Treat to Target #4 – TBS
Our goal is NO NEW FRACTURES. Cancellous (spongy, like the ends of the drumstick) bone should be a strong latticework of struts called trabeculi. Clinical Osteoporosis, an increased fracture risk, occurs when some of the struts disappear.
Trabecular Bone Score (TBS) evaluates the spongy bone in the DXA images of the vertebrae (spine) looking for irregularities. When TBS finds uneven bone mineral density within the spine DXA, that indicates a higher fracture risk, regardless of the total BMD.
Adding the TBS feature to a DXA machine allows the quality of bone in the spine to influence the FRAX score, just like the BMD in the femoral neck part of the hip influences the FRAX score. Adding TBS detects more patients at high fracture risk who should be treated to avoid fractures.
Diabetes increases a person’s fracture risk for any given DXA BMD or T-score. Controlled diabetes adds about the same risk as rheumatoid arthritis, so we usually check that box in FRAX. Uncontrolled diabetes is more serious requiring further adjustment to FRAX.
FRAX is pre-empted by a hip fracture. “Do not pass GO, do not collect $200, start a pharmaceutical” Vertebral (spine) Fracture is the same, but the majority of spine fractures are not noticed clinically. “Morphometric” (first noticed on x-ray) vertebral fractures count, but how to find them?
VFA next time
Jay Ginther, MD