Trabecular Bone Score (TBS)
Trabecular Bone Score (TBS) is measured from a lumbar spine DXA image and thus no extra scan is required. TBS is a measure of bone texture which correlates to bone microarchitecture. Chatswood Densitometry, with our partner site at St Vincents Clinic, were first to introduce TBS to Australia. It is routinely performed in patients 40 and older at no additional charge
In patients with normal or osteopenic bone density who have sustained a minimal trauma fracture, TBS can provide a measure of bone quality. With a high TBS score, bone microarchitecture is dense and well-connected. Conversely, a low TBS score means that bone microarchitecture is incomplete and weakened. In combination with routine bone density results, the TBS score can be useful in predicting fracture risk in patients with other risk factors such as prolonged steroid therapy or hyperthyroidism.
For example, a patient with low bone density and a high TBS score will have a lower fracture risk than a patient with low bone density and low TBS score.
TBS is particularly useful in patients with BMD values in the low osteopenic range (T score between -2.0 and -2.5) in whom a low TBS indicates possible need to consider commencing treatment. TBS is unreliable in individuals with a body mass index (BMI - kg/m2) of over 35.
Below is an interpretation guide for doctors to aid in evaluating your patient's BMD and TBS results.
Medimaps group provides the TBS software. A list of publications regarding this software is available on their website: http://www.medimapsgroup.com/
Below is a downloadable atlas for TBS
Like regular bone density, TBS also has a reference range matched for age and sex.