HIP-FRACTURES IN YOUNG-PATIENTS - IS THIS EARLY OSTEOPOROSIS

Hip fracture in patients under age 50 is rare, and is often not attributable solely to the energy of injury. Our aim was to determine if trabecular bone mineral density (BMD) is abnormal in young patients with hip fractures. We reviewed all hip fractures treated at our institution between 1979 and 1986 and contacted 20 patients under the age of 50 at the time of injury, all of whom wished to be studied. The mean age at the time of injury was 39 (range 24-47). Subjects were questioned for osteoporosis risk factors, classified by level of energy producing their injury, and then underwent quantitative computed tomography (QCT) bone densitometry of trabecular bone in the lumbar spine. Bone mineral density by QCT was below the mean for age in 90% of the patients, and was greater than 1 SD below the mean in 75%. Mean percentage BMD decrease from age-matched controls was 34% (P<0.005) in women and 19% (P<0.005) in men. There was an inverse correlation in the degree of BMD decrease and the energy level of injury. There was a direct correlation of the severity of BMD decrease and the cumulative number of osteoporosis risk factors. This investigation has found that 1-7 years following hip fracture, otherwise presumedly healthy young patients demonstrate a statistically significant decrease in spinal BMD from age/sex-matched controls. These data do not determine if osteopenia is the cause or the result of injury, nor do we wish to infer that measurement of bone density at one site can predict future fractures at other sites. However, as current thinking supports continuous age-related BMD decrease, this young group of patients with relatively low BMD for their age may be at increased risk for future development of more severe osteopenia. These findings suggest that the significance of hip fractures in young patients may currently be underestimated, and such patients may provide the unique opportunity for early identification of a group at increased risk for developing osteoporosis. © 1990 Springer-Verlag New York Inc.