Continuously rising problem of osteoporotic knee fractures in elderly women: nationwide statistics in Finland in 1970-1999 and predictions until the year 2030.

We assessed the current trends in the number and incidence of osteoporotic knee fractures in Finland by collecting data from the National Hospital Discharge Register for all patients > or =60 years of age who were admitted to Finnish hospitals in 1970-1999 for primary treatment of such fractures. The knee fracture was defined "osteoporotic" if it was caused by a low-energy trauma only; that is, a fall from standing height or less. We also predicted fracture development until the year 2030 by a regression model, which took into account the predicted changes in the fracture incidences and population at risk. The number and incidence (per 100,000 persons) of osteoporotic knee fractures in Finnish women aged > or =60 years clearly rose during the study period, from 218 (number) and 55 (incidence) in 1970 to 685 and 113 in 1999. Even after age adjustment, the incidence of women's fractures showed a clear increase, from 59 in 1970 to 105 in 1999. If this trend continues, there will be about 2.5 times more osteoporotic knee fractures in Finnish women in the year 2030 than there were in 1999. In Finnish men aged > or =60 years, the annual number of fractures and its changes were clearly smaller (77 in 1970 vs. 138 in 1999), and the fracture incidence did not show consistent trend changes over time (30 in 1970 vs. 34 in 1999). We conclude that in elderly Finnish women the number of osteoporotic knee fractures shows a rise with a rate that cannot be explained merely by demographic changes and, therefore, vigorous preventive measures are needed to control this development.