Background: Of the many studies of slipped capital femoral
epiphysis, none have specifically addressed Amish children. The Amish reflect
a small gene pool relative to the general white North American population.
Additional knowledge of the demographics of this disorder in Amish children
may provide genetic insights. The purpose of this study was to review the
demographics of slipped capital femoral epiphysis in the Amish population.
Methods: A retrospective review of the cases of twenty-five Amish
children with slipped capital femoral epiphysis treated at two institutions
was performed. The child's gender, age, weight, height, and body mass index at
the time of the diagnosis; duration of symptoms; laterality of the slip; birth
weight; family history; and slip severity were recorded. The slip was
classified as stable or unstable. Patients who had been included in a
previously published multicenter study served as a control group.
Results: There were seventeen boys and eight girls with a total of
thirty-three slipped capital femoral epiphyses; eight of the slips were
bilateral. At the time of the diagnosis, the mean age (and standard deviation)
was 13.4 ± 1.6 years, the mean weight and height were 55.6 ±
12.4 kg and 155.5 ± 10.2 cm, and the mean body mass index was 23.4
± 5.4 kg/m2. The mean duration of symptoms was 6.6 ±
9.0 months. There were thirty-one stable and two unstable slips with a mean
slip angle of 38° ± 20°. Nine (39%) of twenty-three children
for whom the information had been recorded had a positive family history of
slipped capital femoral epiphysis, a rate that is higher than the 9% and 14.5%
rates reported in two other series (p = 0.002). The Amish children were not as
heavy as their non-Amish counterparts (55.6 ± 12.4 kg compared with
66.4 ± 17.7 kg, p = 0.0036).
Conclusions: Although the children in this study were moderately
heavy, they could not be classified as obese on the basis of weight-for-age or
body-mass-index percentiles. The high prevalence of family members with
slipped capital femoral epiphysis may reflect either a genetic or
environmental component, or an interaction between genetics and environment
(for example, work load or common chores requiring particular physical
positions) in the Amish population.
Level of Evidence: Prognostic Level II. See Instructions
to Authors for a complete description of levels of evidence.