Rt. Loder et al., THE EPIDEMIOLOGY OF BILATERAL SLIPPED CAPITAL FEMORAL EPIPHYSIS - A STUDY OF CHILDREN IN MICHIGAN, Journal of bone and joint surgery. American volume, 75A(8), 1993, pp. 1141-1147
The records of 224 children who had a slipped capital femoral epiphysi
s and who had no underlying metabolic or endocrine disorder were studi
ed retrospectively to investigate the epidemiology of bilateral slippe
d capital femoral epiphysis. Eighty-two (37 per cent) of the 224 child
ren (fifty-one boys and thirty-one girls) had a bilateral slip. Sixty-
four of these children were black and eighteen were white. The age at
the time of the diagnosis of the first slip was 13 +/- 1.7 years (mean
and standard deviation), the duration of the symptoms was 5 +/- 5.0 m
onths, and the angle of the slip was 26 +/- 16 degrees. Obese children
were younger at the time of the diagnosis of the first slip (12 +/- 1
.6 compared with 13 +/- 1.6 years for the children who were not obese,
p = 0.001). The diagnosis of a slipped capital femoral epiphysis was
made simultaneously in both hips in forty-one children and sequentiall
y in forty-one children. Compared with the children in whom both hips
were diagnosed simultaneously, the children in whom the hips were diag
nosed sequentially had had a shorter duration of the symptoms before t
he diagnosis of the first slip (3 +/- 2.4 compared with 7 +/- 5.9 mont
hs, p = 0.0003), were younger at the time of the diagnosis of the firs
t slip (12 +/- 1.9 compared with 13 +/- 1.2 years, p = 0.001), and ten
ded to be more obese (p +/- 0.025). In 88 per cent of the patients who
had sequential slips, the second slip was diagnosed within eighteen m
onths after the diagnosis of the first slip. The children who had a un
ilateral slip and in whom a slip of the contralateral hip developed su
bsequently were younger at the time of the diagnosis of the first slip
than those in whom a contralateral slip did not develop (12 +/- 1.9 c
ompared with 13 +/- 1.6 years, p = 0.002). We recommend frequent follo
w-up examinations for the first two years after the diagnosis of a uni
lateral slip, especially if the patient is a girl who is twelve years
old or less or a boy who is fourteen years old or less. In order to pr
event a delay in the diagnosis of a second slip, follow-up should cont
inue until there is definite radiographic evidence of physeal closure
in both hips.