[Physiopathology and prevention of fractures of the proximal end of the femur].

Hip fracture is the most important skeletal problem in elderly people. Its two main determinants are falls and bone loss leading to an intrinsic bone fragility. Bone fragility results from postmenopausal and senile bone loss. The latter is increased by the secondary hyperparathyroidism of elderly persons which is induced by a combination of vitamin D deficiency and calcium intake, both very common in old age, particularly in Europe. Prophylactic strategies should be based on prevention of falls and of bone fragility. The latter includes the optimization of peak bone mass during childhood, postmenopausal oestrogen replacement therapy and a late prevention of senile secondary hyperparathyroidism by vitamin D and calcium supplements which have recently been shown to reduce by 25% the number of hip fractures in a prospective study performed in a large population of institutionalized women. Therefore, it is never too early to pay attention to the risk of osteoporosis, and never too late to prevent hip fractures.