Dual-energy X-ray Absorptiometry Scores Research Articles

Osteoarthritic Bony Alterations of Temporomandibular Joint and Relation to Low Bone Mineral Density in Postmenopausal Edentulous Females.

This study aimed to evaluate the relationship between osteoarthritic bony alterations in the temporomandibular joint (TMJ) and general bone mineral density (BMD) in postmenopausal edentulous females. Cone beam computed tomography (CBCT) scans for both TMJs were acquired for 80 clinically asymptomatic patients (mean age 72 ± 8.8 y). Both lumbar spine and femoral neck measurements of BMD were performed using dual-energy X-ray absorptiometry (DXA). The most frequently observed bony alterations were flattening of the articular surface (47.5%), sclerosis (41.5%), subcortical cysts (10%), and erosions (5%). Osteophytes were not observed. No statistical differences were observed between those who had or did not have radiological signs of bony alterations according to age or DXA scores. The prevalence of radiological findings of degenerative TMJ bony alterations in clinically asymptomatic postmenopausal females did not confirm a connection with a generally low BMD.

End-to-End Semi-Supervised Opportunistic Osteoporosis Screening Using Computed Tomography.

Osteoporosis is the most common metabolic bone disease and can cause fragility fractures. Despite this, screening utilization rates for osteoporosis remain low among populations at risk. Automated bone mineral density (BMD) estimation using computed tomography (CT) can help bridge this gap and serve as an alternative screening method to dual-energy X-ray absorptiometry (DXA). The feasibility of an opportunistic and population agnostic screening method for osteoporosis using abdominal CT scans without bone densitometry phantom-based calibration was investigated in this retrospective study. A total of 268 abdominal CT-DXA pairs and 99 abdominal CT studies without DXA scores were obtained from an oncology specialty clinic in the Republic of Korea. The center axial CT slices from the L1, L2, L3, and L4 lumbar vertebrae were annotated with the CT slice level and spine segmentation labels for each subject. Deep learning models were trained to localize the center axial slice from the CT scan of the torso, segment the vertebral bone, and estimate BMD for the top four lumbar vertebrae. Automated vertebra-level DXA measurements showed a mean absolute error (MAE) of 0.079, Pearson's r of 0.852 (P<0.001), and R2 of 0.714. Subject-level predictions on the held-out test set had a MAE of 0.066, Pearson's r of 0.907 (P<0.001), and R2 of 0.781. CT scans collected during routine examinations without bone densitometry calibration can be used to generate DXA BMD predictions.

Evaluating alternatives to dual-energy x-ray absorptiometry for assessing bone quality in patients undergoing spine surgery.

The purpose of this study was to compare and contrast lumbar bone quality and osteoporosis/osteopenia screening results via dual-energy x-ray absorptiometry (DEXA), CT, and MRI. A consecutive series of 426 candidates screened for lumbar disc replacement over a 5-year period beginning in 2018 was reviewed. Patients with a preoperative lumbar spine DEXA scan and a CT and/or MRI scan were included. The primary outcome measures included the bone mineral density (BMD) and osteoporosis or osteopenia classification from DEXA scans, Hounsfield units (HUs) for CT, and vertebral bone quality (VBQ) assessment for MRI. Patients were included if they had a DEXA scan within 1 year of an MRI or CT scan. DEXA BMD scores from composite or level-by-level reports were recorded. Asynchronous MRI and CT measurements were conducted using PACS. Interrater and intrarater reliability scores were generated for both CT and MRI measurements and ranged from 1.000 for MRI L1-4 scans to 0.683 for MRI VBQ. All 3 types of scans were statistically significantly correlated with one another; however, CT was more strongly correlated with the lumbar DEXA value (r = 0.439, p < 0.001). The correlation between MRI VBQ and DEXA was -0.103, (p < 0.045). The CT level-by-level measurements correlate with the corresponding level-by-level DEXA BMD values (correlation ranging from 0.531 to 0.289, p < 0.001 to p = 0.007). CT HU values were more strongly related to osteoporosis/osteopenia classification based on DEXA T-scores than were MRI VBQ values. Receiver operating characteristic analyses found that the area under the curve was 0.817 for CT and 0.539 for MRI. These results demonstrate that CT HUs more closely correlate to DEXA scores than MRI VBQ in this population of patients undergoing surgery for symptomatic disc degeneration. Thus, CT may be an alternative to DEXA for assessing VBQ in this population.

Effects of Teriparatide Treatment on Bone Mineral Density in Patients With Osteoporosis: A Short-Term Dose-Response Study.

Osteoporosis is a chronic bone disease that develops with a decrease in bone mineral density (BMD) along with bone mass. An essential measure in the prevention of osteoporosis is the achievement of normal peak bone mass.Teriparatide (TPTD) functions as an osteoanabolic agent, exerting a dual influence on bone remodeling by modulating both osteogenesis and osteoclastogenesis. Bone mass is determined by dual-energy x-ray absorptiometry (DEXA) quantitative CT scan and has outstanding precision (within 1% to 2%) and has the ability to show the effectiveness of drug intervention. To assess the effectiveness of TPTD treatment on BMD in osteoporosis patients. The study is a retrospective, observational, multi-centerstudy of 378 osteoporosis patients who were treated with 20 µg of subcutaneous TPTD every day for six months. DEXA scores of the hip joints of patients were measured both before and after TPTD treatment. TheDEXA scores of the total population pre and post-treatment were -2.75+0.58 and -2.15+0.95 respectively, with a p-value of <0.001, which is statistically significant. In women the pre and post-treatment scores were -2.728+0.52 and -2.276+0.49, with a significant p-value of <0.001 whereas in males, the scores were -2.756+0.72 and -2.108+1.29 respectively, with a significant p-value of <0.05. The six-month treatment with TPTD significantly improved DEXA scores in osteoporosis patients. DEXA score's precision and sensitivity in quantifying impact contribute to effective osteoporosis management, guiding treatment strategies for better outcomes in the Indian population. Further research is warranted to see the long-term effect of TPTD.

Preoperative glenoid bone density is associated with systemic osteoporosis in primary shoulder arthroplasty

BackgroundIn shoulder arthroplasty, poor bone mineral density can impact humeral and glenoid fixation, as well as increase the risk of periprosthetic fracture. The purposes of this study were to (1) determine the association between preoperative glenoid and humeral Hounsfield units (HUs) with systemic bone density in primary shoulder arthroplasty, (2) determine a threshold for HU on preoperative shoulder computed tomography (CT) to classify patients as osteoporotic, and (3) identify which anatomic T-score locations were significantly associated with glenoid and/or humeral HU measurements. MethodsConsecutive patients who had both a preoperative shoulder CT and a dual-energy x-ray absorptiometry (DEXA) scan were included. HU measurements of the glenoid vault and proximal humerus were recorded. DEXA T-scores from the spine, hip, and femoral neck were recorded, and osteoporosis was defined as a T-score of −2.5 or lower in any of the anatomic sites. Patients were grouped into osteoporosis and nonosteoporosis cohorts and these cohorts were compared using standard statistical tests. To assess the association between HUs and DEXA T-score, linear regression analysis was performed. Additional receiver operating characteristic analysis was performed to evaluate the ability of HUs to classify patients as osteoporotic. ResultsA total of 162 patients undergoing primary shoulder arthroplasty with both preoperative CT and DEXA scores were included. The osteoporosis cohort had significantly lower body mass index (P = .001), although no other significant differences in demographics were found between the 2 cohorts. The osteoporosis cohort was associated with significantly lower glenoid vault bone density in HUs (183 ± 104 vs. 303 ± 157, P = .004) and trended toward significantly lower proximal humeral bone density in HUs (34.3 ± 54.8 vs. 64.5 ± 58.2, P = .058). Glenoid HU threshold of 175 had an area under the curve of 0.75, with sensitivity of 80.8% and specificity of 62.5% for classifying systemic osteoporosis. HUs of both the glenoid (P = .031) and proximal humerus (P = .003) were significantly associated with femoral neck T-scores on linear regression analysis. Similarly, HUs of both the glenoid (P < .001) and proximal humerus (P = .009) were significantly associated with spine T-scores on linear regression analysis. DiscussionThis study found that glenoid vault HU is significantly associated with systemic osteoporosis and can be used as a screening tool for detecting osteoporosis preoperatively. In addition to implications for component fixation and periprosthetic fracture, local bone density evaluation on shoulder CT prior to shoulder arthroplasty represents an opportunity for osteoporosis screening.

Opportunistic screening for osteoporosis by abdominal CT in a British population

BackgroundIt has previously been shown that CT scans performed for other indications can be used to identify patients with osteoporosis. This has not yet been tested in a British population. We sought to evaluate the use of vertebral CT attenuation measures for predicting osteoporosis in a British cohort, using dual-energy X-ray absorptiometry (DEXA) as a reference standard.MethodsPatients who underwent abdominal CT in 2018 and concomitantly underwent DEXA within a six-month interval were retrospectively included. CT attenuation values in Hounsfield units (HU) were measured by placement of a region-of-interest at the central portion of the L1 vertebral body and then compared to their corresponding DEXA score. Receiver operating characteristic (ROC) curves were generated to evaluate the performance of a logistic regression model and to determine sensitivity and specificity thresholds.Results536 patients (394 females, mean age 65.8) were included, of which 174 had DEXA-defined osteoporosis. L1 attenuation measures were significantly different (p < 0.01) between the three DEXA-defined groups of osteoporosis (118 HU), osteopenia (143 HU) and normal bone density (178 HU). The area under the ROC curve was 0.74 (95% CI 0.69–0.78). A threshold of 169 HU was 90% sensitive, and a threshold of 104 HU was 90% specific for diagnosing osteoporosis.ConclusionsRoutine abdominal CT can be used to opportunistically screen for osteoporosis without additional cost or radiation exposure. The thresholds identified in this study are comparable with previous studies in other populations. We recommend radiologists engage with primary care and rheumatology providers to determine appropriate cut-off values for further investigation.

Cone-Beam Computed Tomography as a Prediction Tool for Osteoporosis in Postmenopausal Women: A Systematic Literature Review

This literature review was conducted to analyze the capability of cone-beam computed tomography (CBCT) to accurately identify low bone mass density in women. A systematic search of MEDLINE, Embase, Scopus, Google Scholar, the Cochrane Library, and Science Direct was performed to identify relevant articles, and the Cochrane risk of bias criterion was used to determine the methodological quality of the included studies. All ten included studies assessed primary research on the capacity of CBCT to accurately diagnose insufficient bone mineral density. All relevant data were extracted, and the results were summarized narratively. The results indicated that the CBCT has good sensitivity and specificity and high accuracy in predicting osteoporosis. Four of the included studies measured qualitative values, while the others concentrated on quantitative values and found lower values in osteoporosis patients compared to those of osteopenic and healthy patients. All the studies compared CBCT grayscale values with dual energy X-ray absorptiometry scores, which strengthened our confidence in the accuracy of CBCT's diagnostic capability. CBCT is considered a feasible predictive tool for detecting patients who are at risk of osteoporosis, although further research is needed to confirm the evidence and enhance its common use among health care professionals.

Correlation between bone density measurements on CT or MRI versus DEXA scan: A systematic review

BackgroundNovel methods of bone density assessment using computed tomography (CT) and magnetic resonance imaging (MRI) have been increasingly reported in the spine surgery literature. Correlations between these newer measurements and traditional Dual-Energy X-ray Absorptiometry (DEXA) is not well known. The purpose of this study is to perform an updated systematic review of correlations between bone mineral density (BMD) from CT or MRI and DEXA. MethodsArticles published between 2011 and 2021 that reported correlations between the CT-HU or MRI measurements to DEXA t-scores or BMD of lumbar spine or hip were included in this systematic review. ResultsA total of 25 studies (15 CT, 10 MRI) met the inclusion criteria with a total number of 2,745 patients. The pooled correlation coefficient of spine CT-HU versus spine DEXA, spine CT-HU versus hip DEXA and spine CT-HU versus lowest t-score were 0.60, 0.50 and 0.60 respectively. Regarding spine DEXA parameters, the pooled r2 for spine CT-HU versus spine t-score was 0.684 and spine CT-HU versus spine BMD was 0.598. Furthermore, in patients undergoing spine surgery in four studies, the pooled correlation between spine CT and spine DEXA was (r2: 0.64). In MRI studies, the pooled r2 of spine MRI versus spine DEXA and spine MRI versus hip DEXA were -0.41 and -0.44 respectively. ConclusionsCT-HU has stronger correlations with DEXA than MRI measurements. Lumbar CT-HU has the highest pooled correlation (r2 = 0.6) with both spine DEXA and lowest skeletal t-score followed by lumbar CT-HU with hip DEXA (r2 = 0.5) and lumbar MRI with hip (r2 = 0.44) and spine (r2 = 0.41) DEXA. Both imaging modalities achieved only a moderate correlation with DEXA. Few studies in both modalities have investigated the correlation in spine surgery populations and the available data shows that the correlations are worse in the degenerative spine population. A careful interruption of CT HU and MRI measurement when evaluation of BMD as they only moderately correlated with DEXA scores. At this time, it is unclear which modality is a better predictor of mechanical complications and clinical outcomes in spine surgery patients.

Concentrations of total, bioavailable, and free 25OHD in individuals with and without primary hyperparathyroidism and their correlations to DXA and trabecular bone score.

This study aimed to investigate the association between 25OHD (total, bioavailable and free) with bone mass and microarchitecture among primary hyperparathyroidism (PHPT) patients and controls. Sixty-four patients in the preoperative period of PHPT and 63 matched controls, who had not taken vitamin D in the last three months. To calculate the bioavailable and free 25OHD, the genetic variants of the vitamin D-binding protein (DBP) were determined. Bone mineral density (BMD) was determined by dual-energy X-ray absorptiometry (DXA). The distributions of total, bioavailable and free 25OHD and their correlation with TBS and DXA were evaluated. PHPT showed BMD and TBS values lower than CTRL in all locations (p < 0.05). There were no statistical differences in the levels of free, bioavailable and total 25OHD between the PHPT and CTRL groups [mean, min-max: 3.4 (1.4-8.6) vs. 3.1 (1.0- 9.8) pg/mL, 1.51 (0.43-3.58) vs. 1.41 (0.38-3.48) ng/mL, 22.6 (11.0-39.9) vs. 20.6 (8.9-35.3) ng/dL, respectively; (p > 0.05). The distribution of DBP haplotypes was similar between groups. DXA showed no correlation with any form of 25OHD in both groups. TBS presented a weak correlation with the total 25OHD in PHPT (r = 0.28; p = 0.02) and a moderate correlation with the total, free and bioavailable 25OHD in CTRL (r = 0.42; r = 0.42; r = 0.43; respectively, p < 0.01). The concentrations of total, free and bioavailable 25OHD were similar in both the PHPT and control groups. 25OHD concentrations correlated positively with TBS and not with DXA, especially in controls, suggesting that this method may be more sensitive to assessing the consequences of vitamin D deficiency on bone quality in individuals without PHPT.

Hounsfield unit measurement method and related factors that most appropriately reflect bone mineral density on cervical spine computed tomography.

Our study's purpose was to determine the most reliable Hounsfield unit (HU) measurement method to reflect bone mineral density (BMD) on cervical spine computed tomography (CT) and to identify any factors that influence these results. We retrospectively analyzed 439 consecutive patients with mild head and neck injuries. Mean HU values of the C2-C7 vertebra were determined on each sagittal, coronal, and axial CT image. Correlation patterns were analyzed between the HU value and corresponding dual-energy X-ray absorptiometry (DXA) in the lumbar vertebra (T-score) and femoral neck (T-score). A sub-group analysis was performed according to patient age, sex, and degree of spinal degeneration. The correlation coefficients for HU and DXA ranged from 0.52 to 0.65 in all cervical segments. A simple linear regression analysis revealed the following formula: T-score = 0.01 × (HU) - 4.55. The mean HU values for osteopenia and osteoporosis were 284.0 ± 63.3 and 231.5 ± 52.8, respectively. The ROC curve indicated that the HU method has a sensitivity of 89.2% and specificity of 88.7% to diagnose osteoporosis. The HU measurement showed a high correlation value (range: r = 0.64-0.70) with spine DXA score regardless of the degree of degeneration or patient age or sex. HU values using the upper two cervical vertebrae (C2 and C3) reflected a more reliable BMD level than other segments. Additionally, the HU of cervical CT provided reliable information regardless of measurement plane, age or sex, and degree of degeneration.

Usefulness of the trabecular bone score in maintenance dialysis patients : A single center observational study.

BackgroundThe number of dialysis patients is steadily increasing. Associated comorbidities include impaired bone and mineral metabolism, termed chronic kidney disease-mineral and bone disorder (CKD-MBD), leading to a high fracture risk, increased morbidity and mortality and impaired quality of life. While the bone density is assessed with dual-energy X‑ray absorptiometry (DXA), the trabecular bone score (TBS) captures the image texture as a potential index of skeletal microarchitecture. The aim of this study was to evaluate the clinical relevance of DXA and TBS in dialysis patients with and without prevalent fractures.MethodsBone disorders were evaluated in 82 dialysis patients (37% female) at the University Hospital of Graz, Austria, by DXA including the assessment of the TBS based on a patient interview and the local routine patient database software. The patient cohort was stratified by having sustained a fragility fracture in the past or not. Descriptive statistics, t‑tests for continuous variables and χ2-tests for nominal variables including results of DXA and TBS were performed to compare these groups considering the dialysis modality and duration as well as the number of kidney transplantations.ResultsOf the 82 patients, 32 (39%) had a positive history of fractures. There was a significant association between dialysis duration and fracture prevalence (p < 0.05) as well as musculoskeletal pain (p < 0.01). No significant correlation between DXA/TBS parameters and musculoskeletal pain could be established. The DXA scores did not correlate with fracture prevalence with the exception of DXA radius measurements; however, fracture prevalence significantly correlated inversely with TBS (p < 0.001).ConclusionThe use of DXA has a limited role in fracture prediction in dialysis patients; however, the TBS seems to add information as an additional tool for fracture risk estimation in this patient population.

The role of systemic diseases and local conditions as risk factors.

The role of systemic diseases and local conditions as risk factors.

Use of Dual-Energy X-ray Absorptiometry in Children with Inflammatory Bowel Disease: A Large Single Centre Study.

Low bone mineral density (BMD) is a complication in children with inflammatory bowel disease (IBD). There are limited data evaluating dual-energy x-ray absorptiometry (DXA) as a screening tool for low BMD in children with IBD. We performed a single site retrospective analysis of DXA use. Children aged 5-18 years with IBD diagnosed between 2013 to 2017 at the Royal Children's Hospital, Australia, were included. Patient demographics, measures of disease activity, DXA scores, and factors related to BMD were collected. Over a median follow up of 5.1 (4-6.4) years, 72/239 (30.1%) children underwent DXA, and 28/239 (11.7%) children had a second DXA. Our DXA practice differed to consensus guidelines regarding initial screening based on height and/or body mass index (BMI) z-score (8/17 [47.1%]), and repeat surveillance (13/42 [31.0%]). Children had a median lumbar spine (LS) z-score -0.80 (-1.65-0.075). Children with LS z-score≤-2.0 (n=14) had lower weight (6.57 [1.78-23.7] vs. 51.1 [26.5-68.7], p=0.0002) and height centiles (3.62 [1.17-17.1] vs. 42 [16.9-67.1], p=0.0001), and higher faecal calprotectin (FCP) (3041 [1182-4192] vs. 585 [139-2419], p=0.009) compared to children with LS z-score>-2.0. No fractures were reported. Of 28 children who underwent a second DXA 1.6 (1.1-2.2) years following initial DXA, no significant change in z-scores occurred. Children with IBD had low BMD. In addition to height centile and weight centile, FCP was associated with lower BMD, and should be considered in DXA screening guidelines. Greater clinician awareness of DXA consensus guidelines is required. Future prospective studies are required.

Biological therapy for osteoporosis - solving clinical problems - a case report

Introduction. Elucidation of the pathogenetic mechanisms of osteoporosis has led to the development of new and effective drugs from the group of biological agents. Case report. In April 2018, a 64-year-old female patient was presented to the hospital due to low back pain. She was diagnosed with postmenopausal osteoporosis based on bone density scan score and a compression fracture of the L1 vertebral body revealed by X-ray. She was treated with a weekly bisphosphonate and supplementation with vitamin D and calcium. After one year, monthly bisphosphonate was introduced in therapy because of an inadequate response. In April 2020, the patient was treated for COVID-19 according to protocol, and during the treatment, bisphosphonate therapy was discontinued. After five months, she suffered a fracture of her left forearm. Due to the persistence of low mineral bone density, which was complicated by a new fracture, denosumab 60 mg subcutaneously once every six months was initiated with additional vitamin D and calcium supplementation. At six months follow-up, an increase in mineral bone density was verified, and after 12 months, the dual-energy x-ray absorptiometry score was within the osteopenia range. Laboratory findings showed a decrease in bone turnover markers. Conclusion. One-year administration of denosumab led to a significant increase in bone mineral density measured at the lumbar spine and neck of the femur, as well as changes in the levels of biochemical markers of bone synthesis and resorption, and reduced the risk of new fractures.

Assessment of Osteoporosis and Fracture Risk in Mastocytosis within a North American Cohort

Systemic mastocytosis (SM), a clonal expansion of mast cells affecting multiple organs including the skeletal system, puts patients at risk for osteoporosis and fractures. Various aspects of skeletal disease in SM have been reported among European cohorts. To determine fracture prevalence and risk predictors in SM in a North American (NA) cohort and compare findings with studies of other populations. Fifty patients, aged 25-74 years, were grouped based on fracture type and history. Data collected included laboratory findings and radiographic markers such as serum tryptase, bone turnover markers, dual-energy x-ray absorptiometry images, and trabecular bone scores. We performed univariate and multivariate analyses of these findings. Fracture history was found in 74% of patients. Significantly different median age, body mass index, dual-energy x-ray absorptiometry scores, and alkaline phosphatase levels were observed between fracture groups, consistent with French and Dutch studies. Significant findings included the difference in trabecular bone scores among fracture groups, the association between alkaline phosphatase and fracture type and occurrence, and the model for predicting fracture risk based on DXA spine T-scores, alkaline phosphatase, and age (81.3% accuracy and 77.1% sensitivity). Our findings in an NA cohort are in overall agreement with those reported in European studies of skeletal disease and fracture risk for individuals with SM. We include an interactive calculator designed from a predictive model based on the NA cohort, which may be used for improved screening for fracture risk.

Correlation of Hounsfield Unit Measurements on Computed Tomography of the Shoulder With Dual-Energy X-ray Absorptiometry Scans and Fracture Risk Assessment Tool Scores: A Potential for Opportunistic Screening.

The diagnosis of bone mineral density (BMD) abnormalities involves dual-energy x-ray absorptiometry (DXA), but few patients complete this after a fragility fracture. The assessment of BMD using Hounsfield unit (HU) measurements from computed tomography (CT) scans has been correlated with DXA results in previous studies. We aimed to evaluate the correlation between shoulder CT HU and DXA scores. Billing databases of 3 academic institutions were queried for patients who underwent both DXA and CT scan of the upper extremity within 1 year of each other. DXA T-scores for spine, hip, and femoral neck were recorded. BMD status was defined based on composite T-scores, using the lowest T-score in the spine, hip, or proximal femur. CT scans were measured for HU over 4 slices, recorded to create a bone column, then averaged. The patients' risks of major osteoporosis-related fracture and hip fracture were calculated using the Fracture Risk Assessment Tool. In total, 300 patients were included. A positive correlation was found between composite T-scores and HU for glenoid and proximal humerus (0.36; 0.17). The proximal humerus HU was significantly associated with the BMD T-score for the hip (P = 0.01); the glenoid HU was significantly associated with BMD T-scores for the hip, spine, and femoral neck (P = 0.002; P = 0.001; P = 0.002). A 10-year risk of hip fracture >3% was associated with lower proximal humerus HU. Our study is the first to discover significant correlations between HU at the glenoid and proximal humerus and risk factors as established by the Fracture Risk Assessment Tool scoring system. Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Evaluation of femoral head bone quality by Hounsfield units: a comparison with dual-energy X-ray absorptiometry.

Osteoporosis is associated with decreases in bone mineral density (BMD) and is diagnosed using dual-energy X-ray absorptiometry (DXA). Computed tomography (CT), performed in routine practice, can also be used to evaluate bone quality without additional cost. To determine whether Hounsfield units (HU), a standardized CT attenuation coefficient, measured from the femoral head correlated with DXA-measured BMD. We evaluated 82 patients (14 men, 68 women; mean age, 67 years) undergoing femoral DXA and CT (non-enhanced abdominopelvic and hip scans) with 130 kV to determine whether HU correlated with T-scores. HU were measured by two radiologists using the largest spherical region of interest including the medullary bone of the femoral head from the junction point of the most caudal section of the femoral head with the femoral neck in 5-mm axial sections. The correlations of both sides' HU values with their ages and DXA femur T-score were evaluated. HU values obtained from both femoral heads showed significant variation between the osteoporotic and non-osteoporotic groups (both P = 0.000) and strongly correlated with each other and DXA femur T-scores (left r = 0.75, right r = 0.73, respectively). In ROC curve analysis, predictive power of left HU values in identifying patients with osteoporotic femur DXA T-score was 0.905, and for right HU values it was 0.924. Osteoporosis cutoff values were 198 HU and 204 HU for the left and right hips, respectively. HU obtained from CT performed in routine practice correlated with the DXA scores, thus providing an alternative method to determine regional bone quality without additional cost. This may be useful when choosing a fixation method, especially in trauma cases with already-performed abdominopelvic or pelvic CT in emergency services.

P416 Use of DXA in children with Inflammatory Bowel Disease – a large single centre study

Abstract Background Low bone mineral density (BMD) is a complication in children with Inflammatory Bowel Disease (IBD). Dual-energy X-ray absorptiometry (DXA) is an established screening tool for BMD, yet there are limited data to guide its use in children with IBD. We performed a single site retrospective analysis of the use of DXA and evaluated factors associated with low BMD. Methods Children 3-18 years with IBD diagnosed between 2013-2018 at The Royal Children’s Hospital, Melbourne, Australia, were included. Patient, disease and treatment demographics were collected alongside vitamin D, calcium, CRP, ESR, albumin and faecal calprotectin (FCP) (averaged over 6 months before and after DXA). Rates of corticosteroid use, vitamin D and calcium supplementation, bisphosphonate use and fractures were also collected. Mann-Whitney and Fisher exact tests were used for continuous and categorical group comparison, respectively. Data are presented as median (interquartile range). Results 239 children diagnosed at a median age of 12 (9.1-14.2) were followed for 5.1 (4-6.4) years. 72/239 (30%) children had at least one DXA at 11 (1.25-28.8) months post diagnosis. 28/72 (39%) children had a follow-up DXA 2.3 (1.9-2.9) years post diagnosis. Children referred for DXA had a lower weight centile (48.7 (17.1-78.2) vs 59.7 (31.4-84.7), p=0.03), and were more likely to have Crohn’s disease (OR 2.18, p=0.01). At first DXA, median lumbar spine (LS) Z score was -0.80 (-1.65-0.08), height adjusted LS Z score was -0.65 (-1.18-0.10), hip Z score was -1.30 (-1.80--0.35) and total body less head Z score was -1.40 (-2.55--0.70). 18/72 children had LS Z score &amp;gt; 0. Children with LS Z score &amp;lt; -2.0 (n=14) had lower weight (6.57 (1.78-23.7) vs 51.1 (26.5-68.7), p=0.0002) and height centiles (3.62 (1.17-17.1) vs 42 (16.9-67.1), p&amp;lt;0.0001), higher FCP (3041 (1182-4192) vs 585 (139-2419), p=0.009) (Figure 1), and higher odds of calcium supplementation (OR 16 (95% CI 2.93-89.1), p=0.003) and endocrinology review (OR 9.61 (95% CI 2.65-31.0), p=0.001). No fractures were reported. Of the 28 children with serial DXAs, there was no significant change in Z scores. When comparing children with a worse (16/28) Z score at second DXA to those with improvement (12/28), there was a trend toward lower vitamin D levels (37 (25.2-58.3) vs 62 (46.3-87), p=0.06) at first DEXA, and higher ESR at second DEXA (23.4 (19.3-29) vs 8.20 (3.5-21.9), p=0.02). Conclusion Almost one third of children with IBD at a tertiary referral centre underwent DXA, with lower BMD than age and sex matched controls. Disease activity markers FCP and ESR were associated with lower BMD. There was no significant change in DXA score over time. No fractures were identified over the study period.

The clinical features that contribute to poor bone health in young Australians living with cystic fibrosis: A recommendation for BMD screening

For Australians living with cystic fibrosis (CF), increased longevity means greater consideration needs to be given to long-term endocrine sequelae such as CF-related bone disease. Deficits in bone mass accrual are most likely to occur during childhood and adolescence. Current guidelines in Australia suggest repeat dual-energy X-ray absorptiometry (DXA) scans every 2 years. This study aims to stratify clinical factors that determine future bone health in the Australian CF population and use this to guide a more streamlined approach to bone health screening. This study was a retrospective audit of all patients diagnosed with CF who were treated at the Royal Children's Hospital Melbourne, Australia from 2000 to 2016 (n = 453). Two hundred and two patients had a DXA scan in the study period (191 with height-adjusted data) and 111 patients had more than one scan (108 with height-adjusted data). An investigation into the associations between bone mineral density (BMD) Zscore and potential risk factors was conducted using DXA and historical data. The main predictor of future BMD was the previous BMD Zscore (p < .001). Other factors found to be determinants of BMD included nutritional status, lung function (FEV1 ), age, history of previous fracture, oral corticosteroid use, and the number of hospital admissions. However, after adjusting for previous BMD, evidence of an association remained only with nutritional status, FEV1 , and number of hospital admissions. Second yearly scans may be unnecessary in children with an adequate DXA score on the initial scan who remain clinically stable. However, clinical deterioration in those whose BMD was previously normal, may require closer monitoring of bone health. We propose a guideline for the frequency of DXA monitoring in relation to clinical risk factors.

Impact microindentation in men with impaired fasting glucose and type 2 diabetes.

Individuals with type 2 diabetes (T2DM) are at increased fracture risk, with bone mineral density (BMD) measurements underestimating risk. Impact microindentation (IMI), a technique that measures bone microindentation distances, expressed as bone material strength index (BMSi), may improve fracture risk estimation in individuals with T2DM. This study describes the relationship between BMSi and glycaemia status in men and makes a comparison with bone measures from dual energy X-ray absorptiometry (DXA). Participants were 340 men aged 33-96yr from the Geelong Osteoporosis Study. Impaired fasting glucose (IFG) was defined using fasting plasma glucose (FPG) between 5.5 and 6.9mmol/L. Diabetes was defined as FPG≥7.0mmol/L, use of antihyperglycemic medication and/or self-report. Two participants with type 1 diabetes were excluded. BMSi was measured using an OsteoProbe. Femoral neck (FNBMD) and lumbar spine (LSBMD) were measured using DXA (Lunar Prodigy) and trabecular bone score (TBS) was calculated (TBS iNsight Version 2.2). Using linear regression techniques, the relationship between glycaemia status and BMSi was evaluated, adjusting for other potential confounders (including lifestyle factors, clinical measurements and FNBMD). Glycaemia status was also considered as a binary variable (T2DM vs normoglycaemia and IFG). There were 234 (68.8%) men with normoglycaemia, 59 (17.4%) with IFG and 47 (13.8%) with diabetes. When considering glycaemia status as a binary variable, men with T2DM had lower mean BMSi compared to those without T2DM (normoglycaemia and IFG combined) (79.8; 95%CI 77.0-82.6 vs 83.0; 82.2-83.8 p=0.043) and this difference in BMSi was independent of FNBMD. No differences were observed for either FNBMD or LSBMD; however, TBS was lower (1.177; 1.121-1.233 vs 1.256; 1.240-1.272, p=0.015, independent of FNBMD). For glycaemia status considered in three groups, there were no differences in mean BMSi values between men with normoglycaemia, IFG and T2DM (82.9 (95%CI 82.0-83.8), 83.5 (81.8-85.2) and 79.8 (77.0-82.6), respectively; ANCOVA, p=0.104). Measures reflecting bone material properties and microarchitecture (BMSi and TBS) might be better than measures of bone mass (BMD) in identifying individuals with T2DM at risk of fracture.