samples of meat weighing approximately 55 kg, dual X-ray absorptiometry significantly underestimated the absolute fat mass compared with direct analysis (mean 20.4 ± 1.65%) by 5–8% or 1–4 kg of fat. 4. These findings are of direct relevance to both clinical and research work using this technique to measure body composition, in particular in circumstances in which changes in body composition and/or tissue thickness are anticipated.

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Dual-Energy X-Ray Absorptiometry vs Computed Tomography: Comparison of Bone Mineral Density Measurements in Predicting Postoperative Spinal Fusion Outcomes

Neurosurgery ◽

10.1093/neuros/nyz310_607 ◽

2019 ◽

Vol 66 (Supplement_1) ◽

Cited By ~ 1

Author(s):

Awais Vance ◽

Alexander Mazal ◽

Salah G Aoun ◽

Najib El Tecle ◽

Matthew Thomas Davies ◽

...

Keyword(s):

Computed Tomography ◽

Bone Mineral Density ◽

Lumbar Spine ◽

Lumbar Fusion ◽

Dual Energy ◽

Mineral Density ◽

Hounsfield Units ◽

X Ray ◽

Hardware Failure ◽

Increased Risk

Abstract INTRODUCTION Diminished bone mineral density (BMD) places patients at increased risk for complications from lumbar fusion procedures. Dual-energy X-Ray absorptiometry (DEXA) scanners have been used as the gold standard in measuring BMD. More recently, various studies have suggested that Hounsfield unit measurements from computed tomography (CT) scans may be more accurate. METHODS After obtaining IRB approval, we retrospectively reviewed all patients aged 18 and older who underwent lumbar fusion procedures between 01/01/2010 and 12/31/2016 at our institution. We used linear regression to assess for a correlation between CT Hounsfield units and DEXA t scores. Student's t-test was used to compare CT Hounsfield units, lumbar spine t score and hip t scores for patients with and without pseudoarthrosis as well as those with and without hardware failure. RESULTS A total of 167 patients with lumbar fusion procedures met inclusion criteria. Ages ranged 24 to 88 yr old with a mean of 64. Using linear regression there was no correlation between CT Hounsfield units and Dexa T scores. There was no difference between the groups with respect to CT Hounsfield units or DEXA T scores when comparing patients with and without pseudoarthrosis and when comparing patients with or without hardware failure. CONCLUSION Diminished BMD is an important factor to consider when contemplating lumbar spine fusion procedures as this has been associated with increased risk of hardware failure or pseudoarthrosis. Traditionally DEXA scans and more recently CT Hounsfield units have used to screen patients for decreased BMD, however, in this relatively large retrospective series we found that neither correlate well with complications from lumbar spine fusion procedures. CT and DEXA scans may not be as reliable as once thought in assessing BMD.

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A multicenter comparison of dual-energy X-ray absorptiometers: In vivo and in vitro measurements of bone mineral content and density

Journal of Bone and Mineral Research ◽

10.1002/jbmr.5650110217 ◽

2009 ◽

Vol 11 (2) ◽

pp. 275-285 ◽

Cited By ~ 12

Author(s):

Christina D. Economos ◽

Miriam E. Nelson ◽

Maria A. Fiatarone ◽

Gerard E. Dallal ◽

Steven B. Heymsfield ◽

...

Keyword(s):

Bone Mineral Content ◽

Bone Mineral ◽

Mineral Content ◽

Dual Energy ◽

X Ray ◽

In Vitro Measurements

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Precision of measurement by dual-energy X-ray absorptiometry of bone mineral density and content in rat hindlimb in vitro

Journal of Bone and Mineral Research ◽

10.1002/jbmr.5650090406 ◽

2009 ◽

Vol 9 (4) ◽

pp. 473-478 ◽

Cited By ~ 29

Author(s):

Harri Sievänen ◽

Pekka Kannus ◽

Markku Järvinen

Keyword(s):

Bone Mineral Density ◽

Bone Mineral ◽

Dual Energy ◽

Mineral Density ◽

X Ray

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Yield Point in Prediction of Compressive Behavior of Lumbar Vertebral Body by Dual-Energy X-ray Absorptiometry

Journal of Clinical Densitometry ◽

10.1385/jcd:7:4:382 ◽

2004 ◽

Vol 7 (4) ◽

pp. 382-389 ◽

Cited By ~ 8

Author(s):

Antoni Renau ◽

J. Farrerons ◽

B. Yoldi ◽

J. Gil ◽

I. Proubasta ◽

...

Keyword(s):

Yield Point ◽

Vertebral Body ◽

Dual Energy ◽

Compressive Behavior ◽

X Ray ◽

Lumbar Vertebral Body

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Experimental substantiation of osteotransplant application in traumatic vertebral defects

Hirurgiâ pozvonočnika ◽

10.14531/2018.4.41-51 ◽

2018 ◽

Vol 15 (4) ◽

pp. 41-51

Author(s):

V. V. Rerikh ◽

Yu. A. Predein ◽

A. M. Zaidman ◽

A. D. Lastevsky ◽

V.A. Bataev V.A. Bataev V.A. Bataev ◽

...

Keyword(s):

Bone Graft ◽

Bone Tissue ◽

Vertebral Body ◽

Morphological Structure ◽

Allogeneic Bone ◽

X Ray ◽

Organ Specific ◽

Ray Density ◽

Vertebral Defects

Objective. To analyze the features of bone tissue formation during plasty of vertebral body defect or fracture with an allogeneic bone graft in an experiment in vitro. Material and Methods. Models of the vertebral body defect (fracture of the cranioventral part with penetration into the nucleus pulposus) were created in an experiment on 20 mini-pigs of the same age. Plasty of traumatic defects was performed with allogeneic bone graft or autologous bone. CT, histological, and spectrometric studies of microscopic specimens were carried out at 14, 30, 90, and 180 day. Reparative osteogenesis, X-ray density, Ca and P content, and microhardness were studied. Results. After implantation of allogeneic bone graft, an organ-specific bone similar to the recipient’s bone in morphological structure, X-ray density, mineral composition and microhardness, was formed on the 90th day (P = 0.01). After transplantation of autobone, the regenerate formed by this day in the central part was in a phase of resorption and restructuring with lower indices of X-ray density, content of Ca and P, and microhardness (P = 0.01). Conclusion. Аfter plasty of vertebral body traumatic defects with allogeneic bone graft, the organ-specific bone tissue is formed at an earlier time and reliably exhibits greater mineralization and strength.

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