The DXL Calscan heel densitometer: evaluation and diagnostic thresholds

Validation of Quantitative Ultrasonography for Osteoporosis Diagnosis in Postmenopausal Women Compared to Dual-Energy X-Ray Absorptiometry (DEXA)

Introduction Bone mineral density (BMD) is an essential indicator for diagnosing osteoporosis and evaluating the success of osteoporotic treatment. Dual-energy X-ray absorptiometry (DEXA), quantitative ultrasonography (QUS), and quantitative computed tomography (QCT) are frequently used for measuring BMD. The objective of the study was to evaluate the ability of QUS to screen for osteoporosis and bone density in postmenopausal women by calibrating it against DEXA.  Methods This cross-sectional study was conducted at the Department of Orthopedics and Trauma Center of the tertiary care center, Lucknow. A total of 90 patients visited this department from August 2017 to July 2018 for the present study. BMD in the same patient was evaluated by using DEXA and ultrasonography methods. Data were entered in Microsoft Excel and analyzed by using SPSS Software.  Results According to linear regression analysis, T neck was found statistically significant with T QUS (p<0.001) and z QUS (p<0.001). T lumbar and T wrist were found statistically significant with T QUS (p<0.001) but not with z QUS (p>0.001). Z neck was found statistically significant with T QUS (p<0.001) and z QUS (p<0.001). Z lumbar was found statistically significant with T QUS (p<0.001) but not with z QUS (p>0.005). Z wrist was not found statistically significant with T QUS (p>0.005) or with z QUS (p>0.005). Conclusion In the present study, we found that QUS can be used as a screening tool for detecting osteoporosis by measuring BMD in contrast to DEXA. QUS also can be used to predict the DEXA values for osteoporosis and to detect osteoporosis.

Bone Stress Injuries Are Associated With Differences in Bone Microarchitecture in Male Professional Soldiers

Bone stress injuries are commonly due to repetitive loading, as often described in competitive athletes or military recruits. The underlying pathophysiology of bone stress injuries is multifactorial. The present cross-sectional study investigated (i) cortical and trabecular bone microstructure as well as volumetric bone mineral density in subjects with bone stress injuries at the tibial diaphysis, measured at the distal tibia and the distal radius by means of high-resolution peripheral quantitative computed tomography (CT), (ii) areal bone mineral density using dual-energy X-ray absorptiometry as well as calcaneal dual X-ray absorptiometry and laser, and (iii) the influence on bone turnover markers of formation and resorption at the early phase after injury. A total of 26 Caucasian male professional soldiers with post-training bone stress injury at the tibial diaphysis were included (case group). A total of 50 male, Caucasian professional soldiers from the same military institution served as controls (control group). High-resolution peripheral quantitative CT revealed a higher total area at the radius within the case group. Cortical bone mineral density was reduced at the radius and tibia within the case group. The trabecular number and trabecular thickness were reduced at the tibia in the case group. The trabecular network was more inhomogeneous at the radius and tibia within the case group. Calcaneal dual X-ray absorptiometry and laser was significantly reduced in the case group. This study quantified differences in bone microstructure among otherwise healthy individuals. Differences in bone microarchitecture may impair the biomechanical properties by increasing the susceptibility to sustain bone stress injuries. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2516-2523, 2019.

Bone microarchitecture and bone turnover in hepatic cirrhosis

Liver cirrhosis leads to bone loss. To date, information on bone quality (three-dimensional microarchitecture) and, thus, bone strength is scarce. We observed decreased bone quality at both assessed sites, independent of disease severity. Therefore, all patients should undergo early-stage screening for osteoporosis.

INTRODUCTION

Recent studies found low bone mineral density in cirrhosis, but data on bone microstructure are scarce. This study assessed weight-bearing and non-weight-bearing bones in patients with cirrhosis and healthy controls. The primary objective was to evaluate trabecular and cortical microarchitecture.

METHODS

This was a single-center study in patients with recently diagnosed hepatic cirrhosis. Thirty-two patients and 32 controls participated in this study. After determining the type of cirrhosis, the parameters of bone microarchitecture were assessed by high-resolution peripheral quantitative computed tomography.

RESULTS

Both cortical and trabecular microarchitectures showed significant alterations. At the radius, trabecular bone volume fraction was 17% lower (corrected p = 0.028), and, at the tibia, differences were slightly more pronounced. Trabecular bone volume fraction was 19% lower (p = 0.024), cortical bone mineral density 7% (p = 0.007), and cortical thickness 28% (p = 0.001), while cortical porosity was 32% higher (p = 0.023), compared to controls. Areal bone mineral density was lower (lumbar spine - 13%, total hip - 11%, total body - 9%, radius - 17%, and calcaneus - 26%). There was no correlation between disease severity and microarchitecture. Areal bone mineral density (aBMD) measured by dual-energy X-ray absorptiometry (DXA) correlated well with parameters of cortical and trabecular microarchitecture.

CONCLUSIONS

Hepatic cirrhosis deteriorates both trabecular and cortical microarchitecture, regardless of disease severity. Areal bone mineral density is diminished at all sites as a sign of generalized affection. In patients with hepatic cirrhosis, regardless of its origin or disease severity, aBMD measurements are an appropriate tool for osteologic screening.

Relationship between the mandibular cortical index and calcaneal bone mineral density in postmenopausal women

BACKGROUND AND OBJECTIVE

In clinical practice, a comparative analysis of bone mineral density (BMD) is carried out by examining different skeletal bones. This is useful for screening of postmenopausal osteoporosis (OP). The objective of this study was to determine the relation between the mandibular cortical index (MCI) and calcaneal BMD among postmenopausal women.

MATERIALS AND METHODS

The study sample included 129 randomly selected postmenopausal women aged 50-77 years. The participants were examined using panoramic radiography for the analysis of the cortical layer in the mandibular base for MCI determination and using DXL for the examination of calcaneal BMD. According to T scores, the subjects were divided into three groups (Groups 1, 2, and 3). The panoramic radiographic examination of the mandible was performed; the MCI was determined and distributed into groups (C1; C2; C3). The MCI validity in determining the calcaneus BMD status was analyzed.

RESULTS

The differences in BMD were statistically significant between Groups C1 and C3 (P<0.01), Groups C2 and C3 (P=0.01), and between the calcaneal BMD groups (P<0.001). There was a statistically significant inverse correlation between the MCI and calcaneal BMD (r=-0.3; P<0.001). The changes characteristic of Group C2 were documented more frequently than those of other morphological groups. The analysis of the MCI validity in BMD status showed low sensitivity (69.4%) and specificity (53.9%).

CONCLUSIONS

The relation between MCI and calcaneal BMD was determined. The diagnostic discrimination of the MCI was found to be not sufficient in screening the women with postmenopausal osteoporosis and its application in clinical practice might be limited.

Bone structure assessed by HR-pQCT, TBS and DXL in adult patients with different types of osteogenesis imperfecta

Bone microarchitecture by high-resolution peripheral quantitative computed tomography (HR-pQCT) was assessed in adult patients with mild, moderate, and severe osteogenesis imperfecta (OI). The trabecular bone score (TBS), bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA), and dual X-ray and laser (DXL) at the calcaneus were likewise assessed in patients with OI. Trabecular microstructure and BMD in particular were severely altered in patients with OI.

INTRODUCTION

OI is characterized by high fracture risk but not necessarily by low BMD. The main purpose of this study was to assess bone microarchitecture and BMD at different skeletal sites in different types of OI.

METHODS

HR-pQCT was performed in 30 patients with OI (mild OI-I, n = 18 (41.8 [34.7, 55.7] years) and moderate to severe OI-III-IV, n = 12 (47.6 [35.3, 58.4] years)) and 30 healthy age-matched controls. TBS, BMD by DXA at the lumbar spine and hip, as well as BMD by DXL at the calcaneus were likewise assessed in patients with OI only.

RESULTS

At the radius, significantly lower trabecular parameters including BV/TV (p = 0.01 and p < 0.0001, respectively) and trabecular number (p < 0.0001 and p < 0.0001, respectively) as well as an increased inhomogeneity of the trabecular network (p < 0.0001 and p < 0.0001, respectively) were observed in OI-I and OI-III-IV in comparison to the control group. Similar results for trabecular parameters were found at the tibia. Microstructural parameters were worse in OI-III-IV than in OI-I. No significant differences were found in cortical thickness and cortical porosity between the three subgroups at the radius. The cortical thickness of the tibia was thinner in OI-I (p < 0.001), but not OI-III-IV, when compared to controls.

CONCLUSIONS

Trabecular BMD and trabecular bone microstructure in particular are severely altered in patients with clinical OI-I and OI-III-IV. Low TBS and DXL and their significant associations to HR-pQCT parameters of trabecular bone support this conclusion.

Laser-Supported Dual Energy X-Ray Absorptiometry (DXL) Compared to Conventional Absorptiometry (DXA) and to FRAX as Tools for Fracture Risk Assessments

Dual X-ray and Laser (DXL) adds a measure of the external thickness of the heel, measured by laser, to a conventional measurement of bone mineral density (BMD) of the calcaneus, using Dual energy X-ray Absorptiometry (DXA). The addition of heel thickness aims at a better separation of fatty tissue from bone than the standard method of DXA, which may mistake fatty tissue for bone and vice versa. The primary aim of this study was to evaluate whether DXL of the calcaneus can be used to assess the 10-year risk of fractures. Secondary aims were to compare the predictive ability of DXL with the two most established methods, Dual energy X-ray Absorptiometry (DXA) of the hip and spine and the WHO fracture risk assessment tool, FRAX. In 1999 a cohort of 388 elderly Swedish women (mean age 73.2 years) was examined with all three methods. Prospective fracture data was collected in 2010 from health care registers. One SD decrease in BMD of the heel resulted in an age-adjusted Hazard Ratio (HR) of 1.47 for a hip fracture (95% CI 1.09–1.98). Harrell’s C is the Cox regression counterpart of the Area Under Curve (AUC) of the Receiver Operating Characteristic (ROC) as a measure of predictive accuracy. Harrell’s C for BMD of the calcaneus was 0.65 for prediction of hip fractures. These results were not significantly different from those for BMD of the femoral neck or for FRAX. The HR for a hip fracture, for one SD decrease in BMD at the femoral neck, was 1.72 (95% CI 1.21–2.44. Harrell’s C was 0.67 for BMD at the femoral neck and 0.59 for FRAX. We conclude that DXL of the calcaneus could be a useful tool for fracture risk assessments.

The discriminatory capacity of BMD measurements by DXA and dual X-ray and laser (DXL) at the calcaneus including clinical risk factors for detecting patients with vertebral fractures

Osteoporotic fracture risk depends on bone mineral density (BMD) and clinical risk factors (CRF). Five hundred and eighty-eight untreated female and male outpatient subjects were evaluated, 160 with vertebral fractures. BMD was measured both by using calcaneal dual X-ray and laser (DXL) and dual-energy X-ray absorptiometry (DXA), and CRF were evaluated. Detection frequencies for different BMD methods with or without CRF are presented.

INTRODUCTION

Osteoporotic fracture risk depends on bone mineral density and clinical risk factors. DXA of the spine/hip is considered a gold standard for BMD assessment, but due to degenerative conditions, particularly among the older population, assessment of BMD at the lumbar spine has been shown to be of limited significance. Portable calcaneal dual X-ray technology and laser can be an easily obtainable alternative.

METHODS

Vertebral fractures were evaluated in a baseline analysis of 588 females and males (median age 64.4, range 17.6-93.1 years), comparing BMD measurements by using DXL and DXA and CRF with/without BMD. One hundred and sixty subjects had radiological verified vertebral fractures. Area under receiver-operating characteristic curves (AUROCC) and univariate and multiple logistic regressions were calculated.

RESULTS

AUROCC for detection of vertebral fractures was comparable for DXL at calcaneus and DXA at femoral neck (DXL 0.665 and DXA 0.670). Odds ratio for prevalent vertebral fracture was generally weak for DXA femoral neck (0.613) and DXL (0.521). Univariate logistic regression among CRF without BMD revealed age, prevalent fragility fracture, and body mass index significantly associated with prevalent vertebral fracture (AUROCC = 0.805). Combining BMD and CRF, a prognostic improvement in case of DXA at femoral neck (AUROCC 0.869, p = 0.02), DXL at calcaneus (AUROCC 0.869, p = 0.059), and DXA at total hip (AUROCC 0.861, p = 0.06) was observed.

CONCLUSIONS

DXL was similarly sensitive compared with DXA for identification of subjects with vertebral fragility fractures, and combination of CRF with BMD by DXL or DXA further increased the discriminatory capacity for detection of patients susceptible to vertebral fracture.

The relationship between the calcaneal bone mineral density and the mental index in post-menopausal females

OBJECTIVES

The aim of the study was to determine the relationship between the bone mineral density in the calcaneus and the mental index (MI) of the mandible in post-menopausal females, and to evaluate the diagnostic threshold of the index.

METHODS

The post-menopausal females aged 50 years and older were examined using panoramic radiography of the mandible for mandibular cortical width measurements at the mental foramen (mental index, MI) determination and DXL Calscan P/N 031000 (Demetech AB, Solna, Sweden) for the examination of calcaneal bone mineral density (BMD). The statistical analysis was performed to determine the tendencies between the data.

RESULTS

According to the T-score values of calcaneal BMD, the subjects were distributed into T1, T2 and T3 groups. BMD differences between the groups were statistically significant (p < 0.001). The panoramic radiographic examination of the mandible was performed, MI (mm) was determined and the mean values in the groups were calculated. The differences of MI mean values between the groups were statistically significant (p < 0.001). In the general group, a statistically significant relationship was found between calcaneal BMD, T-score and MI (p < 0.001). In the logistic analysis, the diagnostic threshold of MI was 3 mm (sensitivity 73.5%; specificity 72.6%).

CONCLUSIONS

A diagnostic threshold for MI of 3 mm or less is suggested as the appropriate threshold for referral of calcaneal BMD reduction.

Osteoporosis and radial head fractures in female patients: a case-control study

BACKGROUND

Identifying radial head fractures as fragility fractures may improve case-findings for osteoporosis and thus be an indicator other fragility fractures.

MATERIALS AND METHODS

Thirty-five women aged ≥ 50 years with a radial head fracture and 57 controls were retrospectively selected and matched for age in strata of 5 years. Peripheral bone mineral density (BMD) measurement was performed at the calcaneus. A T score of less than -2.7 was considered osteoporosis. If the T value was between -1.4 and -2.7, an additional dual energy X-ray (DXA) scan was performed.

RESULTS

The patients were a median age of 60 years compared with 58 years for the control patients (P = .33). The mean T score of the patients was -1.8 (standard deviation [SD], 1.0; range, -2.2 to -0.3) compared with -1.2 (SD, 1.2; range, -4.0 to 1.3) for the control patients (P = .04). Osteoporosis was diagnosed in 11 patients and in 5 control patients. The patients had an increased risk of osteoporosis compared with the control patients (odds ratio, 3.4; P = .027).

CONCLUSIONS

This study confirms that radial head fractures in women aged ≥ 50 years are potentially osteoporotic fractures. Offering these patients a BMD measurement may prevent future osteoporotic fractures, such as hip and spine fractures.

Radiation exposure in X-ray-based imaging techniques used in osteoporosis

Recent advances in medical X-ray imaging have enabled the development of new techniques capable of assessing not only bone quantity but also structure. This article provides (a) a brief review of the current X-ray methods used for quantitative assessment of the skeleton, (b) data on the levels of radiation exposure associated with these methods and (c) information about radiation safety issues. Radiation doses associated with dual-energy X-ray absorptiometry are very low. However, as with any X-ray imaging technique, each particular examination must always be clinically justified. When an examination is justified, the emphasis must be on dose optimisation of imaging protocols. Dose optimisation is more important for paediatric examinations because children are more vulnerable to radiation than adults. Methods based on multi-detector CT (MDCT) are associated with higher radiation doses. New 3D volumetric hip and spine quantitative computed tomography (QCT) techniques and high-resolution MDCT for evaluation of bone structure deliver doses to patients from 1 to 3 mSv. Low-dose protocols are needed to reduce radiation exposure from these methods and minimise associated health risks.

Femur ultrasound (FemUS)--first clinical results on hip fracture discrimination and estimation of femoral BMD

SUMMARY

A quantitative ultrasound (QUS) device for measurements at the proximal femur was developed and tested in vivo (Femur Ultrasound Scanner, FemUS). Hip fracture discrimination was as good as for DXA, and a high correlation with hip BMD was achieved. Our results show promise for enhanced QUS-based assessment of osteoporosis.

INTRODUCTION

Dual X-ray absorptiometry (DXA) at the femur is the best predictor of hip fractures, better than DXA measurements at other sites. Calcaneal quantitative ultrasound (QUS) can be used to estimate the general osteoporotic fracture risk, but no femoral QUS measurement has been introduced yet. We developed a QUS scanner for measurements at the femur (Femur Ultrasound Scanner, FemUS) and tested its in vivo performance.

METHODS

Using the FemUS device, we obtained femoral QUS and DXA on 32 women with recent hip fractures and 30 controls. Fracture discrimination and the correlation with femur bone mineral density (BMD) were assessed.

RESULTS

Hip fracture discrimination using the FemUS device was at least as good as with hip DXA and calcaneal QUS. Significant correlations with total hip bone mineral density were found with a correlation coefficient R (2) up to 0.72 and a residual error of about one half of a T-score in BMD.

CONCLUSIONS

QUS measurements at the proximal femur are feasible and show a good performance for hip fracture discrimination. Given the promising results, this laboratory prototype should be reengineered to a clinical applicable instrument. Our results show promise for further enhancement of QUS-based assessment of osteoporosis.

Comparison of dual X-ray laser and dual energy X-ray absorptiometry techniques of osteodensitometry

Dual X-ray laser (DXL) heel measurements of bone mineral density (BMD) and dual energy X-ray absorptiometry (DEXA) total hip and lumbar spine BMD measurements were compared for their ability to detect osteoporosis and osteopenia according to World Health Organization criteria. The study included 164 women aged 40 - 83 years. DXL heel measurements were recorded for all patients and 89 of the women underwent DEXA. For DXL heel measurements/DEXA lumbar spine measurements, the relative sensitivity was 50%, relative specificity was 97% and relative reliability (Kappa score) was 0.55 for osteoporosis detection. For detecting osteoporosis or osteopenia, the relative sensitivity increased to 86% but the relative specificity reduced to 38% and the relative reliability was considerably lower (Kappa score 0.21). Although previous studies have shown DXL heel measurement to be a good technique in the diagnosis and assessment of osteoporosis based on BMD, particularly for fast, cost-effective bone scanning, we suggest that there are currently insufficient data to prove its use as a standard measurement technique for BMD.

The usefulness of dual energy X-ray and laser absorptiometry of the calcaneus versus dual energy X-ray absorptiometry of hip and spine in diagnosing manifest osteoporosis

INTRODUCTION

Osteoporosis is a major health problem. Dual energy X-ray absorptiometry (DXA) of the hip and spine is the worldwide standard in diagnosing osteoporosis. Measurement of bone mineral density (BMD) with dual energy X-ray and laser absorptiometry of the calcaneus (Calscan) might be a good alternative. Advantages of the Calscan are that it is quick, widely available and manageable. In this study we compared BMD expressed in T-scores measured by DXA and Calscan. The aim of this study was to define threshold T-scores on the Calscan that could exclude or predict osteoporosis correctly in comparison with DXA.

MATERIALS AND METHODS

Patients > or =50 years attending our emergency department with a fracture were offered osteoporosis screening at our fracture and osteoporosis outpatient clinic (FO-Clinic) and enrolled in this study. BMD was measured at the hip and spine using DXA and at the calcaneus using Calscan. A T-score measured by DXA < or =-2 standard deviations (SD) below the reference population was defined as manifest osteoporosis and was the treatment threshold.

RESULTS

During a 10-month study period, 182 patients were screened with both devices. The mean DXA-T-score was -1.63 SD (range -4.9 to 2.1) and Calscan T-score -1.91 SD (range -5.3 to 1.4). There was a significant correlation between both devices (r = 0.47, P < 0.01). Using an upper threshold for the Calscan T-score of -1.3 SD, 47 patients could be classified as non-osteoporotic with 89.3% sensitivity (95% CI 80.0-95.3%). Using a lower threshold for the Calscan T-score of -2.9 SD, 34 patients could be classified by the Calscan as osteoporotic with 90.7% specificity (95% CI 83.5-95.4). The remaining 101 patients could only be correctly classified by DXA-T-scores.

CONCLUSION

Although DXA is the established modality worldwide in measuring BMD it is restricted to specialized centres. Peripheral bone densitometers like the Calscan are widely available. When BMD measurements with DXA were compared to Calscan measurements it was possible to correctly classify 81 of 182 patients based on the Calscan T-score. Of these 81 patients 34 could be classified as manifest osteoporotic and 47 as non-osteoporotic. Therefore the Calscan seems to be a promising technique which might be used as a screening device at a FO-Clinic, especially when DXA is not easily available.