Trabecular bone score: perspectives of an imaging technology coming of age

Abstract

The trabecular bone score (TBS) is a new method to describe skeletal microarchitecture from the dual energy X-ray absorptiometry (DXA) image of the lumbar spine. While TBS is not a direct physical measurement of trabecular microarchitecture, it correlates with micro-computed tomography (µCT) measures of bone volume fraction, connectivity density, trabecular number, and trabecular separation, and with vertebral mechanical behavior in ex vivo studies. In human subjects, TBS has been shown to be associated with trabecular microarchitecture and bone strength by high resolution peripheral quantitative computed tomography (HRpQCT). Cross--sectional and prospective studies, involving a large number of subjects, have both shown that TBS is associated with vertebral, femoral neck, and other types of osteoporotic fractures in postmenopausal women. Data in men, while much less extensive, show similar findings. TBS is also associated with fragility fractures in subjects with secondary causes of osteoporosis, and preliminary data suggest that TBS might improve fracture prediction when incorporated in the fracture risk assessment system known as FRAX. In this article, we review recent advances that have helped to establish this new imaging technology. Arq Bras Endocrinol Metab. 2014;58(5):493-503 Keywords Trabecular bone score; osteoporosis; fracture risk; bone mineral density; microarchitecture RESUMO TBS (do inglês, "trabecular bone score") é um novo método que estima a microarquitetura óssea a partir de uma imagem de densitometria óssea (DXA) da coluna lombar. Apesar de o TBS não ser uma medida física direta da microarquitetura trabecular, ele correlaciona-se com o volume ósseo, densidade da conectividade trabecular, número de trabéculas e separação trabecular medidos por microtomografia computadorizada (µCT), e com medidas mecânicas da resistência óssea vertebral em estudos ex vivo. Estudos em humanos confirmaram que o TBS associa-se a microarquitetura trabecular e resistência óssea medidas por tomografia computadorizada quantitativa periférica de alta resolução (HRpQCT). Estudos transversais e prospectivos, envolvendo um grande número de indivíduos, mostraram que o TBS é associado com fratura vertebral, de colo de fêmur e com outros tipos de fraturas osteoporóticas em mulheres na pós-menopausa. Dados em homens, apesar de escassos, mostram resultados semelhantes. Além disso, o TBS foi associado a fraturas por fragilidade em indivíduos com diversas causas secundárias de osteoporose e, dados preliminares, sugerem que o uso do TBS pode melhorar a previsão de fratura quando incorporado ao sistema de avaliação de risco de fratura (FRAX). Este artigo faz uma revisão de avanços recentes que têm ajudado a estabelecer esse novo mé-todo de imagem. Arq Bras Endocrinol Metab. 2014;58(5):493-503 Descritores

Trabecular bone score (TBS) as a new complementary approach for osteoporosis evaluation in clinical practice

“…The precision of the measurement is critical, both within and between instruments [64]. However, sensitivity to measure changes is also affected by responsiveness, the ratio of responsiveness to precision being an indicator of sensitivity to measure (treatment-induced) changes [65].…”

High-normal free thyroxine levels are associated with low trabecular bone scores in euthyroid postmenopausal women

“…Low TBS values are related to altered bone microarchitecture and increased risk of fragility fractures, independent of BMD [18]. An international working group of TBS users has proposed TBS cut-off values for postmenopausal women: normal for TBS values over 1.350, partly degraded microarchitecture for values between 1.200 and 1.350, and degraded for values 1.200 or less [19] (http://www. medimapsgroup.com/upload/MEDIMAPS-UK-WEB.pdf).…”

Effect of three months of periodized hydrogymnastics exercise program on urinary concentration of deoxypyridinoline in older women

“…In spite of the hydrogimnastic training program in these research was designed five times a week whit periodization in order to produce grater adaptations (23), increasing the load heart rate reserve of 40-50% (1-6 th week) increasing the load to 50-60% heart rate reserve (7)(8)(9)(10)(11)(12) th week) these result was not consistent with a controlled trial than evaluate with biochemical markers of bone turnover in elderly who practice aquatic exercise than showed serum osteocalcin, intra and intergroup statistical differences of p = 0.042 and p = 0.027 (22), other study than showed benefits in bone formation marker assessed by procollagen type 1 amino-terminal propeptide (15.8 %; p = 0.001) after a high-intensity of aquatic exercise program in postmenopausal women (27); these discrepancies with our results may be owing to de time than were performed through 24 weeks of aquatic exercises but with lower frequency (3 times a week) and lower work load intensity by other hand some of these programs where attendance in strength modalities in to the water than may have influence the improvements in bone turnover (9,27).…”

“…Controlled trials in post-menopausal women have been considered physical exercise along with medication and diet one of the three cornerstones of osteoporosis (10,11). By other hand, there are different accepted diagnostic criteria to identify osteoporosis than may partly explain the variability of prevalence (12); also the incidence of physical exercise to induce changes in bone metabolism is determined for the duration, intensity and type of exercises (9).…”