Effect of sex and age on the ratio of cervical to trochanteric hip fracture. A meta-analysis of 16 reports on 36,451 cases.

We analyzed 15 published reports and our own data. In women, the ratio of cervical to trochanteric fractures (C/T) evolved in 3 periods. 1) Before the age of 50 years, the annual incidence of cervical fracture is close to that of trochanteric fracture. 2) Between 50 and 60 years, cervical fracture increases markedly, and the C/T ratio is well above unity at an age when the fracture incidence is still very low. 3) This imbalance progressively diminishes to reach unity in the very old, as the result of a progressive increase in trochanteric fractures. In men, cervical fractures are progressively more common with increasing age, and the C/T ratio exceeds unity after 70 years of age. In both genders, the incidence of cervical fracture is thus greater than that of trochanteric fracture during a limited period of time, in the perimenopausal period for women and in elderly men. Several hypotheses on the mechanics of falls and bone strength have been advanced, without any satisfactory explanation for the C/T sex and age changes.