Introduction: A secular trend in hip fracture incidence shows a decrease in Europe and North America. Although the results are age adjusted – is there a decreasing trend in all age groups or is just the fracture curve drifting?

Material and Methods: In this population based material includes all hip fractures 1993–2005, in men and women, age 50 years or older admitted to the University Hospital in Ume̊ in the northern part of Sweden. The total numbers of hip fractures in this age group over this 13 years period were 2919 (909(31%) in men and 2010 (69%) in women). The crude numbers of fractures and incidence were mean value over the time periods 1993–96 and 2001–05.

Results: The age adjusted incidence were showing a declining trend X 1993–96, Y 1997–2000, Z 2001–05(ska kolla med Hans hur jag räknar ut). The crude numbers of hip fractures per year are more or less constant 93–96 222,25 (150 women and 72,25 men), 01–05 221,1 (152,4 women and 68,8 men) When analyzing the age groups separately a 50% increase in crude fracture rate was noted in women age 90 or older (11,5 hip fractures/year(93–96) and 24,6 hip fractures/year(01–05). The latter fracture rate can be compared with the crude number of hip fractures in women age 75–79 (27,2 fractures/year 2001–05).

The incidence was also increasing during this period of time, from 270/10.000 to 390/10.000 among the women age 90 or older.

In men there were a declining trend in both incidence and crude numbers, only a small increase of crude fractures were noted among the oldest men age 90 or older.

Conclusion: Though the age adjusted incidence shows a declining secular trend the crude facture rate and incidence are increasing in the oldest women age 90 year or older. Changes in this particular age group does not affect the age adjusted incidence when analyzing the whole population age 50 years or older. (kolla upp) Women 90 years and older do now account for the same amount of hip fractures every year as the women 75–79 years. There seem to be a drifting in the hip fracture incidence pattern towards older. It is therefore important to analyze secular changes in incidence separately in different age groups so that changes in fracture pattern can be identified.

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