Potential drawbacks
The TBS software used in Dr. Thacker’s study has been validated only in Asian and White patients between certain ages and weights, meaning the system is not designed to be used for other populations. Other researchers have highlighted a need for trabecular bone scoring to be validated more broadly. The authors of a recent analysis, however, suggest that TBS can be used the same way no matter a patient’s race.
TBS “is going to be most helpful in those with osteopenia who are right near the threshold for treatment,” said Marcella Donovan Walker, MD, MS, in a presentation on bone quality at the meeting.
Many studies have shown that TBS “provides additive information to bone density,” said Dr. Walker, a professor of medicine in the division of endocrinology at Columbia University, New York. For example, a large study of women in Manitoba found that, regardless of whether their bone density was normal, osteopenic, or osteoporotic, those with a low TBS had a much higher risk for fracture.
‘Opportunistic screening’ with CT?
TBS relies on the same DXA scans that are used to calculate bone mineral density, so obtaining the score does not add time or radiation to the scanning process, Dr. Thacker said.
But many patients who should receive DXA scans do not, which adds to the promise of “opportunistic screening” for osteoporosis, Dr. Walker said. With this approach, physicians would analyze a CT scan that a patient received for another purpose, such as to investigate abdominal pain or chest pain.
“In these images is information about the bone,” Dr. Walker said.
Researchers have used high-resolution peripheral quantitative CT to perform finite element analysis, where a computer program simulates compression of the bone to create a measure of bone stiffness and determine the load required for a break.
One study found that including those elements predicted fractures better than bone mineral density or the Fracture Risk Assessment Tool alone, Dr. Walker noted.
Other aspects of bone quality include how many cracks are in the bone, the amount of adipose in the marrow space, and the rate at which bone is broken down and rebuilt. But Dr. Walker suggested that the longstanding focus on bone mineral density in clinical practice makes sense.
“By far, bone mass is the most important bone quality,” Dr. Walker said.
Dr. Thacker is the executive director of the nonprofit Speaking of Women’s Health. Dr. Walker reported receiving funding from the National Institute of Arthritis and Musculoskeletal and Skin Diseases and Amgen.
A version of this article first appeared on Medscape.com.