ACTA PÆDIATR 90 (2001)
896
JE Andersson and A Ode´n
Table 1. Distribution of neonatal hip instability and frequencies of treatment in the population.
Dislocation or instability
Treated neonates
Neonates (n) (%)
Total no. Neonates (n) Hips (n)
A. Vertex presentation
B. Breech presentation
C. External version attempted
D. Version successful, vaginal delivery
E. Version failed, caesarean section
F. No version attempted, caesarean section
6314
257
137
62
75
120
68
10
95
14
9
4
0.1
1.6
3
2
5
6
2
6
2
1
1
3.2
1.0
ª
breech presentations was vaginally delivered during the of the ultrasound screening undergo an additional
period of this study.
ultrasound examination 1 wk later.
In total, 120 children (70M, 50F) were delivered by
caesarean section without attempts to perform an
external version, 75 children (41M, 34F) were delivered
by caesarean section following an unsuccessful external
version, and 62 children (31M, 31F) were vaginally
delivered following a successful external version (Table
1).
During the rst day of life and before release from
the maternity ward, the hips of all neonates were
clinically examined by paediatricians using Ortolani’s
and Palme´n/Barlow’s tests. During the rst or second
day of life, a supplementary ultrasound screening
examination using the anterior-dynamic method was
performed on all newborns (4, 5). Neonates found to
have dislocated or dislocatable hip-joints during the
Statistics
For comparison between groups the two-tailed Fisher’s
exact test was used. The same test was also applied for
the comparison regarding the probability that a second
hip is also affected given that one hip is affected. A test
for trend in contingency table was used for the
comparison of the number of affected hips. For
calculations the SPSS statistical package was used.
<
The statistical signi cance level used was p 0.05.
Results
Out of a total of 6571 live births, 78 children had 109
ultrasound examination underwent follow-up examina- dislocated or dislocatable hip-joints during the screen-
tions according to a special programme for the control ing examinations, which corresponds to a neonatal hip-
of neonatal hip instability (4). All children were
joint instability frequency of 0.83% of all hip-joints.
examined regularly at the child welfare clinic up to Thirteen children were treated with a von Rosen splint,
the age of 1.5 y, including their hip status. Neither equalling a treatment frequency of 0.2%.
during this observation period nor later has any child
Out of 120 neonates delivered by caesarean section
been referred to the paediatric orthopaedic centre with without an attempted version, one hip was dislocated
late diagnosed dislocation of the hip. The programme (1M) and ve hips were dislocatable (3M, 2F), totalling
for the treatment and follow-up of neonatal hip ve neonates. The dislocated hip was treated with a von
instability is solely based on the results of the Rosen splint and the dislocatable hips reached a
ultrasound examination. A dislocated hip-joint, where spontaneous stability. All six of these hips had normal
the femoral head lies outside the acetabulum without radiological acetabulum angles at the age of 4.5 mo.
provocation, is treated immediately with a von Rosen During the paediatrician’s clinical examination, there
splint for a period of 12 wk. The hip is examined by were eight suspected unstable hips, three of which were
ultrasound at least once a week until stability is also present during the ultrasound examination. The
reached and subsequently at 4, 8 and 14 wk of age. dislocated hip was not diagnosed clinically.
Radiological check-ups then follow at 18 wk of age
Out of 75 neonates delivered by caesarean section
and when the child starts to walk. A dislocatable hip- following unsuccessful version attempts, there was one
joint, where the femoral head lies spontaneously in the dislocated and one dislocatable hip-joint (2F). The
acetabulum but where provocation with Palme´n/ dislocated hip was treated and both hips had normal
Barlow’s test can move the head more than the mean acetabulum angles at the age of 4.5 mo. During the
value for physiological “maximal movement” accord- clinical examination there were four suspected unstable
ing to normal case material ‡2 SD (5), is followed up hips; one was also present at the time of the ultrasound
weekly until stability has been reached. If any degree examination. The dislocated hip-joint was not diag-
of instability remains after the age of 3 wk, the hip is nosed clinically.
treated with a von Rosen splint for a period of 6 wk
Out of 62 neonates delivered vaginally following a
and under the implementation of the same ultrasound successful version, there were six dislocatable hips (2M,
and radiological follow-ups as for dislocated hips. 1F). One boy and one girl (two hip-joints) received
Ortolani-positive hip-joints which are stable at the time treatment. All six hips had normal acetabulum angles