Bone Mineral Density Measurements and Fracture Prediction in the Very Elderly

Bone density decreases with age, increasing the risk of fragility fractures. Dual-energy X-ray absorptiometry (DEXA) scanning may be used to measure bone density and estimate this risk. Degenerative changes in the spine may decrease the accuracy of DEXA results. We present the clinical course of a 92-year-old woman with a diagnosis of osteopenia of the left femoral neck and a risk for fragility fracture that was previously below the threshold for treatment, who underwent routine follow-up bone density screening. The DEXA scan showed an increase in bone density at the lumbar spine. Within a week of this study, she experienced severe back pain rated eight to nine out of 10 without a precipitating event. The following day, a lumbar X-ray showed disk space narrowing at multiple levels, spondylolisthesis at L4/5, diffuse spondylosis, and a new compression fracture at T12. This case illustrates the challenges of preventing and treating low bone density in the very elderly.