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Vertebral Fracture Assessment: Ounce of Prevention


 

NEW ORLEANS — Patients with vertebral fractures have a four- to fivefold higher risk for subsequent fragility fractures and should be targeted for aggressive therapy, Michael McClung, M.D., said at the annual meeting of the International Society for Clinical Densitometry.

“The combination of bone density testing and vertebral fracture assessment is a powerful combination as we attempt to stratify patients into those at very high risk who would clearly benefit from treatment,” added Dr. McClung of the Oregon Osteoporosis Center in Portland.

Both severity and number of existing vertebral fractures are the best predictors of future vertebral fracture risk, regardless of bone density.

Payers are also starting to appreciate the benefit of assessing patients for such fractures. Medicare has agreed to reimburse physicians for vertebral fracture assessment (VFA) based on the new CPT code, 76077. Reimbursement is set at $43 and a referring physician must order the test. The International Society for Clinical Densitometry is set to take up the subject of VFA criteria at its position development conference later this year in Vancouver, B.C.

VFA is conducted using dual-energy x-ray absorptiometry and has a number of advantages that make it an attractive marker for evaluating an individual's future fracture risk. As an in-office procedure, patients don't have to be sent elsewhere as is the case with radiography. The radiation dose required for VFA is also substantially lower than for conventional radiographs. The whole spine is pictured in one image, not in a series, making it easier to read.

The images are also digitized which allows for magnification and other image manipulation. The images can be archived and reviewed side by side with images from follow-up examinations.

The main drawback is that VFA resolution is lower than for conventional radiographs. In particular, the upper spine is harder to visualize because of artifacts related to the lungs and ribs.

VFA should be considered for:

▸ Women aged 65 years or older.

▸ Men aged 70 years or older.

▸ Patients who have known height loss of at least 1.5 inches.

▸ Patients with a clinical history or nonradiologic assessment findings suggestive of vertebral fracture.

▸ Patients with bone density evidence of osteoporosis at the hip or spine.

▸ Patients with kyphosis on physical exam.

▸ Patients on long-term glucocorticoid therapy.

Vertebral Fracture Assessment Tips

In performing VFA, the Genant semiquantitative method provides a visual reference for grading fracture types (wedge, biconcave, or crush) and severity (mild, moderate, and severe). Wedge compression fractures are more likely to occur in the thoracic spine, while biconcave fractures are more likely to occur in the lumbar spine, Dr. McClung said.

It's important to be very cautious in attempting to diagnose mild or grade 1 fractures using VFA alone unless the resolution of the scan is very good, he added. This is particularly true of wedge fractures of the thoracic spine and biconcave fractures of the lumbar spine. But the technique is very good for identifying grades 2 and 3 fractures, which have more clinical significance. There are a number of conditions that make it difficult to interpret VFA findings, including severe scoliosis, motion, rib/scapular shadows, bowel gas, and calcifications. Dr. McClung, therefore, advises against making the diagnosis of an osteoporotic fracture until considering the differential diagnoses and identifying the cause of the fracture.

Follow up with x-ray when there is an equivocal fracture; if vertebrae (T6-L4) are unidentifiable; if there are confounding factors or artifacts; or there are osteosclerotic, lytic, or suspect deformities. Also, get an x-ray if there are unspecified soft tissue or bone abnormalities.

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