Even in patients with pronounced osteoporosis, fragility is rarely a sufficient or necessary cause of fracture. Almost always a trauma involved. Exposure to injuries varies with eg sociologic and climatologic. Since 1993 all injuries admitted to Ume̊ University hospital, Sweden, up to 58 parameters have been registered, eg mechanism, environment, involved products and diagnoses. The 12-year population-based injury register now comprises113,668 injuries (29,190 fractures).

The absolute number of fractures is important from a practical clinical point of view. Most fractures occur in the extremities of life, perhaps due to both a weaker skeleton in growth and senescence and to exposure to injury. The earlier fracture peak in girls is caused by their earlier growth spurt. The higher and broader fracture peak in boys also reflects behavioural factors. Men continue to have more fractures until around 50, showing the effect of menopause.

Radius fracture incidence in Ume̊ was about 15% higher than in Malmö, Sweden. But surprisingly hip fracture incidences were in the same order of magnitude in Malmö and Ume̊, which is remarkable considering the 8o latitude difference. But this may be explained by the different injury mechanisms in the two fractures

Low energy-trauma (fall in the same level) was most common in the extremities of life. However, most of the other mechanisms also involved low-moderate trauma, and high-energy trauma was rare. In this sub arctic register, outdoor slips was a common cause of fracture in middle age but as in other materials such injuries became less common with age.

A further detailed analysis of the mechanisms causing fractures and soft tissue injuries could be a useful tool in prevention of fall injuries. Is it possible to identify frequent fallers or other accident prone people, before an incapacitating injury? This would indeed be a major public health challenge