Diagnosis of vertebral fractures by vertebral fracture assessment

Vertebral fractures are independent risk factors for both vertebral and peripheral fractures and only one-third of these fractures come to clinical attention. Vertebral fracture assessment (VFA) is a radiographic method using dual X-ray absorptiometry (DXA) to assess vertebral deformities during bone density measurement. We performed VFA of the spine from T4 to L5 on a Delphi W device (Hologic, Bedford, MA) in 136 postmenopausal patients (69+/-10 yr). These patients also had X-rays of the thoracic and lumbar spine. VFA was independently compared with X-rays by two rheumatologists, for the diagnosis of vertebral fractures at both the patient and vertebral levels. Using X-rays, 61 patients (45%) had at least one vertebral fracture. The percentage of unreadable vertebrae was 1% and 12.4% on X-rays and VFA, respectively (p<0.0001). At the patient level, VFA allowed to diagnose if the patient had no fracture or had at least one fracture in 74% of patients. In 11.2% of cases, VFA misclassified the patients. At the vertebral level, diagnostic efficacy of VFA as compared with X-rays was 97%. Concordance between both observers was good (kappa-score=0.69). We designed an algorithm for decision of performing X-rays in postmenopausal women: Using results of VFA would avoid X-rays in 32% of our patients. VFA is a reliable technique with low radiation, and is easily and rapidly applicable during bone density measurement by DXA, which could improve management of osteoporotic patients.