Developmental dysplasia of the hip: a new approach to incidence

Selective ultrasound screening for developmental hip dysplasia: effect on management and late detected cases. A prospective survey during 1991-2006

BACKGROUND

Early treatment is considered essential for developmental dysplasia of the hip (DDH), but the choice of screening strategy is debated.

OBJECTIVE

We evaluated the effect of a selective ultrasound (US) screening programme.

MATERIALS AND METHODS

All infants born in a defined region during 1991-2006 with increased risk of developmental dysplasia of the hip, i.e. clinical hip instability, breech presentation, congenital foot deformities or a family history of DDH, underwent US screening at age 1-3 days. Severe sonographic dysplasia and dislocatable/dislocated hips were treated with abduction splints. Mild dysplasia and pathological instability, i.e. not dislocatable/dislocated hips were followed clinically and sonographically until spontaneous resolution, or until treatment became necessary. The minimum observation period was 5.5 years.

RESULTS

Of 81,564 newborns, 11,539 (14.1%) were identified as at-risk, of whom 11,190 (58% girls) were included for further analyses. Of the 81,564 infants, 2,433 (3.0%) received early treatment; 1,882 (2.3%) from birth and 551 (0.7%) after 6 weeks or more of clinical and sonographic surveillance. An additional 2,700 (3.3%) normalised spontaneously after watchful waiting from birth. Twenty-six infants (0.32 per 1,000, 92% girls, two from the risk group) presented with late subluxated/dislocated hips (after 1 month of age). An additional 126 (1.5 per 1,000, 83% girls, one from the risk group) were treated after isolated late residual dysplasia. Thirty-one children (0.38 per 1,000) had surgical treatment before age 5 years. Avascular necrosis was diagnosed in seven of all children treated (0.27%), four after early and three after late treatment.

CONCLUSION

The first 16 years of a standardised selective US screening programme for developmental dysplasia of the hip resulted in acceptable rates of early treatment and US follow-ups and low rates of late subluxated/dislocated hips compared to similar studies.

Use of ultrasonography in developmental dysplasia of the hip

PURPOSE

Ultrasonography has been used as a diagnostic tool in developmental dysplasia of the hip (DDH) during early infancy since the early 1980s. The aim of this review article is to summarise the technique, benefits and shortcomings of four infantile hip ultrasonography methods, focusing mainly on the Graf method, and to assess the effectiveness of ultrasonographic newborn hip screening programmes.

METHODS

Several infantile hip ultrasonography methods have been defined to assess the relationship between the femoral head and acetabulum. The Graf, Harcke, Terjesen and Suzuki methods are the universally known ones. The Graf method is composed of a quantitative classification system, while the Harcke and Suzuki methods have qualitative definitions and the Terjesen method contains both quantitative and qualitative descriptions.

RESULTS

Although the results of several studies assessing the sensitivity and consistency of the ultrasonography methods have still not proven a clear dominance of one of these techniques, the primary advantage of the Graf method is that it has a standardised examination technique, as well as a very well defined numeric hip typing system. The importance of newborn hip screening has been universally accepted, but there is still no strong evidence regarding the superiority of either universal (screening of all newborns) or selective (screening of high-risk newborns) ultrasonographic newborn hip screening programmes.

CONCLUSIONS

An effective ultrasonographic method should include simple, precise, quantitative and consistent definitions for a proper examination and diagnosis. Both universal and selective ultrasonographic newborn hip screening programmes have significantly decreased the rate of late detected DDH and lessened the need for surgical treatment.

Association of a single nucleotide polymorphism in HOXB9 with developmental dysplasia of the hip: a case-control study

Developmental dysplasia of the hip (DDH) is one of the most common skeletal disorders. It comprises a spectrum of abnormalities, including shallow acetabulum and decreased coverage of the femoral head. Genetic component plays a considerable role in the aetiology of DDH. HOXB9 may be involved in the aetiology and pathogenesis of DDH, as it plays an important role in the development of the limbs. Our objective was to evaluate whether single nucleotide polymorphisms (SNPs) of HOXB9 (rs2303486 and rs8844) were associated with DDH in Chinese population. The HOXB9 tag SNPs were genotyped in 460 DDH cases and 562 control subjects by Taqman assay, and their association was examined. rs8844 was not associated with DDH. rs2303486 was associated with DDH in the dominant genetic model (p = 0.037; odds ratio (OR) = 1.32; 95% confidence interval (CI) = 1.02–1.71). After stratification by sex, significant association of the dominant genetic model still existed in the female subjects (p = 0.015; OR = 1.46; 95% CI = 1.08–1.98),but not in the male subjects. After stratification by severity, we discovered an association with hip dislocation in the dominant model(p=0.042; OR = 1.35; 95% CI = 1.01–1.80), but not with subluxation or instability. HOXB9 is associated with DDH in Chinese.

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.

Is it worthwhile to screen the hip in infants born with clubfeet?

PURPOSE

There is some disagreement about whether idiopathic congenital talipes equinovarus (CTEV) increases the risk of neonatal developmental dysplasia of the hip (DDH). This study aimed to investigate the incidence of DDH in our infants with idiopathic CTEV.

METHODS

We conducted an observational cohort study over a three-year period to assess the relationship between idiopathic CTEV and DDH. All neonates younger than six weeks with idiopathic CTEV who were treated in our medical centre were admitted to this study. Each subject underwent hip ultrasound examination using the Graf method at the age of six weeks. DDH was diagnosed when a hip was type IIa(-) or worse according to the Graf classification of sonographic hip type.

RESULTS

A total of 184 patients were diagnosed with idiopathic CTEV and underwent hip sonography. In total, seven hips of five individuals underwent treatment (four girls and one boy). The results indicated that 2.7% of babies (five of 184) with idiopathic CTEV had DDH. However, we did not find any statistically significant difference (p = 0.5776) in the Pirani scores between the DDH group and group with normal hips.

CONCLUSIONS

This study revealed that the idiopathic CTEV group had a greater incidence of DDH in comparison with the general population. It is recommended that hip sonography be undertaken particularly in patients with idiopathic CTEV.

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 strategies for hip dysplasia: long-term outcome of a randomized controlled trial

OBJECTIVE

Screening for hip dysplasia is controversial. A previous randomized controlled trial revealed that adding universal or selective ultrasound to routine clinical examination gave a nonsignificant reduction in rates of late presenting cases, but with higher treatment rates. This study assesses differences in outcome at skeletal maturity for the 3 newborn screening strategies in terms of radiographic markers of acetabular dysplasia and early degenerative change and avascular necrosis (AVN) secondary to neonatal treatment.

METHODS

From the initial trial including 11 925 newborns, a population-based sample of 3935 adolescents was invited for follow-up at age 18 to 20 years. A standardized weight-bearing anteroposterior view was obtained. The outcomes evaluated were the radiographic findings of dysplasia (center-edge angle, femoral head extrusion-index, acetabular depth-width ratio, Sharp's angle, subjective evaluation of dysplasia) and degenerative change (joint-space width). Signs of AVN were documented.

RESULTS

Of the 3935 subjects invited, 2038 (51.8%) attended the maturity review, of which 2011 (58.2% female patients) were included: 551, 665, and 795 subjects from the universal, selective, and clinical groups, respectively. Rates per group of positive radiographic findings associated with dysplasia or degenerative change varied depending on radiographic marker used. No statistically significant differences were detected between groups. No AVN was seen.

CONCLUSIONS

Although both selective and universal ultrasound screenings gave a nonsignificant reduction in rates of late cases when compared with expert clinical programs, we were unable to demonstrate any additional reduction in the rates of radiographic findings associated with acetabular dysplasia or degenerative change at maturity. Increased treatment rates were not associated with AVN.

Breech preterm infants are at risk of developmental dysplasia of the hip

AIM

There is uncertainty about the risk of developmental dysplasia of the hip (DDH) in breech preterm infants and therefore uncertainty about the benefits of using ultrasound screening in this population. The aim of this study was to determine if preterm infants born in the breech position are at risk of DDH.

METHODS

A retrospective audit of preterm and term infants born in the breech position was performed to determine the incidence of DDH. Group 1 included breech preterm infants (<37 weeks gestational age) born between 2004 and 2008. Group 2 included breech term infants (≥37 weeks gestational age) born between 2005 and 2007. Infants were screened with clinical examination and ultrasound of the hip and were classified into two outcome groups: positive or negative for DDH.

RESULTS

Three out of 129 (2.3%) preterm infants screened had DDH. For term infants, 3 out of 163 (1.8%) infants screened had DDH. The odds ratio for DDH in breech preterm infants compared with breech term infants was 1.27 (95% confidence interval 0.25 to 6.40).

CONCLUSION

Preterm infants born in the breech position appear to have a similar incidence of DDH to term infants and thus require similar screening guidelines.

Heritability and sibling recurrent risk of developmental dysplasia of the hip in Chinese population

BACKGROUND

Previous familial segregation studies supported that developmental dysplasia of the hip (DDH) is a multifactorial genetic disease. However, the exact extent of genetic effects has not been fully evaluated, especially in Asian population. The aim of this study is to estimate the sibling recurrent risk and heritability of DDH in a large Chinese cohort.

MATERIALS AND METHODS

Four hundred and twenty-nine DDH probands and 534 matched normal controls were recruited from a screening programme for DDH, including 628 siblings in families of probands and 889 siblings in those of controls, respectively. The detailed information of family history was obtained, and the prevalence of DDH among siblings of probands, as well as controls, was determined. The sibling recurrent risk and heritability was estimated using classical liability threshold model.

RESULTS

Eighty-seven siblings (13.85%) in families of proband and 14 siblings (1.57%) in normal control families were diagnosed as DDH. The recurrent risk in siblings of probands was at least tenfolds that in siblings of controls. Compared with the normal controls, the sibling recurrent risk was about 12-fold increase in male sib, and 9-fold increase in female sib. Overall, a high heritability of 83.59 ± 4.90% (h(2) ± SE) was observed. When stratified by genders, it was even higher for female siblings (91.02 ± 7.25%).

CONCLUSION

This study for the first time exhibits a high sibling recurrent risk and heritability for DDH in Asian population. It also shows there is a high probability to identify the underlying predisposition genes in future genetic study.

Ultrasonography in developmental dysplasia of the hip: what have we learned?

Developmental dysplasia of the hip (DDH) is an important but poorly defined entity, the natural history of which is incompletely understood. The term encompasses a disease spectrum ranging from a stable hip with a mildly dysplastic acetabulum to complete hip dislocation. Much controversy surrounds the diagnosis, imaging and management of this condition. We present a review of the history of US imaging of DDH from the radiologist's perspective, summarising the most widely recognised US methods described to date. We discuss controversies in the approach to US examination, with particular emphasis on current opinions. The existing scientific evidence for and variations in the practice of US screening for DDH, including recommendations from the United States Preventive Services Task Force and the ESPR DDH Taskforce Group respectively, are discussed.

Developmental dysplasia of the hip: controversies and current concepts

Developmental dysplasia of the hip is an important but poorly understood disorder as evidenced by the vast amount of literature published to date on this topic. The precise definition of hip dysplasia is controversial and it encompasses a spectrum of abnormalities, rather than a single condition, which at one end overlap with normal hip maturation. We review the risk factors, clinical examination and radiological imaging of the hip in the infant and young child, the controversies of ultrasound screening for hip dysplasia and the current management, both operative and non-operative, of this condition according to patient age.

Risk factors for developmental dysplasia of the hip: a meta-analysis

Early detection and subsequent treatment of developmental dysplasia of the hip (DDH) is thought to improve its prognosis. Frequently reported risk factors for DDH are a positive family history of DDH, female sex and breech presentation, but there is not a lot of systematic knowledge about DDH risk factors. We performed a systematic review and meta-analysis of the available evidence on DDH risk factors. We searched Medline, EMBASE and The Cochrane Library from conception up until October 2011 for primary articles on the subject. All studies reporting on potential risk factors for DDH that allowed construction of a two-by-two table were selected. Language restrictions were not applied. Two reviewers independently selected studies, extracted data and assessed study quality. The association between risk factors and DDH was expressed as a common odds ratio (OR) with a 95% confidence interval (CI). We identified 30 relevant studies reporting on 1,494,387 children; 26 studies were cohort studies and four studies used a case-control design. The risk of DDH was strongly increased in case of breech delivery (OR 5.7, 95% CI 4.4-7.4), female sex (OR 3.8, 95% CI 3.0-4.6) a positive family history of DDH (OR 4.8, 95% CI 2.8-8.2) and clicking hips at clinical examination (OR 8.6, 95% CI 4.5-16.6). This meta-analysis shows that infants born in breech presentation, female infants, infants with a positive family history and clicking hips at clinical examination have an increased risk for DDH. This knowledge can be helpful in the development of screening programs for DDH.

Prevention of hip dysplasia in children and adults

Klisic and Pajic summarized the history of early diagnosis and treatment of hip dysplasia when they wrote, Devising the preventive approach to developmental dysplasia of the hip (DDH) required much time.... Despite the 2400-year-old suggestion made by Hippocrates that children's hip dislocations are curable if treatment is started very early, the preventive approach was proposed by Roser only in 1879 [who] described early diagnosis in newborns and performed reduction by abduction... He also advocated early treatment by fixing babies' hips in abduction. However, surgeons did not readily accept these proposals, despite the good results shown by Froelich in 1906 and Le Damany in 1911. In 1927, Putti succeeded in interesting some orthopedic surgeons in the procedure by showing the results of early treatment. But the practical problem remained: ie, how to detect the DDH in patients at an early age. The turning point came in 1935 when pediatrician Ortolani introduced early detection of DDH by “early clinical search” shortly after a child's birth, instructing obstetricians, pediatricians, and midwives to perform the search. Rediscovering the diagnostic “segno della scatto,” ie, reducible displacement, he popularized the prophylactic approach to DDH by early detection and treatment. Fifteen years later, another pediatrician, Palmen, organized systematic screening in nurseries by pediatricians. Since Klisic and Pajic wrote this in 1993, the use of ultrasound, albeit still controversial in some ways, has influenced the treatment and prevention of DDH. Klisic's attempts to universally prevent the disease may still be able to be incorporated into further efforts at disease prevention through education and the systematic trials of hip abduction pillows or braces similar to his wide-diaper diapering technique. The goal of prevention is to eradicate a disease so that it does not present to the physician. For DDH, this goal may be tenable.

Hip joint development in children with type IIb developmental dysplasia

PURPOSE

The aim of this study was to analyse the results of treatment of sonographically diagnosed type IIb developmental hip dysplasia and to identify residual hip dysplasia using clinical and radiological assessment.

METHODS

We retrospectively reviewed the data of 49 children (59 type IIb and 39 type I hips, according to Graf's monographic classification) treated in abduction braces. The mean age was 9.1 years (range 4-15) at latest follow-up.

RESULTS

According to the clinical classification of Mckay in Barrett's modification, all the type I and type IIb hips had very good results. No statistical differences were found between type I and IIb hips when comparing both measured radiological parameters and radiological results according to the Severin classification at latest follow-up. Using our criteria (two or more radiological parameters were outside of their normal range), 12 out of 49 type IIb hips demonstrated persistent dysplasia. Of the 12 hips, eight sonograms were normal at the end of treatment and four patients failed to normalise. No type I hips demonstrated two or more abnormal radiographic parameters at latest follow-up.

CONCLUSIONS

Despite obtaining normal sonograms at the end of treatment, some children with type IIb dysplasia may demonstrate radiographic evidence of persistent hip dysplasia over a longer follow-up period. Our results suggest that these children should be monitored until skeletal maturity.

Developmental dysplasia in male infants: risk factors, instability and ultrasound screening

OBJECTIVE

To evaluate the relationship between risk factors and presence of developmental dysplasia of the hip (DDH) in male infants, and to compare the efficiency of different ultrasound (US) screening protocols.

MATERIALS AND METHODS

1321 male infants were included in the study. Ultrasound examinations were performed by combining Graf's static method and Harcke's dynamic method. The relationship between the risk factors and DDH and the effect of risk factors on sonographic worsening in type 2a hips were assessed by the chi-square test and Fisher`s exact test.

RESULTS

The incidence of DDH was 1.4%. 13% of the cases had type 2a morphology, among whom in 3.1% sonographic deterioration occurred. The treatment rate was 1.8%. The rate of follow-up US was 17.5%. No risk factor was found to have a statistically significant influence on DDH (= type 2b morphology). Among the 32 cases with DDH, 23(72%) had a risk factor or positive clinical finding while 9(28%) did not (p:0.006).

CONCLUSION

Risk factors do not have a statistically significant relationship with DDH in male cases. In our study 28% of the cases with DDH would be missed by a selective US screening protocol. We recommend assessment of all male infants with hip US.

A meta-analysis of common risk factors associated with the diagnosis of developmental dysplasia of the hip in newborns

BACKGROUND

Although there is no clear consensus about the process of screening for developmental dysplasia of the hip (DDH), there are six common risk factors associated with DDH in patients less than 6 months of age (breech presentation, sex, family history, first-born, side of hip, and mode of delivery).

METHODS

A meta-analysis of published studies was conducted to identify the relative risk ratio of the six commonly known risk factors. A total of 31 primary studies consisting of 20,196 DDH patients met the following inclusion criteria: (1) contained empirical data on at least one common risk factor, (2) were peer-reviewed from an English language scientific journal, (3) included patients less or equal to 6 months of age, and (4) identified method of diagnosis (e.g., ultrasound, radiographs or clinical examination).

RESULTS

Fixed effect and random effects models with 95% confidence intervals were calculated for each of the six risk factors. Reported relative risk ratio (RR) for each factor in newborns was: breech presentation 3.75 (95% CI: 2.25-6.24), females 2.54 (95% CI: 2.11-3.05), left hip side 1.54 (95% CI: 1.25-1.90), first born 1.44 (95% CI: 1.12-1.86), and family history 1.39 (95% CI: 1.23-1.57). A non-significant RR value of 1.22 (95% CI: 0.46-3.23) was found for mode of delivery.

CONCLUSION

Results suggest that ultrasound and radiology screening methods be used to confirm DDH in newborns that present with one or a combination of the following common risk factors: breech presentation, female, left hip affected, first born and family history of DDH.

Developmental dysplasia of the hip

Developmental dysplasia of the hip (DDH) is a spectrum of anatomical abnormalities of the hip joint in which the femoral head has an abnormal relationship with the acetabulum. Most studies report an incidence of 1 to 34 cases per 1,000 live births and differences could be due to different diagnostic methods and timing of evaluation. Risk factors include first born status, female sex, positive family history, breech presentation and oligohydramnios. Clinical presentations of DDH depend on the age of the child. Newborns present with hip instability, infants have limited hip abduction on examination, and older children and adolescents present with limping, joint pain, and/or osteoarthritis. Repeated, careful examination of all infants from birth and throughout the first year of life until the child begins walking is important to prevent late cases. Provocative testing includes the Barlow and Ortolani maneuvers. Other signs, such as shorting of the femur with hips and knees flexed (Galeazzi sign), asymmetry of the thigh or gluteal folds, and discrepancy of leg lengths are potential clues. Treatment depends on age at presentation and outcomes are much better when the child is treated early, particularly during the first six months of life.

The epidemiology and demographics of hip dysplasia

The etiology of developmental dysplasia of the hip (DDH) is unknown. There are many insights, however, from epidemiologic/demographic information. A systematic medical literature review regarding DDH was performed. There is a predominance of left-sided (64.0%) and unilateral disease (63.4%). The incidence per 1000 live births ranges from 0.06 in Africans in Africa to 76.1 in Native Americans. There is significant variability in incidence within each racial group by geographic location. The incidence of clinical neonatal hip instability at birth ranges from 0.4 in Africans to 61.7 in Polish Caucasians. Predictors of DDH are breech presentation, positive family history, and gender (female). Children born premature, with low birth weights, or to multifetal pregnancies are somewhat protected from DDH. Certain HLA A, B, and D types demonstrate an increase in DDH. Chromosome 17q21 is strongly associated with DDH. Ligamentous laxity and abnormalities in collagen metabolism, estrogen metabolism, and pregnancy-associated pelvic instability are well-described associations with DDH. Many studies demonstrate an increase of DDH in the winter, both in the northern and southern hemispheres. Swaddling is strongly associated with DDH. Amniocentesis, premature labor, and massive radiation exposure may increase the risk of DDH. Associated conditions are congenital muscular torticollis and congenital foot deformities. The opposite hip is frequently abnormal when using rigorous radiographic assessments. The role of acetabular dysplasia and adult hip osteoarthritis is complex. Archeological studies demonstrate that the epidemiology of DDH may be changing.

Screening programmes for developmental dysplasia of the hip in newborn infants

BACKGROUND

Uncorrected developmental dysplasia of the hip (DDH) is associated with long term morbidity such as gait abnormalities, chronic pain and degenerative arthritis.

OBJECTIVES

To determine the effect of different screening programmes for DDH on the incidence of late presentation of congenital hip dislocation.

SEARCH STRATEGY

Searches were performed in CENTRAL (The Cochrane Library), MEDLINE and EMBASE (January 2011) supplemented by searches of clinical trial registries, conference proceedings, cross references and contacting expert informants.

SELECTION CRITERIA

Randomised, quasi-randomised or cluster trials comparing the effectiveness of screening programmes for DDH.

DATA COLLECTION AND ANALYSIS

Three independent review authors assessed study eligibility and quality, and extracted data.

MAIN RESULTS

No study examined the effect of screening (clinical and/or ultrasound) and early treatment versus not screening and later treatment.One study reported universal ultrasound compared to clinical examination alone did not result in a significant reduction in late diagnosed DDH or surgery but was associated with a significant increase in treatment.One study reported targeted ultrasound compared to clinical examination alone did not result in a significant reduction in late diagnosed DDH or surgery, with no significant difference in rate of treatment.Meta-analysis of two studies found universal ultrasound compared to targeted ultrasound did not result in a significant reduction in late diagnosed DDH or surgery. There was heterogeneity between studies reporting the effect on treatment rate.Meta-analysis of two studies found delayed ultrasound and targeted splinting compared to immediate splinting of infants with unstable (but not dislocated) hips resulted in no significant difference in the rate of late diagnosed DDH. Both studies reported a significant reduction in treatment with use of delayed ultrasound and targeted splinting.One study reported delayed ultrasound and targeted splinting compared to immediate splinting of infants with mild hip dysplasia on ultrasound resulted in no significant difference in late diagnosed DDH but a significant reduction in treatment. No infants in either group received surgery.

AUTHORS' CONCLUSIONS

There is insufficient evidence to give clear recommendations for practice. There is inconsistent evidence that universal ultrasound results in a significant increase in treatment compared to the use of targeted ultrasound or clinical examination alone. Neither of the ultrasound strategies have been demonstrated to improve clinical outcomes including late diagnosed DDH and surgery. The studies are substantially underpowered to detect significant differences in the uncommon event of late detected DDH or surgery. For infants with unstable hips or mildly dysplastic hips, use of delayed ultrasound and targeted splinting reduces treatment without significantly increasing the rate of late diagnosed DDH or surgery.

Screening for developmental dysplasia of the hip in Hong Kong

PURPOSE

To review records of children referred to our hospital for developmental dysplasia of the hip (DDH) and evaluate the effectiveness of hip screening in Hong Kong.

METHODS

Records of children suspected of DDH and referred to our hospital between 1 January 2005 and 31 March 2010 were reviewed. The diagnosis was based on static and dynamic ultrasonography of the hips and/or radiographic features of hip subluxation, dislocation, and pelvic dysplasia. The age of the children at presentation was recorded. Late diagnoses were those presenting after the age of 6 months. Late presentations were those presenting after the walking age.

RESULTS

Of 213 referred children, 33 were diagnosed to have DDH. Their mean age at presentation was 90.8 (range, 9-559) days. The female-to-male ratio was 2.9:1, and the mean follow-up duration was 25.1 (range, 4.2-50.3) months. 30 of the DDH infants were diagnosed before the age of 6 months, one at 8 months, and 2 were late presenters. Hence, the failure rate of the hip screening was 0.09 per 1000 live births. The remaining 180 were confirmed to be normal and followed up until the walking age. The point prevalence of DDH on Hong Kong Island was 0.87/1000 live births.

CONCLUSION

In light of the low point prevalence of DDH in Hong Kong born children, the protocol of universal clinical assessment and selective ultrasonographic screening of suspected cases is justified.

New "L value" parameter simplifies and enhances hip ultrasound interpretation in the detection of developmental dysplasia of the hip

PURPOSE

The purpose of this study was to simplify and enhance the ultrasound (US) analysis of the infant's hip by introducing a novel parameter named "L value" into the widely used Graf method.

METHODS

We analysed 508 ultrasonographic images of the hips in infants aged three months. The images were first evaluated using the Graf measurements. On the same images, two additional measurements were performed in order to define the new parameter that was named L value. The threshold values of the new L value were identified based on the highest specificity as well as sensitivity for discrimination between the Graf groups. Those values were then used in order to reclassify the hips into three simplified groups. Inter-observer agreement was estimated by Cohen's kappa coefficient.

RESULTS

The threshold values for the L value between Graf groups Ia and Ib was 0.46, between Ib and IIb was 0.68 and between IIb and IIc was 0.92. Correlation analysis between Graf's classification and the values of the L value was performed and was proved to be statistically significant, r = 0.49; p < 0.001. After simplifying the classification into three newly defined groups of patients depending on the degree of hip development, the correlation coefficient was much higher, r = 0.94, r (2) = 0.88 for p < 0.001. Inter-observer agreement for the L value was substantial.

CONCLUSIONS

The new L value parameter in Graf's ultrasound hip evaluation enables a faster, simpler, more reliable and more unbiased classification for developmental dysplasia of the hip as the L value changes proportionally with the hip maturity.

Popliteal angle as an indicator for successful closed reduction of developmental dysplasia of the hip

PURPOSE

To evaluate the use of the popliteal angle as an indicator for successful closed reduction of developmental dysplasia of the hip (DDH) in children with delayed presentation.

METHODS

29 patients aged 6 to 18 months underwent successful closed reduction for unilateral DDH under general anaesthesia. Using a graduated goniometer, the popliteal angle was measured with the hip abducted within the safe zone (to avoid redislocation and injury to the femoral capital epiphysis) before and after reduction and after 6 weeks of spica casting.

RESULTS

The mean popliteal angles before and after reduction and after 6 weeks of spica casting were 5.1, 37.5, and 17.9 degrees, respectively (p<0.0001, paired t test). Because of discomfort, the spica casts were altered in 3 patients (2 at week 1 and one at week 3).

CONCLUSION

Reduction of the hip in DDH results in an increased popliteal angle of >20 degree. This may be used to indicate the diagnosis and safe closed reduction.

Association of a single nucleotide polymorphism in Tbx4 with developmental dysplasia of the hip: a case-control study

OBJECTIVE

Developmental dysplasia of the hip (DDH), formerly known as congenital dislocation of the hip, comprises a spectrum of abnormalities, including abnormal acetabular shape (dysplasia) and malposition of the femoral head during embryonic, fetal and infantile growth periods. Genetic factors play a considerable role in the pathogenesis of DDH. As a key regulator for the hindlimb outgrowth and identification, Tbx4 may be involved in the aetiology and pathogenesis of DDH. Our objective is to evaluate whether the Tbx4 (rs3744438 and rs3744448) single nucleotide polymorphisms (SNPs) are associated with DDH in Chinese.

METHOD

The Tbx4 SNPs were genotyped in 505 children with DDH and 551 control subjects and their association was evaluated statistically.

RESULTS

Rs3744438 was not associated with DDH. Rs3744448 was significantly associated with DDH in the dominant genetic model of males (P=0.039; odds ratio (OR)=0.56; 95% confidence interval (CI)=0.32-0.97) and allele G was significantly lower in patients than controls compared with allele C (P=0.02; OR=0.59; 95% CI=0.37-0.92). After adjusted for gender, we discovered a significant association with hip dislocation in the dominant genetic model when stratified by severity (P=0.03; OR=0.73; 95% CI=0.55-0.97), but not with subluxation and instability.

CONCLUSIONS

Tbx4 tends to play an important role in the aetiology of DDH.

Neonatal hip dysplasia: Differental diagnosis

Introduction. Hip dysplasia is the elementary form of the developmental dysplasia of the hip (DDH). The diagnosis may be made by the ultrasound examination (types II a-, II b). Objective. The aim of the authors was to define the congenital structural neonatal hip dysplasia, and to differentiate hip hypoplasia, hip dysplasia and teratogenic anomalies. Methods. In all the cases, the uniform clinical and ultrasound tests were performed. All the patients were examined in the neonatal period of life (the first six weeks). The following clinical tests were used: Le Damany-Ortolany, Coleman-Barlow-Palmen and Weissman-Strinovic. For the ultrasound examination, the Graph?s method was used. Results. The investigation was performed in the period 2007- 2008. 2,878 neonates were included. The distribution of the sonotypes, according to Graph, was as follows: Ia in 16.17%. Ib in 65.08%; IIa+ in 18.17%, IIc in 0.28%, IId in 0.19%; IIIa in 0.009%, IIIb in 0.02%; and IV in 0.01%. It was found that DDH was 8 times more frequent in girls; located more frequently at the left side than bilaterally. Conclusion. Hip sonoscreening has to be performed in all newborns in the first 72 hours. The suggested follow-up period is six weeks: for the diagnosis - the first three weeks, and for the prevention and treatment - all six weeks.

Treatment duration of developmental dysplasia of the hip: age and sonography

We retrospectively assessed babies treated according to Pavlik's method and followed up in our outpatient clinic between the years 2001 and 2005, investigating the influence of age at onset of treatment and severity of sonographic pathologies on the rates of avascular necrosis and treatment duration of 343 pathological hips in 311 neonates. No osteonecrosis was observed at the 1-year follow-up. Early detection of developmental dysplasia of the hip and early initiation of treatment using Pavlik's method are important in preventing osteonecrosis, and have high success rates. When using Pavlik's method for treating developmental dysplasia of the hip, starting treatment at 13 weeks and later increases the duration of treatment.

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.

Neonatal incidence of hip dysplasia: ten years of experience

The advantages of sonographic examination are well known, but its main disadvantage is that it might lead to overdiagnosis, which might cause overtreatment. Variations in the incidence of developmental dysplasia of the hip are well known. We ascertained the incidence of neonatal sonographic developmental dysplasia of the hip without considering the development of those joints during followup. All 45,497 neonates (90,994 hips) born in our institute between January 1992 and December 2001 were examined clinically and sonographically during the first 48 hours of life. Sonography was performed according to Graf's method, which considers mild hip sonographic abnormalities as Type IIa. We evaluated the different severity type incidence pattern and its influence on the total incidence during and between the investigated years. According to our study, sonographic Type IIa has major effects on the incidence of overall developmental dysplasia of the hip with a correlation coefficient of 0.95, whereas more severe sonographic abnormalities show relatively stable incidence patterns.

LEVEL OF EVIDENCE

Level I, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Treatment of Graf's ultrasound class III and IV hips using Pavlik's method

When Pavlik introduced his method of treating congenital dislocation of the hip, he emphasized reducing the rate of osteonecrosis. Graf's method of sonographic evaluation afforded earlier accurate diagnosis and subsequent treatment of developmental dysplasia of the hip. To ascertain whether treatment duration, gender, age at diagnosis, clinical stability, and/or treatment onset correlate with the risk of osteonecrosis in Graf Type III or IV hips, we clinically and sonographically screened 18,067 neonates (36,134 hips) for developmental dysplasia of the hip over a 4-year period; 151 had Graf Type III or IV hips, and 78 of these were treated by us and had known outcomes. Of these 78 hips, 65 (0.18%) had Graf Type III and 13 (0.036%) had Graf Type IV hips. Sixteen of the 65 Type III hips (25%) reduced spontaneously. Using Pavlik's method, reduction was achieved in 46 of 65 (88.5%) Type III hips and eight of 13 Type IV hips. None of the hips treated exclusively by Pavlik's method developed osteonecrosis. Thus, the method achieves one of Pavlik's original goals of decreasing osteonecrosis incidence to close to zero.

LEVEL OF EVIDENCE

Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

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.

The natural history of developmental dysplasia of the hip: sonographic findings in infants of 1-3 months of age

The natural history of sonographic developmental dysplasia of the hip was determined in a population-based study in which 5170 infants were screened by ultrasound using Graf's method. Of the normal hips at the age of 1 month, 99.6% were still normal at the age of 3 months. Of the immature type IIa/IIa+ and type IIa- hips, if untreated, 95.3 and 84.4% had become normal, respectively. Of the infants with type IIc, D and III/IV hips at the age of 1 month 70, 58.3 and 90.9% were treated, respectively. This study shows that normal hips remain normal in nearly 100% of cases, but development to abnormality is possible. It shows also that most of the immature hips at the age of 1 month become normal without treatment. Although treatment seems to be indicated in the majority of sonographically abnormal hips, the occurrence of overtreatment could not be excluded in our study.

Imaging methods used for children with hip dysplasia

Ultrasound has been used to examine the infant hip for more than 20 years. The Thornbury model for assessing the clinical efficacy of a diagnostic imaging procedure has been used in this review to determine what has been achieved and what remains to be learned. To accomplish the effective and efficient treatment of patients with developmental dysplasia of the hip, orthopaedic, radiologic, and pediatric organizations must collaborate in writing and revising standards of care and guidelines for treatment as our knowledge base grows.

Sonography of hip dysplasia

Early diagnosis of developmental dysplasia of the hip (DDH) is important to institute appropriate treatment and reduce the incidence of long-term complications. Risk factors for DDH include genetic, developmental, mechanical, and physiologic factors. Physical examination using Ortolani and Barlow maneuvers is standard for early detection. Plain film radiography is limited for the diagnosis of DDH even when applying several classic landmarks, lines, and measurements, due to the lack of visualization of the cartilaginous components of the infant's hip. Ultrasound arose as a tool for evaluation of the cartilaginous structures of the hip in the early 1980s. Graf's method of examination by ultrasound stresses morphology, whereas dynamic examination uses physical maneuvers to elicit laxity of the hip. The Pavlik harness is the mainstay of treatment of DDH in the young infant, and ultrasound examination in the harness is useful to monitor progress. Closed or open surgical reduction is reserved for unresponsive or advanced cases. Universal ultrasound screening of newborns is not deemed cost effective by most North American authors, although in Europe non-selective screening has been more widely used.

Treatment of developmental dysplasia of the hip with Pavlik harness: prospective study in Graf type IIc or more severe hips

Successful treatment of developmental dysplasia of the hip (DDH) is associated with early diagnosis and appropriate treatment. In this prospective study, the results of the treatment with Pavlik harness followed by an abduction brace in patients with severe DDH were presented. Twenty-two hips of 18 patients with a mean age of 14.8+/-5.9 weeks (range, 6-26) when diagnosed were followed for an average of 24.2+/-10.8 months (range, 10-46). The hips were staged according to the classification of Graf with ultrasonography and Pavlik harness was instituted as the first line of treatment in all hips. If there was no improvement of ultrasonographic stage at the third week follow-up the harness treatment was discontinued. After the infant became too large for Pavlik harness an abduction brace was used. In all but one hip the treatment was successful (95.4%). In two hips type I avascular necrosis was noted. Of the dislocated hips 90% were reduced. The Pavlik harness is a safe and effective method of treatment of severe DDH in infancy if potential pitfalls are avoided.

Mechanobiological predictions of growth front morphology in developmental hip dysplasia

Developmental dysplasia of the hip (DDH) is the most common orthopedic problem of newborn children. Most clinicians and researchers agree that the primary cause of DDH is abnormal mechanical forces on the head of the femur due to limb position, pressure from the womb, or ligament laxity. The abnormal mechanical forces result in altered growth and bony deformities, in particular large neck-shaft and anteversion angles in the proximal femur and a shallow acetabulum. Previous studies have suggested that intermittent octahedral shear stress promotes growth and ossification, while intermittent hydrostatic compressive stress inhibits growth and ossification. We implemented these mechanobiological principles into a finite element model to predict the rate of progression of the growth front and the formation of coxa valga (large neck-shaft angle) in DDH. Under the assumed normal fetal loading conditions the hydrostatic stress was even across the growth front, but the octahedral shear stress was higher in the center than at the edges. This stress profile promoted growth in the center and a produced a convex growth front shape. Under loading conditions of the dysplastic hip, the octahedral shear stress was much larger on the medial side than on the lateral side, which promoted growth on the medial side and resulted in coxa valga. These results indicate that abnormal forces on the prenatal hip might influence total bone morphology and the development of DDH. These findings might help in understanding the etiology and pathology of other developmental bone deformities.

Detecting developmental dysplasia of the hip

Recent guidelines from the American Academy of Pediatrics mandate the universal screening of all newborns for developmental hip dysplasia, in an effort to promote prompt recognition and treatment of this condition. The effectiveness of universal screening hinges on the appropriate education, training, and experience of health care providers. This article reviews the normal embryologic, natal, and postnatal development of the hip. Historical risk factors that may have an impact on this developmental sequence are outlined. A step-by-step guide to the examination of the hip is offered, along with a discussion of the sensitivity and specificity of the Ortolani and Barlow maneuvers. Clear guidelines for referral are presented. The indications for the use of ultrasound studies as a secondary screening tool are outlined. Treatment options and important aspects of counseling and teaching families are reviewed.

Developmental dysplasia of the hip incidence in Ethiopian Jews revisited: 7-year prospective study

We describe the sonographic and true incidence of developmental dysplasia of the hip among Ethiopian Jews compared with the general Israeli population. Previous results were based on a small number of Jewish Ethiopian children; this study is based on over 7 years of experience, during which 34,048 newborns, 768 of whom were Ethiopian, were examined clinically and sonographically. The incidence of sonographic developmental hip dysplasia was 5.5% in the general Israeli population, compared with 1.24% for the Ethiopian Jews. True developmental hip dysplasia incidence for Arabs and other Jews was 0.51%, as compared with 0.15% in the Ethiopians. Our data support the theory that either a single unknown gene or a multiple gene system plays a major role in the incidence of the dysplasia.

Risk factors for developmental dysplasia of the hip: ultrasonographic findings in the neonatal period

The relationship between ultrasonographic findings at birth and risk factors for developmental dysplasia of the hip have not been prospectively evaluated. Since implementing a routine screening programme for all new-born babies in 1989 we have collected 48 000 sets of data, including family history, birth presentation, mode of delivery and birth weight. Of the 92 babies (three per 1000 live births) with persistent ultrasonographic abnormality at 6 weeks only 20% displayed evidence of clinical instability at the original examination. Female babies without the additional risks of breech birth or positive family history were quantitatively the most significant group, accounting for 75% of cases treated. The majority of babies requiring intervention would not have been identified utilizing present criteria for selective ultrasound screening.

Paediatric hip--ultrasound screening for developmental dysplasia of the hip: a review

This paper will try to deal with the following questions: Which is the correct screening model for the developmental dysplasia of the hip (DDH)? What is the clinical significance of "sonographic" DDH? Can overtreatment produced by ultrasound (US) screening cause a waste of resources and eventually morbidity? We reviewed the literature since January, 1996 through December, 2000. To compare our experience with the literature, we analysed the results of the US examinations of the hip performed in our Institute. Over 4 years of US screening 11326 infants (22652 hips), aged 3 days to 4 months, were examined consecutively. Sonographic hip findings were abnormal in 531 infants (4.7%). The screening showed 381 subjects (3.36% of the population) with a type IIa hip (bilateral or unilateral); 65% of these infants were normal at follow up and only 35% worsened. On the whole we treated 282 infants (2.5%). No open reduction was performed. Avascular necrosis appeared in 2/282 treated cases (1.06%). We support the routine generalised US screening of neonatal hips. The excess of doubtful cases and, consequently, of the extra referrals may be limited, and the overtreatment decreased to the lowest rates reported by optimisation of everyone's approach.

Congenital hip dysplasia and bone mineral density of the hip--a new risk factor for osteoporotic fracture?

Decreased bone mineral density (BMD) at the hip is an important risk factor for hip fractures, which are a major socioeconomic problem in the elderly. The incidence of congenital hip dysplasia (CHD) is about 7-13% in the Middle European population. We assessed the question of whether a conservatively treated CHD may be a risk factor for low BMD at the hip in adult women. We evaluated prospectively 240 premenopausal women (33 +/- 7 years). Past medical history was recorded including the presence or absence of CHD. Lumbar and femoral BMD using dual-energy X-ray absorptiometry (DXA) and biochemical parameters of bone metabolism were measured. X-rays of the pelvis were performed in CHD patients. Thirty-one (12.9%) of the patients had a history of conservatively treated CHD, four (1.2%) had undergone surgery; all other patients served as control group. Patients and controls were comparable for anthropometric data, lifestyle factors, and hip axis length. BMD in CHD patients was significantly lower at the hip (difference by 1 STD) but comparable at the spine. OC was significantly higher in patients with CHD than in controls. In a logistic regression model, CHD was associated with a 6.3-fold increased risk for low BMD at the hip. We therefore conclude that a history of conservatively treated CHD may be a major risk factor for low BMD at the hip in about 1 out of 10 women. Whether this translates into an increased risk for future hip fractures will have to be assessed in further prospective studies.

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.