What Is A Trabecular Bone Score?

Today I want to talk briefly about your Trabecular Bone Score (TBS).

You probably already know that your DXA scan and the resulting T score don't give you the full picture of your bone health. It is a score of bone density and doesn't give you a lot of information about your fragility.

The next step in figuring out your risk of fracture is your Trabecular Bone Score.

Anatomy first. You have two types of bone, cortical and trabecular.

Cortical bone is the hard, outer part of your bone, it is dense and compact.

Trabecular bone is the inner bone. It is honeycomb-like, and filled with marrow and fat.

The TBS is calculated from the lumbar spine image in your DXA scan. It is important to note that not all DXA scans can give you the TBS value, as it is computed from a specific software program your imaging center has to have.

Getting a TBS can add to the bone health picture by helping to predict your risk of bone fracture. It takes information about the number and spacing characteristics of the trabecular bone and gives you a score.

While a high TBS number indicates strong inner bone, a low TBS number is related to an increased risk of fracture. This is valuable because the DXA scan alone may indicate very mild osteopenia or normal bone mass while the inner bone may be more fragile.

Having two scores (the TBS and the DXA) will give you a better picture of what is happening with both the cortical and trabecular bone. You can then add your medical history to the puzzle to help you determine how to proceed with getting stronger bones and eventually reducing your risk of fracture.

I hope this is helpful. As always, my references are listed below. You can read more in-depth if that is your thing - I gave you an overview here today.

Get active today!

Andrea Trombley PT, DPT

References:​
Harvey, N. C., Glüer, C. C., Binkley, N., McCloskey, E. V., Brandi, M. L., Cooper, C., Kendler, D., Lamy, O., Laslop, A., Camargos, B. M., Reginster, J. Y., Rizzoli, R., & Kanis, J. A. (2015). Trabecular bone score (TBS) as a new complementary approach for osteoporosis evaluation in clinical practice. Bone, 78, 216–224. https://doi.org/10.1016/j.bone.2015.05.016

Sangondimath, G., Sen, R. K., & T, F. R. (2023). DEXA and Imaging in Osteoporosis. Indian journal of orthopaedics, 57(Suppl 1), 82–93. https://doi.org/10.1007/s43465-023-01059-2