Reference Ranges for Trabecular Bone Score in Australian Men and Women: A Cross-Sectional Study

Canadian Adult Reference Data for Body Composition, Trabecular Bone Score and Advanced Hip Analysis Using DXA

DXA-derived reference data for visceral adipose tissue (VAT) and advanced hip analysis (AHA) parameters spanning the entire adult lifespan are limited. The purpose of this study was to develop age-, site- and sex-specific reference data for dual X-ray absorptiometry (DXA) -derived body composition, trabecular bone score (TBS) and advanced hip analysis (AHA) parameters across the adult lifespan. Adults (N = 908; female: 561 and male: 347) from Calgary and the surrounding area over the age of 20 years participated in this study. Participants received DXA scans of their hip (total hip [TH] and femoral neck [FN]), lumbar spine [LS], forearm [33 % site] and total body (iDXA, GE Lunar, GE Healthcare). Areal bone mineral density (aBMD, g/cm2) was captured at all sites, and body composition variables, including lean mass, fat mass and percent fat, were analyzed from the total body scan. VAT mass was assessed from total body DXA scans. Advanced hip analysis (AHA) was performed on hip scans and trabecular bone score (TBS) on the LS scans to assess bone quality. Site- and sex-specific centile curves and tables were generated using the Generalized Additive Models for Location, Scale, and Shape (GAMLSS) method. Clinicians and researchers can use these Canadian reference data as a tool to assess body composition, TBS and AHA parameters across the adult lifespan.

Trabecular bone score norms in Asian-Indians and associations with serum 25(OH)D and parathyroid hormone

OBJECTIVE

There is limited information on population-specific norms of trabecular-bone-score (TBS) and its associated factors. Here, we provide norms of TBS in Asian-Indians and its relationship with serum 25-hydroxyvitamin D [25(OH)D] and intact-parathyroid hormone (iPTH).

PARTICIPANTS AND MEASUREMENTS

TBS, bone-mineral-density (BMD), and vertebral-fractures (VFs) were assessed using dual-energy X-ray absorptiometry in 923 healthy Asian-Indians (aged 20-60 years). Serum 25(OH)D, iPTH, T4/TSH,, glycosylated-haemoglobin (HbA1c) were measured and associations with TBS assessed using multivariable linear regression. Subjects with BMD Z-score ≤ -2.0 or ≥2.0 at any sites, VFs, TSH > 10.0 or <0.05 µIU/ml, blood-glucose >11.1 mmol/L or HbA1c > 8.0% were excluded for generating Asian-Indian norms.

RESULTS

TBS norms were generated in 744 healthy Asian-Indians (M:F,389:385). The cut-offs generated for 'normal', 'partially-degraded', and 'degraded' TBS were >1.305, 1.204-1.305 and <1.204, respectively. Mean TBS was lower in females than males (p < .001). There was 75% congruency in TBS categories between Asian-Indian and existing norms. Specificity (97.8 vs. 77.9%, p < .001) and diagnostic-accuracy (97.8% vs. 78.4%, p < .001) of TBS to detect osteoporosis were higher with Asian-Indian norms. The sensitivity of 'partially-degraded' TBS to diagnose osteopenia was also higher with Asian-Indian norms. In multivariable regression, gender, body-mass-index (BMI), BMD-L1-L4, serum PTH, daily dietary-calorie intake and calcium intake were associated with TBS. Though 25(OH)D inversely correlated with PTH, 25(OH)D was not associated with TBS.

CONCLUSION

This study provides norms for TBS in Asian-Indians with gender-specific differences. Increasing age and higher BMI were associated with lower TBS. Associations of TBS with circulating PTH and/or 25(OH)D need confirmation in further studies.

Utility of Trabecular Bone Score in the Management of Patients with Osteoporosis

Trabecular bone score (TBS) enhances assessment of fracture risk in older women and men across many race/ethnicities and with a broad range of comorbidities. The best validated clinical utility of TBS is for input in the FRAX algorithm to modify assessment of fracture risk in patients who are close to FRAX-based intervention thresholds, thereby possibly influencing treatment decisions. TBS has been shown to increase with anabolic therapy and to a lesser degree with denosumab. TBS-adjusted T-scores may be useful with treatment guidelines that do not include FRAX.

Clinical significance of trabecular bone score of DXA in hip fracture patients-comparative study between trochanteric fractures and neck fractures

BACKGROUND

Studies have shown that the clinical efficacy of TBS (Trabecular Bone Score) of DXA in hip fracture patients. This study aimed to investigate the difference of TBS in trochanteric fractures and femoral neck fractures in hip fracture patients.

METHODS

Data were derived from the University affiliated hospital, the participants included 249 patients aged 60 years or older who were available of TBS prescribe by DXA. 89 femoral neck fracture patients and 160 trochanteric fractures were enrolled. Spine T- score, hip T- score (neck), hip T- score (total), lowest T- score in hip, L1-L4 TBS. TBS Z-score, L1-L4 BMD(g/cm²), L1-L4 BMD T-score, L1 TBS, L1 BMD(g/cm2), L1 BMD T-score, L2 TBS, L2 BMD(g/cm2), L2 BMD T-score, L3 TBS, L3 BMD(g/cm2), L3 BMD T-score, L4 TBS, L4 BMD(g/cm2), L4 BMD T-score, lowest TBS score, highest TBS score were analyzed.

RESULTS

Demographic data (age, sex, height, weight, BMI) and T-score of hip and spine in two groups showed no significant difference. TBS in spine in two groups revealed higher TBS in femoral neck fracture groups.

CONCLUSION

There is no difference of age, sex, and BMI in two groups. The T-score was not statistically significant in comparison of bone quality in hip fracture groups. The TBS in femoral neck fracture group is higher than trochanteric fractures. The TBS in spine can be more valuable than T-score of DXA for the proper evaluation of bone quality in the hip fracture patients.

Hip structure and incident fracture: a time-updating survival analysis over 20 years of data from the Geelong Osteoporosis Study

Hip structural analysis parameters are associated with risk of fracture in women across a long follow-up period, with buckling ratio persisting independent of total hip BMD.

PURPOSE

Hip structural analysis (HSA) uses dual X-ray absorptiometry (DXA) hip scans to calculate geometries of narrow neck (NN), intertrochanter (IT), and shaft (S), which may complement bone mineral density (BMD) for assessing fracture risk. We aimed to determine whether HSA parameters were associated with fracture.

METHODS

Participants were women (n = 986, ages 40-94 year) from the Geelong Osteoporosis Study. HSA was calculated from Lunar DPX-L scans. Low-trauma incident fractures were identified radiologically. Participants were followed from baseline to first fracture, death, or end of follow-up period (31/12/16) (13,487 person-years follow-up). Time-updating Cox-proportional hazards modelling investigated associations between HSA parameters and fracture.

RESULTS

Three hundred thirty-five participants reported fractures (rate: 24.99/1000 person-years [95% CI 22.46-27.80]). Higher NN BMD (HR:0.12, 95% CI:0.05-0.29), cross-sectional area (CSA) (0.37, 0.26-0.52), cross-sectional moment of inertia (CSMI) (0.66, 0.50-0.89), section modulus (SM) (0.40, 0.24-0.68) and cortical thickness (CT) (0.00, 0.00-0.01 due to rounding) were associated with decreased risk. IT BMD (0.08, 0.04-0.20), CSA (0.58, 0.49-0.69), CSMI (0.90, 0.85-0.94), and SM (0.69, 0.59-0.81) were similarly associated. Decreased risk was observed at increased values of S BMD (0.20, 0.10-0.38), CSA (0.60, 0.47-0.76), SM (0.60, 0.43-0.83), and CT (0.03, 0.01-0.14). Higher S endocortical diameter (1.81, 1.29-2.53), and buckling ratio (BR) at all sites (NN: 1.07, 1.04-1.11; IT: 1.08, 1.05-1.11, S: 1.31, 1.19-1.46) were associated with increased risk. After adjustment for total hip BMD, the associations with BR at the shaft (1.14, 1.00-1.30) were sustained. Other associations were attenuated.

CONCLUSION

A greater shaft buckling ratio was associated with an increased risk for fracture, independent of total hip BMD.

Increase in lumbar spine but not distal radius bone mineral density in adults after pancreas kidney transplantation

Osteoporosis occurs in every third individual after simultaneous pancreas kidney transplantation (SPKT). Currently used bone measures insufficiently predict their fracture risk. Lumbar spine Trabecular bone score (TBS) and distal radius areal and volumetric bone mineral density (BMD) were monitored for the first time in patients with type 1 diabetes and chronic renal failure after SPKT with steroid-sparing protocol. In 33 subjects (mean age 43.4 ± 9.8 years), dual-energy X-ray absorptiometry and peripheral quantitative computed tomography were performed just after SPKT (baseline) and one and three years later. While TBS Z-scores increased (-1.1 ± 1.2 and -0.3 ± 1.0; p˂0.001, at baseline and year three, respectively), trabecular volumetric BMD Z-scores at distal radius metaphysis did not change during the study (-1.3 ± 1.3 and -1.3 ± 1.0; p = 0.38). Similarly, areal BMD Z-scores increased at lumbar spine, total hip and femoral neck (all p < 0.01), but not at the distal radius. SPKT induced bone measures' improvement at lumbar spine and hip but not at distal radius. Before suggesting changes in current clinical care, predictive value of individual bone measures or its combination for fracture risk assessment remains to be elucidated.

Bone involvement in the early stages of Parkinson's disease: a case-control study

OBJECTIVE

To evaluate the qualitative and quantitative alterations of bone tissue in patients with early-stage Parkinson's disease (PD) and to measure the associations between bone mineral density (BMD), trabecular bone score (TBS) and physical performance.

METHODS

This case-control study enrolled patients with early-stage PD and age-matched controls. BMDs for the left femoral neck (L-FN) and lumbar spine (LS) were measured. Bone microarchitecture for the LS was determined using TBS. Muscle performance was assessed using the short physical performance battery (SPPB). Patients and controls were stratified in two groups based on the SPPB score: a poor performance group (SPPB score ≤8) and high performance group (SPPB > 8).

RESULTS

This study included 26 patients: 13 in the PD group and 13 age-matched controls. The mean ± SD BMD results in the PD group were: L1-L4 BMD = 0.935 ± 0.183 g/cm2; L-FN BMD = 0.825 ± 0.037 g/cm2; with bone microarchitecture degraded in four patients and partially degraded in three patients. TBS was significantly different in the patients with PD stratified according to SPPB. Among the controls, there was a significant difference in body mass index between the two SPPB groups.

CONCLUSION

TBS might identify bone involvement earlier than BMD in the initial stages of PD.

Clinical Use of Trabecular Bone Score: The 2023 ISCD Official Positions

Osteoporosis can currently be diagnosed by applying the WHO classification to bone mineral density (BMD) assessed by dual-energy x-ray absorptiometry (DXA). However, skeletal factors other than BMD contribute to bone strength and fracture risk. Lumbar spine TBS, a grey-level texture measure which is derived from DXA images has been extensively studied, enhances fracture prediction independent of BMD and can be used to adjust fracture probability from FRAX® to improve risk stratification. The purpose of this International Society for Clinical Densitometry task force was to review the existing evidence and develop recommendations to assist clinicians regarding when and how to perform, report and utilize TBS. Our review concluded that TBS is most likely to alter clinical management in patients aged ≥ 40 years who are close to the pharmacologic intervention threshold by FRAX. The TBS value from L1-L4 vertebral levels, without vertebral exclusions, should be used to calculate adjusted FRAX probabilities. L1-L4 vertebral levels can be used in the presence of degenerative changes and lumbar compression fractures. It is recommended not to report TBS if extreme structural or pathological artifacts are present. Monitoring and reporting TBS change is unlikely to be helpful with the current version of the TBS algorithm. The next version of TBS software will include an adjustment based upon directly measured tissue thickness. This is expected to improve performance and address some of the technical factors that affect the current algorithm which may require modifications to these Official Positions as experience is acquired with this new algorithm.

Bone density and trabecular bone score to predict fractures in adults aged 20-39 years: a registry-based study

Trabecular bone score (TBS) enhances fracture risk assessment in older adults; whether this is true in younger people is uncertain. In this registry-based study of adults aged 20-39 years, low BMD, but not low TBS, predicted fracture.

PURPOSE

Trabecular bone score (TBS), a bone texture measurement, is associated with fracture risk independent of bone mineral density (BMD) in older adults. In adults aged 20-40 years, TBS remains stable and its role in fracture risk assessment is unclear. We utilized the Manitoba Bone Density Registry to explore the relationship of fracture risk with BMD and TBS in younger adults.

METHODS

Women and men aged 20-39 years referred for DXA testing were studied. Incident major and any fractures were captured from health records. Categories based on WHO BMD T-score classification and TBS tertile were considered using Cox regression models to estimate covariate-adjusted (including sex) hazard ratios (aHR, 95%CI) for incident fracture by category, and each SD decrement in BMD and TBS.

RESULTS

The study included 2799 individuals (77% female, mean age 32 years). Mean (SD) minimum T-score was - 0.9 (1.1) and TBS 1.355 (0.114); 7% had osteoporosis and 13% were in the lowest TBS tertile. Incident major osteoporotic fracture (MOF) and any fracture risk was elevated in those with osteopenia (aHRs 1.20/1.45) and osteoporosis (aHRs 4.60/5.16). Fracture risk was unrelated to TBS tertile. Each SD decrement in BMD was associated with increased MOF risk (aHR 1.64) and any fracture (aHR 1.71); lower TBS was unrelated to fractures.

CONCLUSION

In young adults, low BMD, but not low TBS, was predictive of MOF and any fracture. Routine clinical TBS measurement is not recommended for young adults. Further study is indicated to evaluate whether TBS is beneficial in subsets of younger adults.

Abnormal Trabecular Bone Score, Lower Bone Mineral Density and Lean Mass in Young Women With Premature Ovarian Insufficiency Are Prevented by Oestrogen Replacement

Background

Low bone density (BMD) and fractures commonly affect women with premature ovarian insufficiency (POI). However, bone microarchitecture and body composition data are lacking.

Objective

To assess and characterise musculoskeletal phenotype and effects of oestrogen replacement therapy (ERT) in women with POI.

Method

Cross-sectional and longitudinal studies of 60 normal karyotype women with POI, aged 20-40 years, from 2005-2018. Dual x-ray absorptiometry (DXA)-derived spinal (LS) and femoral neck (FN) BMD, trabecular bone score (TBS), appendicular lean mass (ALM), total fat mass (TFM), and fracture prevalence were compared with 60 age-, and BMI-matched population-based controls. Longitudinal changes in bone and body composition variables and ERT effects were analysed using linear mixed models over a median duration of 6 years.

Results

Women with POI were subdivided into spontaneous (s)-POI (n=25) and iatrogenic (i)-POI (n=35). Median(range) age of POI diagnosis was 34 (10-40) years with baseline DXA performed at median 1(0-13) year post-diagnosis. ERT was used by 82% women (similar for both POI groups). FN-BMD were lowest in s-POI (p<0.002). Low TBS was more common in s-POI [(44%), p=0.03], versus other groups. LS-BMD and ALM were lower in both s-POI and i-POI groups than controls (p<0.05). Fracture prevalence was not significantly different: 20% (s-POI), 17% (i-POI), and 8% (controls) (p=0.26). Longitudinal analysis of 23 POI women showed regular ERT was associated with ALM increment of 127.05 g/year (p<0.001) and protected against bone loss. However, ERT interruption was associated with annual reductions in FN BMD and TBS of 0.020g/cm2 and 0.0070 (p<0.05), respectively.

Conclusion

Deficits in BMD, trabecular microarchitecture, and lean mass were present in women with POI. However, regular ERT protected against declines in bone variables, with an increase in ALM. Assessment of skeletal and muscle health, and advocating ERT adherence, is essential in POI to optimise musculoskeletal outcomes.

Trabecular Bone Score Reference Values for Children and Adolescents According to Age, Sex, and Ancestry

Trabecular bone score (TBS) is used for fracture prediction in adults, but its utility in children is limited by absence of appropriate reference values. We aimed to develop reference ranges for TBS by age, sex, and population ancestry for youth ages 5 to 20 years. We also investigated the association between height, body mass index (BMI), and TBS, agreement between TBS and lumbar spine areal bone mineral density (aBMD) and bone mineral apparent density (BMAD) Z-scores, tracking of TBS Z-scores over time, and precision of TBS measurements. We performed secondary analysis of spine dual-energy X-ray absorptiometry (DXA) scans from the Bone Mineral Density in Childhood Study (BMDCS), a mixed longitudinal cohort of healthy children (n = 2014) evaluated at five US centers. TBS was derived using a dedicated TBS algorithm accounting for tissue thickness rather than BMI. TBS increased only during ages corresponding to pubertal development with an earlier increase in females than males. There were no differences in TBS between African Americans and non-African Americans. We provide sex-specific TBS reference ranges and LMS values for calculation of TBS Z-scores by age and means and SD for calculation of Z-scores by pubertal stage. TBS Z-scores were positively associated with height Z-scores at some ages. TBS Z-scores explained only 27% and 17% of the variance of spine aBMD and BMAD Z-scores. Tracking of TBS Z-scores over 6 years was lower (r = 0.47) than for aBMD or BMAD Z-scores (r = 0.74 to 0.79), and precision error of TBS (2.87%) was greater than for aBMD (0.85%) and BMAD (1.22%). In sum, TBS Z-scores provide information distinct from spine aBMD and BMAD Z-scores. Our robust reference ranges for TBS in a well-characterized pediatric cohort and precision error estimates provide essential tools for clinical assessment using TBS and determination of its value in predicting bone fragility in childhood and adolescence. © 2022 American Society for Bone and Mineral Research (ASBMR).

Usefulness of the Trabecular Bone Score in Assessing the Risk of Vertebral Fractures in Patients with Cirrhosis

The trabecular bone score (TBS), a surrogate measure of bone microarchitecture, provides complementary information to bone mineral density (BMD) in the assessment of osteoporotic fracture risk. This cross-sectional study aimed to determine whether TBS can identify patients with liver cirrhosis that are at risk of vertebral fractures. We enrolled 275 patients who completed evaluations for lumbar BMD, TBS, and vertebral fractures between November 2018 and April 2021. BMD was measured using dual-energy X-ray absorptiometry (DXA), TBS was calculated by analyzing DXA images using TBS iNsight software, and vertebral fractures were evaluated using Genant’s semi-quantitative method with lateral X-ray images. Factors associated with vertebral fractures and their correlation with the TBS were identified using regression models. Of the enrolled patients, 128 (47%) were female, the mean age was 72 years, and 62 (23%) were diagnosed with vertebral fractures. The prevalence of vertebral fractures was higher in women than in men (33% vs. 14%; p < 0.001). The unadjusted odds ratio (OR) of the vertebral fractures for one standard deviation decrease in TBS and BMD was 2.14 (95% confidence interval [CI], 1.69−2.73) and 1.55 (95% CI, 1.26−1.90), respectively. After adjusting for age, sex, and BMD, the adjusted OR of the vertebral fractures in TBS was 2.26 (95% CI, 1.52−3.35). Multivariate linear regression analysis showed that TBS was independently correlated with age (β = −0.211), body mass index (β = −0.251), and BMD (β = 0.583). TBS can help identify patients with cirrhosis at risk of vertebral fractures.

Age-Specific Normative Values of Lumbar Spine Trabecular Bone Score (TBS) in Taiwanese Men and Women

Trabecular bone score (TBS) is a novel method for assessing trabecular microarchitecture. Normative values of TBS are available for various populations of the world but are not yet available for Taiwanese adults. Therefore, the purpose of this study was to estimate age-specific, normative TBS curves for Taiwanese men and women. Medical records of general health examinations from a regional hospital in Southern Taiwan were reviewed. Individuals aged 30–90 years with data on lumbar spine bone mineral density (BMD) were included. TBS was retrospectively calculated from dual-energy X-ray absorptiometry scans using TBS iNsight software. Of the 12,028 patients included, 4533 (37.7%) were male and the mean age was 55.8 years. The mean TBS was 1.392 (standard deviation (SD) 0.089) for men and 1.344 (SD 0.107) for women. In women, TBS declined at a rate of 0.0004/year among those aged 30.0–45.9 years, 0.0106/year among those 46.0–60.7 years, and 0.0028/year among those 60.8–90.0 years. In men, TBS declined at a constant rate of 0.0023/year over the entire age range. In conclusion, age-adjusted, normative curves of TBS for Taiwanese men and women are presented, which could be used to facilitate the use of TBS in assessing bone status in clinical practice.

Association between bone measures and use of angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers

Angiotensin-converting enzyme inhibitor use in women was associated with lower femoral neck and lumbar spine bone mineral density as well as trabecular bone score compared to non-users. No differences were identified for men or for those who used ARB medications.

PURPOSE

Many individuals at high fracture risk use medications such as angiotensin-converting enzyme inhibitors (ACEI) or angiotensin II receptor blockers (ARB) that could affect bone; thus, this study aimed to investigate whether there are any differences in bone mineral density (BMD) and trabecular bone score (TBS) between ACEI users, ARB users, and non-users.

METHODS

Participants (685 men, 573 women) were from the Geelong Osteoporosis Study. Current medication use was self-reported. BMD at the femoral neck (FNBMD) and lumbar spine (LSBMD) were measured using DXA. TBS was calculated using TBS iNsight software. Linear regression models were used to investigate associations between ACEI or ARB use and bone measures, adjusting for other potential confounders. Due to interaction terms, data were stratified by age.

RESULTS

There were 88 (12.8%) men and 41 (7.2%) women taking an ACEI medication, and 71 (10.4%) men and 76 (13.3%) women taking an ARB medication. Compared to non-users, ACEI use was associated with lower FNBMD (- 7.2%), LSBMD (- 12.2%), and TBS (- 9.0%) for women aged < 65 years. Lower TBS was also observed for women aged ≥ 65 years (- 17.3%). No differences were identified for ARB use.

CONCLUSIONS

Women who used an ACEI medication had lower values for FNBMD, LSBMD and TBS compared to non-users. No differences were identified for men or for those who used ARB medications.

Description of Normative Spine TBS Data for Men and Women in Mexican Population

Trabecular Bone Score (TBS) has proven its usefulness to improve areal Bone Mineral Density in diagnosing fracture risk and bone status evaluation. For it to be better interpreted, local reference values are recommended to account for population differences and, if possible, both in women and men, the former being scarcer. Using TBS, we reanalyzed data obtained from the Mexican population included in the Latin American Vertebral Osteoporosis Study and the Mexican Vertebral Study in men that included a random probability sample of 408 women and 414 men aged 50 and older without fractures. Data was used to obtain reference curves in such a population. Mean TBS in women ranged from an average of 1.359 ± 0.118 standard deviation (SD) 50 to 59 and decreased down to 1.211 ± 0.128 SD in women 80 and above. In men ranged from 1.382 ± 0.116 SD in the first group down to 1.315 ± 0.118 SD in the latter with little differences in age groups. Mean values in women are lower than previously suggested cutoff points to establish microarchitecture status using TBS: 1.350 and above normal, 1.200 to 1.349 partially degraded and 1.199 and below, degraded. Our TBS data have the strength of being a random sample drawn from the population, although limited in its extent to one city in Mexico. The means and curves may be used to diagnose bone status with better sensibility and specificity, although these values are yet to be evaluated.

What Role Does Trabecular Bone Score Play in Chronic Inflammatory Rheumatic Diseases?

Patients suffering from rheumatic inflammatory diseases, e.g., systemic sclerosis, rheumatoid arthritis, and ankylosing spondylitis, are at risk of low bone mass. Dual-energy X-ray Absorptiometry (DXA) is the traditional radiological measurement technique for bone mineral density (BMD). The recently developed trabecular bone score (TBS) enhances the skeletal information provided by standard BMD. It re-analyzes the spatial dynamics of pixel intensity changes in lumbar spine DXA images, defining a quantitative index, characterizing trabecular bone microarchitecture. It has been demonstrated that low TBS values are associated with an increased incidence of fractures in patients with rheumatic diseases. These methods used together for bone damage evaluation can be of value to identify individuals who will potentially fracture. The main scientific literature on the clinical aspects of osteoporosis, including the use of TBS in evaluating this pathology, are herein reported aimed at shedding light on the role trabecular bone score plays in chronic inflammatory rheumatic diseases.

Bone Features of Unaffected Skeletal Sites in Melorheostosis: A Case Report

BACKGROUND

Melorheostosis is a rare sporadic sclerosing bone dysplasia, which commonly affects appendicular skeleton with bone hyperostosis and soft tissues sclerosis; fragility fractures are rare in melorheostotic patients. We investigated bone features at unaffected sites in a postmenopausal woman with melorheostosis of the right lower limb and with a fracture of the melorheostosis-free T11 vertebral.

METHODOLOGY

Melorheostotic lesions were evaluated by plain radiography, magnetic resonance of the right lower limb, and whole-body bone scintigraphy. Dual X-ray absorptiometry, trabecular bone score, and quantitative computed tomography were performed to investigate unaffected bone sites. Biochemical assessment of bone metabolism was obtained.

RESULTS

Dual X-ray absorptiometry was indicative of normal mineralization at femoral sites and osteopenia at lumbar spine (T-score -1.1), which was confirmed by spinal quantitative computed tomography (volumetric bone mineral density 89 mg/cm³). Trabecular bone score suggested only mildly altered bone microarchitecture (1.304, normal values >1.350). Bone markers were consistent with high bone turnover. Causes of secondary osteoporosis or alterations in bone metabolism were excluded. Zoledronic acid induced a reduction in bone turnover markers after 6 months without significant changes in clinical features.

CONCLUSIONS

Fragility fractures at apparently unaffected sites may occur in adults with melorheostosis, in absence of significant demineralization diagnosed by dual X-ray absorptiometry, trabecular bone score, and quantitative computed tomography, which may underestimate the fracture risk in this set of patients. Treatment with zoledronate could be considered also to prevent fragility fractures.

The reference value of trabecular bone score (TBS) in the Iranian population

Background

Trabecular bone score (TBS), as a tool for measurement of bone microarchitecture, represents fracture risk independently of bone density. The aim of this study was to estimate the reference values of TBS in both genders among the Iranian population to evaluate osteoporotic fractures in the future.

Methods

The study was performed on healthy Iranian subjects who live in urban areas of Bushehr city, the capital of Bushehr province in southwestern Iran. The participants in this study were selected through a multistage, age and sex stratified, cluster random sampling. The TBS of L1-L4 was assessed by spine DXA images using TBS iNsight software (Discovery WI, Hologic Inc, USA). Age-related models of TBS were constructed using piecewise linear regression analysis.

Results

In total, 691 participants aged ≥ 18 years (381 men and 310 women) were selected for the study. The mean and standard deviation (SD) of TBS value for men was 1.420 ± 0.094 and the age at the peak TBS was 30.0 years. Among women, the corresponding value for the mean of TBS was 1.428 ± 0.070 and the age at the peak TBS was 24.5 years. Two SDs below the mean of TBS were 1.326 in men and 1.357 in women. Therefore, the following normal range for TBS values has been proposed: Among men, TBS ≥ 1.326 is considered to be normal; TBS between 1.231 and 1.326 is considered to be partially degraded microarchitecture; and TBS ≤ 1.231defined degraded microarchitecture. Among women, TBS categories are defined as normal ≥ 1.357, partially degraded between 1.287 and 1.357 and degraded ≤ 1.287.

Conclusions

This was the first study to propose evaluation of the normal range for TBS values in both genders in the Middle- East and Iran. According to our results: TBS ≤ 1.231 in men and TBS ≤ 1.287 in women is considered to be degraded microarchitecture among the Iranian population.

Bone material strength index is associated with prior fracture in men with and without moderate chronic kidney disease

BACKGROUND

Patients with chronic kidney disease (CKD) are at high risk for fracture. The ability of bone mineral density (BMD) to predict fractures in CKD patients has been inconsistent. Other measures such as trabecular bone score (TBS) and impact microindentation (IMI) may be more useful in this group. This study aimed to determine if TBS or IMI values differed between men with and without CKD and examine associations between prior fracture, TBS and IMI values.

METHODS

Men (n = 343, age 33-96 yr) from the Geelong Osteoporosis Study were included. Femoral neck (FNBMD) and lumbar spine BMD (LSBMD) were measured using DXA (Lunar ProdigyPro). TBS was determined from lumbar spine scans (TBS iNsight software Version 2.2). IMI values (bone material strength index; BMSi) were measured using an OsteoProbe. CKD was defined as an eGFR<60 mL/min/1.73m² (n = 53). Prior low trauma fractures (n = 37) were ascertained from radiological reports. Associations were examined using binary logistic regression, adjusting for potential confounders. Interaction terms were tested in all models.

RESULTS

Men with CKD tended to have a higher likelihood of prior fracture (adjusted OR 2.27, 95%CI 1.02-5.01). Higher BMSi was associated with a lower likelihood of prior fracture (adjusted OR for 1SD increase: 0.70; 95%CI 0.51-0.97). This association was sustained after adjustment for FNBMD (OR 0.68; 95%CI 0.49-0.96) or LSBMD (OR 0.69; 95%CI 0.49-0.95). No interaction was detected between BMSi and CKD (p = 0.898). No associations were detected between FNBMD, LSBMD or TBS and prior fracture in either population and there were no interactions with CKD for FNBMD, LSBMD or TBS.

CONCLUSIONS

BMSi was associated with prior fracture in men with and without CKD, however, FNBMD, LSBMD and TBS were not. Lack of an interaction term suggests that BMSi performed similarly in identifying the likelihood of prior fracture, regardless of CKD status. IMI may have clinical utility for assessing fracture risk in patients with CKD.