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Original
research

Volume 362, Number 9399
06 December 2003

Articles

Effect of ultrasound
screening on the rate of first operative procedures for
developmental hip dysplasia in Germany

Rüdiger von Kries, Nicola Ihme, Doris Oberle, Anette
Lorani, Renee Stark, Lutz Altenhofen, Fritz Uwe Niethard

Department for Paediatric Epidemiology, Institute for Social
Paediatrics and Adolescent Medicine, Ludwig-Maximilians University,
Munich, Germany (Prof R von Kries MD, D Oberle PhD, R Stark
MD); Orthopaedic Department, University Aachen (N Ihme MD, A
Lorani MD, Prof F Uwe Niethard MD); and Central Research
Institute of Ambulatory Health Care in Germany, Cologne (L
Altenhofen PhD)

Correspondence to: Prof Rüdiger von Kries, Department for
Paediatric Epidemiology, Institute for Social Paediatrics and
Adolescent Medicine, Ludwig-Maximilians University, Heiglhofstr 63,
81377 Munich, Germany (e-mail:[email-masked])

Summary

Introduction

Methods

Results

Discussion

References

Summary

Background Ultrasound screening for developmental hip
dysplasia and early conservative treatment might prevent later hip
operations. A national hip ultrasound-screening programme,
undertaken during the first 6 weeks of life, was introduced across
Germany in 1996 and was continued for 5 years. We assessed the rate
of first operation on the hip during this programme.

Methods A national active surveillance programme of
initial operations for developmental hip dysplasia was started in
1997 and continued for 5 years. Screening participation was assessed
by a random digit dialling telephone survey. Cases were children
aged between 10 weeks and 5 years at first operation, who had had no
underlying disease leading to developmental hip dysplasia.
Completeness of case ascertainment was validated with a
capture-recapture study in a representative subsample. Calculated
incidences were compared with previously established rates.

Findings About 90% of all children were screened. 147
cases in the first year, and between 81 and 105 for subsequent years
were reported. Treatment included closed reductions 353 (66%), open
reductions 61 (11%), and osteotomies 121 (23%). Developmental hip
dysplasia was diagnosed by ultrasound before 6 weeks of age in 272
(55%) of cases, 64 (13%) were screened at the recommended time but
had normal findings, 70 (14%) had delayed screening, and 89 (18%)
were not screened. Capture-recapture estimates suggested that 52% of
cases were reported. The corrected incidence for first operation was
0·26 per 1000 livebirths (95% CI 0·22-0·32).

Interpretation Ultrasound screening seems to prevent
many, but not all, operations for developmental hip dysplasia. Rates
of timely screening (ie, before 6 weeks of age) and training of
doctors in ultrasound screening need to be improved.

Lancet 2003; 362: 1883-87

Introduction

Developmental hip dysplasia can lead to impaired hip function
and premature degenerative joint disease because of higher than
normal load and shearing forces.1 Diagnosis of this
abnormality within the first weeks of life is essential for early
abduction treatment, which aims to prevent a deleterious course,
leading to hip disease.2,3 Universal screening based on
clinical signs has therefore been recommended for more than half a
century.4

A report by Godward and Dezateux5 showed that the
clinical screening programme for developmental hip dysplasia in the
UK was not universally successful in preventing operative procedures
related to the disease. The researchers challenged the present
screening programme that is based on clinical signs and symptoms,
and called for an assessment of alternative screening policies,
including universal ultrasound imaging.5 Since the
numbers of children with the disease who need an operation is small,
randomised trials assessing the effectiveness of ultrasound
screening on the rate of such procedures would need to assess large
numbers of children to achieve significant results. Valid survey
data might provide an alternative.

In Germany, a screening programme for developmental hip
dysplasia that included universal static6 ultrasound
imaging for all children was started in January, 1996.7
All children are screened clinically for the abnormality in the
first week of life. Children with a family history, breech delivery,
or suspicious findings after clinical examination are screened with
ultrasound in the first week of life. Screening for all other
children is scheduled at age 4-6 weeks--the latest at end of week 6.

Active surveillance for operations for this condition in
children younger than 5 years was initiated in 1997 and maintained
until 2002. The goal of this active surveillance was to establish
whether the rates of first operation for developmental hip dysplasia
were lower with a universal ultrasound screening programme compared
with historical data in Germany8 and other
countries,9,10 where screening was based only on clinical
signs and symptoms. A further goal was to see which, if any,
operative procedures became necessary despite early diagnosis by the
ultrasound screening programme.

Methods

Cases who had had operations were identified through active
surveillance from May, 1997 to April, 2002, by use of the German
paediatric surveillance unit (ESPED).11 Monthly postcards
were sent to all heads of orthopaedic hospitals or departments
caring for children younger than 5 years. They were to report the
number of cases admitted for operative procedures in the previous
month, or had the option of nothing to report. Reported cases were
validated by a follow-up questionnaire for country of birth,
underlying disease (such as arthrogryposis, myelomeningocele, or
cerebral palsy), date of ultrasound screening, ultrasound findings
( angle, type according to Graf6), type of
operation done during the reported admission, and any other such
procedures previously done on the same child.

Eligibility criteria for cases were: born in Germany, aged
older than 9 weeks and younger than 5 years with a first operation
in the month of surveillance, and no underlying disease leading to
developmental hip dysplasia or acquired dislocations. Operative
procedures included closed reduction, open reduction, and osteotomy
with or without reduction, in a child admitted to hospital. Closed
reduction could mean any of the following: arthrography, adductor
tenotomy, traction treatment, plaster-of-Paris casts, harness, or a
combination of these. All questionnaires were validated by an
orthopaedic surgeon.

Completeness of the case ascertainment was assessed with the
capture-recapture method in southern Bavaria,12 where
representatives from all orthopaedic hospitals were asked to give
permission for an onsite visit. The investigator attempted to
identify all children younger than 5 years who had had an operative
procedure for the disease between May, 1997 and April, 2001, in the
respective hospitals from international classification of disease
coding lists, or operative or admission records. These cases
constituted the independent second data source, and were linked to
those from the same hospitals identified by the active surveillance
programme.

Cases with first operations in every year of the surveillance
study could have been born up to 5 years before the year in which
the outcome of interest was assessed. Thus, estimation of true
incidence for defined birth cohorts was impossible. British
investigators5 reported incidence estimates as the number
of events recorded during the observation period related to the
number of births during this period. We estimated incidence
accordingly--first operative procedures for every year of
surveillance by the respective numbers of livebirths in 1997, 1998,
1999, 2000, and 2001.

Screening programme participation was assessed in a
population of children identified by random digit dialling. Parents
were asked whether their children had had ultrasound screening of
the hip, and, if the answer were yes, they were asked when this
examination had been done. The answer options were during your stay
in the maternity unit, during the third wellbaby check-up test
between the 4th and 6th week of life, or other time. In a survey
undertaken in 1999, roughly 25000 randomly selected households were
asked whether they had children aged younger than 3 years. If they
had, they were invited to participate in a vaccination coverage
survey.13 Families with children born between 1996 and
1998 were contacted again in 2002 by telephone or mail to answer the
ultrasound screening questions. For the 1999 to 2001 cohorts, a
similar random digit dialling survey was undertaken in 2002 to
assess vaccination coverage. Questions about ultrasound screening
were included in this survey, and families were under no obligation
to participate. We obtained approval from the Bavarian office for
protection of data confidentiality. Since our investigation used
anonymous data and did not interfere with treatment decisions, we
did not contact any of the patients with developmental hip dysplasia
or their parents. The data were entered in an Access data bank.
Descriptive statistics were calculated in SAS, version 6.12.

Role of the funding source

The funding source had no role in study design, data
collection, data analysis, data interpretation, or in the writing of
the report.

Results

The proportion of children who were screened by ultrasound
increased from 83% in 1996 to 95% or above in most subsequent years
(figure). Yearly, between 26% and 45% children had ultrasound
screening for developmental hip dysplasia in the first week of life,
with no trend over time.

Proportion of children screened by
ultrasound for developmental hip dysplasia

Vertical bars are 95% CI.

The orthopaedic surgeons returned the cards on which cases
were reported and follow-up questionnaires validating the cases in
1997-2002, at a rate that ranged from 89% to 98% (cards) and from 90
to 98% (questionnaires) per year. Many of the 1887 returned
questionnaires were for children who did not meet criteria for
inclusion--608 were younger than 10 weeks, 27 were older than 5
years, 102 had had no operative procedure according to the case
definition, 36 were not treated in hospital, 91 had not been born in
Germany, 134 had either acquired or teratological developmental hip
dysplasia, 112 had had previous operations, and 33 were treated
before the study period. Additionally, there were 181 double reports
and 28 reports without essential information, which left 535
children with first operative procedures for final analyses. The
yearly number of first procedures reported ranged between 81 and 147
cases per year (table 1) with the highest number of first operative
procedures recorded in 1997. This finding was mainly due to a higher
number of closed reductions in 1997 than in subsequent years. In 54
of the 121 osteotomies, a reduction of the hip was also done.

May, 1997-April, 1998

May, 1998-April, 1999

May, 1999-April, 2000

May, 2000-April, 2001

May, 2001-April, 2002

Total

Closed reduction

91 (62%)

73 (70%)

65 (64%)

60 (74%)

64 (63%)

353 (66%)

Open reduction

20 (14%)

14 (13%)

14 (14%)

6 (7%)

7 (7%)

61 (11%)

Osteotomy

36 (25%)

18 (17%)

22 (22%)

15 (19%)

30 (30%)

121 (23%)

Total

147 (100%)

105 (100%)

101 (100%)

81 (100%)

101 (100%)

535 (100%)

Data are number (%).

Table 1: Children with first operative
procedures by year of observation

Closed reductions accounted for two-thirds of all operative
procedures (table 1). Of the 353 children treated with closed
reduction, 216 were treated by fixation with a plaster-of-Paris cast
or a harness, 166 had traction treatment, 95 had arthrography, and
13 had adductor tenotomy. 236 (67%) children had only one procedure
for closed reduction, 97 (28%) had two, and 20 (6%) had three
operative procedures.

For 495 of the 535 cases, time of ultrasound screening and
screening result were known (table 2). For 259 of the 272 children
with a first operative procedure and an abnormal screening
ultrasound within the recommended timeframe, the date of the final
diagnosis of was reported: 133 (51%) were 28 days old or younger and
227 (88%) were 90 days old or younger. There were 40 cases screened
in time with screening results missing (22 with closed reduction,
two with open reduction, and 16 with osteotomy). The type of
operative procedure did not differ between children screened within
the recommended timeframe or late (2 test, p=0·25). With respect to the 495 cases
with information on ultrasound, 272 (55%) had abnormal findings at
screening within the recommended timeframe, 64 (13%) had normal
findings at screening within the recommended timeframe, 69 (14%)
were screened too late, and 89 (18%) were identified outside the
routine screening programme. In analysis of only cases screened
within the recommended timeframe, 64 (19%) had a normal ultrasound
despite being a case.

Correct timing of ultrasound
screening†

Delayed ultrasound screening‡

No ultrasound screening

Total

Positive screen

Negative screen

Closed reduction

176 (53%)

44 (13%)

53 (16%)

58 (18%)

331 (100%)

Open reduction

36 (61%)

7 (12%)

6 (10%)

10 (17%)

59 (100%)

Osteotomy

60 (57%)

13 (12%)

11 (11%)

21 (20%)

105 (100%)

Total

272 (55%)

64 (13%)

70 (14%)

89 (18%)

495 (100%)

Data are number (%). *Only cases with complete
information about screening results were included. †Up to the
age of 6 weeks. ‡Beyond the age of 6 weeks.

Table 2: Children with first operative
procedures by time of screening and screening
results*

During the 5 years of observation, the incidence calculated
by division of the number of recorded cases by the number of
livebirths per year was 0·10-0·18 per 1000 livebirths, with a yearly
average of 0·14 (95% CI 0·13-0·15). The capture-recapture estimates
for cases born in southern Bavaria between May, 1997 and April,
2001, yielded 18 cases reported only in the active surveillance
programme, 13 in both data sources, and 12 were identified only
during hospital visits. The capture-recapture estimate for the true
number of cases was 60, and 31 of these (52%) had been ascertained
by the active surveillance system. Thus, the true rate of first
operative procedures is likely to be 0·26 per 1000 (95% CI
0·25-0·28). Since 272 (55%) of the cases had timely screening and
abnormal findings (table 2), the true rate of first operative
procedures despite timely screening and early diagnosis of
developmental hip dysplasia was 0·14 cases per 1000 livebirths.

Discussion

The adjusted rate of first operative procedures that we
calculated--0·26 per 1000 livebirths--was considerably lower than
that in other investigations,5,9,10 and much lower than
previously estimated in Germany. In 1983, before ultrasound
screening, Katthagen and colleagues8 reported 616 first
operative procedures on children younger than 6 years (yearly birth
rates in Germany 1977 to 1983 ranging between 590000 and 620000),
accounting for a rate of about one per 1000 livebirths. Our finding
of low incidence cannot be explained by our case definition, which
excluded children younger than 10 weeks, since in 1983, 548 (89%) of
the 616 cases with a first operative procedure were 4 months or
older (mean age 9 months).8 Because the historical
data8 originate from a cross-sectional survey with one
mailed questionnaire only, and a participation rate of 61%, this
rate is probably an underestimate.

Follow-up studies over more than 50 years would be necessary
to assess the potential benefit of ultrasound screening for impaired
hip function and premature degenerative joint disease. Thus,
previous researchers have used the rate of first operative
procedures during preschool age as a useful and feasible endpoint to
determine the effectiveness of screening.5,9,10 Such an
assessment of the effect of clinical screening, based on signs and
symptoms, led to controversial results. In one study, investigators
recorded little beneficial effect of such screening (first operative
procedure rate of 0·78 per 1000 livebirths).5 In another,
workers reported low rates of first operative procedures (0·46 per
1000 livebirths).9 Finally, some researchers noted a
reduction in the rate of operative procedures with improved early
diagnosis, from 1·75 per 1000 livebirths to 1·03 per 1000
livebirths.10

The capture-recapture study detected considerable
under-reporting in our active surveillance study, and thus, the
recorded rates had to be adjusted. Data for the capture-recapture
analysis were obtained in hospitals by an independent investigator
who was masked with respect to details of reported cases. The
southern Bavarian population analysed for the capture-recapture
estimate consisted of 7·5% of all livebirths in Germany (yearly
livebirth rate in southern Bavaria of 60 000 compared with an
average yearly livebirth rate in Germany of 780 000) and 7·1% of the
cases observed. We believe that the data from southern Bavaria are
representative of the general population because, of the 535 cases
reported over 5 years across Germany, 33 would be expected to be
identified by the active surveillance programme over 4 years in this
area, on the basis of its annual livebirth rate. The number recorded
was 31. The capture-recapture analysis showed that the proportion of
cases identified by the active surveillance programme was 51·9%,
which was identical to the proportion detected in the
UK,5 and was in the range of results from other studies
that used the ESPED logistics in Germany.11

After comparison with historical data, our results suggest
that an ultrasound-screening programme might substantially reduce
the rate of first operation. However, historical data are not ideal
for comparison, since other factors can also affect the rate of
first operative procedures and might also have changed with time.
Another important issue is the quality of previous clinical
screening in Germany to which ultrasound screening has been
compared. Before the introduction of ultrasound screening in
Germany, screening for developmental hip dysplasia was part of a
well-baby check-up programme. Clinical screening included the
Ortolani test, a check of abduction and for length differences of
the leg.14 In 1982-83 a cohort of 2021 livebirths was
recruited in four maternity wards in Cologne, and followed-up for 2
years.15 Of these livebirths, 545 had had radiographical
examination, of which 25 cases were diagnosed according to at least
one radiologist's judgment. The disease had been treated in 23;
however, only three were treated before the age of 4 months,
although seven had been identified by abnormal screening in the
first week.

Results of three other investigations indicate that an
ultrasound-screening programme might reduce the rate of first
operative procedures. Andersson16 reported in an
observational study a rate of 0·15 first operative procedures per
1000 livebirths for 22 047 children screened by ultrasound. However,
only open reductions were considered in this study. Investigators in
two randomised controlled studies17,18 used late
detection of dislocation, subluxation, or acetabular dysplasia to
assess the effect of screening. In the first investigation,
researchers compared universal ultrasound screening with clinical
screening with ultrasound for at-risk children only and also with
clinical screening with no ultrasound. The rates of late
dislocations or subluxations, were 0·3, 0·7, and 1·3 per 1000
livebirths, respectively.18 Researchers of another study
also compared universal ultrasound screening alone with clinical
screening plus ultrasound for at-risk children only. The respective
rates of late detection were 0·13 and 0·65 per 1000
livebirths.17 Although universal ultrasound screening
seemed to lead to improved outcome in both investigations, the
differences were not substantial in either.

Other important results were that 19% of children who were
screened within the recommended timeframe had normal findings
despite being actual cases, with no evidence of geographical
clustering of those cases with a normal ultrasound. Since review of
the ultrasound imaging was not possible, we could not distinguish
between failures related to imaging and true screening failures.
More cases were related to insufficient parental compliance with the
programme, 14% because of delayed screening and 18% because no
screening was done.

Although early treatment for developmental hip dysplasia has
not been proven to prevent operative procedures, screening
programmes are based on the assumption that such treatment is
effective. This assumption might not be true for all children
identified during screening. The surveillance data collected over 5
years in Germany showed that about 0·14 (55%) of the 0·26 first
operative procedures per 1000 livebirths were for cases with early
detection by an ultrasound screening programme. These children might
represent a proportion of children with the disease who might not
benefit from early conservative treatment. Similar rates of first
operative procedure despite early diagnosis have been
reported.9,10,16,19 All cases with timely diagnosis had
received some kind of early splinting treatment. Unfortunately, on
the basis of our data and that of other
investigators,9,10,16,19 differentiation between failure
to respond to adequate early conservative treatment, compliance
difficulties, and inadequate treatment, is not possible. Such
information could only be obtained by an audit, which is beyond the
scope of this questionnaire study.

Although the ultrasound-screening programme seems effective
in reducing the rate of operative procedures, the negative
consequences of such a programme must be considered. An independent
assessment of such consequences showed that initially, 24% of the
children screened had had at least one repeat ultrasound examination
of the hip,20 which fell to 19% by 2000 (internal
documents of the Central Research Institute of Ambulatory Health
Care in Germany). This continuing high rate of repeat examinations
will be an issue in cost-effectiveness calculations. Improved
training of doctors might further reduce repeat examinations.
Initially, 7% of children had a recommendation for
treatment.20 By 2000, this percentage was reduced to 5%.
High indications for treatment in relation to ultrasound screening
(3·1%)have been reported,21 whereas rates for defined
treatment (Pavlik Harness) have been noted to be as low as 0·24
%.22 Unfortunately, there are no data for conservative
treatment rates for developmental hip dysplasia (eg, splinting) in
Germany. In a Swedish municipality, clinical screening resulted in
treatment rates of 0·6-3·5%. 23 If all recommendations
for treatment were followed by splinting or other invasive
treatments, the rate of overtreatment would be unacceptably
high.24 This issue of potential overtreatment and
side-effects of treatment should be addressed.

Thus, although the German ultrasound screening programme
seems effective in reducing the rate of operative procedures,
further improvements are needed with respect to timely participation
and doctors assessment of ultrasound imaging. Better quality data
for conservative treatment rates for developmental hip dysplasia are
needed to monitor and possibly reduce over-treatment.

Contributors

R von Kries, L Altenhofen, and F Uwe Niethard were
responsible for concept and study design. N Ihme and A Lorani
assessed the questionnaires. R Stark and D Oberle did the
capture-recapture study. D Oberle contributed to data management,
and, with R von Kries, analysed the data. R von Kries and R Stark
wrote the report.

Conflict of interest
statement

None declared.

Acknowledgments

The authors thank all the orthopaedic surgeons who
contributed to this surveillance by monthly replies to our report
cards and filling in the questionnaires, especially Bernd-Dietrich
Katthagen (Dortmund), Klausdieter Parsch (Stuttgart), and Franz Löer
(Essen). The help of Susanne Stoll and Klaus-Peter Günther, Dresden
in initiating the programme, and of Andrea Schilling in keeping the
surveillance programme going was invaluable.The study was funded by
Kassenärztliche Bundesvereinigung (National Association of Statutory
Health Insurance Physicians) and Spitzenverbände der gesetzlichen
Krankenkassen (National Associations of Health Insurance Funds,
Sickness Funds).

References

1 Pauwels F. Biomechanics of the normal and diseased hip.
Berlin: Springer, 1976.

2 Barlow TG. Early diagnosis and treatment of congenital
dislocation of the hip joint.  J Bone Jt
Surg 1962; 44: 292-301. [PubMed]

3 von Rosen S. Early diagnosis and treatment of congenital
dislocation of the hip joint.  Acta Orthop
Scand 1956; 26: 136-40. [PubMed]

4 Ortolani M. Un segno poco noto es sua importanza per la
dignosi precoce de prelussazione congenita dell'anca.
Pediatri 1937; 45: 129-34. [PubMed]

5 Godward S, Dezateux C. Surgery for congenital dislocation
of the hip in the UK as a measure of outcome of screening.
Lancet 1998; 351: 1149-52. [Text]

6 Graf R. New possibilities for the diagnosis of congenital
hip joint dislocation by ultrasonography.  J Pediatr
Orthop 1983; 3: 354-59. [PubMed]

7 Altenhofen LH. Leitlinie für das hüftsonographische
Screening im Rahmen des Programms Krankheitsfrüherkennung im
Kindesalter, Leitlinie Konsensusstatement.  Deutsches
Ärzteblatt  1996; 93: 57-60. [PubMed]

8 Katthagen BD, Mittermeier H, Becker D. Häufigkeit und
stationärer Behandlungsbeginn kindlicher Hüftgelenksluxationen in
der BR Deuschland.  Z
Orthop 1988; 126: 475- 83. [PubMed]

9 Chan A, Cundy PJ, Foster BK, Keane RJ, Byron-Scott R. Late
diagnosis of congenital dislocation of the hip and presence of a
screening programme: South Australian population-based study.
Lancet 1999; 354: 1514-17. [Text]

10 Maxwell SL, Ruiz AL, Lappin KJ, Cosgrove AP. Clinical
screening for developmental dysplasia of the hip in Northern
Ireland.
BMJ 2002; 324: 1031-33. [PubMed]

11 von Kries R, Heinrich B, Hermann M. Pädiatrische
Epidemiologie in Deutschland: Forschungsinstrument ESPED
(Erhebungseinheit für seltene pädiatrische Erkrankungen in
Deutschland).  Monatsschr
Kinderheilkd 2001; 149: 1191-97. [PubMed]

12 Hook EB, Regal RR. Capture-Recapture methods in
epidemiology: Methods and limitations.  Epidemiol
Rev 1995; 17: 243-64. [PubMed]

13 Laubereau B, Hermann M, Weil J, Schmitt HJ, von Kries R.
Durchimpfungsraten bei Kindern in Deutschland 1999: Grundsätzliche
Impfbereitschaft, aber Impfungen häufig zu spät und inkomplett.
Monatsschr Kinderheilkd
2001; 149: 367-73. [PubMed]

14 Zentralinstitut. Hinweise zur Durchführung der
Früherkennungsuntersuchungen im Kindesalter. Köln: Deutscher
Ärzte-Verlag, 1991.

15 Weidtman V, von Heeremann B, Herrmann F. Ermittlung der
Ursachen von Fehlbeurteilungen angeborener Hüftgelenksveränderungen
zur Operationalisierung optimaler Screeningstrategien. Köln:
Bundesministerium für Forschung und Technologie, 1984.

16 Andersson JE. Neonatal hip instability: results and
experiences from ten years of screening with the anterior-dynamic
ultrasound method.  Acta Paediatr
2002; 91: 926-29. [PubMed]

17 Holen KJ, Tegnander A, Bredland T, et al. Universal or
selective screening of the neonatal hip using ultrasound?  J
Bone Joint Surg
2002; 84: 886-90. [PubMed]

18 Rosendahl K. MT, Lie R.T. Ultrasound screening for
developmental dysplasia of the hip in the neonate: the effect on
treatment rate and prevalence of late cases.
Pediatrics 1994; 94: 47-52. [PubMed]

19 Elbourne D, Desateux C, Arthur R, et al. Ultrasonography
in the diagnosis and management of developmental hip dysplasia (UK
Hip Trial): clinical and economical results of a multicenter
randomised controlled trial.
Lancet 2002; 360: 2009-17. [Text]

20 Niethard FU, Günther KP, von Kries R, Altenhofen L.
Klinisches und sonographisches Screening der Säuglingshüfte.
Dt Ärztebl
2000; 97: 1593-99. [PubMed]

21 Rosendahl K, Markestad T, Lie RT. Congenital dislocation
of the hip: a prospective study comparing ultrasound and clinical
examination.  Acta Paediatr
1992; 81: 177-81. [PubMed]

22 Marks DS, Clegg J, al-Chalabi AN. Routine ultrasound
screening for neonatal hip instability. Can it abolish
late-presenting congenital dislocation of the hip? J Bone
Joint Surg Br 1994; 76: 534-38. [PubMed]

23 Duppe H, Danielsson LG. Screening of neonatal instability
and of developmental dislocation of the hip: a survey of 132,601
living newborn infants between 1956 and 1999. J Bone Joint
Surg Br 2002; 84: 878-85. [PubMed]

24 Eastwood DM. Neonatal hipscreening.
Lancet 2003; 361: 595-97. [Text]

© 2003 Elsevier Limited. THE LANCET® is a
registered trademark of Elsevier Properties S.A.

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