Changes in bone mass and fracture type in patients with hip fractures. A comparison between the 1950s and the 1980s in Malmö, Sweden.

A consecutive series of 970 hip fractures from 1950 to 1958 were reevaluated and compared with roentgenograms of 1359 hip fractures from 1983 to 1985. The femoral neck index (FNI) was measured and the Singh index (SI) determined. The number of trochanteric fractures has increased more than the number of cervical fractures during the past 30 years. There has been a shift during the last 30 years toward more dislocated cervical fractures. There has been no change in the distribution between stable and unstable trochanteric fractures. The FNI was significantly lower in the 1980s compared with the 1950s, both in men and women. In the 1980s, men and women with cervical fractures had a lower FNI compared with men and women with trochanteric fractures, even after age correction. The SI was significantly lower in the 1980s than in the 1950s, both in men and women, but the difference was significant in trochanteric fractures only. In the 1980s, trochanteric fractures had a lower SI compared with cervical fractures; this relationship was significant both in men and women. Our findings indicate that the bone mass, both cortical and trabecular, measured on roentgenograms of the hip, has diminished in the urban population during the past three decades. This could be one of many reasons for the increased incidence of hip fractures.