Occurrence of vertebral fracture more closely associated with decreased anteroposterior than lateral lumbar bone mineral density

OBJECTIVES: While it has been pointed out that an anteroposterior (AP) view of the lumbar spine may lead to overestimation of the bone mineral density (BMD), a lateral view is expected lead to the early detection of BMD loss on scanning cancellous bone. Vertebral fracture is often seen in aged osteoporotic patients, and it is important to prevent this fracture. Therefore, we aimed to identify the optimal site for BMD measurement to assess the risk of vertebral fracture. METHODS: Forty-seven female patients with fresh osteoporotic vertebral fracture and BMD measurements were included in this study (Fracture group). As a non-fractured control group, 218 female patients with BMD measurements were enrolled (Control group). We compared BMD values based on AP and lateral views of the lumbar spine from L2 to L4 and the femoral neck. With a lateral view of the lumbar spine, we measured both the total vertebral body and vertebral body center, mainly composed of cancellous bone. RESULTS: BMD of the AP lumbar spine in the Fracture group was significantly lower than in the Control group (P < 0.05). In the subanalyses for comparisons between age-matched fracture and control groups, BMD of only the AP lumbar spine in the Fracture group was significantly lower than in the Control group (P < 0.01). CONCLUSIONS: AP lumbar spine BMD is optimal for assessing vertebral fracture occurrence.