Lateral Dual-energy X-ray Absorptiometry Research Articles

Abdominal Aorta Calcification Identified on DXA Scans and the Risk of Mortality in Adults.

Abdominal aortic calcification (AAC) on lateral lumbar radiographs increases the risk of cardiovascular events and mortality. However, data on the association between AAC detected in dual energy X-ray absorptiometry (DXA) and the risk of mortality in the general population are scarce. The present study was based on data from participants aged ≥40 years in the National Health and Nutrition Examination Survey (NHANES) cycle of 2013 to 2014. Vertebral assessment of lateral spine DXA scans was used to provide AAC measurements at vertebrae L1-L4. The extent of AAC was defined according to the Kauppila AAC-24 scores (0-1, 2-5, ≥6), and the NHANES 2019 public-use linked mortality files were used to assess mortality status. Of the 2,962 participants who were included in this study, with a mean age of 57.4 years and a median follow-up of 69.9 months, 252 (8.5%) died. Of the deaths, 84 (33.3%) occurred due to cardiovascular disease. The Cox proportional hazards models revealed that participants with AAC-24 scores ≥6 were 1.7 times more likely to die than those with AAC-24 scores 0-1 (Hazard ratio, 1.75; 95% confidence interval, 1.13-2.71). Moreover, older adults and women with AAC-24 scores ≥6 were 2.8 and 2.4 times more likely to die than their counterparts with AAC-24 scores 0-1, respectively. Conversely, a non-significant risk of cardiovascular mortality was found among participants with AAC-24 scores ≥6. The extent of AAC detected on vertebral fracture assessment DXA was associated with an increased risk of all-cause mortality in adults, particularly older adults and women.

Associations between the composite dietary antioxidant index and abdominal aortic calcification among United States adults: A cross-sectional study.

Oxidative stress has previously been shown to play a pivotal role in the pathogenesis of vascular calcification. In the present study, we aimed to investigate the association between the composite dietary antioxidant index (CDAI) and abdominal aortic calcification (AAC). We conducted a cross-sectional study of United States adults using data from the 2013-2014 National Health and Nutrition Examination Survey. The CDAI was calculated from vitamins A, C, E, selenium, zinc, and caretenoid through two rounds of 24-h dietary recall interviews. AAC was assessed by a lateral dual-energy x-ray absorptiometry scan of the thoraco-lumbar spine. The association between CDAI and AAC was evaluated with weighted multivariable logistic regression. Overall, an unweighted 1081 participants were analyzed, including 110 with AAC and 971 without AAC. In the multivariable fully adjusted logistic regression model, CDAI was significantly associated with AAC (odds ratio = 0.89, 95% CI 0.81-0.98; P = 0.02). Compared with the lowest quartile, the highest quartile of CDAI was related to a 0.33-fold risk of AAC (95% CI 0.12-0.90; P = 0.03). Subgroup analysis showed that the significant association between CDAI and AAC was only observed in participants without hypertension (P for interaction = 0.002). A higher CDAI was associated with a lower prevalence of AAC among adults without hypertension in the US. Further large-scale prospective studies are required to analyze the protective role of the CDAI in AAC progression.

Trabecular structural difference between the superior and inferior regions of the vertebral body: a cadaveric and clinical study.

Osteoporotic vertebral compression fractures commonly involve the superior vertebral body; however, their associated causes have not yet been clearly established. This study aimed to determine the trabecular structural differences between the superior and inferior regions of the vertebral body using cadaveric and clinical studies. First, five vertebrae were collected from three human cadavers. The trabecular structures of the superior and inferior regions of each vertebral body were analyzed using micro-computed tomography (micro-CT), finite element analysis (FEA), and biomechanical test. Based on the results of the ex vivo study, we conducted a clinical study. Second, spine CT images were retrospectively collected. Bone volume and Hounsfield unit were analyzed for 192 vertebral bodies. Finally, after sample size calculation based on the pilot study, prospectively, 200 participants underwent dual-energy X-ray absorptiometry (DXA) of the lateral spine. The bone mineral densities (BMDs) of the superior and inferior regions of each lumbar vertebral body were measured. The paired t-test and Wilcoxon signed-rank test were used for the statistical analyses, and p-value < 0.05 was considered significant. Cadaver studies revealed differences between the superior and inferior trabecular bone structures. The bone volume ratio, BMD, and various other trabecular parameters advocated for decreased strength of the superior region. Throughout the biomechanical study, the limitations of the compression force were 3.44 and 4.63 N/m2 for the superior and inferior regions, respectively. In the FEA study, the inferior region had a lower average displacement and higher von Mises stress than the superior region. In the clinical spine CT-based bone volume and BMD study, the bone volume was significantly higher in the inferior region than in the superior region. In the lateral spine DXA, the mean BMD of the superior region of vertebral bodies was significantly lower compared with that of the inferior region. The superior trabecular structure of the lumbar vertebral bodies possesses more biomechanical susceptibility compared with the inferior trabecular structure, confirming its dominant role in causing osteoporotic vertebral fractures. Physicians should also focus on the BMD values of the superior region of the vertebral body using lateral spine DXA to evaluate osteoporosis.

Genetics implicates overactive osteogenesis in the development of diffuse idiopathic skeletal hyperostosis

Diffuse idiopathic skeletal hyperostosis (DISH) is a condition where adjacent vertebrae become fused through formation of osteophytes. The genetic and epidemiological etiology of this condition is not well understood. Here, we implemented a machine learning algorithm to assess the prevalence and severity of the pathology in ~40,000 lateral DXA scans in the UK Biobank Imaging cohort. We find that DISH is highly prevalent, above the age of 45, ~20% of men and ~8% of women having multiple osteophytes. Surprisingly, we find strong phenotypic and genetic association of DISH with increased bone mineral density and content throughout the entire skeletal system. Genetic association analysis identified ten loci associated with DISH, including multiple genes involved in bone remodeling (RUNX2, IL11, GDF5, CCDC91, NOG, and ROR2). Overall, this study describes genetics of DISH and implicates the role of overactive osteogenesis as a key driver of the pathology.

Bone Marrow Adipose Tissue Is Increased in Postmenopausal Women With Postsurgical Hypoparathyroidism.

Suppression of bone turnover, greater trabecular volume, and normal-high normal all-site bone mineral density (BMD) are hallmarks of postsurgical hypoparathyroidism (HypoPT). Impairment in the trabecular microarchitecture with possible higher risk of vertebral fractures (VF) in women with postmenopausal HypoPT has also been described. Currently, no data on bone marrow adipose tissue (BMAT) are available in HypoPT. To assess BMAT by magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (1H-MRS) in postmenopausal women with chronic postsurgical HypoPT. This cross-sectional pilot study, conducted at an ambulatory referral center, included 29 postmenopausal women (mean age 66 ± 8.4 years) with postsurgical HypoPT and 31 healthy postmenopausal women (mean age 63 ± 8.5). Lumbar spine MRI was performed and BMAT was measured by applying PRESS sequences on the L3 body. Lumbar spine, femoral neck, and total hip BMD were measured by dual x-ray absorptiometry (DXA); site-matched spine trabecular bone score (TBS) was calculated by TBS iNsight (Medimaps, Switzerland); VF assessment was performed with lateral thoracic and lumbar spine DXA. Fat content (FC) and saturation level (SL%) were higher (P <.0001 and P <.001), while water content (W) was lower in HypoPT compared to controls (P <.0001). FC significantly correlated with years since menopause and body weight (P <.05) in HypoPT, while TBS negatively correlated with FC and SL% (P <.05) and positively with residual lipids (RL) and W (P <.05). We demonstrate for the first time that BMAT is increased in postmenopausal women with postsurgical hypoparathyroidism and negatively associated with trabecular microarchitecture.

Predicting Pedicle Screw Pullout and Fatigue Performance: Comparing Lateral Dual-Energy X-Ray Absorptiometry, Anterior to Posterior Dual-Energy X-Ray Absorptiometry, and Computed Tomography Hounsfield Units.

As the prevalence and associated health care costs of osteoporosis continue to rise in our aging population, there is a growing need to continue to identify methods to predict spine construct integrity accurately and cost-effectively. Dual-energy x-ray absorptiometry (DEXA) in both anterior to posterior (AP) and lateral planes, as well as computed tomography (CT) Hounsfield units (HU), have all been investigated as potential preoperative predictive tools. The purpose of this study is to determine which of the 3 bone density analysis modalities has the highest potential for predicting pedicle screw biomechanics. Lumbar spine specimens (L2, L3, and L4) from 6 fresh frozen cadavers were used for testing. AP-DEXA, lateral-DEXA, and CT images were obtained. Biomechanical testing of pedicle screws in each vertebrae was then performed including pullout strength and fatigue testing. Statistical analysis was performed. Pullout strength was best predicted by CT HU, followed by AP-DEXA, then lateral-DEXA (R 2 = 0.78, 0.70, and 0.40, respectively). Fatigue testing showed a significant correlation of relative rotation between HU value and AP-DEXA bone mineral density (R 2 = 0.54 and R 2 = 0.72, respectively), and there was a significant correlation between relative translation and HU value (R 2 = 0.43). There was a poor correlation between relative rotation and lateral-DEXA (R 2 = 0.13) as well as a poor correlation between relative translation and both AP- and lateral-DEXA (R 2 = 0.35 and R 2 = 0.02). CT is the only modality with a statistically significant correlation to all biomechanical parameters measured (pullout strength, relative angular rotation, and relative translation). AP-DEXA also predicts the biomechanical measures of screw pullout and relative angular rotation and is superior to lateral-DEXA. CT may provide an incremental benefit in assessing fatigue strength, but this should be weighed against the disadvantages of cost and radiation. The results of this study can help to inform clinicians on different bone density analyses and their implications on pedicle screw failure.

Vascular calcification of the abdominal aorta has minimal impact on lumbar spine bone density in patients with chronic kidney disease

Dual-energy X-ray absorptiometry (DXA) measurements are sensitive to artifacts from surrounding tissues. This study investigates the impact of abdominal aortic calcification (AAC) on bone mineral density (BMD) in patients with chronic kidney disease (CKD). In 88 patients with CKD stage G5D, lumbar spine BMD was measured in both anterior-posterior (AP) and lateral DXA projections. AAC was determined from lateral lumbar radiographs. Median age was 51 ± 14 years, and 61 % were men. AAC was present in 59 %. There was no difference in lumbar spine BMD between patients with and without AAC (AP: 0.823 vs. 0.806 g/cm 2 , p = 0.66). The ΔBMD between AP and lateral projections was similar in patients with and without AAC (13.4 ± 6.7 % vs. 11.5 ± 6.3 %; difference 1.9 %, 95 % CI −0.9 to 4.7 %, p = 0.18). When comparing single vertebrae at levels with high vs. low degree of AAC within the same individual, there was no difference in BMD (AP: 0.827 ± 0.202 vs. 0.818 ± 0.291 g/cm 2 , p = 0.78), nor in the ΔBMD between AP and lateral projections (12.9 ± 8.1 % vs. 14.3 ± 8.3 %, p = 0.12). We could not detect an impact of AAC on lumbar spine BMD. These findings challenge the dogma that lumbar spine BMD by DXA is unreliable due to widespread AAC in patients with CKD. • Low BMD is a risk factor for fractures in chronic kidney disease. • Lumbar spine BMD bias by aortic calcification is often cited as a concern. • Anterior-posterior and lateral lumbar spine BMD were compared in this study. • No impact of aortic calcification on lumbar spine BMD was detected. • Any effect of aortic calcification on BMD is likely of limited clinical relevance.

Association of Abdominal Aortic Calcification with Peripheral Quantitative Computed Tomography Bone Measures in Older Women: The Perth Longitudinal Study of Ageing Women

We have previously shown that abdominal aortic calcification (AAC), a marker of advanced atherosclerotic disease, is weakly associated with reduced hip areal bone mineral density (aBMD). To better understand the vascular–bone health relationship, we explored this association with other key determinants of whole-bone strength and fracture risk at peripheral skeletal sites. This study examined associations of AAC with peripheral quantitative computed tomography (pQCT)-assessed total, cortical and trabecular volumetric BMD (vBMD), bone structure and strength of the radius and tibia among 648 community-dwelling older women (mean ± SD age 79.7 ± 2.5 years). We assessed associations between cross-sectional (2003) and longitudinal (progression from 1998/1999–2003) AAC assessed on lateral dual-energy X-ray absorptiometry (DXA) images with cross-sectional (2003) and longitudinal (change from 2003 to 2005) pQCT bone measures at the 4% radius and tibia, and 15% radius. Partial Spearman correlations (adjusted for age, BMI, calcium treatment) revealed no cross-sectional associations between AAC and any pQCT bone measures. AAC progression was not associated with any bone measure after adjusting for multiple comparisons, despite trends for inverse correlations with total bone area at the 4% radius (rs = − 0.088, p = 0.044), 4% tibia (rs = − 0.085, p = 0.052) and 15% radius (rs = − 0.101, p = 0.059). Neither AAC in 2003 nor AAC progression were associated with subsequent 2-year pQCT bone changes. ANCOVA showed no differences in bone measures between women with and without AAC or AAC progression, nor across categories of AAC extent. Collectively, these finding suggest that peripheral bone density and structure, or its changes with age, are not associated with central vascular calcification in older women.

Lateral spine dual-energy X-ray absorptiometry and the risk of fragility fractures in long-term kidney graft recipients.

Although the prevalence of osteoporosis and fractures in the first 6-12months post-renal transplantation is high, little is known about the utility of bone mineral density (BMD) to predict fractures in long-term kidney graft recipients. Lateral spine dual-energy X-ray absorptiometry (DXA) scanning is a reliable tool for measuring glucocorticoid-induced and age-related bone loss in the elderly population. However, little is known about the utility of lateral spine DXA for patients with chronic kidney diseases. This study aimed to analyze the utility of lateral spine BMD for fragility fractures in long-term kidney graft recipients. A total of 357 stable kidney transplant recipients for a minimum of 1year after kidney transplantation underwent DXA measurements at several sites, including the lateral spine between January 2017 and December 2018. We collected data on new incident fractures from the patients' medical records. The median post-transplantation time at baseline DXA measurement was 12.6years. During the median follow-up period of 3.5years, 41 (11.4%) fractures occurred. The lateral spine BMDs were independently associated with fractures (adjusted hazard ratio 0.076; 95% confidence interval 0.012-0.42, p = 0.003). The cumulative incidence rate of fractures was significantly higher in the lower lateral spine BMD group (< 0.471g/cm2, optimal cut-off value by receiver operating characteristic curve) than in the higher lateral spine BMD group (23.4 vs. 7.4%, adjusted hazard ratio 4.92; 95% confidence interval 2.33-10.74, p < 0.001). Lateral lumbar spine BMD can be used to predict the risk of fragility fractures in long-term kidney graft recipients.

Prevalent Morphometrically Assessed Vertebral Fractures in Individuals With Type 2 Diabetes, Prediabetes and Normal Glucose Metabolism: The Maastricht Study.

BackgroundType 2 diabetes (T2D) is frequently reported to be associated with an increased fracture risk. Epidemiological data on prevalent morphometric vertebral fractures (VFs) in T2D are sparse and even less is known in the prediabetic state.PurposeTo determine the association between prevalence and severity of morphometric VFs and glucose metabolism state: normal glucose metabolism (NGM), impaired glucose metabolism (prediabetes) or T2D.MethodsThis study included cross-sectional data from 3625 participants of the Maastricht Study who had a vertebral fracture assessment on lateral Dual Energy X-Ray Absorptiometry images. VFs were classified based on morphometric assessment into mild, moderate and severe VFs (respectively 20–24%, 25–39% or ≥40% reduction in expected vertebral body height). Logistic regression models were used to investigate the association between glucose metabolism status and the prevalence and severity of VFs. Analyses were adjusted for subject characteristics and life-style factors.ResultsT2D individuals were older (62.8 ± 7.5 years old) and less often female (30.5%) compared to the NGM group (57.7 ± 8.5 years old, and 58.8% female, respectively). At least one mild, moderate or severe prevalent VF was found in 8.6% of the men and 2.2% of the women in the T2D group, in 9.4% and 8.4% in the prediabetes group and in 9.1% and 4.8% in the NGM group, respectively. After adjustment T2D in women was associated with a lower probability of having a prevalent VF compared to NGM [adjusted OR 0.25 (95% CI 0.09-0.65)], while this was not the case for prediabetes. Furthermore, women with T2D had a significantly lower probability of a prevalent moderate or severe VF [adjusted OR 0.32 (95% CI 0.11-0.96)]. In men there was no significant association between T2D or prediabetes and prevalent VFs.ConclusionWomen with T2D had a lower probability of prevalent VFs compared to women with a normal glucose metabolism, while this was not the case for men with T2D and participants with prediabetes.

Novel lateral whole-body dual-energy X-ray absorptiometry of lumbar paraspinal muscle mass: results from the SarcoSpine study.

BackgroundHere, we aimed to propose novel lateral whole‐body dual‐energy X‐ray absorptiometry (lateral DXA) as a simple tool for measuring spinal muscle mass and investigate the feasibility of lateral DXA to measure lumbar paraspinal muscle (LPM) mass compared with lumbosacral spine three‐dimensional magnetic resonance imaging (3D MRI).MethodsTwenty consecutive participants were enrolled from a prospective observational cohort (SarcoSpine study). Lateral DXA was scanned with each participant in the lateral decubitus position. The region of interest was defined to analyse the LPM mass. LPM total volume, LPM cross‐sectional area at the L3 mid‐vertebra and L4/5 mid‐disc levels and each signal intensity were measured by 3D MRI. Isokinetic and isometric back extensor muscle strengths as well as back extensor endurance were examined. The correlation between lateral DXA‐based mass (weight) and 3D MRI‐based LPM volume was analysed.ResultsThe mean age of the 20 participants (15 women, 5 men) was 72.2 ± 4.9 years. LPM mass by lateral DXA was positively correlated with LPM volume by 3D MRI (β = 0.333, r = 0.692, p < 0.001) and negatively correlated with signal intensity of the total LPM (β = −0.263, r = −0.530, p = 0.016). LPM mass was also correlated with appendicular limb muscle mass, handgrip strength and gait speed as well as back extensor endurance (r = 0.620, p = 0.004).ConclusionsOur data suggest that LPM mass assessed by lateral DXA was positively correlated with LPM volume by 3D MRI in older adults. Lateral DXA may be a potential substitute for the cross‐sectional area measurement of LPM mass. Further studies are required to validate this lateral DXA technique.

Reliability of the assessment of disc degeneration on the lateral DXA scans.

Given the prevalence and costs induced by osteoarthritis (OA), it is necessary to find a cheap and safe technique to evaluate it reliably. To assess the value of the lateral dual energy X-ray absorptiometry (DXA) spine scans for the diagnosis of disc degeneration. Seventy-seven individuals aged 18 and over, with or without disc degeneration, had both lateral thoracolumbar spine radiographs and DXA spine scans (≤6months between both exams). Disc degeneration was assessed using the Lane score. The images of 20 randomly selected individuals were assessed by two readers. Almost 13% of the thoracic levels were not assessable on the DXA scans. For the identification of the intervertebral levels on the DXA scans as interpretable or not, the intra-reader agreement was good (κ=0.81) and the inter-reader agreement was fair (κ=0.27-0.36). For the diagnostic criteria (osteophytes, disc space narrowing, osteosclerosis, overall grade), the intra-reader agreement was excellent for the radiographs (κ=0.89-0.92), good for the DXA scans (κ=0.64-0.83) and fair to moderate for the between-method comparison (κ=0.25-0.44). The inter-reader agreement was moderate to good for the radiographs (κ=0.49-0.66) and fair to good for the DXA scans (κ=0.32-0.74). In the per patient analysis (the most severe grade), the intra-reader agreement was excellent for the radiographs (κ=0.85-0.94), moderate to excellent for the DXA scans (κ=0.53-0.85) and poor to good for the between-methods comparison (κ=0.17-0.63). Our results do not support the use of DXA scans for the assessment of thoracolumbar disc degeneration.

Exploring thoracic kyphosis and incident fracture from vertebral morphology with high-intensity exercise in middle-aged and older men with osteopenia and osteoporosis: a secondary analysis of the LIFTMOR-M trial

The Lifting Intervention For Training Muscle and Osteoporosis Rehabilitation for Men (LIFTMOR-M) trial examined efficacy and safety of an eight-month, supervised, high-intensity progressive resistance and impact training (HiRIT) program compared with machine-based isometric axial compression (IAC) training in middle-aged and older men with low areal bone mineral density (aBMD). The primary purpose of the current work was to explore change in thoracic kyphosis and incident fracture from vertebral morphology following eight-months of HiRIT or IAC training. The secondary purpose was to explore change in clinical kyphosis measures for HiRIT, IAC and a non-randomized, matched control group. Men (≥ 45yrs), with low aBMD, were recruited and randomized to HiRIT or IAC, or designated control. Clinical measures of thoracic kyphosis with inclinometry were determined. Cobb angle of kyphosis and vertebral fracture assessment using the Genant semi-quantitative method were determined from lateral thoracolumbar DXA (Medix DR, Medilink, France). Per-protocol (n = 40) and intention-to-treat (n = 93) analyses were conducted. Forty participants (HiRIT n = 20, IAC n = 20; 66.1 ± 7.8yrs.; lumbar spine T-score - 0.1 ± 0.8; femoral neck T-score - 1.5 ± 0.5) underwent clinical kyphosis measures and thoracolumbar DXA at baseline and follow-up. No between-group differences were detected in kyphosis change, however, within-group improvements in neutral (HiRIT - 2.3 ± 0.8°; IAC - 2.5 ± 0.8°) and 'standing tall' (HiRIT - 2.4 ± 0.8°; IAC - 2.0 ± 0.8°) postures were observed (p < 0.05). HiRIT improved Cobb angle (- 3.5 ± 1.5°, p = 0.027) from baseline. Over the 8months, no incident vertebral fractures nor progression of prevalent vertebral fractures occurred for HiRIT participants. Five incident fractures of thoracic vertebrae occurred for IAC and one wedge fracture progressed. Ninety-three participants underwent clinical kyphosis measures at both time-points (HiRIT n = 34, IAC n = 33, control n = 26). HiRIT exhibited a reduction in 'standing tall' kyphosis compared to control (- 2.3 ± 0.6° versus 1.4 ± 0.7°, p < 0.05), but no other between-group differences were detected. Although there was no difference in change between intervention groups, thoracic kyphosis appeared to improve in both HiRIT and IAC with exercise exposure. HiRIT improved 'standing tall' posture in comparison to usual activities. HiRIT was not associated with vertebral fracture progression or incident vertebral fracture, but for some IAC participants there was evidence of progression of vertebral fracture severity and incident vertebral fractures, in our small sample. Larger trials are required to confirm the observations of the current work, which was exploratory in nature.

Association of Compartmental Leg Lean Mass Measured by Dual X-Ray Absorptiometry With Force Production.

Raymond-Pope, CJ, Dengel, DR, Fitzgerald, JS, and Bosch, TA. Association of compartmental leg lean mass measured by dual X-ray absorptiometry with force production. J Strength Cond Res 34(6): 1690-1699, 2020-We recently reported a novel method for measuring upper leg anterior/posterior compartmental composition. The purpose of this study was to determine the association of this method with measures of muscle-specific and explosive strength and to compare this method with traditional dual energy X-ray absorptiometry (DXA) measurements of total and upper leg masses. We hypothesize this method will be related to muscle-specific strength measured by isokinetic dynamometry and explosive strength measured by jump mechanography. Nineteen NCAA Division I college athletes (10 women; age = 20.4 ± 1.4 years; height = 1.8 ± 0.1 m; body mass = 73.8 ± 17.0 kg) underwent 3 DXA scans (1 total body, 2 lateral) and knee extension/flexion strength assessment using isokinetic dynamometry at 3 velocities (60, 120, and 180°·s). A subset of 10 participants also completed a squat jump on a force platform on a different day. Pearson correlations compared 3 separate lean soft-tissue mass (LSTM) regions of interest (total leg, upper leg, and compartmental leg) with (a) isokinetic peak torque and (b) squat jump height, peak force, and peak and average rate of force development. Compartmental leg LSTM demonstrated similar correlations (r = 0.437-0.835) with peak torque in comparison with total leg (r = 0.463-0.803) and upper leg (r = 0.449-0.795) LSTM. Summed right and left total leg (r = 0.830-0.940), total upper leg (r = 0.824-0.953), and anterior (r = 0.582-0.798) and posterior (r = 0.750-0.951) compartmental leg LSTM demonstrated moderate-to-strong correlations with all squat jump variables, particularly jump height (p < 0.05). The lateral segmentation DXA scanning method demonstrated feasibility in assessing compartmental leg LSTM in relation with isokinetic and squat jump measurements-important outcomes when examining an athlete's response to training and rehabilitation.

Diagnostic performance of morphometric vertebral fracture analysis (MXA) in children using a 33-point software program.

There is significant inter and intraobserver variability in diagnosing vertebral fractures in children. We aimed to evaluate the diagnostic accuracy of morphometric vertebral fracture analysis (MXA) using a 33-point software program designed for adults, on dual-energy x-ray absorptiometry (DXA) images of children. Lateral spine DXA images of 420 children aged between 5 and 18years were retrospectively reviewed. Vertebral fracture assessment (VFA) by an expert pediatric radiologist using Genant's semiquantitative scoring system served as the gold standard. All 420 DXA scans were analyzed by a trained radiographer, using semi-automated software (33-point morphometry). VFA of a random sample of 100 DXA was performed by an experienced pediatric clinical scientist. MXA of a random sample of 30 DXA images were analyzed by three pediatric radiologists and the pediatric clinical scientist. Diagnostic accuracy and inter and intraobserver agreement (kappa statistics) were calculated. Overall sensitivity, specificity, false positive (FP) and false negative (FN) rates for the radiographer using the MXA software were 80%, 90%, 10%, and 20% respectively and for mild fractures alone were 46%, 92%, 8%, and 54% respectively. Overall sensitivity, specificity, FP, and FN rates for the four additional observers using MXA were 89%, 79%, 21%, and 11% respectively and for mild fractures alone were 36%, 86%, 14%, and 64% respectively. Agreement between two expert observers was fair to good for VFA and MXA [kappa=0·29 to 0·76 (95% CI: 0·17-0·88) and 0·29 to 0·69 (95% CI: 0·17-0·83)] respectively. MXA using a 33-point technique developed for adults is not a reliable method for the identification of mild vertebral fractures in children. A pediatric standard is required which not only incorporates specific vertebral body height ratios but also the age-related physiological changes in vertebral shape that occur throughout childhood.

Clinical Utility of a Semiquantitative Method Using Lumbar Radiography as a Screening Tool for Osteoporosis in Elderly Subjects.

BackgroundOsteoporosis is a major global public health problem in the current aging era. Osteoporosis is often diagnosed only after patients have a fracture that causes a severe decline in ability to perform activities of daily life. Although the current criterion standard for diagnosing osteoporosis is dual-energy X-ray absorptiometry (DXA), this modality remains less prevalent among general practitioners in geriatric medicine. The aim of this study was to determine the diagnostic utility of visual inspection of lumbar radiography in detecting bone mineral density (BMD) decline.Material/MethodsWe retrospectively reviewed medical data of 78 patients who underwent both lateral lumbar radiography and DXA. Board-certified radiologists determined the clinical grade of each patient’s condition according to the semiquantitative (SQ) method of lumbar fracture assessment. We compared the grades and young adult means of BMD in the lumbar spine and hips as measured using DXA.ResultsBMD of the femoral neck was significantly lower in patients with severe osteoporosis (grades 2 and 3 as classified using the SQ method) than in those with mild osteoporosis (grades 0 and 1; P<0.05). A receiver operating characteristic curve analysis showed that the SQ method can help predict the decrease in BMD (young adult mean score of <70%) in the femoral neck with moderate accuracy (sensitivity, 0.621; specificity, 0.829; area under the curve, 0.742).ConclusionsThese results suggest that lateral lumbar radiography can provide useful information about bone mineral status and can serve as a tool for osteoporosis screening by general practitioners.

Lumbar bone mineral asymmetry in elite cricket fast bowlers.

Bone responds to mechanical loading by increasing bone mineral density (BMD) and/or bone area to enhance bone strength at the site of the greatest strain. Such localised adaptation has not been demonstrated at the spine. The aim of this study is to determine if BMD and/or bone mineral content (BMC) differs between dominant (ipsilateral to bowling/throwing arm) and non-dominant sides of the vertebrae in cricket fast bowlers, and whether this asymmetry differs according to stress fracture or disc injury history. A further aim was to determine if regional BMD and BMC in the lumbar spine differ between fast bowlers, other cricketers, rugby players and non-active controls, to highlight the site-specific response of lumbar vertebra to unilateral activity. 23 fast bowlers, 14 other cricketers, 22 rugby players and 20 controls underwent an antero-posterior (AP) and lateral DXA scans of their lumbar spine to assess BMD, BMC and area. A custom analysis measured BMD and BMC of the dominant and non-dominant sides (lateral 33%) of the AP lumbar spine. BMD and BMC were compared between groups, injury status, vertebrae and sides using ANOVA. Analysis of medical records showed that 6 fast bowlers had a history of lumbar stress fracture. Significantly greater BMD and BMC was found in the L4 non-dominant vertebra compared with the dominant vertebra in fast bowlers. BMD and BMC differed significantly according to vertebra, side and group, with fast bowlers having significantly greater BMD and BMC at the L3 and L4 non-dominant vertebra compared with other groups (L3: 13.3%-45.3%, L4: 15.7%-44.0%) compared with other groups. Fast bowlers who never suffered lumbar stress fracture had 3.6% and 1.7% greater BMD in the dominant and non-dominant sides of lumbar vertebrae respectively compared with those who did suffer lumbar stress fracture, but evidence of this was weaker (P = 0.08). The lumbar spine responds to a unique unilateral high loading activity through site-specific increased bone mass at the site of most strain. Fast bowlers had increased lumbar BMD, particularly on the non-dominant side of L4, although this adaptation was less marked in those with history of lumbar stress fracture. Site-specific low bone mineral density within the lumbar side may be implicated in the aetiology of lumbar stress fracture.

Assessing Agreement of Lateral Leg Muscle and Bone Composition Using Dual X-ray Absorptiometry

Background: Recently, a lateral-view dual X-ray absorptiometry (DXA) scanning method for measuring leg total, lean, and fat masses demonstrated accuracy vs the standard whole-body frontal DXA scanning view on the GE Lunar iDXA. The current study examined the lateral scanning method's agreement using a Hologic Horizon A DXA scanner. Methodology: Thirty healthy college-age participants (16 female; X̅age = 21.5 ± 1.7 yr) received 3 DXA scans (1 whole-body, 2 lateral leg scans) to quantify leg composition in the frontal and lateral plane. To mark regions of interest for postscan analysis, metallic markers were placed at 60% of the length above and below each leg's lateral epicondyle. Using lateral subject positioning, leg composition was measured with participants lying on their right and left sides. Paired t tests examined the lateral DXA scanning method's agreement when quantifying total, fat, and lean masses, bone mineral content, and bone mineral density compared to measurements of equal area in the whole-body frontal scanning view. Results: Comparisons of frontal and lateral view DXA scan measurements for right leg total mass (7.12 ± 0.91kg vs 6.39 ± 0.85kg), fat mass (1.70 ± 0.44kg vs 1.36 ± 0.33kg), lean mass (5.14 ± 1.05kg vs 4.77 ± 0.92kg), bone mineral content (0.28 ± 0.06kg vs 0.23 ± 0.05kg), and bone mineral density (1.39 ± 0.14g/cm2vs 1.36 ± 0.15g/cm2), respectively, were significantly different (p < 0.001–0.028). Similarly, comparisons of frontal and lateral left leg total mass (7.12 ± 0.97kg vs 6.38 ± 0.92kg), fat mass (1.70 ± 0.44kg vs 1.39 ± 0.36kg), lean mass (5.15 ± 1.12kg vs 4.76 ± 0.97kg), bone mineral content (0.28 ± 0.06kg vs 0.24 ± 0.06kg), and bone mineral density (1.39 ± 0.15g/cm2vs 1.36 ± 0.17g/cm2), respectively, were significantly different (p < 0.001–0.046). Conclusion: Unlike a previous study in which agreement of lateral vs frontal leg composition measurements of equal area was reported utilizing the GE Lunar iDXA, agreement was not observed using the Hologic Horizon A DXA scanner. Therefore, lateral view assessment may not be reliably performed on DXA scanner models produced by different manufacturers.

High-intensity exercise did not cause vertebral fractures and improves thoracic kyphosis in postmenopausal women with low to very low bone mass: the LIFTMOR trial.

The LIFTMOR trial demonstrated a novel, HiRIT program notably improved bone mass in postmenopausal women with osteopenia and osteoporosis. While no clinical signs or symptoms of vertebral crush fracture were evident during the trial, anecdotal feedback suggests that concerns about safety of HiRIT in the osteoporosis demographic remain.The aim of the current work was to assess vertebral body morphology, Cobb angle, and clinical measures of thoracic kyphosis in participants in the LIFTMOR trial for evidence of vertebral fracture following 8 months of supervised HiRIT. Participants were randomized to either 8months of 30-min, twice-weekly, supervised HiRIT or unsupervised, low-intensity, home-based exercise (CON). Lateral thoracolumbar DXA scans (Medix DR, Medilink, France) were performed at baseline and follow-up. Cobb angle was determined, and vertebral fracture identification was performed using the semiquantitative Genant method. Clinical kyphosis measurements were performed in relaxed standing (neutral posture) and standing tall using an inclinometer and a flexicurve. The HiRIT group exhibited a reduction in inclinometer-determined standing tall thoracic kyphosis compared to CON (- 6.7 ± 8.2° vs - 1.6 ± 8.1°, p = 0.031). Both the HiRIT and CON groups exhibited within-group improvement in kyphosis in relaxed standing as measured by both inclinometer and flexicurve (p < 0.05). There were no changes in vertebral fracture classification in the HiRIT group post-intervention. A single, new, wedge deformity was observed for CON. Supervised HiRIT was not associated with an increased risk of vertebral fracture in postmenopausal women with low bone mass. Indeed, a clinically relevant improvement in thoracic kyphosis was observed following 8months of supervised HiRIT, further supporting its efficacy as an osteoporosis intervention for postmenopausal women with low to very low bone mass.

Investigating a relationship between body composition and spinal curvature in farmed adult New Zealand king salmon (Oncorhynchus tshawytscha): A novel application of dual-energy X-ray absorptiometry

Characterising the pathology of skeletal anomalies in farmed finfish is key to elucidating the underlying causes. Spinal curvature is frequently observed in farmed New Zealand king salmon (Oncorhynchus tshawytscha), but its cause is currently unknown and knowledge about its pathology is limited. Dual-energy X-ray absorptiometry (DXA) was used to investigate the relationship between spinal curvature and body composition in farmed adult New Zealand king salmon. Differences in fat mass (FM), lean mass (LM) and bone mineral content (BMC) between harvest-sized fish affected and unaffected by spinal curvature were evaluated. As there is presently no evidence of an association between spinal curvature and vertebral mineral loss, between-group differences in BMC were not anticipated. Conversely, as spinal anomalies can alter the swimming and feeding of affected fish, and existing research suggests a role for soft tissues in spinal curvature development, differences in FM and LM were expected. Whole-body and regional (cranial, trunco-cranial, trunco-caudal and caudal spine) measurements of percent FM, LM and BMC were obtained from lateral DXA scans of size-matched adult female king salmon (1890–6903 g) affected (n = 31) and unaffected (n = 31) by spinal curvature. Repeatability was comparable to previous DXA studies. Measurements of FM and LM by DXA and chemical carcass analysis (CCA) were highly similar. As frequently reported in previous animal-based studies, DXA-derived BMC values were significantly lower than those obtained from CCA. Contrary to the overarching hypothesis, there were no significant between-group differences in whole-body or regional FM, LM or BMC, suggesting that there was no relationship between body composition and spinal curvature. Though the relationship between soft tissue changes and spinal curvature remains to be determined, DXA appears to be a viable tool for non-invasive assessment of king salmon body composition. However, studying end-stage disease has recognised limitations, so future investigations should utilise longitudinal designs.