A prior fragility fracture is one of the strongest predictors for a subsequent one, and this should be a target for secondary fracture prevention. All injured patients admitted to the emergency floor, Ume̊ University Hospital, Sweden, were registered. Between 1993–2004, there were 113,668 injury events, including 29,190 fracture events (one or more fractures at the same time), of whom 12,635 patients were _ 50 years. 1,994 of them had at least two fracture events; 500 had 3; 131 had 4; 35 had 5; and 11 had _ 6 fracture events. Mean age at the baseline fracture was 72.2 years and 75.5 at the second one. Thus, over 50 years of age, not less than 37% of all fractures were serial fractures, and 20% of the patients are serial fracturers.

Hip and radius fracture were the most common ones, but 20% were fractures not traditionally labelled as fragility fractures. However, since more than 78% were caused by falls in the same level, most presumably have a fragility component.

The interval between the two first fractures was longer than reported in several previous studies, mostly on patients participating in clinical trials. However, our material is population-based and unselected, since there is just one trauma facility in the area, and the general population is healthier than in-hospital or trial patients. On the other hand, there is a cut-off bias, so the interval is likely to be even longer.

Interestingly, the difficult-to-treat hip fracture was the second common baseline fracture, the most common subsequent one, and hip-hip fractures were the most common combination, not less than 8.5% of the serial fractures. It is therefore clinically important to use the information provided by the fracture event, a fragility fracture may actually be regarded as a biomechanical test or a natural experiment. Trauma units, therefore, have an onus to screen for risk factors and inform patients about the treatment options, and to organize fracture liaison services. This seems to be especially cost-efficient for our oldest and frailest patients, but alas this is rarely done. A similar neglect of secondary prophylaxis and treatment after cardiovascular disorders would be an outrage! Secondary prevention is especially important since serial fractures are so common, often preventable, having a high impact on health-related quality of life

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