Secular trends in the incidence of hip fractures.

To explore possible changes in proximal femur (hip) fracture incidence over time, an earlier study among Rochester, Minnesota residents for 1928-1977 was updated through 1982. Reanalysis of data demonstrated rising age-adjusted rates for men over this time. Crude rates rose for women as well, but age adjusted rates leveled off in the mid-1950s, as did overall rates, since the majority of hip fractures were in women. Secular trends were primarily due to changes in the incidence of initial hip fractures associated with moderate trauma, the sort usually attributed to osteoporosis. No differences were noted in trends for cervical vs. intertrochanteric femur fractures; and, excluding the low values for 1928-1942, no significant trends were noted for women within various age groups. Our results for women conflict with estimates from a number of other studies, but these differences may provide a basis for hypothesis development.