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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.

Osteogenesis imperfecta is a hereditary connective tissue disorder, resulting in low bone mass and high bone fragility. Dual-energy X-ray absorptiometry (DXA) and in adulthood also the trabecular bone score (TBS) are well established to assess bone health and fracture risk. The purpose of this investigation was to assess the usefulness of TBS in respect to different treatment regimes in children with osteogenesis imperfecta. Changes of areal bone mineral density (aBMD) and TBS using DXA scans of children treated with antiresorptive therapies were evaluated.DXA scans (aBMD, TBS) of 8 children with OI were evaluated. The scans were taken during a 1 yr period of treatment with bisphosphonates and during 1 yr pilot trial using denosumab. Changes of aBMD and TBS during both treatment regimens were compared.During bisphosphonate treatment aBMD increased about 6.2%, while TBS increased about 2.1%. The difference between aBMD and TBS before and after bisphosphonate treatment was not significant (p = 0.25). During denosumab treatment aBMD increased around 25.1%, while TBS increased 6.7%. The change of aBMD was significant (p = 0.007), as was the difference between aBMD and TBS (p0.001).Denosumab had a significant effect on both aBMD and TBS but was significantly more pronounced in aBMD. These results suggest a stronger effect of denosumab on cortical bone and the growth plate in comparison to bisphosphonates. Beside the lack of paediatric reference data and the small sample size, the results suggest TBS to be a useful tool for monitoring skeletal changes during development, growth, and antiresorptive therapy in children with OI.

We thank the Editor for the opportunity to respond to the Letter to the Editor: “Concerns regarding the use of 3D-DXA” in relation to our recent publication, Harding et al., Bone, 136, 2020, 115,362. The Letter author writes “It is my understanding that it is not possible to measure the cortical parameters from a two-dimensional dual-energy X-ray absorptiometry (DXA) image.” This is correct. Technically, all so-called ‘measures’ from indirect densitometry are estimates, but more to the writer's point, it is typically not possible to parse out cortical from trabecular bone from a standard areal BMD exam. The 3D-DXA modelling software was built from a database of Quantitative Computed Tomographic scans of the proximal femur, to develop a statistical shape and density model; technical details of the modelling algorithm have been published previously.

Purpose Patients with type 2 diabetes mellitus (T2DM) have an increased fracture risk despite having higher areal bone mineral density (aBMD). This study aimed to clarify the association between glycemic and insulin resistance status and bone microarchitecture, and whether pentosidine and bone turnover markers play any roles in the association. Methods A total of 2012 community-dwelling men aged ≥ 65 years completed baseline measurements of spine aBMD, fasting plasma glucose (FPG) and serum insulin, hemoglobin A1c (HbA1c), osteocalcin, type I procollagen N-terminal propeptide, type I collagen C-terminal crosslinking telopeptide, tartrate-resistant acid phosphatase isoenzyme 5b, pentosidine, height and weight and an interview regarding past disease history. Homeostasis model assessment-insulin resistance (HOMA-IR) was also calculated. T2DM was defined as physician-diagnosed middle age or elderly-onset diabetes mellitus, or according to biochemical test results. To evaluate bone microarchitecture, trabecular bone score (TBS) was calculated at the same vertebrae as those used for aBMD measurement. Results After excluding participants who had a disease history and/or were taking medications affecting bone metabolism, 1683 men (age, 72.9 ± 5.2 years) were analyzed. Men with T2DM had significantly higher aBMD compared to those without T2DM. There was no significant difference in TBS. However, FPG, HbA1c and HOMA-IR levels were significantly inversely correlated with TBS after adjusting for age, BMI and aBMD. Multivariate linear regression analyses revealed that glycemic indices (FPG and HbA1c) were significantly associated with increased aBMD and decreased TBS, and that HOMA-IR was associated only with TBS. These associations did not change after further adjusting for bone turnover makers and pentosidine levels. Conclusions Hyperglycemia and elevated insulin-resistance were associated with low TBS independently of bone turnover and pentosidine levels.

The objective of the study was to assess longitudinal effects of different osteoporosis treatments on TBS and aBMD at lumbar spine.We analyzed 390 patients (men: 72; women: 318; age40 years; mean follow-up of 20 months and BMI37 kg/m(2)). We stratified the cohort by treatments: Naive of treatment (Naive, n=67), Calcium and Vitamin D (CaVitD, n=87), Testosterone (Te, n=36), Alendronate (AL, n=88), Risedronate (Ri, n=39), Denosumab (Dmb, n=43) and Teriparatide (PTH, n=30). The follow-up changes from baseline were normalized at 24 months.After 24 months, Naive group TBS decreased by 3.1% (p0.05) whereas a non-significant increase was observed for spine aBMD (Δ=+0.5%). Compared to the Naive group, significant improvement (p0.05) was observed in both TBS and aBMD for Te, AL, Ri, Dmb and PTH groups and in the CaVitD group for TBS. At the end of the follow-up, significant improvement have been observed for aBMD in Te (+4.4%), AL (+4.1%), Ri (+4.8), D (+8.8%) and PTH (+8.8%) groups. Significant improvement was observed only in the AL (+1.4%), Dmb (+2.8%) and PTH (+3.6%) groups for TBS.As expected, TBS of Naive subjects decreased with age. As expected a TBS preservation has been observed under AL and Ri. Te and CaVitD effects on TBS were evaluated for the first time: a similar preservation effect has been observed. A significant TBS increase was observed under Denosumab and PTH. TBS could be a useful tool to monitor treatment effects.

The trabecular bone score (TBS, Med-Imaps, Pessac, France) is an index of bone microarchitecture texture extracted from anteroposterior dual-energy X-ray absorptiometry images of the spine. Previous studies have documented the ability of TBS of the spine to differentiate between women with and without fractures among age- and areal bone mineral density (aBMD)-matched controls, as well as to predict future fractures. In this cross-sectional analysis of data collected from 3 geographically dispersed facilities in the United States, we investigated age-related changes in the microarchitecture of lumbar vertebrae as assessed by TBS in a cohort of non-Hispanic US white American women. All subjects were 30 yr of age and older and had an L1–L4aBMDZ-score within ±2 SD of the population mean. Individuals were excluded if they had fractures, were on any osteoporosis treatment, or had any illness that would be expected to impact bone metabolism. All data were extracted from Prodigy dual-energy X-ray absorptiometry devices (GE-Lunar, Madison, WI). Cross-calibrations between the 3 participating centers were performed for TBS and aBMD. aBMD and TBS were evaluated for spine L1–L4 but also for all other possible vertebral combinations. To validate the cohort, a comparison between the aBMD normative data of our cohort and US non-Hispanic white Lunar data provided by the manufacturer was performed. A database of 619 non-Hispanic US white women, ages 30–90 yr, was created. aBMD normative data obtained from this cohort were not statistically different from the non-Hispanic US white Lunar normative data provided by the manufacturer (p = 0.30). This outcome thereby indirectly validates our cohort. TBS values at L1–L4 were weakly inversely correlated with body mass index (r = −0.17) and weight (r = −0.16) and not correlated with height. TBS values for all lumbar vertebral combinations decreased significantly with age. There was a linear decrease of 16.0% (−2.47 T-score) in TBS at L1–L4 between 45 and 90 yr of age (vs. −2.34 for aBMD). Microarchitectural loss rate increased after age 65 by 50% (−0.004 to −0.006). Similar results were obtained for other combinations of lumbar vertebra. TBS, an index of bone microarchitectural texture, decreases with advancing age in non-Hispanic US white women. Little change in TBS is observed between ages 30 and 45. Thereafter, a progressive decrease is observed with advancing age. The changes we observed in these American women are similar to that previously reported for a French population of white women (r2 > 0.99). This reference database will facilitate the use of TBS to assess bone microarchitectural deterioration in clinical practice.

Introduction The trabecular bone score (TBS) is a new parameter that is determined from grey level analysis of DXA images. It relies on the mean thickness and volume fraction of trabecular bone microarchitecture. This was a preliminary case–control study to evaluate the potential diagnostic value of TBS, both alone and combined with bone mineral density (BMDa), in the assessment of vertebral fracture. Methods Out of a subject pool of 441 Caucasian, postmenopausal women between the ages of 50 and 80 years, we identified 42 women with osteoporosis-related vertebral fractures, and compared them with 126 age-matched women without any fractures (1 case: 3 controls). Primary outcomes were BMDa and TBS. Inter-group comparisons were undertaken using Student's t-tests and Wilcoxon signed ranks tests for parametric and non-parametric data, respectively. Odds ratios for vertebral fracture were calculated for each incremental one standard deviation decrease in BMDa and TBS, and areas under the receiver operating curve (AUC) calculated and sensitivity analysis were conducted to compare BMDa alone, TBS alone, and the combination of BMDa and TBS. Subgroup analyses were performed specifically for women with osteopenia, and for women with T-score-defined osteoporosis. Results Across all subjects (n = 42, 126) weight and body mass index were greater and BMDa and TBS both less in women with fractures. The odds of vertebral fracture were 3.20 (95% CI, 2.01–5.08) for each incremental decrease in TBS, 1.95 (1.34–2.84) for BMDa, and 3.62 (2.32–5.65) for BMDa + TBS combined. The AUC was greater for TBS than for BMDa (0.746 vs. 0.662, p = 0.011). At iso-specificity (61.9%) or iso-sensitivity (61.9%) for both BMDa and TBS, TBS + BMDa sensitivity or specificity was 19.1% or 16.7% greater than for either BMDa or TBS alone. Among subjects with osteoporosis (n = 11, 40) both BMDa (p = 0.0008) and TBS (p = 0.0001) were lower in subjects with fractures, and both OR and AUC (p = 0.013) for BMDa + TBS were greater than for BMDa alone (OR = 4.04 [2.35–6.92] vs. 2.43 [1.49–3.95]; AUC = 0.835 [0.755–0.897] vs. 0.718 [0.627–0.797], p = 0.013). Among subjects with osteopenia, TBS was lower in women with fractures (p = 0.0296), but BMDa was not (p = 0.75). Similarly, the OR for TBS was statistically greater than 1.00 (2.82, 1.27–6.26), but not for BMDa (1.12, 0.56–2.22), as was the AUC (p = 0.035), but there was no statistical difference in specificity (p = 0.357) or sensitivity (p = 0.678). Conclusions The trabecular bone score warrants further study as to whether it has any clinical application in osteoporosis detection and the evaluation of fracture risk.

[95% CI 1.16-1.250, P

To have an added value over BMD, a CRF of osteoporotic fracture must be predictable of the fracture, independent of BMD, reversible and quantifiable. Many major recognized CRF exist.Out of these factorsmany of themare indirect factor of bone quality. TBS predicts fracture independently of BMD as demonstrated from previous studies. The aim of the study is to verify if TBS can be considered as a major CRF of osteoporotic fracture. Existing validated datasets of Caucasian women were analyzed. These datasets stem from different studies performed by the authors of this report or provided to our group. However, the level of evidence of these studies will vary. Thus, the different datasets were weighted differently according to their design. This meta-like analysis involves more than 32000 women (≥50 years) with 2000 osteoporotic fractures from two prospective studies (OFELY&MANITOBA) and 7 crosssectional studies. Weighted relative risk (RR) for TBS was expressed for each decrease of one standard deviation as well as per tertile difference (TBS=1.300 and 1.200) and compared with those obtained for the major CRF included in FRAX®. Overall TBS RR obtained (adjusted for age) was 1.79 [95%CI-1.37-2.37]. For all women combined, RR for fracture for the lowest comparedwith themiddle TBS tertilewas 1.55[1.46- 1.68] and for the lowest compared with the highest TBS tertile was 2.8[2.70-3.00]. TBS is comparable to most of the major CRF (Fig 1) and thus could be used as one of them. Further studies have to be conducted to confirm these first findings.

X-ray is a technology that is used for numerous applications in the medical field. The process of X-ray projection gives a 2-dimension (2D) grey-level texture from a 3- dimension (3D) object. Until now no clear demonstration or correlation has positioned the 2D texture analysis as a valid indirect evaluation of the 3D microarchitecture. TBS is a new texture parameter based on the measure of the experimental variogram. TBS evaluates the variation between 2D image grey-levels. The aim of this study was to evaluate existing correlations between 3D bone microarchitecture parameters - evaluated from μCT reconstructions - and the TBS value, calculated on 2D projected images. 30 dried human cadaveric vertebrae were acquired on a micro-scanner (eXplorer Locus, GE) at isotropic resolution of 93 μm. 3D vertebral body models were used. The following 3D microarchitecture parameters were used: Bone volume fraction (BV/TV), Trabecular thickness (TbTh), trabecular space (TbSp), trabecular number (TbN) and connectivity density (ConnD). 3D/2D projections has been done by taking into account the Beer-Lambert Law at X-ray energy of 50, 100, 150 KeV. TBS was assessed on 2D projected images. Correlations between TBS and the 3D microarchitecture parameters were evaluated using a linear regression analysis. Paired T-test is used to assess the X-ray energy effects on TBS. Multiple linear regressions (backward) were used to evaluate relationships between TBS and 3D microarchitecture parameters using a bootstrap process. BV/TV of the sample ranged from 18.5 to 37.6% with an average value at 28.8%. Correlations' analysis showedthat TBSwere strongly correlatedwith ConnD(0.856≤r≤0.862; p

Poster: "ECR 2011 / C-1980 / Assessment of correlations between 3D µCT microarchitecture parameters and TBS: effects of resolution and correlation with TBS DXA measurements." by: "R. winzenrieth1, T. Piveteau1, D. Hans2; 1PESSAC/FR, 2Lausanne/CH"

45-85 years BMI < 36 kg/m2 -2.5< T-score ≤-1 at lombar spine (L1-L4) or at femoral neck or at the total femur Fractured subjects have at least one grade 2 vertebral fracture quali ed as "low energy" and con rmed by VFA-DXA. For each fractured subject, 3 control subjects matched for age (±3years) were included No treatment or disease a ecting bone, no surgery at spine or scoliosis At least two evaluable vertebrae at lumbar spine