Vertebral Body Cross-sectional Area Research Articles

Developmental cervical spinal canal size: population reference range.

The developmental size of the cervical spinal canal varies considerably. Neural compression and injury are more likely with a developmentally small spinal canal. This study was designed to develop a population reference range for developmental cervical spinal canal size for the Hong Kong population. Prospective study of 522 ambulatory patients (256 males, 266 females, mean age 55±18 years; range, 20-89 years) who underwent computed tomography (CT) neck examinations. Using a manually operated segmentation program, spinal canal, and vertebral body cross-sectional area (CSA), anteroposterior (AP) sagittal diameter, and width were measured at each level from C3-C7. Patient height and weight were measured. Considerable variation in spinal canal size existed with, for example, a 164-168% variation exists for males and females between the largest and smallest spinal canal CSA at C5. All spinal canal measurements increased slightly with height (r=0.25-0.36, P<0.001), while vertebral body AP sagittal diameter increased with age (r=0.48-0.51, P<0.001). All spinal canal measurements were larger (<0.0001) in males. Although spinal canal CSA was larger in males (at C5, males 276.0±41.5 mm2; females 252.6±38.4 mm2), relative to vertebral body CSA, spinal canal CSA was larger in females. Arbitrary population thresholds indicating the smallest 25% spinal canal CSA and AP sagittal diameter as well as other parameters were defined. There is a large variation in developmental cervical spinal canal size within the Hong Kong population. A reference range of developmental spinal canal size was developed which will enable an objective assessment of an individual's cervical spinal canal size relative to the wider population.

Optimal cutoff point of vertebral body cross-sectional area as a morphological parameter for predicting lumbar spondylolysis.

The relationship between vertebral body cross-sectional area (VBCSA) and spinal conditions associated with increased lumbar lordosis, such as lumbar spondylolysis (LSL), is not known. We investigated the morphological parameter, VBCSA, to predict LSL. The VBCSA on MRI has not been studied for its association with LSL. We hypothesized that VBCSA is an important morphological parameter for LSL prediction. We collected VBCSA data from 90 patients (43 males and 47 females) with LSL and 91 control subjects (44 males and 47 females) who underwent lumbar spine magnetic resonance imaging (LS-MRI). Axial T2-weighted LS-MRI images were obtained from all participants. Using our picture archiving and communications system, we analyzed the VBCSA at the level of the L5 vertebral body by utilizing MRI. The average VBCSA was 2263.51 ± 306.02 mm2 in the male control group and 1820.92 ± 224.89 mm2 in the male LSL group. LSL patients had significantly lower VBCSAs (P < .001) than did the male controls. The average VBCSA was 1985.21 ± 258.05 mm2 in the female control group and 1553.73 ± 250.02 mm2 in the female LSL group, and the LSL patients also had significantly lower VBCSAs (P < .001) than did the female controls. The optimal VBCSA cutoff value in the male group was 2014.69 mm2 with 76.7% sensitivity, 75.0% specificity, and an area under the receiver operating curve (AUC) of 0.89 (95% CI: 0.82-0.95). In the female group, the optimal cutoff score was 1814.11 mm2 with 76.6% sensitivity, 76.6% specificity, and an AUC of 0.88 (95% CI: 0.82-0.95). VBCSA is a sensitive objective morphological parameter for assessing LSL, and a lower VBCSA is associated with a higher possibility of LSL. We believe that these results will be useful in diagnostic radiology for evaluating patients with LSL.

Opportunistic Screening for Atrial Fibrillation on Routine Chest Computed Tomography.

Quantitative biomarkers from chest computed tomography (CT) can facilitate the incidental detection of important diseases. Atrial fibrillation (AFib) substantially increases the risk for comorbid conditions including stroke. This study investigated the relationship between AFib status and left atrial enlargement (LAE) on CT. A total of 500 consecutive patients who had undergone nongated chest CTs were included, and left atrium maximal axial cross-sectional area (LA-MACSA), left atrium anterior-posterior dimension (LA-AP), and vertebral body cross-sectional area (VB-Area) were measured. Height, weight, age, sex, and diagnosis of AFib were obtained from the medical record. Parametric statistical analyses and receiver operating characteristic curves were performed. Machine learning classifiers were run with clinical risk factors and LA measurements to predict patients with AFib. Eighty-five patients with a diagnosis of AFib were identified. Mean LA-MACSA and LA-AP were significantly larger in patients with AFib than in patients without AFib (28.63 vs. 20.53cm 2 , P <0.000001; 4.34 vs. 3.5cm, P <0.000001, respectively), both with area under the curves (AUCs) of 0.73. Multivariable logistic regression analysis including age, sex, and VB-Area with LA-MACSA improved the AUC for predicting AFib (AUC=0.77). An LA-MACSA threshold of 30cm 2 demonstrated high specificity for AFib diagnosis at 92% and sensitivity of 48%, and LA-AP threshold at 4.5cm demonstrated 90% specificity and 42% sensitivity. A Bayesian machine learning model using age, sex, height, body surface area, and LA-MACSA predicted AFib with an AUC of 0.743. LA-MACSA or LA-AP can be rapidly measured from routine chest CT, and when >30 cm 2 and >4.5cm, respectively, are specific indicators to predict patients at increased risk for AFib.

SARCOPENIA AS A PREDICTOR OF MORTALITY IN PATIENTS WITH METASTATIC TUMOURS IN THE SPINAL COLUMN

Sarcopenia has been observed to be a predictor of mortality in international studies of patients with metastatic disease of the spine. This study aimed to validate sarcopenia as a prognostic tool in a New Zealand setting. A secondary aim of this study was to assess the intra-observer reliability of measurements of psoas and vertebral body cross sectional areas on computed tomography imaging.A cohort of patients who had presented to Waikato Hospital with secondary neoplasia in the spinal column from 2014 to 2018 was selected. Cross sectional psoas and vertebral body areas were measured at the mid-pedicle L3 level, followed by calculation of the psoas to vertebral body cross sectional area ratio. Psoas to vertebral body cross sectional area ratio was compared with survivorship. The strength of the correlation between sarcopenia and survivorship was compared with the correlation between serum albumin and survivorship, as well as the correlation between the Metastatic Spine Risk Index (MSRI) and survivorship.A total of 110 patients who received operative (34) and non-operative (76) were included. The results demonstrate that psoas to vertebral body cross sectional area ratio is not statistically significantly correlated with survivorship (p=0.53). Serum albumin is significantly correlated with survivorship (p&lt;0.0001), as was the MSRI. There is good intra-observer and inter-observer reliability for measurements of psoas to vertebral body cross sectional area.This study failed to demonstrate the utility for the psoas to vertebral body cross sectional area ratio that other studies have demonstrated in estimating survivorship. Serum albumin levels remain a useful prognostic indicator in patients with secondary tumours in the vertebral column.

Sarcopenia 'made simple' and outcomes from emergency laparotomy.

Emergency Laparotomy (EL) is recognized as high-risk surgery with high mortality. Established surgical risk assessment tools (NELA Risk Prediction Calculator, P-POSSUM, ACS-NSQIP) are accurate predictors of morbidity and mortality. However, their multicomponent complexity limits their use in practice. Sarcopenia is associated with poorer surgical outcomes. This study tests for an association between a simple measure of radiological sarcopenia and mortality in EL patients in an Australian cohort. A retrospective analysis was conducted of 500 patients admitted to four Australian hospitals who underwent EL during 2016-2017. All patients had a contemporaneous abdomino-pelvic CT scan. Radiological sarcopenia was measured as the ratio of total psoas muscle area (PM) to L3 vertebral body cross sectional area (PM:L3). Patients were followed up to 12 months. Primary outcomes were 30-, 90- and 365-day mortality. The mean 30-day mortality predictions for NELA, P-POSSUM and ACS-NSQIP were 11.36%, 17.28% and 11.30% respectively. PM:L3 ratio was associated with 30-, 90- and 365-day mortality (P < 0.001) and sex (P < 0.001) and negatively correlated with age (r=-0.4612; P < 0.001). Radiological sarcopenia had a weak negative correlation with NELA (r=-0.2737; P < 0.001), P-POSSUM (r=-0.1880; P < 0.001) and ACS-NSQIP (r=-0.2351; P < 0.001). The latter three metrics were significantly correlated (r > 0.5696; P < 0.001). Radiological sarcopenia (CT-assessed PM:L3) is a significant predictor of mortality in EL patients in Australia. The results of this study suggest that radiological sarcopenia is equivalent to established risk assessment tools. The more timely and easily accessible CT-assessed PM:L3 metric is potentially automatable and may have significant utility in clinical practice.

Increased vertebral body area, disc and facet joint degeneration throughout the lumbar spine in patients with lumbosacral transitional vertebrae.

Lumbosacral transitional vertebrae (LSTV), developmental spinal canal stenosis, lumbar disc and facet joint degeneration are all common lumbar spine conditions. This study explores the relationship between these entities. Five hundred and five patients (254 females, 251 males), mean age 57 ± 13 years, who underwent abdominopelvic CT examinations were studied. Vertebral body cross-sectional area (CSA), spinal canal CSA, width and depth were measured from L1 to L5. The presence of LSTV was documented and the severity of disc/facet joint degeneration graded. LSTV was present in 155 (31%) of 505 patients, being twice as common in males than in females. After controlling for age, height and weight, vertebral body CSAs from L1 to L5 in male LSTV patients were, on average, 9.8% larger than those in male non-LSTV patients (p < 0.0001 for all) while vertebral body areas at L3 and L4 were 4.5% larger in female LSTV patients than in non-LSTV female patients. Disc degeneration from L2/3 to L5/S1 and facet joint degeneration from L2/3 to L4/5 were more severe in LSTV patients. LSTV Castellvi Type II patients appear to be most prone to disc and facet degeneration. LSTV patients, and particularly male patients, have an increased vertebral body CSA compared to non-LSTV patients throughout the lumbar spine. LSTV patients also have more severe disc and facet joint degeneration. The increase in vertebral body area may be contributing to the increased lumbar and facet joint degeneration seen in LSTV patients. • LSTV patients have increased vertebral body cross-sectional area throughout their lumbar spine compared to non-LSTV patients. This vertebral body area increase was more pronounced in male patients and also apparent in younger patients with LSTV. • LSTV patients have increased disc and facet joint degeneration affecting most of the lumbar spine than non-LSTV patients. • Increased vertebral body area may contribute to the increased lumbar disc and facet joint degeneration seen in LSTV patients.

Assessing Fatty Infiltration of Paraspinal Muscles in Patients With Lumbar Spinal Stenosis: Goutallier Classification and Quantitative MRI Measurements.

Objective: Fatty infiltration of paraspinal muscle is associated with spinal disorders. It can be assessed qualitatively (i.e., Goutallier classification) and quantitatively using image processing software. The aims of this study were to compare paraspinal muscle fatty infiltration as assessed using the Goutallier classification vs. quantitative magnetic resonance images (MRI) measurements and to investigate the association between anthropometric parameters and paraspinal muscle morphology and fatty infiltration in patients with symptomatic lumbar spinal stenosis (LSS).Methods: Patients affected by symptomatic LSS scheduled for surgery with available MRI of the lumbar spine were included in this retrospective cross-sectional study. Fatty infiltration at each lumbar level was rated qualitatively according to the Goutallier classification and quantified based on the cross-sectional area (CSA) of the paraspinal muscle, of its lean fraction (LeanCSA), and the ratio between LeanCSA and CSA and the CSA relative to the CSA of vertebral body (RCSA). Considering the muscle as a single unit, overall fatty infiltration according to Goutallier, overall CSA, LeanCSA, LeanCSA/CSA, and RCSA were computed as averages (aGoutallier, aCSA, aLeanCSA, aLeanCSA/aCSA, and aRCSA). Associations among parameters were assessed using Spearman's respective Pearson's correlation coefficients.Results: Eighteen patients, with a mean age of 71.3 years, were included. aGoutallier correlated strongly with aLeanCSA and aLeanCSA/aCSA (R = −0.673 and R = −0.754, both P < 0.001). There was a very strong correlation between values of the left and right sides for CSA (R = 0.956, P < 0.001), LeanCSA (R = 0.900, P < 0.001), and LeanCSA/CSA (R = 0.827, P < 0.001) at all levels. Among all anthropometric measurements, paraspinal muscle CSA correlated the most with height (left: R = 0.737, P < 0.001; right: R = 0.700, P < 0.001), while there was a moderate correlation between vertebral body CSA and paraspinal muscle CSA (left: R = 0.448, P < 0.001; right: R = 0.454, P < 0.001). Paraspinal muscle CSA correlated moderately with body mass index (BMI; left: R = 0.423, P < 0.001; right: R = 0.436, P < 0.001), and there was no significant correlation between aLeanCSA or aLeanCSA/CSA and BMI.Conclusions: The Goutallier classification is a reliable yet efficient tool for assessing fatty infiltration of paraspinal muscles in patients with symptomatic LSS. We suggest taking body height as a reference for normalization in future studies assessing paraspinal muscle atrophy and fatty infiltration.

Assessing fatty infiltration of paraspinal muscles in patients with lumbar spinal stenosis: Goutallier classification and quantitative MRI measurements

Objective: Fatty infiltration of paraspinal muscle is associated with spinal disorders. It can be assessed qualitatively (i.e., Goutallier classification) and quantitatively using image processing software. The aims of this study were to compare paraspinal muscle fatty infiltration as assessed using the Goutallier classification vs. quantitative magnetic resonance images (MRI) measurements and to investigate the association between anthropometric parameters and paraspinal muscle morphology and fatty infiltration in patients with symptomatic lumbar spinal stenosis (LSS). Methods: Patients affected by symptomatic LSS scheduled for surgery with available MRI of the lumbar spine were included in this retrospective cross-sectional study. Fatty infiltration at each lumbar level was rated qualitatively according to the Goutallier classification and quantified based on the cross-sectional area (CSA) of the paraspinal muscle, of its lean fraction (LeanCSA), and the ratio between LeanCSA and CSA and the CSA relative to the CSA of vertebral body (RCSA). Considering the muscle as a single unit, overall fatty infiltration according to Goutallier, overall CSA, LeanCSA, LeanCSA/CSA, and RCSA were computed as averages (aGoutallier, aCSA, aLeanCSA, aLeanCSA/aCSA, and aRCSA). Associations among parameters were assessed using Spearman's respective Pearson's correlation coefficients. Results: Eighteen patients, with a mean age of 71.3 years, were included. aGoutallier correlated strongly with aLeanCSA and aLeanCSA/aCSA (R = -0.673 and R = -0.754, both P < 0.001). There was a very strong correlation between values of the left and right sides for CSA (R = 0.956, P < 0.001), LeanCSA (R = 0.900, P < 0.001), and LeanCSA/CSA (R = 0.827, P < 0.001) at all levels. Among all anthropometric measurements, paraspinal muscle CSA correlated the most with height (left: R = 0.737, P < 0.001; right: R = 0.700, P < 0.001), while there was a moderate correlation between vertebral body CSA and paraspinal muscle CSA (left: R = 0.448, P < 0.001; right: R = 0.454, P < 0.001). Paraspinal muscle CSA correlated moderately with body mass index (BMI; left: R = 0.423, P < 0.001; right: R = 0.436, P < 0.001), and there was no significant correlation between aLeanCSA or aLeanCSA/CSA and BMI. Conclusions: The Goutallier classification is a reliable yet efficient tool for assessing fatty infiltration of paraspinal muscles in patients with symptomatic LSS. We suggest taking body height as a reference for normalization in future studies assessing paraspinal muscle atrophy and fatty infiltration.

Sex Estimation of Typical Adult Vertebrae Morphology in Central China Based on CT Technique

Objective The morphological data of the second thoracic vertebra and the third lumbar vertebra were measured by computerized tomography （CT）. The sex differences were analyzed and the discrimination equation was obtained. Methods The data of 274 adults （203 cases from experimental group and 69 cases from validation group） from central China were collected. Four linear data （maximum transverse length of vertebral body, maximum longitudinal length of vertebral body, maximum transverse length of vertebral foramen, maximum longitudinal length of vertebral foramen）, one angle data （angle between spinous processes） and two area （vertebral foramen area, total cross-sectional area of vertebral body） data of the second thoracic vertebra and the third lumbar vertebra were collected, respectively. Then three ratios ［maximum transverse length/ maximum longitudinal length of vertebral body, maximum transverse length/ maximum longitudinal length of vertebral foramen, vertebral foramen area/ （total cross-sectional area of vertebral body-vertebral foramen area）］ and one angle （angle between spinous processes） were obtained. The discriminant equation was established for sexual discriminant analysis. Results The morphology of the second thoracic vertebra and the third lumbar vertebra was related with gender. Four single index discriminant formulae and eleven multi-index discriminant formulae were established. The 69 validation group samples were substituted into the formula for testing, and the maximum discriminant accuracy rate of the single-index discriminant formula was 75%. The maximum discriminant accuracy rate of multi-index discriminant formula was 83%. Conclusion It is feasible to conduct individual sex analysis by the morphological indexes of second thoracic vertebra and the third lumbar vertebra. The indexes have important application values in practice.

Lumbar lordosis reduction and disc bulge may correlate with multifidus muscle fatty infiltration in patients with single-segment degenerative lumbar spinal stenosis

ObjectivesTo investigate the correlation between fatty infiltration in the multifidus muscle related to the involved nerve root and structural parameters associated with stenosis in patients with degenerative lumbar spinal stenosis (DLSS). Patients and methodsSixty-four patients with single-segment DLSS at L4-5 were retrospectively enrolled. The fatty infiltration rate (FIR) of the multifidus muscle at L5-S1, lumbar lordosis and the cross-sectional area (CSA) of the structural parameters at L4-5, such as dural sac, disc bulge, ligamentum flava and vertebral body of L5 were measured on magnetic resonance images using ImageJ software. All enrolled patients were divided into an FIR < 25 % group and an FIR ≥ 25 % group according to the FIR of the multifidus muscle at L5-S1. The propensity scores matching and adjustment of potential covariates were performed to reduce the confounding bias between the two groups. ResultsLumbar lordosis in the FIR ≥ 25 % group was significantly lower than that in the FIR＜25 % group in both cohorts. The mean differences in lumbar lordosis of 14.16 degrees between the two groups in the complete cohort and of 14.23 degrees in the matched cohort remained significant after adjustment. The disc bulge CSA/ vertebral body CSA in the FIR ≥ 25 % group was greater than that in the FIR＜25 % group in both cohorts. The mean differences in the disc bulge CSA/ vertebral body CSA between the two groups of 0.67 in the complete cohort and 0.96 in the matched cohort were statistically significant after adjustment. There was no significant difference in the dural sac CSA/ vertebral body CSA and ligamentum flava CSA/ vertebral body CSA between the two groups in either cohort regardless of adjustment. Logistic regression analysis for FIR ≥ 25 % in the multifidus muscle at L5-S1 exhibited that the disc bulge CSA/ vertebral body CSA were independent risk factors with odds ratio (OR) of 8.52, while lumbar lordosis were independent protective factors (OR = 0.72). ConclusionsThe disc bulge at the stenosis segment and lumbar lordosis reduction may be correlated with fatty infiltration in the multifidus muscles at L5-S1 in patients with L4-5 single-segment DLSS.

Morphologic Characteristics of the Deep Cervical Paraspinal Muscles in Patients with Single-Level Cervical Spondylotic Myelopathy

This study aimed to compare morphologic changes of deep paraspinal muscles at C4-7 in patients with C5-6 single-level cervical spondylotic myelopathy (CSM), and to evaluate the relationship between morphologic changes and the level of spinal cord compression. The study included 15 patients with C5-6 single-level CSM and 15 age- and sex-matched healthy subjects. Cross-sectional area (CSA) and functional CSA of the bilateral longus capitis (LCap), longus colli (LC), multifidus (MF), semispinalis cervicis (SSC), semispinalis capitis, splenius capitis, and splenius cervicis were measured on preoperative magnetic resonance images at C4-7, and calculated as ratios with respect to the corresponding vertebral body CSA. The mean maximum spinal cord compression was 22.30% in the CSM group. At the cranial level (C4-5), the CSM group had more fat infiltration in the MF and SSC (P < 0.05). At the spinal cord compression segment and caudal adjacent segment (C5-6 and C6-7), the degree of fat infiltration of all paravertebral muscles was aggravated, accompanied by atrophy of LCap, LC, and MF (P < 0.05). Compared between different levels, fat infiltration in the MF at C5-6 was greater than adjacent levels. In patients with C5-6 single-level CSM, fat infiltration and atrophy of deep paraspinal muscles, especially the Lcap, LC, and MF, mainly occurred in the level of spinal cord compression and caudal adjacent level. In the cranial adjacent segment, the degree of MF and SSC fat infiltration in patients with CSM was also aggravated. This may suggest that multiple mechanisms are involved in paraspinal muscles degeneration in CSM.

요추 주변 근육 단면적과 척추전방전위증의 상관성에 대한 후향적 연구

Objectives To investigate correlation between slip percentage (SP) of spondylolisthesis and cross-sectional area (CSA) of lumbar paraspinal muscles; psoas major (PM), multifidus (MU) and erector spinae (ES). Methods A retrospective study was carried out in 120 spondylolisthesis patients who had visited the Spine center of Kyung Hee University Hospital at Gangdong and had taken lumbar MRI. CSA of lumbar paraspinal muscles was measured from axial T2-weighted MRI and divided by CSA of vertebral body to avoid weight`s influence. SP was also measured from sagittal MRI. Results SP increase has significant correlation with decreased CSA-MU (r

Cross-sectional study of C1-S5 vertebral bodies in human fetuses.

IntroductionKnowledge on the normative spinal growth is relevant in the prenatal detection of its abnormalities. The present study determines the height, transverse and sagittal diameters, cross sectional area, and volume of individual C1–S5 vertebral bodies.Material and methodsUsing the methods of computed tomography (CT), digital image analysis, and statistics, the size of C1–S5 vertebral bodies in 55 spontaneously aborted human fetuses aged 17–30 weeks was examined.ResultsAll the 5 examined parameters changed significantly with gestational age (p < 0.01). The mean height of vertebral bodies revealed an increase from the atlas (2.39 ±0.54 mm) to L2 (4.62 ±0.97 mm), stabilized through L3–L4 (4.58 ±0.92 mm, 4.61 ±0.84 mm), and then was decreasing to S5 (0.43 ±1.06 mm). The mean transverse diameter of vertebral bodies was increasing from the atlas (1.20 ±1.96 mm) to L1 (6.24 ±1.46 mm), so as to stabilize through L2–L3 (6.12 ±1.65, 6.12 ±1.61 mm), and finally was decreasing to S5 (0.26 ±0.96 mm). There was an increase in sagittal diameter of vertebral bodies from the atlas (0.82 ±1.34 mm) to T7 (4.76 ±0.85 mm), its stabilization for T8–L4 (4.73 ±0.86 mm, 4.71 ±1.02 mm), and then a decrease in values to S5 (0.21 ±0.75 mm) was observed. The values for cross-sectional area of vertebral bodies were increasing from the atlas (2.95 ±5.25 mm2) to L3 (24.92 ±11.07 mm2), and then started decreasing to S5 (0.48 ±2.09 mm2). The volumetric growth of vertebral bodies was increasing from the atlas (8.60 ±16.40 mm3) to L3 (122.16 ±74.73 mm3), and then was decreasing to S5 (1.60 ±7.00 mm3).ConclusionsThere is a sharp increase in size of fetal vertebral bodies between the atlas and the axis, and a sharp decrease in size within the sacral spine. In human fetuses the vertebral body growth is characterized by maximum values in sagittal diameter for T7, in transverse diameter for L1, in height for L2, and in both cross-sectional area and volume for L3.

Vertebral size, bone density, and strength in men and women matched for age and areal spine BMD.

To explore the possible mechanisms underlying sex-specific differences in skeletal fragility that may be obscured by two-dimensional areal bone mineral density (aBMD) measures, we compared quantitative computed tomography (QCT)-based vertebral bone measures among pairs of men and women from the Framingham Heart Study Multidetector Computed Tomography Study who were matched for age and spine aBMD. Measurements included vertebral body cross-sectional area (CSA, cm(2) ), trabecular volumetric BMD (Tb.vBMD, g/cm(3) ), integral volumetric BMD (Int.vBMD, g/cm(3) ), estimated vertebral compressive loading and strength (Newtons) at L3 , the factor-of-risk (load-to-strength ratio), and vertebral fracture prevalence. We identified 981 male-female pairs (1:1 matching) matched on age (± 1 year) and QCT-derived aBMD of L3 (± 1%), with an average age of 51 years (range 34 to 81 years). Matched for aBMD and age, men had 20% larger vertebral CSA, lower Int.vBMD (-8%) and Tb.vBMD (-9%), 10% greater vertebral compressive strength, 24% greater vertebral compressive loading, and 12% greater factor-of-risk than women (p < 0.0001 for all), as well as higher prevalence of vertebral fracture. After adjusting for height and weight, the differences in CSA and volumetric bone mineral density (vBMD) between men and women were attenuated but remained significant, whereas compressive strength was no longer different. In conclusion, vertebral size, morphology, and density differ significantly between men and women matched for age and spine aBMD, suggesting that men and women attain the same aBMD by different mechanisms. These results provide novel information regarding sex-specific differences in mechanisms that underlie vertebral fragility.

Interaction between playing golf and HRT on vertebral bone properties in post-menopausal women measured by QCT

We investigated the effect of playing regular golf and HRT on lumbar and thoracic vertebral bone parameters (measured by QCT) in 72 post-menopausal women. The main finding of this study was that there was positive interaction between golf and HRT on vertebral body CSA and BMC at the thoracic 12 and lumbar 2 vertebra but not the third and seventh thoracic vertebras. Identifying specific exercises that load the spine sufficiently to be osteogenic is an important component of primary osteoporosis prevention. The aim of this study was to determine if in postmenopausal women regular participation in golf resulted in greater paravertebral muscle mass and improved vertebral bone strength. Forty-seven postmenopausal women who played golf regularly were compared to 25 controls. Bone parameters at the mid-vertebral body were determined by QCT at spinal levels T3, T7, T12 and L2 (cross-sectional area (CSA), total volumetric BMD (vBMD), trabecular vBMD of the central 50% of total CSA, BMC and cortical rim thickness). At T7 and L2, CSA of trunk muscles was determined. There was a positive interaction between golf and HRT for vertebral CSA and BMC at T12 and L2, but not at T3 or T7 (p ranging < 0.02 to 0.07). Current HRT use was associated with a 10-15% greater total and trabecular vBMD at all measured vertebral levels. Paravertebral muscle CSA did not differ between groups. Vertebral CSA was the bone parameter significantly related to muscle CSA. These findings provide preliminary evidence that playing golf may improve lower spine bone strength in postmenopausal women who are using HRT.

A Novel Method for the Quantitative Evaluation of Lumbar Spinal Stenosis

A retrospective study of computed tomography (CT) myelographic images in patients with degenerative lumbar spinal stenosis (LSS). To introduce a new technique for the quantitative evaluation of LSS. Advances in hardware and software technology now permit inexpensive digitalization of radiological images, and enable methodologies for quantifying space available for neural elements in spinal canal. However, a valid method with quantitative evaluation of spinal stenosis in living patients has not been developed yet. Preoperative CT myelographic scans of 50 patients with degenerative LSS were collected for retrospective investigation. The patients subsequently underwent lumbar decompressive surgery. They included scans from thoracic vertebra 12 (T12) to sacrum (S1), in which each segment was scanned through both the vertebral body and disk. All CT scan films were digitized using a high-resolution digital camera. ImageTool software was used to measure three parameters: cross-sectional area of dural sac at disk level (A), cross-sectional area of spinal canal at midpedicular level (B), and cross-sectional area of vertebral body (C). The dural sac canal ratio (DSCR) was calculated as A/B x 100%. Low DSCR implied severe dural sac compression with a high degree of stenosis. The spinal canal vertebral ratio (CVR) was also calculated as B/C x 100%. Low CVR implied a low baseline of canal capacity for neural elements. They were calculated from T12 to S1. The study consisted of 26 male and 24 female patients, with an average age of 68.4 (35-97) years. A total of 295 segments were evaluated, of which 118 (40%) were surgically decompressed. There were wide ranges of canal cross-sectional areas (140-475 mm(2)) and dural sac cross-sectional area (54-435 mm(2)). Male patients had a slightly larger canal cross-sectional area than female patients at each level. The mean CVR was found decreased from T12 (26.1%) to L4 (18.3%). This was higher in female than in male patients, especially from T12 to L2 (P < 0.01). There were significant correlations between spinal canal and dural sac cross-sectional area (r = 0.55, P < 0.001), and also between CVR and DSCR (r = 0.31, P < 0.001). Of the levels decompressed, 82% was performed from the level L2 to L5, in which there was no significant difference in canal cross-sectional area and CVR between decompression and nondecompression (P > 0.05). There was a good correspondence between decreasing mean DSCR and increasing percentile of levels decompressed. DSCR represents a useful method for the quantitative diagnosis of lumbar spinal canal stenosis. ImageTool software is a useful tool in measuring spinal morphometry.

Sexual dimorphism in vertebral fragility is more the result of gender differences in age-related bone gain than bone loss.

Spine fractures usually occur less commonly in men than in women. To identify the structural basis for this gender difference in vertebral fragility, we studied 1013 healthy subjects (327 men and 686 women) and 76 patients with spine fractures (26 men and 50 women). Bone mineral content (BMC), cross-sectional area (CSA), and volumetric bone mineral density (vBMD) of the third lumbar vertebral body (L3) were measured by posteroanterior (PA) and lateral scanning using dual-energy X-ray absorptiometry (DXA). In this cross-sectional study, the diminution in peak vertebral body BMC from young adulthood to old age was less in men than in women (6% vs. 27%). This diminution was the net result of two opposing changes occurring concurrently throughout adult life: the removal of bone adjacent to marrow on the inner (endosteal) surface by bone resorption and the deposition of bone on the outer (periosteal) surface by bone formation. For L3, we estimated that men resorbed 3.7 g and deposited 3.1 g, producing a net loss of 0.6 g from young adulthood to old age and women resorbed 3.1 g and deposited only 1.2 g, producing a net loss of 1.9 g. Thus, based on our indirect estimates of periosteal gain and endosteal loss across life, the observed net diminution in BMC during aging was less in men than women because absolute periosteal bone formation was greater in men than women (3.1 g vs. 1.2 g) not because absolute bone resorption was less in men. On the contrary, the absolute amount of bone resorbed was greater in men than women (3.7 g vs. 3.1 g). Periosteal bone formation also increased vertebral body CSA 3-fold more in men than in women, distributing loads onto a larger CSA, so that the load imposed per unit CSA decreased twice as much in men than in women (13% vs. 5%). In men and women with spine fractures, CSA and vBMD were reduced relative to age-matched controls. However, vBMD was no different to the adjusted vBMD in age-matched controls derived assuming controls had no periosteal bone formation during aging. Thus, large amounts of bone are resorbed in men as well as in women, accounting for the age-related increase in spine fractures in both genders. Periosteal bone formation increases CSA and offsets bone loss in both genders but more greatly in men, accounting for the lower incidence of spine fractures in men than in women. We speculate that reduced periosteal bone formation, during growth or aging, may be in part responsible for both reduced vertebral size and reduced vBMD in men and women with spine fractures. Sexual dimorphism in vertebral fragility is more the result of gender differences in age-related bone gain than age-related bone loss.

The biomechanical basis of vertebral body fragility in men and women.

The aim of this study was to quantify the biomechanical basis for vertebral fracture risk in elderly men and women. A bone is likely to fracture when the loads imposed are similar to or greater than its strength. To quantify this risk, we developed a fracture risk index (FRI) based on the ratio of the vertebral body compressive load and strength. Loads were determined by upper body weight, height, and the muscle moment arm, and strength was estimated from cross-sectional area (CSA) and volumetric bone mineral density (vBMD). With loads less than the strength of the bone, the FRI remains < 1. For any given load, once bone strength diminishes due to a falling vBMD, the FRI will increase. Should FRI approach or exceed unity, structural failure of the vertebra is likely. We measured vertebral body CSA vBMD of the middle zone of third lumbar vertebra by lateral and posteroanterior (PA) scanning using dual-energy X-ray absorptiometry (DXA) and calculated vertebral compressive stress (load per unit area) in 327 healthy men and 686 healthy women and 26 men and 55 postmenopausal women with vertebral fractures. Activities that require forward bending of the upper body caused approximately 10-fold more compressive stress on the vertebra compared with standing upright. Men and women had similar peak vBMD in young adulthood. Because men have greater stature than women, the loads imposed on the vertebral body are higher (3,754 +/- 65 N vs. 3,051 +/- 31 N; p < 0.001). However, because CSA also was higher in men than women, peak load per unit CSA (stress) did not differ by gender (317.4 +/- 4.7 N/cm2 vs. 321.9 +/- 3.3 N/cm2, NS). The FRI was similar in young men and women and well below unity (0.42 +/- 0.02 vs. 0.43 +/- 0.01; NS). Gender differences emerged during aging; CSA increased in both men and women but more so in men, so load per unit area (stress) diminished but more so in men than in women. vBMD decreased in both genders but less so in men. These changes were captured in the FRI, which increased by only 21% in men and by 102% in women so that only 9% of elderly men but 26% of elderly women had an FRI > or = 1. Men and women with vertebral fractures had an FRI that was greater than or equal to unity (1.03 +/- 0.13 vs. 1.35 +/- 0.13; p < 0.05) and was 2.04 SD and 2.26 SD higher than age-matched men and women, respectively. In summary and conclusion, young men and women have a similar vBMD, vertebral stress, and FRI. During aging, CSA increases more, and vBMD decreases less in men than in women. Thus, fewer men than women are at risk for fracture because fewer men than women have these structural determinants of bone strength below a level at which the loads exceed the bone's ability to tolerate them. Men and women with vertebral fractures have FRIs that are equal to or exceed unity. The results show that a fracture threshold for vertebrae can be defined using established biomechanical principles; whether this approach has greater sensitivity and specificity than the current BMD T score of -2.5 SD is unknown.

Vertebral Body Trabecular Density at the Thoracolumbar Junction Using Quantitative Computed Tomography

Quantitative computed tomography was used to assess vertebral trabecular density in 26 post-mortem spines from individuals aged between 14 and 80 years. All vertebrae from T10 to L1 were scanned transversely near the mid-vertebral level with calculations of trabecular density in HUs averaged and referenced to a mineral equivalent phantom. An age-related decline in trabecular density was recorded (r = 0.55, p less than 0.0001). Density measures from the anterior aspect of the vertebral body were significantly greater than from postero-lateral regions. From T10 to L1, there was a significant decrease in trabecular density, whereas density measures multiplied by vertebral body cross-sectional area were constant. Predictions of vertebral compressive strength using quantitative computed tomography may become more accurate by increasing the sampling area per scan and including vertebral body cross-sectional area as part of the radiologic assessment.

Vertebral Body Trabecular Density at the Thoracolumbar Junction using Quantitative Computed Tomography

Quantitative computed tomography was used to assess vertebral trabecular density in 26 post-mortem spines from individuals aged between 14 and 80 years. All vertebrae from T10 to L1 were scanned transversely near the mid-vertebral level with calculations of trabecular density in HUs averaged and referenced to a mineral equivalent phantom. An age-related decline in trabecular density was recorded (r = 0.55, p < 0.0001). Density measures from the anterior aspect of the vertebral body were significantly greater than from postero-lateral regions. From T10 to L1, there was a significant decrease in trabecular density, whereas density measures multiplied by vertebral body cross-sectional area were constant. Predictions of vertebral compressive strength using quantitative computed tomography may become more accurate by increasing the sampling area per scan and including vertebral body cross-sectional area as part of the radiologic assessment.