Results of a 25-year screening programme for neonatal hip instability

Who performs neonatal hip assessment: is there a cause for concern?

OBJECTIVE

The UK falls behind other European countries in the early detection of developmental dysplasia of the hip (DDH) and screening strategies differ for early detection. Clinical detection of DDH is challenging and recognised to be dependent on examiner experience. No studies exist assessing the number of personnel currently involved in such assessments.Our objective was to review the current screening procedure by studying a cohort of newborn babies in one teaching hospital and assess the number of health professionals involved in neonatal hip assessment and the number of examinations undertaken during one period by each individual.

METHODS

This was a retrospective observational study assessing all babies born consecutively over a 14-week period in 2020. Record of each initial baby check was obtained from BadgerNet. Follow-up data on ultrasound or orthopaedic outpatient referrals were obtained from clinical records.

RESULTS

1037 babies were examined by 65 individual examiners representing 9 different healthcare professional groups. The range of examinations conducted per examiner was 1-97 with a median of 5.5 examinations per person. 49% of individuals examined 5 or less babies across the 14 weeks, with 18% only performing 1 examination. Of the six babies (0.48%) treated for DDH, one was picked up on neonatal assessment.

CONCLUSION

In a system where so many examiners are involved in neonatal hip assessment, the experience is limited for most examiners. Currently high rates of late presentation of DDH are observed locally, which are in accordance with published national experience. The potential association merits further investigation.

Comparison of clinical and radiological outcomes for the anterior and medial approaches to open reduction in the treatment of bilateral developmental dysplasia of the hip: a systematic review protocol

BACKGROUND

Developmental dysplasia of the hip (DDH) affects 1-3% of newborns and 20% of cases are bilateral. The optimal surgical management strategy for patients with bilateral DDH who fail bracing, closed reduction or present too late for these methods to be used is unclear. There are proponents of both medial approach open reduction (MAOR) and anterior approach open reduction (AOR); however, there is little evidence to inform this debate.

METHODS

We will perform a systematic review designed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocol. We will search the medical and scientific databases including the grey and difficult to locate literature. The Medical Subject Headings "developmental dysplasia of the hip", "congenital dysplasia of the hip", "congenital hip dislocation", "developmental hip dislocation", and their abbreviations, "DDH" and "CDH" will be used, along with the qualifier "bilateral". Reviewers will independently screen records for inclusion and then independently extract data on study design, population characteristics, details of operative intervention and outcomes from the selected records. Data will be synthesised and a meta-analysis performed if possible. If not possible we will analyse data according to Systematic Review without Meta-Analysis guidance. All studies will be assessed for risk of bias. For each outcome measure a summary of findings will be presented in a table with the overall quality of the recommendation assessed using the Grading of Recommendations Assessment Development and Evaluation approach.

DISCUSSION

The decision to perform MAOR or AOR in patients with bilateral DDH who have failed conservative management is not well informed by the current literature. High-quality, comparative studies are exceptionally challenging to perform for this patient population and likely to be extremely uncommon. A systematic review provides the best opportunity to deliver the highest possible quality of evidence for bilateral DDH surgical management.

SYSTEMATIC REVIEW REGISTRATION

The protocol has been registered in the International Prospective Register of Systematic Reviews (PROSPERO ID CRD42022362325).

Automatic Segmentation of the Paediatric Femoral Head

Developmental dysplasia of the hip (DDH) is a developmental deformity occurring in 0.1-3.4% of infants. Timely surgical intervention can ameliorate the condition in stable hips and reduce future cases of osteoarthritis and total hip replacement. However, current definitions of DDH are subjective, and thus would benefit from a more objective and reliable assessment metric. Since the shape of the femoral head and its congruence with the acetabulum are disrupted by DDH, analysis of the femoral head could potentially play a role in the development of novel objective morphological metric for stable DDH. Therefore, this paper aimed to segment the paediatric femoral head in stable hips from radiographs, which has not been attempted before in the chosen focus age group (1-16 years) where the pelvis and hip joint undergo significant development. Two techniques were compared against a baseline U-Net: data augmentation and region-of-interest (ROI) networks. Four models were developed either without, with just one, or with both techniques. Evaluated using tenfold cross-validation, the U-Net trained with both techniques achieved the best results, with a Dice Similarity Coefficient (DSC) of 0.951±0.037 (mean ± standard deviation, calculated with 720 images). Future work will use this segmentation algorithm to accurately characterise hip joint morphology and estimate the benefit of early surgical intervention in DDH.

The evaluation of ultrasonographic hip measurement differences among physicians according to the Graf method in newborns

Background/Aim: Hip ultrasonography (USG) is the most important diagnostic method in developmental hip dysplasia in newborns. However, a disadvantage of the ultrasonography method is that there can be measurement differences among doctors measuring the same hip. We aimed to investigate the causes and solutions of this situation. We further strived to measure the hip ultrasonography performed by different physicians using the Graf method and comparing the obtained values. Methods: Hip USGs of newborns admitted to Malatya Turgut Ozal University Faculty of Medicine Hospital between Jan. 8, 2020 and Jan. 5,.2021 were measured and classified using the Graf method. The study type is consistent with retrospective cohort studies. Newborns aged 0-22 weeks without any additional pathology were included in the study. A radiologist and two orthopedists measured and interpreted the images separately in accordance with the Graf method. The first hip measurements (R1) were made by the radiologist (R) with the USG device, and they were classified according to alpha and beta angles; two printouts were made. The first orthopedic specialist (OS1) and the second orthopedic specialist (OS2) made their measurements with printouts. Subsequently, the results from the physicians were compared. Results: A statistically significant difference was found between R1-OS2 (P < 0.001) and OS1-OS2 (P < 0.001) in terms of the Graf classifications. No statistically significant difference was found between R1 and OS1 in terms of the Graf classification (P = 0.562). A statistically significant difference was found between R1-OS2 (P < 0.001) and OS1-OS2 (P = 0.048) angles (alpha and beta) measurements. While R1 and OS1 measurements were compatible with each other, OS2 measurements were found to be inconsistent. Conclusion: We think that there may be differences in angle measurements and the Graf classification among physicians who perform hip ultrasonography in newborns, and the most important way to correct this is through regular participation of physicians in subject-specific trainings.

Incidence of Late-Diagnosed Hip Dislocation After Universal Clinical Screening in Sweden

IMPORTANCE

Developmental dysplasia of the hip, including late-diagnosed hip dislocation, is the leading cause of hip arthroplasties in young adults. Early treatment is essential for a good prognosis. Before the institution of a national screening program, a minimum of 0.9 per 1000 Swedish children were affected.

OBJECTIVES

To evaluate the incidence of late-diagnosed hip dislocation among children who undergo clinical screening as neonates and to study antenatal and perinatal risk factors for late-diagnosed hip dislocation.

DESIGN, SETTING, AND PARTICIPANTS

This nested case-control study included children born in Sweden from January 1, 2000, through December 31, 2009. All maternity wards, maternal health units, and orthopedic departments in Sweden participated. Children with a late-diagnosed hip dislocation were matched by sex and birth year to randomly selected controls in a 1:10 ratio. Potential risk factors in pregnant women and newborns were recorded, and cases of hip dislocation were registered. Observation time ranged from 8 to 18 years, with the last data analysis in January 2019.

EXPOSURES

Clinical hip examinations neonatally and at 6 to 8 weeks, 6 months, and 10 to 12 months.

MAIN OUTCOMES AND MEASURES

Hip dislocation diagnosed more than 14 days after birth, age at diagnosis, and severity of dislocation.

RESULTS

Among 1 013 589 live births (521 728 [51.5%] boys), 126 children (0.12 [95% CI, 0.10-0.15] per 1000 live births) had a late-diagnosed hip dislocation at a median age of 31.4 weeks (interquartile range, 16.1-67.1 weeks; 95% CI, 27.4-44.1 weeks). The incidence of late-diagnosed hip dislocation was 9 times higher among girls (113 of 491 861; 0.23 [95% CI, 0.19-0.28] per 1000 live births) than among boys (13 of 521 728; 0.02 [95% CI, 0.01-0.04] per 1000 live births). Twenty-one children (0.02 per 1000 live births) had high (severe) dislocations. Breech delivery (adjusted odds ratio, 3.07; 95% CI, 1.34-7.02), short body length at birth (adjusted odds ratio, 0.86; 95% CI, 0.76-0.98, per additional 1 cm), and being large for gestational age (adjusted odds ratio, 3.59; 95% CI, 1.30-9.95) were independent risk factors. Maternal smoking at the first visit to the maternal health care center was less common among children with hip dislocation (adjusted odds ratio, 0.16; 95% CI, 0.04-0.70).

CONCLUSIONS AND RELEVANCE

Compared with historical data, the incidence of late-diagnosed hip dislocation in Swedish-born children appears to have decreased substantially since the screening program was initiated, as have the age at detection and disease severity. Similar screening programs should also be possible to institute in upper-middle- and lower-middle-income countries.

Universal versus selective ultrasound screening for developmental dysplasia of the hip: a single-centre retrospective cohort study

A total of 28 068 infants were studied to investigate whether universal ultrasound screening for developmental dysplasia of the hip results in fewer delayed presentations than selective screening, and whether the screening protocol affects subsequent treatment. The rate of delayed presentation was not lower with selective screening compared with universal screening but all cases of delayed presentation in this cohort were administrative errors. There were no sonographic errors (false-negatives). The treatment rate was significantly higher with universal screening but infants were treated earlier and were significantly less likely to require any surgical intervention. Those requiring surgery were less likely to require open reduction or pelvic osteotomy.

Universal or selective ultrasound screening for developmental dysplasia of the hip? A discussion of the key issues

PURPOSE

To summarize recent developments and provide recommendations as to whether universal or selective programmes are advisable.

METHODS

A literature review was performed and preference given to studies with higher levels of evidence. All programmes reviewed included clinical screening.

RESULTS

Recent studies underline the need for high quality screening programmes to promote the early detection of developmental dysplasia of the hip (DDH). A small number of cases may be missed clinically but with universal ultrasound screening programmes the late presentation rates appear to be virtually zero. Contemporary studies show treatment rates with universal screening programmes which are now lower than those with selective ultrasound. There is little agreement over the criteria used for selective programmes. Alternative outcome measures, such as the first operation rate or the percentage undergoing major (open) surgery are both lowest with universal ultrasound screening programmes. Furthermore, a significant reduction in the rate of surgery for DDH later in life was seen after the introduction of universal ultrasound screening, whereas the defined criteria for selective screening may not detect the majority of patients who require late surgery. Abduction bracing with modern orthoses is associated with a zero rate of avascular necrosis (AVN), whereas closed reduction techniques have an overall risk of 10%.

CONCLUSION

On clinical grounds, if future studies confirm that hip abduction in flexible orthoses is not associated with AVN, it may be time for a paradigm shift of screening for DDH towards a universal ultrasound protocol. The costs associated both with each type of screening programme and with the management of late presenting cases are also important but may be secondary to clinical benefit.

Neonatal screening and selective sonographic imaging in the diagnosis of developmental dysplasia of the hip

Aims

The aim of this prospective cohort study was to evaluate the effectiveness of the neonatal hip instability screening programme.

Patients and Methods

The study involved a four-year observational assessment of a neonatal hip screening programme. All newborns were examined using the Barlow or Ortolani manoeuvre within 72 hours of birth; those with positive findings were referred to a ‘one-stop’ screening clinic for clinical and sonographic assessment of the hip. The results were compared with previous published studies from this unit.

Results

A total of 124 newborns with a positive Barlow or Ortolani manoeuvre, clunk positive, or ‘unstable’ were referred. Five were found to have clinical instability of the hip. Sonographically, 92 newborns had Graf Type I hips, 12 had Graf Type II hips, and 20 had Graf Type IV hips. The positive predictive value (PPV) of clinical screening was 4.0% and the PPV of sonography was 16.1%. This has led to an increased rate of surgery for DDH.

Conclusion

Compared with previously published ten-year and 15-year studies, there has been a marked deterioration in the PPV in those referred with potential instability of the hip. There appears to be a paradox, with rising referrals and a decreasing PPV combined with an increasing rate of surgery in newborns with developmental dysplasia of the hip. Cite this article: Bone Joint J 2018;100-B:806–10.

The positive predictive value of asymmetrical skin creases in the diagnosis of pathological developmental dysplasia of the hip

Aims

The aim of this study was to identify the association between asymmetrical skin creases of the thigh, buttock or inguinal region and pathological developmental dysplasia of the hip (DDH).

Patients and Methods

Between 1 January 1996 and 31 December 2016, all patients referred to our unit from primary or secondary care with risk factors for DDH were assessed in a "one stop" clinic. All had clinical and sonographic assessment by the senior author (RWP) with the results being recorded prospectively. The inclusion criteria for this study were babies and children referred with asymmetrical skin creases. Those with a neurological cause of DDH were excluded. The positive predictive value (PPV) for pathological DDH was calculated.

Results

A total of 105 patients met the inclusion criteria. There were 71 girls and 34 boys. Only two were found to have pathological DDH. Both also had unilateral limited abduction of the hip in flexion and a positive Galeazzi sign with apparent leg-length discrepancy. Thus, if the specialist examination of a patient with asymmetrical skin creases was normal, the PPV for DDH was 0%.

Conclusion

Isolated asymmetrical skin creases are an unreliable clinical sign in the diagnosis of pathological DDH. Greater emphasis should be placed on the presence of additional clinical signs to guide radiological screening in babies and children. Cite this article: Bone Joint J 2018;100-B:675-9.

Introducing universal ultrasound screening for developmental dysplasia of the hip doubled the treatment rate

AIM

There is no evidence on the effect of universal ultrasound screening on developmental dysplasia of the hip. We examined the impact of adding an ultrasound examination to a one examiner clinical screening strategy on treatment, follow-up rates and the number of cases detected late in a low-prevalence population.

METHODS

All eligible babies born at Kongsberg Hospital, Norway, from 1998 to 2006 (n = 4245) underwent both clinical and ultrasound hip examinations within three days of life. Indications for immediate treatment were positive Barlow or Ortolani manoeuvres and, or, sonographic dysplasia. Sonographic immature hips were followed until normalisation. Treatment rates and rates from the 1989 to 1997 prestudy period (n = 3594), including late diagnoses, were collected from hospital records.

RESULTS

Treatment was initiated in 90 (2.1%) infants (74 girls), 63 (70%) from birth, compared to 33 (0.9%) during the prestudy period. The follow-up rate did not change (11%). There were two (0.5/1000) and four (1.0/1000) cases detected late, respectively. No one underwent surgery during the first year of life and no avascular necrosis was seen.

CONCLUSION

Adding universal ultrasound to clinical screening performed by the same, experienced paediatrician doubled the treatment rate, without influencing the already low numbers of late cases.

Screening in Developmental Dysplasia of the Hip (DDH)

Screening for Developmental Dysplasia of the Hip (DDH) is a controversial subject. Screening may be by universal neonatal clinical examination (Ortolani or Barlow manoeuvres) with the addition of sonographic imaging of the hip (selective 'at risk' hips or universal screening in the neonate). In the UK, the NIPE guidelines recommend universal neonatal clinical assessment of the hip joints, a General Practitioner 6-8 week clinical 'hip check' and assessment clinically with sonographic imaging at 4-6 weeks for certain 'at risk' hips for pathological DDH. The effectiveness and difficulties arising from the UK current screening policy (clinical and sonographic) are highlighted. The purpose of the review was to assess the risk factors and efficacy of diagnostic methods in DDH, based on longitudinal cohort studies of 10 years or more.

CONCLUSION

Hip screening in DDH does not meet most of the World Health Organisation's criteria for an effective screening programme and should only be considered as surveillance due to its low sensitivity and positive predictive value (PPV). There is a significant risk of over diagnosis and over treatment. There is no International consensus on screening in DDH. Pathological DDH is mainly a female condition and 'at risk'/General Practitioner screening identifies few pathological cases in male subjects. The General Practitioner 6-8 week 'hip check' has a very low PPV for pathological DDH and is of doubtful value in screening and diagnosis. Unilateral limitation of hip abduction is a time dependent and useful clinical sign in the diagnosis of pathological DDH. The majority of the previously considered 'at risk' factors are not true risk factors with little or no association with pathological DDH.

Disparity between Clinical and Ultrasound Examinations in Neonatal Hip Screening

BACKGROUND

For early detection of developmental dysplasia of the hip (DDH), neonatal hip screening using clinical examination and/or ultrasound has been recommended. Although there have been many studies on the reliability of both screening techniques, there is still controversy in the screening strategies; clinical vs. selective or universal ultrasound screening. To determine the screening strategy, we assessed the agreement among the methods; clinical examination by an experienced pediatric orthopedic surgeon, sonographic morphology, and sonographic stability.

METHODS

From January 2004 to June 2009, a single experienced pediatric orthopedic surgeon performed clinical hip screenings for 2,686 infants in the neonatal unit and 43 infants who were referred due to impressions of hip dysplasia before 3 months of age. Among them, 156 clinically unstable or high-risk babies selectively received bilateral hip ultrasound examinations performed by the same surgeon using the modified Graf method. The results were analyzed statistically to detect any correlations between the clinical and sonographic findings.

RESULTS

Although a single experienced orthopedic surgeon conducted all examinations, we detected only a limited relationship between the results of clinical and ultrasound examinations. Ninety-three percent of the clinically subluxatable hips were normal or immature based on static ultrasound examination, and 74% of dislocating hips and 67% of limited abduction hips presented with the morphology below Graf IIa. A total of 80% of clinically subluxatable, 42% of dislocating and 67% of limited abduction hips appeared stable or exhibited minor instability on dynamic ultrasound examination. About 7% of clinically normal hips were abnormal upon ultrasound examination; 5% showed major instability and 3% showed dysplasia above Graf IIc. Clinical stability had small coefficients between ultrasound examinations; 0.39 for sonographic stability and 0.37 for sonographic morphology. Between sonographic stability and morphology, although 71% of hips with major instability showed normal or immature morphology according to static ultrasound examination, the coefficient was as high as 0.64.

CONCLUSIONS

Discrepancies between clinical and ultrasound examinations were present even if almost all of the exams were performed by a single experienced pediatric orthopedic surgeon. In relation to screening for DDH, it is recommended that both sonographic morphology and stability be checked in addition to clinical examination.

Delayed diagnosis of developmental dysplasia of the hip in Northern Ireland

Developmental dysplasia of the hip (DDH) should be diagnosed as early as possible to optimise treatment. The current United Kingdom recommendations for the selective screening of DDH include a clinical examination at birth and at six weeks. In Northern Ireland babies continue to have an assessment by a health visitor at four months of age. As we continue to see late presentations of DDH, beyond one year of age, we hypothesised that a proportion had missed an opportunity for earlier diagnosis. We expect those who presented to our service with Tonnis grade III or IV hips and decreased abduction would have had clinical signs at their earlier assessments.

We performed a retrospective review of all patients born in Northern Ireland between 2008 and 2010 who were diagnosed with DDH after their first birthday. There were 75 856 live births during the study period of whom 645 children were treated for DDH (8.5 per 1000). The minimum follow-up of our cohort from birth, to detect late presentation, was four years and six months. Of these, 32 children (33 hips) were diagnosed after their first birthday (0.42 per 1000).

With optimum application of our selective screening programme 21 (65.6%) of these children had the potential for an earlier diagnosis, which would have reduced the incidence of late diagnosis to 0.14 per 1000. As we saw a peak in diagnosis between three and five months our findings support the continuation of the four month health visitor check. Our study adds further information to the debate regarding selective versus universal screening.

Cite this article: Bone Joint J 2015;97-B:1572–6.

Late recurrence of developmental dysplasia of the hip following Pavlik harness treatment until normal ultrasound appearance

PURPOSE

Establish whether recurrent dysplasia once a dysplastic hip has been treated to ultrasonographic normality is possible.

METHODS

370 babies were referred to a hip ultrasound clinic from June 2005 to 2007 to assess for dysplasia. 96 dysplastic hips underwent appropriate treatment until normal hip morphology achieved on follow-up ultrasounds. Minimum further 12 months follow-up.

RESULTS

3 children (4%) developed late recurrence of dysplasia. Two required a plaster hip spica. One had an additional adductor tenotomy. One required late pelvic osteotomy.

CONCLUSION

This study highlights the need for long-term follow-up of dysplastic hips with an early pelvic X-ray at around six months.

Neonatal clinical screening of the hip in the diagnosis of developmental dysplasia of the hip

Over a 15-year prospective period, 201 infants with a clinically unstable hip at neonatal screening were subsequently reviewed in a ‘one stop’ clinic where they were assessed clinically and sonographically. Their mean age was 1.62 weeks (95% confidence interval (CI) 1.35 to 1.89). Clinical neonatal hip screening revealed a sensitivity of 62% (mean, 62.6 95%CI 50.9 to 74.3), specificity of 99.8% (mean, 99.8, 95% CI 99.7 to 99.8) and positive predictive value (PPV) of 24% (mean, 26.2, 95% CI 19.3 to 33.0). Static and dynamic sonography for Graf type IV dysplastic hips had a 15-year sensitivity of 77% (mean, 75.8 95% CI 66.9 to 84.6), specificity of 99.8% (mean, 99.8, 95% CI 99.8 to 99.8) and a PPV of 49% (mean, 55.1, 95% CI 41.6 to 68.5). There were 36 infants with an irreducible dislocation of the hip (0.57 per 1000 live births), including six that failed to resolve with neonatal splintage.

Most clinically unstable hips referred to a specialist clinic are female and stabilise spontaneously. Most irreducible dislocations are not identified from this neonatal instability group. There may be a small subgroup of females with instability of the hip which may be at risk of progression to irreducibility despite early treatment in a Pavlik harness.

A controlled study is required to assess the value of neonatal clinical screening programmes.

Cite this article: Bone Joint J 2015;97-B:265-9.

How are outcomes affected by performing a one-stage combined procedure simultaneously in bilateral developmental hip dysplasia?

PURPOSE

The aim of this study was to compare the outcomes of one-stage combined surgical treatment in children of unilateral and bilateral developmental hip dysplasia diagnosed after walking age.

METHODS

We reviewed 24 patients who underwent one-stage combined surgery for DDH diagnosed after walking age. Group I consisted of 12 patients with bilateral disease who underwent bilateral operation at one operative setting. Group II consisted of 12 patients with unilateral disease. Pre-operatively the hips were classified according to Tönnis classification. Acetabular dysplasia was evaluated by measuring acetabular index (AI) angles pre-operatively. The acetabular improvements with time regarding AI was noted immediately postoperatively, every six months, and at the final follow-up examination.

RESULTS

Mean follow up of the bilateral group I and group II were 54.8 months (range 20-84 months) and 52.6 months (24-80), respectively. There were no statistically significant differences between immediate postoperative and final follow up acetabular index improvement rates in both groups. Also there was no significant difference when both hips were compared in group I. The clinical final outcome of both groups and within group I was similar.

CONCLUSIONS

Simultaneous combined surgery is a challenging but worthwhile procedure for late diagnosed patients with bilateral DDH. The short-mid term outcomes of the procedure are encouraging.

Is limitation of hip abduction a useful clinical sign in the diagnosis of developmental dysplasia of the hip?

AIM

The relationship between the presence and severity of sonographically diagnosed developmental dysplasia of the hip (DDH) and the clinical abnormality of limitation of hip abduction (LHA) was investigated.

METHODS

A prospective, longitudinal, selective 'at risk' and neonatal instability hip ultrasound programme between 1 January 1996 and 31 December 2005. 2876 neonates/infants were initially screened for DDH by clinical examination and by hip ultrasound imaging. Pathological sonographically evaluated DDH was considered to be Graf Type III, IV and irreducible hip dislocation. Inclusion criteria were cases of unilateral or bilateral limitation of hip abduction hip.

EXCLUSION CRITERIA

syndromal, neuromuscular and skeletal dysplasia cases.

RESULTS

492 children presented with LHA (55 unilateral LHA). The mean age of neonates/infants with either unilateral or bilateral LHA was significantly higher than those without (p<0.001). In the sonographic diagnosis of Graf Type III and IV dysplasias, unilateral LHA had a PPV of 40% compared with only 0.3% for bilateral LHA. The sensitivity of unilateral LHA increased to 78.3% and a PPV 54.7% after the age of 8 weeks for Graf Types III, IV and irreducible hip dislocation.

CONCLUSIONS

This study identifies a time-dependent association with unilateral LHA in the diagnosis of 'pathological' DDH after the age of 8 weeks. The presence of bilateral LHA in the young infant may be a normal variant and is an inaccurate clinical sign in the diagnosis of pathological DDH. LHA should be actively sought after 8 weeks of age and if present should be followed by a formal ultrasound or radiographic examination to confirm whether or not the hip is developing in a satisfactory manner.

Acetabular dysplasia at the age of 1 year in children with neonatal instability of the hip

BACKGROUND AND PURPOSE

As much as one-third of all total hip arthroplasties in patients younger than 60 years may be a consequence of developmental dysplasia of the hip (DDH). Screening and early treatment of neonatal instability of the hip (NIH) reduces the incidence of DDH. We examined the radiographic outcome at 1 year in children undergoing early treatment for NIH.

SUBJECTS AND METHODS

All children born in Malmö undergo neonatal screening for NIH, and any child with suspicion of instability is referred to our clinic. We reviewed the 1-year radiographs for infants who were referred from April 2002 through December 2007. Measurements of the acetabular index at 1 year were compared between neonatally dislocated, unstable, and stable hips.

RESULTS

The incidence of NIH was 7 per 1,000 live births. The referral rate was 15 per 1,000. 82% of those treated were girls. The mean acetabular index was higher in dislocated hips (25.3, 95% CI: 24.6-26.0) than in neonatally stable hips (22.7, 95% CI: 22.3-23.2). Girls had a higher mean acetabular index than boys and left hips had a higher mean acetabular index than right hips, which is in accordance with previous findings.

INTERPRETATION

Even in children who are diagnosed and treated perinatally, radiographic differences in acetabular shape remain at 1 year. To determine whether this is of clinical importance, longer follow-up will be required.

Screening of selected risk factors in developmental dysplasia of the hip: an observational study

BACKGROUND

Developmental dysplasia of the hip (DDH) is the most common neonatal musculoskeletal condition. In 2008, the NHS Newborn and Infant Physical Examination committee added selective 'at risk' screening to the existing universal neonatal and general practitioner clinical hip screening guidelines.

OBJECTIVE

Assessment of breech and family history risk factors in DDH.

DESIGN

A 15 year prospective, observational, longitudinal cohort study.

METHOD

Breech presentation and evidence of a strong family history for DDH were the 'risk factors' studied. All infants referred were clinically and sonographically screened by one consultant paediatric orthopaedic surgeon.

RESULTS

From a cohort of 64 670 live births, 2984 neonates/infants, 46.1 (95% CI 44.6 to 47.8) per 1000 live births, were referred and sonographically screened with these risk factors alone. 1360 were male, of which four were identified as having 'pathological' DDH (an incidence of 0.003 (95% CI 0.001 to 0.008)). 1624 were female, of which 45 were identified as having 'pathological' DDH (an incidence of 0.028 (95% CI 0.021 to 0.037)). This difference in incidence of 0.025 (95% CI 0.016 to 0.033) was statistically significant (p<0.001). From those who were clinically stable and screened with either or both of the two risk factors, four individuals were diagnosed with irreducible hip dislocation (0.06 (95% CI 0.024 to 0.159) per 1000 live births). All were females.

CONCLUSIONS

This study questions the current UK screening policy for DDH in clinically stable males referred with risk factors, and may influence future DDH screening programme policy.

Screening and treatment in developmental dysplasia of the hip-where do we go from here?

PURPOSE

Developmental dysplasia of the hip (DDH) is a leading cause of disability in childhood and early adult life. Clinical and sonographic screening programmes have been used to facilitate early detection but the effectiveness of both screening strategies is unproven. This article discusses the role for screening in DDH and provides an evidence-based review for early management of cases detected by such screening programmes.

METHODS

We performed a literature review using the key words 'hip dysplasia,' 'screening,' 'ultrasound,' and 'treatment.'

RESULTS

The screening method of choice and its effectiveness in DDH still needs to be established although it seems essential that screening tests are performed by trained and competent examiners. There is no level 1 evidence to advise on the role of abduction splinting in DDH although clinicians feel strongly that hip instability does improve with such a treatment regime. The definition of what constitutes a pathological dysplasia and when this requires treatment is also poorly understood.

CONCLUSION

Further research needs to establish whether early splintage of clinically stable but sonographically dysplastic hips affects future risk of late-presenting dysplasia/dislocation and osteoarthritis. There is a need for high quality studies in the future if these questions are to be answered.

The role of community screening for developmental dysplasia of the hip at the 8-month baby check

BACKGROUND

Screening for developmental dysplasia of the hip (DDH) after the neonatal period is controversial. Due to recent changes in the screening policy in England & Wales, routine clinical screening for DDH at the 8-month baby check is no longer recommended.

RESULTS

This paper looks at the effectiveness of screening for DDH by health visitors in the Flintshire area. A total of 525 8-month baby checks were performed in our area in 2007. Thirty babies were referred to their general practitioner of which six were referred on to a specialist children's orthopaedic surgeon. None of these required treatment for DDH. One patient who was screened by the health visitor but not referred was later diagnosed with DDH.

CONCLUSION

Screening for DDH at 8 months using clinical examination by a trained health visitor has a high false-positive rate. This paper therefore supports the current UK National Screening Committee position.

To screen or not to screen? A decision analysis of the utility of screening for developmental dysplasia of the hip

BACKGROUND

The United States Preventive Services Task Force recently determined that they could not recommend any screening strategies for developmental dysplasia of the hip. Disparate findings in the literature and treatment-related problems have led to confusion about whether or not to screen for this disorder. The purpose of the present study was to determine, with use of expected-value decision analysis, which of the following three strategies leads to the best chance of having a non-arthritic hip by the age of sixty years: (1) no screening for developmental dysplasia of the hip, (2) universal screening of newborns with both physical examination and ultrasonography, or (3) universal screening with physical examination but only selective use of ultrasonography for neonates considered to be at high risk.

METHODS

Developmental dysplasia of the hip, avascular necrosis, and the treatment algorithm were carefully defined. The outcome was determined as the probability of any neonate having a non-arthritic hip through the age of sixty years. A decision tree was then built with decision nodes as described above, and chance node probabilities were determined from a thorough review of the literature. Foldback analysis and sensitivity analyses were performed.

RESULTS

The expected value of a favorable hip outcome was 0.9590 for the strategy of screening all neonates with physical examination and selective use of ultrasonography, 0.9586 for screening all neonates with physical examination and ultrasonography, and 0.9578 for no screening. A lower expected value implies a greater risk for the development of osteoarthritis as a result of developmental dysplasia of the hip or avascular necrosis; thus, the optimum strategy was selective screening. This model was robust to sensitivity analysis, except when the rate of missed dysplasia rose as high as 4/1000 or the rate of treated hip subluxation/dislocation was the same; then, the optimum strategy was to screen all neonates with both physical examination and ultrasonography.

CONCLUSIONS

Our decision analytic model indicated that the optimum strategy, associated with the highest probability of having a non-arthritic hip at the age of sixty years, was to screen all neonates for hip dysplasia with a physical examination and to use ultrasonography selectively for infants who are at high risk. Additional data on the costs and cost-effectiveness of these screening policies are needed to guide policy recommendations.

Developmental dysplasia of the hip: ultrasound screening and treatment. How are they related?

An assessment of the current clinical and ultrasound screening programmes. Early treatment by splintage is advocated for instability and Graf type III dysplasia of the hip.

The effectiveness of a programme for neonatal hip screening over a period of 40 years: a follow-up of the New Plymouth experience

Since September 1964, neonates born in New Plymouth have undergone clinical examination for instability of the hip in a structured clinical screening programme. Of the 41 563 babies born during this period, 1639 were diagnosed as having unstable hips and 663 (1.6%) with persisting instability were splinted, five of which failed. Also, three unsplinted hips progressed to congenital dislocation, and there were four late-presenting (walking) cases, giving an overall failure rate of 0.29 per 1000 live births, with an incidence of late-walking congenital dislocation of the hip of 0.1 per 1000 live births. This study confirms that clinical screening for neonatal instability of the hip by experienced orthopaedic examiners significantly reduces the incidence of late-presenting (walking) congenital dislocation of the hip.

Role of ultrasound in the diagnosis and management of developmental dysplasia of the hip: an international perspective

Early diagnosis of developmental dysplasia of the hip is very important for proper treatment. Different ultrasound techniques have been used for early diagnosis of developmental dysplasia of the hip, but two of them are widely used in orthopedic practice: Graf's technique in Europe and Harcke's method in the United States. Our experience has led us to use an ultrasound technique that combines the two methods. Use of ultrasound has reduced the number of late-presenting cases, shortened treatment time, and decreased the number of surgical procedures of the hip joint in Poland.

Screening for developmental dysplasia of the hip: a systematic literature review for the US Preventive Services Task Force

BACKGROUND

Developmental dysplasia of the hip (DDH) represents a spectrum of anatomic abnormalities that can result in permanent disability.

OBJECTIVE

We sought to gather and synthesize the published evidence regarding screening for DDH by primary care providers.

METHODS

We performed a systematic review of the literature by using a best-evidence approach as used by the US Preventive Services Task Force. The review focused on screening relevant to primary care in infants from birth to 6 months of age and on interventions used in infants before 1 year of age.

RESULTS

The literature on screening and interventions for DDH suffers from significant methodologic shortcomings. No published trials directly link screening to improved functional outcomes. Clinical examination and ultrasound identify somewhat different groups of newborns who are at risk for DDH. A significant proportion of hip abnormalities identified through clinical examination or ultrasound in the newborn period will spontaneously resolve. Very few studies examine the functional outcomes of patients who have undergone therapy for DDH. Because of the high rate and unpredictable nature of spontaneous resolution of DDH and the absence of rigorous comparative studies, the effectiveness of interventions is not known. All surgical and nonsurgical interventions have been associated with avascular necrosis of the femoral head, the most common and most severe harm associated with all treatments of DDH.

CONCLUSIONS

Screening with clinical examination or ultrasound can identify newborns at increased risk for DDH, but because of the high rate of spontaneous resolution of neonatal hip instability and dysplasia and the lack of evidence of the effectiveness of intervention on functional outcomes, the net benefits of screening are not clear.

Screening for hip abnormality in the neonate

Clinical screening policies for the detection of hip instability or dysplasia of the hip vary internationally. There is general agreement in the Western world that at birth all hip joints should be clinically assessed by the Ortolani and Barlow tests. Currently, there is no consistency regarding who should undertake the examination, the results being worse when inexperienced personnel are used. These clinical tests have poor sensitivity and should be regarded as surveillance, not screening methods. Since the 1980s ultrasonographic assessment of the hip has become a valuable diagnostic tool. However there is continuing controversy on whether this imaging method should be used universally or selectively for 'at risk' and clinically unstable hip joints. Universal ultrasonographic evaluation may result in over-treatment and selective screening may be no better than the best clinical screening programs in reducing the incidence of 'late' irreducible dislocation of the hip. It is generally accepted that all clinically unstable hips should be imaged by ultrasound by static and dynamic methods in order to confirm the diagnosis and to monitor treatment.

The diagnosis and management of neonatal hip instability: results of a clinical and targeted ultrasound screening program

This article reports the results of a neonatal hip screening program comprising clinical screening and targeted ultrasound performed by orthopaedic surgeons. Over 7 years, from 1995 to 2001, there were 15,397 live births in the authors' region. Seven hundred thirty-three babies (4.8% of births) were referred for hip ultrasound: 80% for risk factors and 20% for instability. Eighty-three babies (5.4/1,000) were splinted in a Pavlik harness. Three of these subsequently required surgery (1.9/1,000). Ten patients (0.65/1000) presented with hip dislocation after 12 weeks of age, nine of whom required open or closed reduction (0.56/1,000). From 1978 to 1985, when neonatal pediatricians clinically screened all babies, 18 babies presented late from 13,707 births (1.3/1000). Since the introduction of orthopaedic screening and targeted ultrasound, there has been a significant reduction in late diagnosis in the authors' institution.

Auditing hip ultrasound screening of infants at increased risk of developmental dysplasia of the hip

BACKGROUND

Clinical examination, while useful, has been shown to be insufficient as the sole screening method in infants. Ultrasound examination at 8 weeks in high risk infants is an integral part of the screening process in some units.

AIMS

To show the efficiency of hip sonography in detection of developmental dysplasia of the hips in those without clinically dislocated hips.

METHODS

All infants born at the National Maternity Hospital between January 1994 and December 2001 were included. All those with clinically dislocated hips were treated by a Pavlik harness and referred for follow up to a paediatric orthopaedic surgeon. An 8 week hip ultrasound scan was performed for those infants with stable hips on examination but who met the following criteria: (1) a first degree relative with congenital dislocation of hips; (2) breech presentation at birth; and (3) a persistent "click" at birth in an otherwise stable hip.

RESULTS

During the period of study a total of 52 893 infants were born in the National Maternity Hospital. Based on the criteria above, 5485 hip ultrasound scans were performed. Of those scanned, 18 (0.33%) were found to have dislocated hips and 153 (2.78%) to have dysplasic hips. The 18 infants with dislocation were treated with Pavlik harness; the remaining 153 were followed up by serial ultrasound examinations but did not require active intervention.

CONCLUSIONS

Among the population of infants at increased risk of developmental dysplasia of the hip, the hip screening programme identified 18 cases among 5485 infants; a rate of 3.2 per 1000. Hip sonography is therefore worthwhile.

Value of limited hip abduction in developmental dysplasia of the hip

BACKGROUND

Developmental dysplasia of the hip (DDH) continues to be missed by routine physical examination in up to 50% of cases. Ultrasound (US) supplementation is the best method of screening for DDH, but the resources required should not be underestimated. Limited abduction of the hip (LHA) in an infant triggers suspicion, and often an urge to treat, in most orthopaedic surgeons and pediatricians alike. This study aimed to document the value of unilateral LHA in the diagnosis and decision making of DDH, and the correlation between LHA and US.

METHODS

In total, 464 infants referred from the pediatrics clinic with LHA, aged between 30 and 120 days, were included in the study.

RESULTS

Physical examination revealed LHA in 186 (41%) infants, 26 of which were unilateral and 160 were bilateral. US examination showed that 13 (8.1%) patients in the bilateral LHA group and 18 (69.2) patients in the unilateral LHA group, had DDH (total number 31, 7%).

CONCLUSION

Unilateral limitation of hip abduction was found to be a sensitive sign for developmental hip dysplasia, but US could be defined once again as the best golden standard before initiating treatment.

Screening for developmental dysplasia of the hip: results of a 7-year follow-up study

BACKGROUND

Screening for developmental dysplasia of the hip (DDH) is widely recommended for all infants to prevent disability from late diagnosis of dislocation of the hip. The present study evaluates the results of screening for developmental dislocation of hip in a clinic in Turkey over the course of 7 years.

METHODS

Hospital records of 5798 infants who were examined regularly until walking age at Gazi University well child clinics between January 1995 and December 2001 were reviewed. Infants with known risk factors for DDH such as breech presentation, family history of DDH or swaddling, and of infants with physical examination findings suggestive of DDH, were referred to orthopedic surgeons for diagnosis. Based on this final diagnosis, sensitivity, specificity, positive and negative predictive values of risk factors and physical examination findings were calculated.

RESULTS

Of the 5798 infants, risk factors were detected in the medical history of 111 infants, and in 14 infants a musculoskeletal deformity was detected. In 606 infants the physical examination findings were suggestive of DDH. Ten patients were subsequently diagnosed with DDH. The sensitivity, specificity, positive predictive value and negative predictive values of having a risk factor for DDH in history were 10.0%, 98.1%, 0.9%, 99.8%, and having abnormal hip examination findings were 100.0%, 88.9%, 1.6% and 100.0%, respectively.

CONCLUSIONS

A careful history and physical examination is the cornerstone of DDH screening. Serial hip examinations performed during health examination visits provide an opportunity to identify DDH cases. The sensitivity of risk factors in history and physical examination findings together is high enough to be accepted as a screening tool.

Efficiency of alternative policy options for screening for developmental dysplasia of the hip in the United Kingdom

AIMS

To assess, using a decision model, the efficiency of ultrasound based and clinical screening strategies for developmental dysplasia of the hip.

METHODS

The additional cost per additional favourable outcome was compared for the following strategies: clinical screening alone using the Ortolani and Barlow tests; addition of static and dynamic ultrasound examination of the hips of all infants (universal ultrasound) or restricted to infants with defined risk factors (selective ultrasound); "no screening" (that is, clinical diagnosis only).

RESULTS

Ultrasound based screening strategies are predicted to be more effective but more costly than clinical screening or no screening. Estimated total costs per 100,000 live births are approximately pound 4 million for universal ultrasound, pound 3 million for selective ultrasound, pound 1 million for clinical screening alone, and pound 0.4 million for no screening. The relative efficiency of selective ultrasound and clinical screening is poorly differentiated, and depends on how infants are selected for ultrasound as well as the expertise of clinical screening examiners. If training costs less than pound 20 per child screened, clinical screening alone would be more efficient than selective ultrasound. Relative to no screening, each of the 16 additional favourable outcomes achieved as a result of selective ultrasound costs approximately pound 0.2 million, while each of the five favourable outcomes achieved through universal ultrasound screening, over and above selective ultrasound, costs approximately pound 0.3 million.

CONCLUSIONS

Policy choice depends on values attached to the different outcomes, willingness to pay to achieve these and total budget.

Performance, treatment pathways, and effects of alternative policy options for screening for developmental dysplasia of the hip in the United Kingdom

AIMS

To compare, using a decision model, performance, treatment pathways and effects of different newborn screening strategies for developmental hip dysplasia with no screening.

METHODS

Detection rate, radiological absence of subluxation at skeletal maturity and avascular necrosis of the femoral head, as favourable and unfavourable treatment outcomes respectively, were compared for the following strategies: clinical screening alone using the Ortolani and Barlow tests; the addition of static and dynamic ultrasound examination of the hips of all infants (universal ultrasound) or restricted to infants with defined risk factors (selective ultrasound); "no screening" (that is, clinical diagnosis only).

RESULTS

Universal or selective ultrasound detects more more affected children (76% and 60% respectively) than clinical screening alone (35%), results in a higher proportion of affected children with favourable treatment outcomes (92% and 88% respectively) than clinical screening alone (78%) or no screening (75%), and the highest proportion of these achieved without recourse to surgery (64% and 79% respectively) compared with clinical screening alone (18%). However, ultrasound based strategies are also associated with the highest number of unfavourable treatment outcomes arising in unaffected children treated following a false positive screening result. The detection rate of clinical screening alone becomes similar to that reported for universal ultrasound when based on studies using experienced examiners (80%) rather than junior medical staff (35%).

CONCLUSION

From the largely observational data available, ultrasound based screening strategies appear to be most sensitive and effective but are associated with the greatest risk of potential adverse iatrogenic effects arising in unaffected children.

Neonatal hip screening

CONTEXT

A "missed" case of congenital hip dislocation (CDH) can be a disaster for the patient and the outcome may be poor. Considerable resources are expended on screening programmes to identify appropriate cases early but a recent change in terminology to developmental dysplasia of the hip (DDH) and a realisation that neonatal hip maturation is poorly understood has made it difficult to know who should be screened and why.

STARTING POINT

Neonatal hip screening is well established although some experts feel that the effectiveness of clinical let alone ultrasound screening programmes is unproven. Several European countries undertake population screening, while selective screening occurs in 93% of UK units. K Holen and colleagues recently reported (J Bone Joint Surg 2002; 84-B: 886-90) a prospective randomised trial of just over 15 500 newborn babies in which they compare universal and selective screening programmes. With a follow-up of 6-11 years, one late-detected hip dysplasia was seen in the universal group compared with six in the selective group (not statistically significant). These investigators found, on the background of an excellent clinical programme, no additional benefit from universal screening and thus advocate selective screening.

WHERE NEXT

The aims of a screening programme must be defined, then evaluated. A consideration of costs can never take into account family pain and distress. The results of the universal screening programme in Coventry, UK, are impressive and significantly better than results from other UK centres. If the Coventry results are the gold standard, then it is necessary to work out how this can be achieved elsewhere rather than worry about whether it is unachievable.

Clinical screening for developmental dysplasia of the hip in Northern Ireland

PROBLEM

The incidence of late diagnosed developmental dysplasia of the hip requiring surgery in Northern Ireland is high. The reported incidence was 1.14 per 1000 children born during 1983-7.

DESIGN

Comparative retrospective study.

BACKGROUND AND SETTING

Clinical screening programme in Northern Ireland. Key measure for improvement: Reduced rate of operative intervention in children with developmental dysplasia of the hip detected after 6 months of age.

STRATEGIES FOR CHANGE

Increased emphasis on staff training, introduction of a centralised nurse led clinic to improve access to orthopaedic surgeons, and increased use of ultrasonography.

EFFECTS OF CHANGE

The incidence of developmental dysplasia of the hip diagnosed after 6 months in children born between January 1991 and December 1997 fell to 0.59 per 1000, presumably due to improved early detection. Nevertheless, 29 (16%) of the affected hips were not diagnosed when the child was first referred in the first 3 months of life. In addition, for 27 affected hips in children diagnosed after the age of 6 months there was a known risk factor (family history or breech delivery).

LESSONS LEARNT

Improvements to screening processes can reduce late incidence of developmental dysplasia of the hip. Further steps to improve detection in children with known risk factors and rate of detection at first referral could reduce late presentation further.

Developmental dysplasia of the hip practice guideline: technical report. Committee on Quality Improvement, and Subcommittee on Developmental Dysplasia of the Hip

OBJECTIVE

To create a recommendation for pediatricians and other primary care providers about their role as screeners for detecting developmental dysplasia of the hip (DDH) in children.

PATIENTS

Theoretical cohorts of newborns.

METHOD

Model-based approach using decision analysis as the foundation. Components of the approach include the following:

PERSPECTIVE

Primary care provider.

OUTCOMES

DDH, avascular necrosis of the hip (AVN).

OPTIONS

Newborn screening by pediatric examination; orthopaedic examination; ultrasonographic examination; orthopaedic or ultrasonographic examination by risk factors. Intercurrent health supervision-based screening. PREFERENCES: 0 for bad outcomes, 1 for best outcomes.

MODEL

Influence diagram assessed by the Subcommittee and by the methodology team, with critical feedback from the Subcommittee. EVIDENCE SOURCES: Medline and EMBASE search of the research literature through June 1996. Hand search of sentinel journals from June 1996 through March 1997. Ancestor search of accepted articles. EVIDENCE QUALITY: Assessed on a custom subjective scale, based primarily on the fit of the evidence to the decision model.

RESULTS

After discussion, explicit modeling, and critique, an influence diagram of 31 nodes was created. The computer-based and the hand literature searches found 534 articles, 101 of which were reviewed by 2 or more readers. Ancestor searches of these yielded a further 17 articles for evidence abstraction. Articles came from around the globe, although primarily Europe, British Isles, Scandinavia, and their descendants. There were 5 controlled trials, each with a sample size less than 40. The remainder were case series. Evidence was available for 17 of the desired 30 probabilities. Evidence quality ranged primarily between one third and two thirds of the maximum attainable score (median: 10-21; interquartile range: 8-14). Based on the raw evidence and Bayesian hierarchical meta-analyses, our estimate for the incidence of DDH revealed by physical examination performed by pediatricians is 8.6 per 1000; for orthopaedic screening, 11.5; for ultrasonography, 25. The odds ratio for DDH, given breech delivery, is 5.5; for female sex, 4.1; for positive family history, 1.7, although this last factor is not statistically significant. Postneonatal cases of DDH were divided into mid-term (younger than 6 months of age) and late-term (older than 6 months of age). Our estimates for the mid-term rate for screening by pediatricians is 0.34/1000 children screened; for orthopaedists, 0.1; and for ultrasonography, 0.28. Our estimates for late-term DDH rates are 0.21/1000 newborns screened by pediatricians; 0.08, by orthopaedists; and 0.2 for ultrasonography. The rates of AVN for children referred before 6 months of age is estimated at 2.5/1000 infants referred. For those referred after 6 months of age, our estimate is 109/1000 referred infants. The decision model (reduced, based on available evidence) suggests that orthopaedic screening is optimal, but because orthopaedists in the published studies and in practice would differ, the supply of orthopaedists is relatively limited, and the difference between orthopaedists and pediatricians is statistically insignificant, we conclude that pediatric screening is to be recommended. The place of ultrasonography in the screening process remains to be defined because there are too few data about postneonatal diagnosis by ultrasonographic screening to permit definitive recommendations. These data could be used by others to refine the conclusions based on costs, parental preferences, or physician style. Areas for research are well defined by our model-based approach.

Clinical practice guideline: early detection of developmental dysplasia of the hip. Committee on Quality Improvement, Subcommittee on Developmental Dysplasia of the Hip. American Academy of Pediatrics

Developmental dysplasia of the hip is the preferred term to describe the condition in which the femoral head has an abnormal relationship to the acetabulum. Developmental dysplasia of the hip includes frank dislocation (luxation), partial dislocation (subluxation), instability wherein the femoral head comes in and out of the socket, and an array of radiographic abnormalities that reflect inadequate formation of the acetabulum. Because many of these findings may not be present at birth, the term developmental more accurately reflects the biologic features than does the term congenital. The disorder is uncommon. The earlier a dislocated hip is detected, the simpler and more effective is the treatment. Despite newborn screening programs, dislocated hips continue to be diagnosed later in infancy and childhood,(1-11) in some instances delaying appropriate therapy and leading to a substantial number of malpractice claims. The objective of this guideline is to reduce the number of dislocated hips detected later in infancy and childhood. The target audience is the primary care provider. The target patient is the healthy newborn up to 18 months of age, excluding those with neuromuscular disorders, myelodysplasia, or arthrogryposis.

Developmental dysplasia of the hip: a new approach to incidence

OBJECTIVE

The controversy over the incidence of developmental dysplasia of the hip (DDH) stems mainly from an ambiguity of criteria for defining a genuinely pathologic neonatal hip. In this study, we evaluate an algorithm we devised for the treatment of DDH, for its ability to identify those neonatal hips which, if left untreated, would develop any kind of dysplasia and, therefore, are to be included in the determination of DDH incidence.

METHODS

Clinical and ultrasonographic examinations for DDH were performed on 18 060 consecutive neonatal hips at 1 to 3 days of life. Newborns with skeletal deformities, neurologic/muscular disorders, and neural tube defects were excluded. Hips that featured any type of sonographic pathology were reexamined at 2 or 6 weeks, depending on the severity of the findings. Only hips in which the initial pathology was not improved or had deteriorated were treated; all others were examined periodically until the age of 12 months.

RESULTS

Sonographic screening of 18 060 hips detected 1001 instances of deviation from normal, indicating a sonographic DDH incidence of 55.1 per 1000. However, only 90 hips remained abnormal and required treatment, indicating a true DDH incidence of 5 per 1000 hips. All the others evolved into normal hips, and no additional instances of DDH were found on follow-up throughout the 12 months.

CONCLUSIONS

The implementation of our protocol enables us to distinguish two categories of neonatal hip pathology: one that eventually develops into a normal hip (essentially sonographic DDH); and another that will deteriorate into a hip with some kind of dysplasia, including full dislocation (true DDH). This approach seems to allow for a better-founded definition of DDH, for an appropriate determination of its incidence, for decision-making regarding treatment, and for assessment of the cost-effectiveness of screening programs for the early detection of DDH.

Evaluating the national screening programme for congenital dislocation of the hip

In 1969 universal clinical screening for neonatal hip instability was formally adopted in the United Kingdom with the aim of detecting and treating children considered to be at high risk of congenital dislocation of the hip (CDH). However, clinical screening is associated with both false positive and false negative diagnoses and has never been evaluated in a randomised trial. The emergence of hip ultrasound provides renewed impetus to reconsider and formally evaluate screening for CDH. Ultrasound imaging of the newborn hip may be used as a screening test and to assess and manage infants with clinically detected hip instability. Universal primary ultrasound screening has been adopted in some European countries, but enthusiasm for this new technology has been tempered by the subsequent large increases in treatment and follow up. This paper reviews the existing evidence to support the different approaches to screening and describes the research agenda of the MRC working party on congenital dislocation of the hip. A randomised trial of screening is required to evaluate the policy options before ultrasound screening becomes widely adopted within the United Kingdom. The feasibility and acceptability of a trial need to be explored and key issues relating to trial design addressed.

High incidence of congenital dislocation of the hip in Northern Ireland

To determine the incidence of congenital hip dislocation (CDH) a retrospective study was carried out of cases occurring in a defined population using multiple information sources. Of 138,600 children born in the period 1983-1987, a total of 243 were diagnosed with CDH, defined as those requiring splintage or surgery whose treatment extended beyond 6 months of age. Incidence and estimates of relative risks for pre-disposing factors were determined. The rate was 1.75 cases per 1000 livebirths. Major risk factors were female gender and breech presentation. The proportions of cases identified before 1, 3 and 6 months of age were 8, 14 and 35%, respectively. Despite using a restrictive definition, we have obtained an incidence rate among the highest reported in any United Kingdom population. Early detection is widely accepted as desirable, but neonatal screening has proved ineffective.

Reliability of the Barlow and Ortolani tests for neonatal hip instability

OBJECTIVE

To investigate if those responsible for screening for neonatal hip instability are using acceptable manual hip stress tests as described by Ortolani and Barlow.

METHOD

A video camera was used to record the technique of 35 personnel who were responsible for screening. They examined both a baby and a simulator. The study comprised five groups, classified by experience and practice: senior orthopaedic surgeons, senior paediatric staff, junior paediatric staff, nurses, community staff.

RESULTS

The seven authors together with six independent expert observers viewed the video and marked the performance with the aid of a specially designed proforma. Although there was some variation between these expert observers, the results showed differences in the scores obtained by the different groups of examiners over all aspects of the test procedure.

CONCLUSION

Video recording for critical analysis and feedback is a useful technique in this situation. Overall, the results suggest that testing for neonatal hip instability was inadequate. A variety of hip stress manoeuvres were being performed. The ability of each subject to perform satisfactory tests seemed to depend on their experience and education. More "hands on" training and experience of testing might provide the necessary competency for screening.

Measurement of the forces and movements involved in neonatal hip testing

The screening for Developmental Dysplasia of the Hip in infants relies on the two manipulative tests developed by Ortolani and Barlow which are often poorly performed. This study investigated the forces applied and the sequences of physical manoeuvres underlying the tests in order to define a standard of safe practice. Eight subjects examined the hips of two training models that closely simulated the behaviour of a range of infant hip pathologies. The forces applied and the manoeuvres employed during each examination were recorded using a purpose-built force and displacement transducer system. The analysis concentrated on the peak forces and the biomechanical conditions necessary to detect an abnormality. The models' legs had to be abducted beyond certain critical angles in order to dislocate and relocate an unstable femoral head and the magnitude of the force required to dislocate the femoral head was significantly less than the peak force applied (12 N vs 33 N, p < 0.001). Also, the Palmen test, a less well known technique, provided the same level of diagnostic performance as the Barlow test but with a lower peak applied force (28 N vs 47 N, p < 0.001). Changes are therefore necessary to the training programmes for medical staff to ensure that the range of abduction during the manoeuvres is large enough to encompass the likely range of critical angles and that the forces applied are just sufficient so as not to overstress the joints.