Examination of prevalence rates of possible risk factors in a population with a fracture of the proximal femur.

No statistical increase in the prevalence of either diabetes, rheumatoid arthritis or primary hyperparathyrodism was found among the hip fracture patient population. Since the relative risks for these diseases is small, the statistics suggest that these conditions are either noncontributory or represent only a minor risk factor in the overall pathogenesis of hip fractures. About 20% of the hip fracture patients had a history of other identifiable risk factors such as thyrotoxicosis, hemiplegia, malabsorption syndromes and corticosteroid therapy. Of these conditions only thyrotoxicosis could be evaluated by comparison of prevalence rates, and a significant increase was found among the fracture patients. A highly significant correlation was found between the side of a previous hemiplegia and side of he subsequent hip fracture; this may be due to the development of disuse osteoporosis in the hemiplegic limb. Recent reports have shown that a reduction in the number of hip fractures is associated with a high calcium intake or prophylactic estrogen therapy. Preventive therapy in patients with hemiplegia, thyrotoxicosis, or other predisposing conditions leading to osteopenia might result in a further reduction of the hip fracture rate.