Utility of Spine Bone Mineral Density in Fracture Prediction Within FRAX

Predicting individuals at risk for fracturing and modifying that risk are important in preventative health. Our aim was to quantify the impact of spine bone mineral density (BMD) on fracture risk prediction and determine the positive predictive value of fracture prediction using the lowest BMD value at the femoral neck, total hip, or lumbar spine. A retrospective cross-sectional analysis of 15,033 women was performed, assessing the contribution of age, body mass index, number of clinical risk factors, T-score, and osteoporosis category to the presence of fracture. In patients whose lumbar spine T-scores are 1 or 2 osteoporosis categories lower than femoral neck, there is an approximately 30% increased risk of fracture compared with the femoral neck alone. For patients younger than 60 yr, the odds ratio of having a fracture based on the presence of lumbar spine osteoporosis was greater than that based on femoral neck osteoporosis. Osteoporosis at the total hip correlated best with the presence of fracture. When using FRAX, we recommend that the 10-yr fracture prediction be adjusted when lumbar spine T-score is 1-2 osteoporosis categories lower than the femoral neck T-score or when lumbar spine T-score is ≥1 standard deviation less than femoral neck T-score.