The trabecular bone score is a measure of bone texture correlated with bone microarchitecture and a marker for the risk of osteoporosis. Introduced in 2008,[1] its main projected use is alongside measures of bone density in better predicting fracture risk in people with metabolic bone problems.
To diagnose osteoporosis, despite the inclusion of bone mineral density (BMD), biological markers and clinical factors of fracture risk, many not detected patients are at risk and many fractures are not explained. Bone mineral density is an assessment of the quantity of bone. It does not provide information on bone quality, another important parameter to describe the bone. In addition, clinical risk factors for fracture are at best an indirect assessment of the bone quality. One way to describe the quality of the bone is to assess its microarchitecture. Bone microarchitecture is related to the mechanical strength of bone and hence its greater or lesser risk of fracture. Indeed, for the same quantity of bone, different mechanically resistant bone structures may exist (few large trabeculae or numerous thin trabeculae that are mechanically stronger). Actually, bone loss is often accompanied by a deterioration of bone architecture, resulted in a decreased number of trabeculae, increased inter-trabecular distances, and a loss connectivity of the trabecular meshwork. Moreover, reduction of cortical bone thickness and increased porosity accompany trabecular bone loss, and in particular promote the fragility of the femoral neck. Osteoporotic bone is called "porous".[citation needed]
Technical
Relative Risk of TBS expressed by standard deviation and compared with relative risks of major clinical risk factors for fracture
The trabecular bone score is a textural parameter that can be applied to DEXA, which quantifies the local variations in gray level. TBS is derived from the evaluation of the experimental variogram, obtained from the grayscale DEXA.[citation needed]
It was found that TBS is a reflection of the structural condition of the bone microarchitecture. TBS is strongly correlated with the number of trabeculae and their connectivity and negatively with the space between trabeculae.[2][3] That is to say that a high TBS value means that microarchitecture bone is dense, well connected with little spaces between trabeculaes. Conversely, a low TBS value means that the microarchitecture of bone is incomplete and poorly connected with wide spaces between trabeculae.[4]
in combination with BMD, increase the number of patients at risk (correctly) identified;[5][6][7]
improvement the management of patients with secondary osteoporosis;[8]
follow-up of the evolution of microarchitecture of a patient over time;[4]
monitoring of the effect of anti-resorptive or anabolic.[citation needed]
All these studies have shown that TBS can be used as a clinical risk factor for osteoporotic fracture since it is reversible (with or without treatment), quantitative and independent of BMD. It should therefore be used as such in the same way that taking corticosteroids, rheumatoid arthritis or prevalent fracture after age 50.[citation needed]
The FRAX calculator has an option to include TBS for a TBS adjusted FRAX risk score. The calculated probabilities of fracture have been shown to be more accurate when computed including TBS.[9]
As TBS relies on measurement of soft tissue, it is considered unreliable in individuals with a BMI over 37,[10] or with extremely high waist circumference.[11]
↑ Pothuaud, Laurent; Carceller, Pascal; Hans, Didier (2008). "Correlations between grey-level variations in 2D projection images (TBS) and 3D microarchitecture: Applications in the study of human trabecular bone microarchitecture". Bone. 42 (4): 775–87. doi:10.1016/j.bone.2007.11.018. PMID18234577.
↑ Hans, Didier; Barthe, Nicole; Boutroy, Stephanie; Pothuaud, Laurent; Winzenrieth, Renaud; Krieg, Marc-Antoine (2011). "Correlations Between Trabecular Bone Score, Measured Using Anteroposterior Dual-Energy X-Ray Absorptiometry Acquisition, and 3-Dimensional Parameters of Bone Microarchitecture: An Experimental Study on Human Cadaver Vertebrae". Journal of Clinical Densitometry. 14 (3): 302–12. doi:10.1016/j.jocd.2011.05.005. PMID21724435.
↑ Piveteau, Teddy; Winzenrieth, Renaud; Hans, Didier (2011). "Assessment of correlations between 3D μCT microarchitecture parameters and TBS: Effects of resolution and correlation with TBS DXA measurements". Journal of Clinical Densitometry. 14 (2): 169. doi:10.1016/j.jocd.2011.02.056.
1 2 Pothuaud, Laurent; Barthe, Nicole; Krieg, Marc-Antoine; Mehsen, Nadia; Carceller, Pascal; Hans, Didier (2009). "Evaluation of the Potential Use of Trabecular Bone Score to Complement Bone Mineral Density in the Diagnosis of Osteoporosis: A Preliminary spine BMD–Matched, Case-Control Study". Journal of Clinical Densitometry. 12 (2): 170–6. doi:10.1016/j.jocd.2008.11.006. PMID19181553.
↑ Winzenrieth, Renaud; Dufour, Rémy; Pothuaud, Laurent; Hans, Didier (2009). "A Retrospective Case–Control Study Assessing the Role of Trabecular Bone Score in Postmenopausal Caucasian Women with Osteopenia: Analyzing the Odds of Vertebral Fracture". Calcified Tissue International. 86 (2): 104–9. doi:10.1007/s00223-009-9322-y. PMID19998029. S2CID24345190.
↑ Rio, L. M.; Winzenrieth, R.; Cormier, C.; Gregorio, S. (2012). "Is bone microarchitecture status of the lumbar spine assessed by TBS related to femoral neck fracture? A Spanish case–control study". Osteoporosis International. 24 (3): 991–8. doi:10.1007/s00198-012-2008-8. PMID22581295. S2CID5844264.
Osteoporosis is a systemic skeletal disorder characterized by low bone mass, micro-architectural deterioration of bone tissue leading to bone sterility, and consequent increase in fracture risk. It is the most common reason for a broken bone among the elderly. Bones that commonly break include the vertebrae in the spine, the bones of the forearm, the wrist, and the hip. Until a broken bone occurs there are typically no symptoms. Bones may weaken to such a degree that a break may occur with minor stress or spontaneously. After the broken bone heals, the person may have chronic pain and a decreased ability to carry out normal activities.
Dual-energy X-ray absorptiometry is a means of measuring bone mineral density (BMD) using spectral imaging. Two X-ray beams, with different energy levels, are aimed at the patient's bones. When soft tissue absorption is subtracted out, the bone mineral density (BMD) can be determined from the absorption of each beam by bone. Dual-energy X-ray absorptiometry is the most widely used and most thoroughly studied bone density measurement technology.
Teriparatide, sold under the brand name Forteo, is a form of parathyroid hormone (PTH) consisting of the first (N-terminus) 34 amino acids, which is the bioactive portion of the hormone. It is an effective anabolic agent used in the treatment of some forms of osteoporosis. Teriparatide is a recombinant human parathyroid hormone analog. It has an identical sequence to the 34 N-terminal amino acids of the 84-amino acid human parathyroid hormone.
A trabecula is a small, often microscopic, tissue element in the form of a small beam, strut or rod that supports or anchors a framework of parts within a body or organ. A trabecula generally has a mechanical function, and is usually composed of dense collagenous tissue. It can be composed of other material such as muscle and bone. In the heart, muscles form trabeculae carneae and septomarginal trabeculae. Cancellous bone is formed from groupings of trabeculated bone tissue.
Osteopenia, known as "low bone mass" or "low bone density", is a condition in which bone mineral density is low. Because their bones are weaker, people with osteopenia may have a higher risk of fractures, and some people may go on to develop osteoporosis. In 2010, 43 million older adults in the US had osteopenia. Unlike osteoporosis, osteopenia does not usually cause symptoms, and losing bone density in itself does not cause pain.
Bone density, or bone mineral density, is the amount of bone mineral in bone tissue. The concept is of mass of mineral per volume of bone, although clinically it is measured by proxy according to optical density per square centimetre of bone surface upon imaging. Bone density measurement is used in clinical medicine as an indirect indicator of osteoporosis and fracture risk. It is measured by a procedure called densitometry, often performed in the radiology or nuclear medicine departments of hospitals or clinics. The measurement is painless and non-invasive and involves low radiation exposure. Measurements are most commonly made over the lumbar spine and over the upper part of the hip. The forearm may be scanned if the hip and lumbar spine are not accessible.
Quantitative computed tomography (QCT) is a medical technique that measures bone mineral density (BMD) using a standard X-ray Computed Tomography (CT) scanner with a calibration standard to convert Hounsfield Units (HU) of the CT image to bone mineral density values. Quantitative CT scans are primarily used to evaluate bone mineral density at the lumbar spine and hip.
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Mary Larsen Bouxsein is an American biomechanical engineer and an orthopedic researcher. She is the president of the American Society for Bone and Mineral Research, director of the Centre of Advanced Orthopaedic Studies at Beth Israel Deaconess Medical Center, professor at the department of Orthopedic Surgery at Harvard Medical School. She is known for her work on bone density and the use of imaging to define the factors leading to bone fractures.
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