Trabecular Bone Score
Also called: TBS
What it means
Trabecular Bone Score (TBS) is a measurement taken from your spine DEXA image that estimates how well-connected your bone's internal scaffolding is, adding information beyond simple bone density.
Your fracture risk depends on more than density alone, so TBS can reveal quality issues a density number might miss.
Trabecular Bone Score, or TBS, is a texture analysis done on the same lumbar spine image from your DEXA scan. Instead of just measuring how dense your bone is, it looks at how well-connected the internal scaffolding, or trabecular bone, appears to be. Two people can have the exact same bone density number and still have different TBS results, because density and architecture are not the same thing.
This matters because strength comes from more than density alone — it also depends on architecture and material quality. TBS adds independent information about fracture risk that a density number by itself can't capture. For example, someone whose density is only in the osteopenia range but who has already had a fracture from a minor fall may have a quality problem that density alone doesn't explain.
Because of this, fracture history is considered more telling than any single scan number in risk models. If your results are available, it's worth asking your physician whether a TBS or similar fragility score was calculated alongside your regular DEXA report, and discussing what it adds to the full picture of your bone health.
How sure is this?
Graded Strong Clinical Evidence: Supported by multiple well-designed clinical studies in humans. Read each study with its grade in mind. One study is a piece of the picture, not the whole of it.
Where the Academy teaches it
This page is the short version. The lessons teach it in full, with the context around it and a quiz to lock it in.
Questions people ask about this
A T-score compares your bone density to that of a healthy young adult, measured in standard deviations: -1.0 and above is normal, -1.0 to -2.5 is osteopenia, and -2.5 or below is osteoporosis. But it's just one snapshot of density — it doesn't capture bone quality, your fall risk, or your overall fracture probability, so it's worth tracking several other things alongside it and discussing them with your physician.
Read the full answer →A DEXA scan uses a low dose of X-ray to measure bone mineral density at the hip and spine, and it's the long-established standard that generates your T-score. A REMS scan uses ultrasound instead of radiation to assess the same areas, comparing the echo signal to reference models to produce its own T-score (not directly interchangeable with a DEXA T-score) plus a separate "fragility score" reflecting tissue quality. REMS is newer, has less long-term data, and is best used alongside DEXA rather than replacing it, especially if you already have a DEXA history.
Read the full answer →No. A higher bone density score lowers your statistical risk on average, but it doesn't guarantee you won't fracture. Density is only part of what makes bone strong — architecture, bone quality, and your risk of falling all matter too, and many fragility fractures actually happen in people whose scans look normal or only mildly low (osteopenic).
Read the full answer →Related words
Bone mineral density (BMD) measures how much mineral is packed into your bones, usually estimated with a DEXA scan,…
A DEXA scan is a low-radiation X-ray test that measures how much mineral is in your hip and spine bones, giving you…
A T-score shows how your bone density compares to a healthy young adult, measured in standard deviations, and it's…
FRAX is a free online tool that calculates your 10-year probability of having a major osteoporotic fracture or hip…
A fragility fracture is a broken bone caused by a fall or bump that normally wouldn't break a healthy bone, often at…
Osteopenia means your bone density, as measured by a DEXA scan, is lower than average but not as low as osteoporosis…
Education only, not medical advice. Decisions about tests, medications and treatment belong with your own doctor. OsteoStrong does not diagnose, treat or cure any disease.
