Context The incidence of distal forearm fractures in children peaks around the
time of the pubertal growth spurt, possibly because physical activity increases
at the time of a transient deficit in cortical bone mass due to the increased
calcium demand during maximal skeletal growth. Changes in physical activity
or diet may therefore influence risk of forearm fracture.
Objective To determine whether there has been a change in the incidence of distal
forearm fractures in children in recent years.
Design, Setting and Patients Population-based study among Rochester, Minn, residents younger than
35 years with distal forearm fractures in 1969-1971, 1979-1981, 1989-1991,
Main Outcome Measure Estimated incidence of distal forearm fractures in 4 time periods.
Results Comparably age- and sex-adjusted annual incidence rates per 100 000
increased from 263.3 (95% confidence interval [CI], 231.1-295.4) in 1969-1971
to 322.3 (95% CI, 285.3-359.4) in 1979-1981 and to 399.8 (95% CI, 361.0-438.6)
in 1989-1991 before leveling off at 372.9 (95% CI, 339.1-406.7) in 1999-2001.
Age-adjusted incidence rates per 100 000 were 32% greater among male
residents in 1999-2001 compared with 1969-1971 (409.4 [95% CI, 359.9-459.0]
vs 309.4 [95% CI, 259.3-359.5]; P = .01) and 56%
greater among female residents in the same time periods (334.3 [95% CI, 288.6-380.1]
vs 214.6 [95% CI, 174.9-254.4]; P<.001). The peak
incidence and greatest increase occurred between ages 11 and 14 years in boys
and 8 and 11 years in girls.
Conclusions There has been a statistically significant increase in the incidence
of distal forearm fractures in children and adolescents, but whether this
is due to changing patterns of physical activity, decreased bone acquisition
due to poor calcium intake, or both is unclear at present. Given the large
number of childhood fractures, however, studies are needed to define the cause(s)
of this increase.