Bone Mineral Density Estimation Research Articles

Bone density of the humeral condyle in Labrador retrievers with medial coronoid process disease.

To estimate, using CT imaging, differences in the regional bone density of the humeral condyle in Labrador retriever elbows with and without medial coronoid process disease. The elbows of Labrador Retrievers that had undergone CT were reviewed. Scans were divided into three categories: elbows without medial coronoid process disease; elbows with medial coronoid process disease involving fragmentation of the radial incisure; elbows with medial coronoid process disease involving fragmentation of the medial coronoid apex. A templating technique was employed to define the weight-bearing regions of the medial and lateral portion of the humeral condyle and estimates of volumetric bone density (defined by Hounsfield unit measurement) were compared across the three groups. CT evaluation was performed on 122 elbows in 81 dogs. There was a higher mean Hounsfield unit measurement in the medial and lateral portions of the humeral condyles in elbows with medial coronoid process disease involving fragmentation of the medial coronoid apex compared with elbows with medial coronoid process disease involving fragmentation of the radial incisure. Dogs with apical fragmentation of the medial coronoid process exhibited significantly higher estimated bone mineral density within the medial portion of the humeral condyle when compared to dogs with radial incisure fragmentation. The medial portion of the humeral condyle may be associated with the pathogenesis of apical but not radial incisure medial coronoid process fragmentation in Labrador Retrievers.

Osteoporosis Screening and Fracture Risk Assessment Tool: Its Scope and Role in General Clinical Practice.

Osteoporosis is a widely prevalent condition among postmenopausal women characterized by low bone mass and skeletal fragility that increases the risk of fractures specifically in the hip, spine, wrist, humerus, and pelvis. It has become a major public health problem around the world. An osteoporotic fracture affects one in every three women and one in every five men aged 50 and above. Hip and spine fractures are linked to a higher death rate and can cause ambulation problems, depression, chronic pain, independence loss, and persistent discomfort. It not only puts a lot of strain on the individual but also causes a significant cost to society. Osteoporosis is a silent disease that goes unrecognized until a patient develops a pathological fracture. Diagnosis of osteoporosis is based on bone mineral density (BMD) estimation by dual-energy x-ray absorptiometry (DXA) as defined by WHO. However, in many resource-constrained and underdeveloped or low-middle income countries, it is not widely available. There are a number of questionnaire-based techniques available to identify such postmenopausal women and older men who may be at risk of having low BMD and osteoporosis. Our aim of the study is to search and compile such simple yet useful and validated screening and assessment tools for osteoporosis that can help to identify people at risk of having low BMD and the potential candidate who can benefit from BMD estimation in a resource-restricted geographical area or low/middle-income countries and benefit from treatment. Though these tools are not diagnostic can have broader applicability in general clinical practice and usefulness in identifying high-risk individuals and may prove cost-effective. Although it has limitations, FRAX is a widely used osteoporotic fracture risk assessment tool around the globe and when used with femoral neck BMD it has greater accuracy.

Estimation of bone mineral density and algorithms of 10-year risk of osteoporotic fractures in women

Osteoporosis is the fourth most common after cardiovascular, cancer and endocrine diseases. With an increase in life expectancy, it becomes one of the main causes of deterioration in health and an increase in mortality.
 Aim of the study. Assess bone mineral density using ultrasonic densitometry and the risk of osteoporotic fractures among women in Cherkasy region.
 Materials and methods. The study was based on a survey of 43 women in the Odessa region, the average age of the subjects was 56,4±9,9 years, the average body weight was 73,5±11,6 kg, height 164,9±5,9 cm, the average BMI was 27,1±4,3. All women were divided into groups by age with a ten-year interval and by densitometry indices.
 Results. Decreased bone density was found in 58,1 % of subjects, osteoporosis - 2 (4,8%). Women with osteopenia and osteoporosis have an increased risk of fractures and significantly reduced ultrasound densitometry compared to respondents with normal BMD. The structure of concomitant pathology was dominated by diseases of the circulatory system (22 cases;51,2 %) and digestive organs (12; 27,9 %). More than half of women (26; 60,5 %) had a total of 50 comorbidities, with an average of 1.2 cases of comorbidity.
 Conclusions. Most women had osteopenic manifestations. Age significantly correlates with BMD parameters. The number of women with changes in the structure of bone tissue increases with age. Algorithms for assessing the 10-year risk of FRAX and Q-Fracture fractures are significantly correlated with densitometry. The combination of ultrasonic densitometry with algorithms for assessing the risk of osteoporotic fractures increases the diagnosis of osteoporosis.

Are Children Suffering From Congenital Pseudarthrosis of the Tibia Associated With Decreased Bone Strength?

Background:Congenital pseudarthrosis of the tibia (CPT) is a rare and difficult-to-treat congenital disease in neonates. Our previous study found that exosomes derived from serum of children with CPT inhibit bone formation. In this study, we used ultrasound bone densitometry to detect the bone strength differences between hospitalized children with CPT and with non-metabolic diseases to determine the bone strength of children with CPT.MethodsA total of 37 children with CPT with a mean age of 3.14 ± 1.81 years and 40 hospitalized children with a mean age of 3.32 ± 2.66 years with supracondylar fracture of the humerus and without a bone metabolic disease (control group) were recruited in our hospital. The ultrasonic bone densitometer was used to examine the bilateral calcaneus of the subjects. We collected the broadband ultrasonic attenuation (BUA), speed of sound (SOS), quantitative ultrasound index (QUI), bone strength index (STI) and bone mineral density estimation (BMDe) values. Multivariable regression was used to examine the associations between quantitative ultrasound measurement differences and age, body mass index (BMI), neurofibromatosis type 1 (NF1) and CPT Crawford type. Intra-class correlation coefficient (ICC) was calculated to estimate intra- and inter-rater agreements.Results74 calcaneus scans were taken from CPT patients (23 boys and 14 girls) and 80 calcaneus scans were taken from the control (24 boys and 16 girls). The CPT patients exhibited significantly lower SOS (1,368.75 ± 136.78 m/s), STI (7.2319 ± 38.6525), QUI (8.2532 ± 56.1720), and BMDe (−0.0241 ± 0.3552 g/cm3) than the control (SOS: 1,416.02 ± 66.15 m/s, STI: 7.96 ± 16.884, QUI: 28.8299 ± 25.461, BMDe: 0.0180 ± 0.1610 g/cm3). Multiple regression revealed that SOS, STI and QUI were statistically significant and negatively correlated with CPT Crawford classification.ConclusionsWe found the incidence of decreased bone strength in CPT group was higher than that in the non-bone metabolic disease group. This phenomenon was not related to NF1 but related to CPT Crawford classification, which suggested that the higher the grade of the CPT Crawford classification, the lower the bone strength and the higher the risk of fracture.

Adaptive Contrast for Image Regression in Computer-Aided Disease Assessment.

Image regression tasks for medical applications, such as bone mineral density (BMD) estimation and left-ventricular ejection fraction (LVEF) prediction, play an important role in computer-aided disease assessment. Most deep regression methods train the neural network with a single regression loss function like MSE or L1 loss. In this paper, we propose the first contrastive learning framework for deep image regression, namely AdaCon, which consists of a feature learning branch via a novel adaptive-margin contrastive loss and a regression prediction branch. Our method incorporates label distance relationships as part of the learned feature representations, which allows for better performance in downstream regression tasks. Moreover, it can be used as a plug-and-play module to improve performance of existing regression methods. We demonstrate the effectiveness of AdaCon on two medical image regression tasks, i.e., bone mineral density estimation from X-ray images and left-ventricular ejection fraction prediction from echocardiogram videos. AdaCon leads to relative improvements of 3.3% and 5.9% in MAE over state-of-the-art BMD estimation and LVEF prediction methods, respectively.

Paraffin Fixed Human Trabecular Bone Specimens for Study of Osteoporosis

Examining and quantifying specific measures of trabecular bone to investigate the progression of osteoporosis presents a challenge. Specifically, the development of analytical and computational strategies to interpret computed tomography (CT) generated data sets requires gross anatomical specimens that closely approximate the intraosseous matrix of the marrow while maintaining the structural integrity of the trabecular network. Moreover, these specimens must be durable, easily transported, and stored at room temperature (e.g., do not require freeze/thaw cycles). Here we investigated if paraffin impregnated bone specimens maintained the trabecular network and bone density of prepared fresh‐frozen specimens used in imaging studies for osteoporosis. Standardized fresh‐frozen human distal tibia specimens (n = 12), from the institution’s Deeded Body Program, were scanned using multi‐row detector computed tomography (MDCT) and micro computed tomography (micro‐CT) imaging at different times in the preparation process to evaluate and quantify the preservation of microstructure and continuity of cortical and trabecular bone constituents. Once scanned, the specimens were placed in a series of acetone baths to remove water and marrow. With the de‐marrowing procedure complete, four specimens were rescanned using MDCT and micro‐CT. De‐marrowed specimens were then impregnated, under vacuum controlled conditions, with either a silicone polymer, gelatin matrix solution, or paraffin wax. After impregnation and curing, the specimens were re‐scanned. Analysis demonstrated a high correlation in the region of interest (ROI) for trabecular bone network area density from micro‐CT data sets of the preprocessed and de‐marrowed states (r = 0.99). Quantitatively, wax impregnated specimens demonstrated congruence in MDCT bone volume fraction (r = 0.92) and trabecular network area (r = 0.94) measures when the preprocessed and impregnated states were correlated. Results were more robust in the micro‐CT data in the bone volume fraction (r = 0.97) and the trabecular network area (r = 0.99). MDCT analysis at the (ROI) corresponding to 14‐16% length measured from the distal aspect of specimens demonstrated an increased estimate of bone mineral density (BMD) relative to scans acquired with the unmodified tissue (polymer +160 mg/cc; gelatin +58 mg/cc), whereas the paraffin wax condition slightly underestimated BMD (‐21 mg/cc). Of the impregnating procedures, paraffin wax provided the best qualitative specimens for handling, storage, and processing time. Together these data suggest that the trabecular structure is preserved through the de‐marrowing procedure and demonstrates that specimens can be transferred away from cold storage. Impregnating bone specimens with paraffin wax effectively provides a space occupying matrix that protects the delicate trabecular network without altering the ability to quantify important biomechanical measures in clinical CT as well as micro‐CT imaging for assessing bone integrity for the study of osteoporosis. This procedure creates specimens that are easily stored and transported, can be scanned across various imaging modalities, and effectively retain the trabecular micro‐structure.

P131 Adult coeliac disease and bone mineral density at the femoral neck, total hip and lumbar spine: an age- and sex-matched case-control study

Abstract Background/Aims Coeliac disease (CD) is characterised by intestinal villous atrophy causing malabsorption. Decreased bone mineral density (BMD) has been reported in CD. To the best of our knowledge, no published paper has documented BMD comparisons in detail at different sites. We aim to determine the prevalence of osteoporosis and BMD values at multiple locations in a group of adult CD patients, and compare them to those of age and sex matched controls. Methods We analysed data of adult patients referred for BMD estimation at a district scanner from 2004 to 2018. Dual-energy x-ray absorptiometry was used for all subjects. Patients diagnosed with CD (cases) were age- and sex-matched with subjects referred with no reason for scanning (controls). Additional FRAX(TM) risk factors for osteoporosis were recorded. Comparison was made using chi-squared for categorical values, student's T test for continuous variables, then a univariate followed by a multivariate stepwise logistic model, adjusting for height, weight and body mass index (BMI), were fitted. Results 645 (474 female) patients in the coeliac group were matched with 645 (474 female) controls. There was no significant difference in the mean age (years) at scan: cases 56.24 (SD 14.79) vs controls 56.24 (SD 14.80), p-value 1.00. The coeliac group had a significantly higher proportion of osteoporotic (T-score ≤-2.5 SD) patients at all locations compared to the control group. Cases had significantly lower mean BMD (gcm-2) and mean Z-scores at all locations than the controls. In the multivariate stepwise model, adjusted for height, weight and BMI, only the total hip, lumbar spine and their sub-sites revealed significant associations between having CD and a BMD (gcm-2) in the lowest tertile for the whole cohort. Key results are summarised in Table 1. Conclusion We confirmed that adult CD patients have higher prevalence of osteoporosis and lower BMD values compared to controls. Bone impairment was pronounced at the L1 and L2 vertebrae; least pronounced at the femoral neck. This might be due to CD preferentially damaging trabecular bone, which is predominant in the lumbar spine than femoral neck. Disclosure P. Shtarbanov: None. M. Bukhari: None.

P141 What are the predictors of fragility fracture in patients with low body mass index: an observational cohort study

Abstract Background/Aims Low body mass index (BMI) is known to be associated with increased risk of fracture and therefore measurements of height and weight contribute towards the Fracture Risk Assessment Tool (FRAX) score, an estimation tool used to calculate approximate risk of fracture to guide therapy decisions. However, data is lacking on which measurement of bone mineral density is best in those that are underweight. Using a large population of patients with low BMI, we aimed to determine which measurement of bone mineral density (BMD) is the most accurate predictor of fragility fracture in this group of patients. We also aimed to explore the relationship of other traditional risk factors for fracture in this subpopulation. Methods Data on risk factors for osteoporosis and fragility fractures was collected on patients presenting for BMD estimation at a district general hospital in North West England between June 2004 and October 2016. All analysis was performed on those with low BMI, defined as < 18.5kg/m2. Firstly, univariate logistic regression was performed to assess risk of fracture using BMD for lumbar spine, femoral neck and total hip; as well as smoking, alcohol use, presence of rheumatoid arthritis, history of steroid use and history of hip fracture in a parent. Risk factors were defined as per FRAX. This was followed by multivariate regression of available risk factors, using the best BMD predictor identified from univariate analysis. All models were controlled for sex and age at first scan. Results for continuous variables are reported as beta coefficients and for categorical variables as odds ratios. All results are reported with 95% confidence intervals. Area under ROC curve for each model was calculated. Results 921 of 35,759 patients had a BMI of under 18.5 and were included in analysis. Of these, 88.4% were female, mean age at time of scan was 58.6 years. Results are shown in the table. Conclusion In those with low BMI, BMD of left total hip was the best predictor of fragility fracture. Smoking, alcohol use and history of hip fracture were also associated, but previous steroid use and diagnosis of rheumatoid arthritis was not. Disclosure S.D. Sharma: None. M. Bukhari: None.

Cluster analysis demonstrates co-existing sites of fragility fracture and associated comorbidities.

Fragility fracture (FF) prevalence is increasing. Subsequent fractures lead to greater morbidity and mortality. Few data are available on the association between FF sites and comorbidities. 1. Establish the most common sites of FF and clusters within patients. 2. Identify patterns of co-existing FF and associated comorbidities. We retrospectively reviewed clinical records of patients undergoing bone mineral density estimation at a district hospital in North-West England, 2004-2016, identifying those who had sustained ≥ 1 FF. Demographics, FF site(s), comorbidities, and medications were recorded. Cluster analysis was performed on fracture sites alone, and sites and comorbidities, using Jaccard similarity coefficient. Results were plotted on a dendrogram and divided into clusters. Of 28,868 patients, 11,003 had sustained ≥ 1 FF, 84.6% female, with overall mean age 67.5years and median T-score - 1.12 SD. FF of the forearm was more frequent (n = 5045), most commonly co-existing with tibia/fibula fractures. Three FF site clusters were identified: ankle and elbow; forearm, tibia/fibula, ribs and spine; and pelvis, femur and humerus. When including comorbidities, four clusters were identified: forearm, tibia/fibula, spine, associated with family history of FF, smoking, corticosteroids and bisphosphonates; pelvis associated with hyperparathyroidism, PMR, coeliac disease and HRT; femur and humerus associated with IBD and RA; and ribs associated with alcohol and hyperthyroidism. Cluster analysis demonstrated three fracture site clusters, and four subgroups of FF sites and comorbidities. Cluster analysis is a novel method to evaluate comorbidities associated with FF sites. Knowledge of factors associated with FF sites will aid prophylaxis in at-risk patients.

Regenerating zebrafish scales express a subset of evolutionary conserved genes involved in human skeletal disease

BackgroundScales are mineralised exoskeletal structures that are part of the dermal skeleton. Scales have been mostly lost during evolution of terrestrial vertebrates whilst bony fish have retained a mineralised dermal skeleton in the form of fin rays and scales. Each scale is a mineralised collagen plate that is decorated with both matrix-building and resorbing cells. When removed, an ontogenetic scale is quickly replaced following differentiation of the scale pocket-lining cells that regenerate a scale. Processes promoting de novo matrix formation and mineralisation initiated during scale regeneration are poorly understood. Therefore, we performed transcriptomic analysis to determine gene networks and their pathways involved in dermal scale regeneration.ResultsWe defined the transcriptomic profiles of ontogenetic and regenerating scales of zebrafish and identified 604 differentially expressed genes (DEGs). These were enriched for extracellular matrix, ossification, and cell adhesion pathways, but not in enamel or dentin formation processes indicating that scales are reminiscent to bone. Hypergeometric tests involving monogenetic skeletal disorders showed that DEGs were strongly enriched for human orthologues that are mutated in low bone mass and abnormal bone mineralisation diseases (P< 2× 10−3). The DEGs were also enriched for human orthologues associated with polygenetic skeletal traits, including height (P< 6× 10−4), and estimated bone mineral density (eBMD, P< 2× 10−5). Zebrafish mutants of two human orthologues that were robustly associated with height (COL11A2, P=6× 10−24) or eBMD (SPP1, P=6× 10−20) showed both exo- and endo- skeletal abnormalities as predicted by our genetic association analyses; col11a2Y228X/Y228X mutants showed exoskeletal and endoskeletal features consistent with abnormal growth, whereas spp1P160X/P160X mutants predominantly showed mineralisation defects.ConclusionWe show that scales have a strong osteogenic expression profile comparable to other elements of the dermal skeleton, enriched in genes that favour collagen matrix growth. Despite the many differences between scale and endoskeletal developmental processes, we also show that zebrafish scales express an evolutionarily conserved sub-population of genes that are relevant to human skeletal disease.

Cortical Thickness of Proximal Femur as a Preliminary Indicator of Bone Mineral Density

Background: Osteoporosis progresses with advancing age. Estimation of bone mineral density (BMD) using dual energy X-ray absorptiometry (DXA) is valuable in predicting fracture risk in the elderly. DXA machines however may not always be available in under-resourced developing countries. Aim: To find values of CTI and CFI in normal adult young and old, male and female population of Southern Punjab. Study design: Cross-sectional population study Methods: Measurements were recorded from 107 anteroposterior radiographs of proximal femur of normal adult male and female subjects divided in two groups: Young: 22 male and 26 females with mean age 28±3.4 and Old: 31 male and 28 females with mean age 61+5.2. Results: Statistical comparison between male and female subjects for CTI was not significant in the Y and O groups. Similar comparison for CFI while not significant in the Y-group was highly significant in the O-group. In overall comparison of Y and O groups the difference was very highly significant for CTI and CFI; both showing higher values in the Y-group. Conclusion; CTI and CFI measured from radiographs of proximal femur are reliable parameters and can be recommended for preliminary assessment of bone mineral density in developing countries. Keywords: Proximal femur, morphometry, cortical thickness index (CTI), canal flare index (CFI), bone mineral density

Diagnosis of osteoporosis and prevention of osteoporotic fractures

Introduction. Osteoporosis is a metabolic bone disease characterized by reduced bone mineral density and damage to the bone microarchitecture, which leads to bone fragility, thus increasing the risk of osteoporotic fractures. While different diagnostic methods can be employed for detecting bone mineral density decrement in a timely manner, dual energy X-ray absorptiometry remains the gold standard in research and clinical practice. Bone mineral density estimation methods. Osteoporosis can be diagnosed through conventional radiography, quantitative ultrasonography, quantitative computed tomography, and magnetic resonance. Nonetheless, dual energy X-ray absorptiometry is the gold standard in the diagnosis of osteoporosis on which further treatment and monitoring are based. The dual energy X-ray absorptiometry apparatus is equipped with the Fracture Risk Assessment Tool, which estimates the 10- year probability of a major fracture and hip fracture due to osteoporosis. The use and interpretation of osteoporosis diagnostic evaluation modalities is based on the International Society for Clinical Densitometry guidelines for diagnosing osteoporosis in adults and children. According to the International Society for Clinical Densitometry recommendations, the aforementioned quantitative visualization modalities should be used alongside laboratory analyses of bone metabolism markers to supplement diagnostics and monitor treatment efficacy in patients suffering from osteoporosis. Conclusion. Assessment of risk factors and early diagnosis are prerequisites for timely treatment and effective monitoring, which is necessary for arresting the progression of bone mineral density loss and preventing the occurrence of osteoporotic fractures.

Preoperative measures of bone mineral density from digital wrist radiographs.

AimsAssessment of bone mineral density (BMD) with dual-energy X-ray absorptiometry (DXA) is a well-established clinical technique, but it is not available in the acute trauma setting. Thus, it cannot provide a preoperative estimation of BMD to help guide the technique of fracture fixation. Alternative methods that have been suggested for assessing BMD include: 1) cortical measures, such as cortical ratios and combined cortical scores; and 2) aluminium grading systems from preoperative digital radiographs. However, limited research has been performed in this area to validate the different methods. The aim of this study was to investigate the evaluation of BMD from digital radiographs by comparing various methods against DXA scanning.MethodsA total of 54 patients with distal radial fractures were included in the study. Each underwent posteroanterior (PA) and lateral radiographs of the injured wrist with an aluminium step wedge. Overall 27 patients underwent routine DXA scanning of the hip and lumbar spine, with 13 undergoing additional DXA scanning of the uninjured forearm. Analysis of radiographs was performed on ImageJ and Matlab with calculations of cortical measures, cortical indices, combined cortical scores, and aluminium equivalent grading.ResultsCortical measures showed varying correlations with the forearm DXA results (range: Pearson correlation coefficient (r) = 0.343 (p = 0.251) to r = 0.521 (p = 0.068)), with none showing statistically significant correlations. Aluminium equivalent grading showed statistically significant correlations with the forearm DXA of the corresponding region of interest (p < 0.017).ConclusionCortical measures, cortical indices, and combined cortical scores did not show a statistically significant correlation to forearm DXA measures. Aluminium-equivalent is an easily applicable method for estimation of BMD from digital radiographs in the preoperative setting.Cite this article: Bone Joint Res 2021;10(12):830–839.

Quantitative Analysis of Temporal Bone Density and Thickness for Robotic Ear Surgery.

Background and Objective: Quantitative assessment of bone density and thickness in computed-tomography images offers great potential for preoperative planning procedures in robotic ear surgery.Methods: We retrospectively analyzed computed-tomography scans of subjects undergoing cochlear implantation (N = 39). In addition, scans of Thiel-fixated ex-vivo specimens were analyzed (N = 15). To estimate bone mineral density, quantitative computed-tomography data were obtained using a calibration phantom. The temporal bone thickness and cortical bone density were systematically assessed at retroauricular positions using an automated algorithm referenced by an anatomy-based coordinate system. Two indices are proposed to include information of bone density and thickness for the preoperative assessment of safe screw positions (Screw Implantation Safety Index, SISI) and mass distribution (Column Density Index, CODI). Linear mixed-effects models were used to assess the effects of age, gender, ear side and position on bone thickness, cortical bone density and the distribution of the indices.Results: Age, gender, and ear side only had negligible effects on temporal bone thickness and cortical bone density. The average radiodensity of cortical bone was 1,511 Hounsfield units, corresponding to a bone mineral density of 1,145 mg HA/cm3. Temporal bone thickness and cortical bone density depend on the distance from Henle's spine in posterior direction. Moreover, safe screw placement locations can be identified by computation of the SISI distribution. A local maximum in mass distribution was observed posteriorly to the supramastoid crest.Conclusions: We provide quantitative information about temporal bone density and thickness for applications in robotic and computer-assisted ear surgery. The proposed preoperative indices (SISI and CODI) can be applied to patient-specific cases to identify optimal regions with respect to bone density and thickness for safe screw placement and effective implant positioning.

Should Q-CT Be the Gold Standard for Detecting Spinal Osteoporosis?

Prospective comparative study. Refinement of the guidelines for screening of osteoporosis and considering quantitative computed tomography (Q-CT) for detecting spinal osteoporosis. Spinal osteoporosis is often underestimated and under-evaluated due to either lack of availability of the diagnostic modality or lack of awareness about the possibility of overestimation by dual X-ray absorptiometry (DXA) scan. There is a need for reconsidering osteoporosis evaluation with a site specific and patient specific inclination. Post-menopausal women that underwent bone mineral density (BMD) evaluation from January-2018 to December-2020 with either Q-CT or DXA were evaluated. Comparison studies of the distribution of age and T-scores of the bone densities obtained from the two study groups: age-matched, sex-matched, and common skeletal site of interest (L1-4 vertebrae) were performed. Mann-Whitney U test, correlation and regression analyses were performed and bell curves were plotted. Of the 718 women evaluated, 447 underwent Q-CT and 271 underwent DXA. There was no significant difference among the age distribution of the two study groups (P-value > 0.05). The mean and mode T-scores obtained by Q-CT and DXA were found to be -2.71, -3.8 and -1.63, -1.7 respectively. A highly significant difference in the T-scores was observed in the Q-CT and DXA groups (P-value < 0.0001). Among those who were screened by Q-CT, 58.16% were osteoporotic, 37.58% were osteopenic, and 4.25% were normal. The respective percentages in the DXA group were 30.63%, 49.82%, and 19.55%. Q-CT provides more precise estimation of cancellous bone mineral density than DXA. With the reliance on DXA for spinal BMD estimation being questionable, new standards have to be established for spinal osteoporosis evaluation. Q-CT can be a better alternative to replace DXA as the gold standard for the evaluation of spinal osteoporosis.Level of Evidence: 2.

P44. Variation of bone mineral density in the lumbar spine

P44. Variation of bone mineral density in the lumbar spine

Estimation of bone mineral density and algorithms of 10-year risk of osteoporotic fractures in women

Osteoporosis is the fourth most common after cardiovascular, cancer and endocrine diseases. With an increase in life expectancy, it becomes one of the main causes of deterioration in health and an increase in mortality.&#x0D; Aim of the study. Assess bone mineral density using ultrasonic densitometry and the risk of osteoporotic fractures among women in Cherkasy region.&#x0D; Materials and methods. The study was based on a survey of 43 women in the Odessa region, the average age of the subjects was 56,4±9,9 years, the average body weight was 73,5±11,6 kg, height 164,9±5,9 cm, the average BMI was 27,1±4,3. All women were divided into groups by age with a ten-year interval and by densitometry indices.&#x0D; Results. Decreased bone density was found in 58,1 % of subjects, osteoporosis - 2 (4,8%). Women with osteopenia and osteoporosis have an increased risk of fractures and significantly reduced ultrasound densitometry compared to respondents with normal BMD. The structure of concomitant pathology was dominated by diseases of the circulatory system (22 cases;51,2 %) and digestive organs (12; 27,9 %). More than half of women (26; 60,5 %) had a total of 50 comorbidities, with an average of 1.2 cases of comorbidity.&#x0D; Conclusions. Most women had osteopenic manifestations. Age significantly correlates with BMD parameters. The number of women with changes in the structure of bone tissue increases with age. Algorithms for assessing the 10-year risk of FRAX and Q-Fracture fractures are significantly correlated with densitometry. The combination of ultrasonic densitometry with algorithms for assessing the risk of osteoporotic fractures increases the diagnosis of osteoporosis.

Opportunistic use of “follow-up” chest and abdominal computed tomography in the assessment of bone mineral density of breast cancer patients in a resource-poor nation

Background: Breast cancer patients experience bone loss from treatment-induced menopause, as well as from the direct effect of cancer. The use of computed tomography (CT) attenuation values of the lumbar spine to estimate bone mineral density has been validated by several studies. Materials and Methods: This was a retrospective study conducted at Sweden Ghana Medical Centre and Korle Bu Teaching Hospital between June 2016 and August 2019. Measurement of Hounsfield unit (HU) of lumbar vertebrae was achieved by drawing an elliptical region of interest (ROI) on an axial image of the vertebra about 2–3 mm from the spinal cortical bone. The mean HU of the ROI was measured on bone window for each of the vertebral bodies, and the values were documented and analyzed. Results: The mean bone densities of the vertebrae were generally higher for the noncancer patients compared to the breast cancer patients for all the age groups. The measured bone densities showed a normal distribution curve. The range of bone density for osteopenia and osteoporosis was between 174.4 and 236.4 HU and &lt;174.4 HU, respectively. A Pearson's correlation analysis between patient age and bone density for both groups showed a negative statistically significant relationship. Conclusion: Using CT attenuation values of lumbar vertebra to estimate bone density established that the bone densities follow a normal distribution, the mean bone density for breast cancer patients were slightly lower than for noncancer patients, and age correlated better with lumbar bone density in noncancer patients than in breast cancer patients.

Rheumatoid arthritis and osteoporosis: shared genetic effect, pleiotropy and causality.

Rheumatoid arthritis (RA) is associated with increased localized and generalized bone loss, but the complex genetic mechanism between them is still unknown. By leveraging large-scale genome-wide association studies summary statistics and individual-level datasets (i.e. UK Biobank), a series of genetic approaches were conducted. Linkage disequilibrium score regression reveals a shared genetic correlation between RA and estimated bone mineral density (eBMD) (rg = -0.059, P = 0.005). The PLACO analysis has identified 74 lead (8 novel) pleiotropic loci that could be mapped to 99 genes, the genetic functions of which reveal the possible mechanism underlying RA and osteoporosis. In European, genetic risk score (GRS) and comprehensive Mendelian randomization (MR) were utilized to evaluate the causal association between RA and osteoporosis in European and Asian. The increase in GRS of RA could lead to a decrease of eBMD (beta = -0.008, P = 3.77E-6) and a higher risk of facture [odds ratio (OR) = 1.012, P = 0.044]. MR analysis identified that genetically determined RA was causally associated with eBMD (beta = -0.021, P = 4.14E-05) and fracture risk (OR = 1.036, P = 0.004). Similar results were also observed in Asian that osteoporosis risk could be causally increased by RA (OR = 1.130, P = 1.04E-03) as well as antibodies against citrullinated proteins-positive RA (OR = 1.083, P = 0.015). Overall, our study reveals complex genetic mechanism between RA and osteoporosis and provides strong evidence for crucial role of RA in pathogenesis of osteoporosis.

Circulating Alpha-Tocopherol Levels, Bone Mineral Density, and Fracture: Mendelian Randomization Study.

Recent cohort studies indicate a potential role of the antioxidant α-tocopherol in reducing bone loss and risk of fractures, especially hip fractures. We performed a Mendelian randomization investigation of the associations of circulating α-tocopherol with estimated bone mineral density (eBMD) using heel ultrasound and fractures, identified from hospital records or by self-reports and excluding minor fractures. Circulating α-tocopherol was instrumented by three genetic variants associated with α-tocopherol levels at p < 5 × 10−8 in a genome-wide association meta-analysis of 7781 participants of European ancestry. Summary-level data for the genetic associations with eBMD in 426,824 individuals and with fracture (53,184 cases and 373,611 non-cases) were acquired from the UK Biobank. Two of the three genetic variants were strongly associated with eBMD. In inverse-variance weighted analysis, a genetically predicted one-standard-deviation increase of circulating α-tocopherol was associated with 0.07 (95% confidence interval, 0.05 to 0.09) g/cm2 increase in BMD, which corresponds to a >10% higher BMD. Genetically predicted circulating α-tocopherol was not associated with odds of any fracture (odds ratio 0.97, 95% confidence interval, 0.91 to 1.05). In conclusion, our results strongly strengthen a causal link between increased circulating α-tocopherol and greater BMD. Both an intervention study in those with a low dietary intake of α-tocopherol is warranted and a Mendelian randomization study with fragility fractures as an outcome.