Ultrasound screening for developmental dysplasia of the hip

Ultrasonographic screening for developmental dysplasia of the hip: the Graf method revisited

Until the 1980s, the diagnosis of developmental dysplasia of the hip (DDH) was based on clinical examination and radiographic imaging. In 1980, Reinhard Graf developed his own ultrasonographic method for the examination of the infant hip joint. Graf's method evaluates the osseous and cartilaginous coverage of the femoral head by the acetabulum in the infantile hip joint by measuring the angles α and β. The validity of Graf method is that with these measurements the hip joint is further classified by Graf classification into types I to IV that guide treatment. Currently, Graf method is considered the gold standard examination for the diagnosis of DDH in many European countries. This review article aims to discuss the incidence, risk factors and pathophysiology of DDH, and to emphasize on the Graf method for the evaluation, classification, prevention and further management of this entity.

Universal screening may reduce the incidence of late diagnosis of developmental dysplasia of the hip : a systematic review and meta-analysis

AIMS

We investigated the prevalence of late developmental dysplasia of the hip (DDH), abduction bracing treatment, and surgical procedures performed following the implementation of universal ultrasound screening versus selective ultrasound screening programmes.

METHODS

A systematic search of PubMed, Embase, The Cochrane Library, OrthoSearch, and Web of Science from the date of inception of each database until 27 March 2022 was performed. The primary outcome of interest was the prevalence of late detection of DDH, diagnosed after three months. Secondary outcomes of interest were the prevalence of abduction bracing treatment and surgical procedures performed in childhood for dysplasia. Only studies describing the primary outcome of interest were included.

RESULTS

A total of 31 studies were identified, of which 13 described universal screening and 20 described selective screening. Two studies described both. The prevalence of late DDH was 0.10 per 1,000 live births (95% confidence interval (CI) 0.00 to 0.39) in the universal screening group and 0.45 per 1,000 live births (95% CI 0.31 to 0.61) in the selective screening group. Abduction bracing treatment was performed on 55.54 per 1,000 live births (95% CI 24.46 to 98.15) in the universal screening group versus 0.48 per 1,000 live births (95% CI 0.07 to 1.13) in the selective screening group. Both the universal and selective screening groups had a similar prevalence of surgical procedures in childhood for dysplasia being performed (0.48 (95% CI 0.32 to 0.63) vs 0.49 (95% CI 0.31 to 0.71) per 1,000 live births, respectively).

CONCLUSION

Universal screening showed a trend towards lower prevalence of late DDH compared to selective screening. However, it was also associated with a significant increase in the prevalence of abduction bracing without a significant reduction in the prevalence of surgical procedures in childhood for dysplasia being performed. High-quality studies comparing both treatment methods are required, in addition to studies into the natural history of missed DDH.Cite this article: Bone Joint J 2023;105-B(2):198-208.

Incidence of Neonatal Developmental Dysplasia of the Hip and Late Detection Rates Based on Screening Strategy: A Systematic Review and Meta-analysis

IMPORTANCE

Universal ultrasonographic screening for developmental dysplasia of the hip (DDH) has gained increasing popularity despite the lack of benefit in terms of reducing the rates of late-detected cases (age ≥12 weeks) in randomized clinical trials.

OBJECTIVE

To report the reported incidence of DDH in the English scientific literature and compare rates of late-detected cases in settings with different DDH screening strategies.

DATA SOURCES

PubMed, Scopus, and Web of Science databases were searched on November 25 and 27, 2021. No time filters were used in the search.

STUDY SELECTION

All observational studies reporting the incidence of early-detected or late-detected (age ≥12 weeks) DDH were included. Non-English reports were excluded if the abstract did not include enough information to be included for analysis.

DATA EXTRACTION AND SYNTHESIS

The number of newborns screened and the detection rates were extracted. Meta-analysis calculated the pooled incidence of DDH per 1000 newborns with 95% CIs using a random- or fixed-effects model. This study is reported according to the PRISMA and MOOSE guidelines.

MAIN OUTCOMES AND MEASURES

The main outcome measures were early detection, early treatment, late detection, and operative treatment incidences.

RESULTS

A total of 1899 studies were identified, 203 full texts were assessed, and 76 studies with 16 901 079 infants were included in final analyses. The early detection rate was 8.4 (95% CI, 4.8-14.8) infants with DDH per 1000 newborns with clinical screening, 4.4 (95% CI, 2.4-8.0) infants with DDH per 1000 newborns with selective ultrasonographic screening, and 23.0 (95% CI, 15.7-33.4) infants with DDH per 1000 newborns with universal ultrasonographic screening. Rates for nonoperative treatment were 5.5 (95% CI, 2.1-14) treatments per 1000 newborns with clinical screening, 3.1 (95% CI, 2.0-4.8) treatments per 1000 newborns with selective ultrasonographic screening, and 9.8 (95% CI, 6.7-14.4) treatments per 1000 newborns with universal ultrasonographic screening. The incidence of late-detected DDH was 0.5 (95% CI, 0.2-1.5) infants with DDH per 1000 newborns with clinical screening, 0.6 (95% CI, 0.3-1.3) infants with DDH per 1000 newborns with selective ultrasonographic screening, and 0.2 (95% CI, 0.0-0.8) infants with DDH per 1000 newborns with universal ultrasonographic screening. The corresponding incidences of operative treatment were 0.2 (95% CI, 0.0-0.9) operations per 1000 newborns with clinical screening, 0.5 (95% CI, 0.4-0.7) operations per 1000 newborns with selective ultrasonographic screening, and 0.4 (95% CI, 0.2-0.7) operations per 1000 newborns with universal ultrasonographic screening.

CONCLUSIONS AND RELEVANCE

This meta-analysis found that early detection rates and nonoperative treatments were higher with universal screening. The late detection and operative treatment rates with universal screening were similar to those among selectively and clinically screened newborns. Based on these results, universal screening may cause initial overtreatment without reducing the rates of late detection and operative treatment.

Clinical examination and patients' history are not suitable for neonatal hip screening

Purpose

To assess the percentage of missed developmental dysplasia of the hip, which escape the German criteria for newborn hip high-risk screening, we analyzed our data gained from the general neonatal sonographic hip screening performed at our department. The aim of the study was to determine the number of potentially belatedly treated developmental dysplasia of the hip.

Methods

The data from 1145 standardized newborn hip ultrasound examinations according to the Graf technique were analyzed retrospectively comparing findings for general neonatal sonographic hip screening and high-risk screening subgroups.

Results

We diagnosed developmental dysplasia of the hip in 18 of the 1145 newborns via ultrasound. A total of 10 out of 18 developmental dysplasia of the hip would have been missed by high-risk screening, which corresponds to a proportion of 55.6% false-negative results. The sensitivity of high-risk screening was only 44.4% and specificity, 78.3%. The positive predictive value was 3.2%. Family history as a screening criterion yielded false-negative results in 77.8% and false-positive results in 16.8%. In all, 83.3% of the children who were born with developmental dysplasia of the hip but not from breech position as a risk factor were false negative. The clinical examination was false negative in 88.9% and false positive in 0.6%.

Conclusion

High-risk screening detected less than every second developmental dysplasia of the hip, rendering the first month as the most effective treatment window unavailable for inapparent dysplastic hips, potentially resulting in the need for more invasive treatment. Due to the high sensitivity of ultrasound in the detection of developmental dysplasia of the hip, we recommend to replace the current German high-risk screening guidelines with a general newborn screening for all neonates using Graf ultrasound in the first week of life.

Level of evidence

Level II.

The natural history of abnormal ultrasound findings in hips of infants under six months of age

PURPOSE

To collect and describe data on the natural history of abnormal ultrasound (US) findings in hips of infants under six months of age to serve as a reference to the design of screening programmes and treatment algorithms in the care for children with hip dysplasia.

METHODS

A search in PubMed of the terms "DDH" and "ultrasound" was done to find hips with abnormal US findings that were not treated. In cases of multiple periods of follow-up, the classification of every period was evaluated separately (individual hip follow-up periods).

RESULTS

Data of 13 561 hips with 16 991 follow-up periods were collected and analyzed. Most quantifiable classifications and follow-up periods were according to Graf (14 876) and a minor number of the hips had follow-up periods with femoral head coverage (FHC) (2115). Normal development without treatment in the first six months was for Graf 2a between 89% and 98%, for Graf 2c between 80% and 100% and for clustered data Graf 2a to 2c between 80% and 97%. For Graf 3 hips more than 50% were reported to develop into normal hips without treatment. As for Graf 4 hips this percentage was reported below 50%. For children with an FHC less than 50%, normalization was reported between 78% and 100%.

CONCLUSION

The natural history of developmental dysplasia of the hip (DDH) shows a benign course, especially in the well-centered hips. This outcome probably contributes to the fact that all studies on US screening of hips for detection of relevant DDH in order to improve outcomes of treatment are rated as substantially underpowered.

Prevalence of different hip sonographic types: A cross-sectional study

BACKGROUND

Developmental dysplasia of the hip (DDH) is an anatomical abnormality, which needs early detection and treatment. Ultrasound (US) is a sensitive method to study neonatal hip joint and detection of different types of sonographic hip. This study was aimed to determine relative frequency of different types of DDH ultrasonographically.

MATERIALS AND METHODS

Ultrasound examination was performed on 380 newborns to determine hip joint status according to the Graf ultrasound classification system for infant hips. In addition, hip joint status was compared based on the hip side, gender, and method of delivery.

RESULTS

In this study, we observed three sonographic types: Ia (74%), type Ib (20%), and IIa (6%). No significant difference was found in relative frequency of different types of DDH regarding the side of the hip (P = 0.18). Type IIa was found significantly more in the female newborns (P < 0.0001) and in newborns who were born by cesarean section (P < 0.0001).

CONCLUSION

This study supports the role of US detection of different types of DDH; however, the frequency of pathologic types of hip sonography is 6%.

[Congenital hip dysplasia in newborns : Clinical and ultrasound examination, arthrography and closed reduction]

OBJECTIVE

Early diagnosis and rapid closed reduction under arthrographic control to initiate retention in a new position during the interval of maximum subsequent maturation power. This allows a (nearly) physiological ripening of the femoral head and acetabulum (AC) with restoration of the congruence of the joint partners (containment) and joint stability.

INDICATIONS

Clinically- and ultrasound-proven dislocation of the hip in the newborn.

CONTRAINDICATIONS

Increased bleeding, increased risk of anesthesia due to immaturity/prematurity, inability to use a retention cast due to malformations of the urogenital system, spinal deformities, or hernias requiring treatment or supervision.

SURGICAL TECHNIQUE

Palpation of the tuberosity of the ischium in 110° flexion and 40-50° abduction of the leg and then puncture lateral to this point. Advance the needle parallel to the plane of the table in the direction of the empty acetabulum and x-ray control. Control of intra-articular needle position by injection of isotonic saline solution. Test reflux by disconnection. Cautious instillation of 0.2-0.4 ml of contrast medium under X-ray control. Closed reduction under X-ray control by pulling slightly, flexion and abduction of the hip joint. Cast applied in approximately 110° hip flexion and 40° abduction.

POSTOPERATIVE MANAGEMENT

MRI control on postoperative day 1. Spica cast for 4 weeks. Then cast removal, clinical and ultrasound examination and immediate start of further treatment with a hip splint in 110° hip flexion and 30-40° abduction. Ultrasound follow-up every 3-4 weeks.

RESULTS

A total of 40 patients (female:male = 33:7) with 49 hip dislocations were analyzed. The mean age at reduction was 73 days (range 1-334 days). In 21 cases, treatment was started at another hospital. Intra- or immediate postoperative complications were not detectable. According to the control MRI on the first postoperative day, the cast had to be removed in 7 cases (17.7 %) due to insufficient reduction, although no classical need for repositioning could be identified in the MRI analysis. Instead, compared to cases with sufficient hip reduction, significantly reduced acetabular articular surfaces were found, so that in these cases, a lack of stability due to the lack of congruency between the femoral head and the AC must be considered. Signs of a fulminant avascular necrosis (AVN, grade 3 and 4 according to Kalamchi) and a pathological acetabular angle (grade 3 and 4 according to Tönnis) were observed during follow-up in 17.3 and 40.7 % of cases, respectively.

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.

Internet search term affects the quality and accuracy of online information about developmental hip dysplasia

BACKGROUND

The recent emphasis on shared decision-making has increased the role of the Internet as a readily accessible medical reference source for patients and families. However, the lack of professional review creates concern over the quality, accuracy, and readability of medical information available to patients on the Internet.

METHODS

Three Internet search engines (Google, Yahoo, and Bing) were evaluated prospectively using 3 difference search terms of varying sophistication ("congenital hip dislocation," "developmental dysplasia of the hip," and "hip dysplasia in children"). Sixty-three unique Web sites were evaluated by each of 3 surgeons (2 fellowship-trained pediatric orthopaedic attendings and 1 orthopaedic chief resident) for quality and accuracy using a set of scoring criteria based on the AAOS/POSNA patient education Web site. The readability (literacy grade level) of each Web site was assessed using the Fleisch-Kincaid score.

RESULTS

There were significant differences noted in quality, accuracy, and readability of information depending on the search term used. The search term "developmental dysplasia of the hip" provided higher quality and accuracy compared with the search term "congenital hip dislocation." Of the 63 total Web sites, 1 (1.6%) was below the sixth grade reading level recommended by the NIH for health education materials and 8 (12.7%) Web sites were below the average American reading level (eighth grade).

CONCLUSIONS

The quality and accuracy of information available on the Internet regarding developmental hip dysplasia significantly varied with the search term used. Patients seeking information about DDH on the Internet may not understand the materials found because nearly all of the Web sites are written at a level above that recommended for publically distributed health information.

CLINICAL RELEVANCE

Physicians should advise their patients to search for information using the term "developmental dysplasia of the hip" or, better yet, should refer patients to Web sites that they have personally reviewed for content and clarity. Orthopaedic surgeons, professional societies, and search engines should undertake efforts to ensure that patients have access to information about DDH that is both accurate and easily understandable.

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.

Pubo-femoral distance: an easy sonographic screening test to avoid late diagnosis of developmental dysplasia of the hip

OBJECTIVES

To propose an easy and reproducible sonographic screening test able to avoid late presentation of developmental dysplasia of the hip (DDH).

METHODS

The pubo-femoral distance (PFD) cut-off point was determined on 980 infants who underwent ultrasonography of the hips in comparison with the final diagnosis, based on clinical, ultrasound data and follow-up. PFD reproducibility was tested on 52 hips by both an experienced and an inexperienced radiologist. After teaching this screening method to general radiologists, its impact was evaluated by analysing the rate of late diagnosis in an entire administrative area.

RESULTS

An abnormal PFD threshold above 6 mm gave a sensitivity of 97.4 % for the diagnosis of DDH (271 hips) and a specificity of 84 %. Sensitivity increased to 100 % when taking into consideration children of 1 month or older. The PFD measurement stayed reproducible even in inexperienced hands (k = 0.795). For 3 years, following the extension of screening to all female infants, there was no late diagnosis of DDH in girls in amongst a catchment area of 1 million inhabitants.

CONCLUSIONS

PFD measurement with a threshold for abnormality of 6 mm at the age of 1 month, without asymmetry above 1.5 mm, could eradicate DDH late diagnosis.

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.

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.

Cost-effectiveness of universal ultrasound screening compared with clinical examination alone in the diagnosis and treatment of neonatal hip dysplasia in Austria

Between 1978 and 1997 all newborns in the Austrian province of Tyrol were reviewed regarding hip dysplasia and related surgery. This involved a mean of 8257 births per year (7766 to 8858). Two observation periods were determined: 1978 to 1982 (clinical examination alone) and 1993 to 1997 (clinical examination and universal ultrasound screening). A retrospective analysis compared the number and cost of interventions due to hip dysplasia in three patient age groups: A, 0 to < 1.5 years; B, ≥ 1.5 to < 15 years; and C, ≥ 15 to < 35 years.

In group A, there was a decrease in hip reductions from a mean of 25.2 (sd 2.8) to 7.0 (sd 1.4) cases per year. In group B, operative procedures decreased from a mean of 17.8 (sd 3.5) to 2.6 (sd 1.3) per year. There was a 75.9% decrease in the total number of interventions for groups A and B.

An increase of €57 000 in the overall cost per year for the second period (1993 to 1997) was seen, mainly due to the screening programme. However, there was a marked reduction in costs of all surgical and non-surgical treatments for dysplastic hips from €410 000 (1978 to 1982) to €117 000 (1993 to 1997). We believe the small proportional increase in costs of the universal ultrasound screening programme is justifiable as it was associated with a reduction in the number of non-surgical and surgical interventions. We therefore recommend universal hip ultrasound screening for neonates.

Follow-up sonographic results for Graf type 2A hips: association with risk factors for developmental dysplasia of the hip and instability

OBJECTIVES

The purpose of the study was to evaluate the association of sonographic worsening in type 2a hips with risk factors of developmental dysplasia of the hip, stability of the hip, and initial sonographic findings.

METHODS

Among infants who were referred for hip sonography between 2007 and 2009, 3450 were included in this study. Sonographic examinations were performed by combining the static Graf technique and the dynamic Harcke technique. The rate of sonographic worsening in type 2a hips and the relationship between sonographic worsening and risk factors for developmental dysplasia, instability of the hip, lateralization (right or left) of immaturity, and the presence of unilateral and bilateral immature hips were evaluated.

RESULTS

Type 2a hips were observed in 529 infants (15.3%; 780 hips [11.3%]). Of these, in 36 cases (6.8%; 44 hips [5.6%]), the sonographic results worsened. Twenty-five of these 36 cases (32 of 44 hips) were diagnosed as type 2 b; in others, the dysplasia worsened, and 6 cases (7 hips) were classified as type 2 c, 3 cases (3 hips) as type D, and 2 cases (2 hips) as type 3. Instability, unilateral type 2a hips, and associated central nervous system anomalies were found to be independent predictors of sonographic worsening in type 2a hips.

CONCLUSIONS

Type 2a hips may worsen sonographically at a rate of 5.6%; hence, sonographic follow-up is needed. Instability, central nervous system anomalies, and unilateral type 2a hips were found to be independent predictors of sonographic worsening. Our study shows that cases with these risk factors should be followed more carefully.

Ultrasound profile of hips of South Indian infants

One thousand consecutive infants, 437 girls and 563 boys, attending their first DPT vaccination at a mean age of 48 days underwent ultrasonological screening of the hips by Graf's technique at the immunization clinic of a tertiary hospital in South India. Graf I (mature) hips were seen bilaterally in 925 children. The incidence of Graf type II hips was 74/1000 infants. The incidence of sonographically abnormal hips (II, III and IV) in this population was 7.5%. The hip dislocation rate was 1 in 1000 (0.1%).

Reproducibility of different screening classifications in ultrasonography of the newborn hip

BACKGROUND

Ultrasonography of the hip has gained wide acceptance as a primary method for diagnosis, screening and treatment monitoring of developmental hip dysplasia in infants. The aim of the study was to examine the degree of concordance of two objective classifications of hip morphology and subjective parameters by three investigators with different levels of experience.

METHODS

In 207 consecutive newborns (101 boys; 106 girls) the following parameters were assessed: bony roof angle (α-angle) and cartilage roof angle (β-angle) according to Graf's basic standard method, "femoral head coverage" (FHC) as described by Terjesen, shape of the bony roof and position of the cartilaginous roof. Both hips were measured twice by each investigator with a 7.5 MHz linear transducer (SONOLINE G60S® ultrasound system, SIEMENS, Erlangen, Germany).

RESULTS

Mean kappa-coefficients for the subjective parameters shape of the bony roof (0.97) and position of the cartilaginous roof (1.0) demonstrated high intra-observer reproducibility. Best results were achieved for α-angle, followed by β-angle and finally FHC. With respect to limits of agreement, inter-observer reproducibility was calculated less precisely.

CONCLUSIONS

Higher measurement differences were evaluated more in objective scorings. Those variations were observed by every investigator irrespective of level of experience.

Immediate treatment versus sonographic surveillance for mild hip dysplasia in newborns

OBJECTIVE

We conducted a blinded, randomized, controlled trial to examine whether mildly dysplastic but stable or instable hips would benefit from early treatment, as compared with watchful waiting.

PATIENTS AND METHODS

A total of 128 newborns with mild hip dysplasia (sonographic inclination angle [alpha angle] of 43 degrees -49 degrees ) and stable or instable but not dislocatable hips were randomly assigned to receive either 6 weeks of abduction treatment (immediate-treatment group) or follow-up alone (active-sonographic-surveillance group). The main outcome measurement was the acetabular inclination angle, measured by radiograph, at 1 year of age.

RESULTS

Both groups included 64 newborns, and there was no loss to follow-up. With the exception of a small but statistically significant excess of girls in the active-sonographic-surveillance group, there were no statistically significant differences in baseline characteristics between the 2 groups. The mean inclination angle at 12 months was 24.2 degrees for both groups (difference: 0.1 [95% confidence interval (CI): -0.8 to 0.9]), and all children had improved and were without treatment. The mean alpha angle was 59.7 degrees in the treatment group and 57.1 degrees in the active-surveillance group for a difference of 2.6 degrees evaluated after 1.5 and 3 months (95% CI: 1.8 to 3.4; P < .001). At 1.5 months of age, the hips had improved in all treated children but not in 5 children under active surveillance (P = .06). Among the sonographic-surveillance group, 47% received treatment after the initial surveillance period of 1.5 months.

CONCLUSIONS

Active-sonographic-surveillance halved the number of children requiring treatment, did not increase the duration of treatment, and yielded similar results at 1-year follow-up. Given a reported prevalence of 1.3% for mildly dysplastic but stable hips, a strategy of active surveillance would reduce the overall treatment rate by 0.6%. Our results may have important implications for families as well as for health care costs.

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.

[When is the optimal time for hip ultrasound screening?]

The perfect time for hip screening is when every pathologically deformed hip can be diagnosed by sonography and after spontaneous resolution of immature, dysplastic hips. In addition, the beginning of therapy should be early enough to provide the best possible outcome concerning the anatomically correct healing of the patient's hip. Even though every child should be screened by sonography in the first few days of life, a reasonable way could be ultrasound screening in the first week for clinically unstable hips or newborns with risk factors such as breech position combined with ultrasound screening of every newborn between the fourth and sixth week.

Hip arthrography in the assessment of children with developmental dysplasia of the hip and Perthes' disease

In our unit, children with developmental dysplasia of the hip or Perthes' disease, for whom an operation is considered, undergo examination under anaesthetic and a hip arthrogram. This prospective study assessed whether the arthrogram modified treatment and analysed the reliability of its interpretation. All children undergoing a hip arthrogram for developmental dysplasia of the hip and Perthes' disease over a 12-month period were included. Treatment plans before and after the arthrogram were compared for each of the three children's consultants. The preoperative and arthrographic appearances were blindly reviewed to monitor reproducibility. Twenty-one patients with developmental dysplasia of the hip and 19 with Perthes' disease were included. The treatment plan was modified in 12 of the 21 (57.1%) patients with developmental dysplasia of the hip as a consequence of the arthrogram and six of the 19 patients (31.6%) with Perthes' disease. Intraobserver consultant agreement was high but interobserver agreement was only moderate. Static and dynamic arthrography helps decision-making in patients with developmental dysplasia of the hip and Perthes' disease.

Developmental dysplasia of the hip

In its severest form, developmental dysplasia of the hip is one of the most common congenital malformations. The pathophysiology and natural history of the range of morphological and clinical disorders that constitute developmental dysplasia of the hip are poorly understood. Neonatal screening programmes, based on clinical screening examinations, have been established for more than 40 years but their effectiveness remains controversial. Whereas systematic sonographic imaging of newborn and young infants has afforded insights into normal and abnormal hip development in early life, we do not clearly understand the longer-term outcomes of developmental hip dysplasia, its contribution to premature degenerative hip disorders in adult life, and the benefits and harms of newborn screening. High quality studies of the adult outcomes of developmental hip dysplasia and the childhood origins of early degenerative hip disease are needed, as are randomised trials to assess the effectiveness and safety of neonatal screening and early treatment.

Clinical examination versus ultrasonography in detecting developmental dysplasia of the hip

Although hip ultrasonography is gaining acceptance as the most effective method for the early diagnosis of developmental dysplasia of the hip, there is still some controversy regarding the use of ultrasonography as a screening method. The purpose of this study was to investigate prospectively the capacity of clinical examination findings and associated risk factors to detect developmental dysplasia of the hip defined ultrasonographically in infants. A total of 3,541 infants underwent clinical examination and hip ultrasonography. Measured against ultrasonography as a standard, the sensitivity and specificity of clinical examination were 97% and 13.68%, respectively. Graf type IIb or more severe developmental dysplasia was found in 167 infants (208 hips), at an overall frequency of 4.71%. Graf type IIa physiological immaturity was encountered in 838 hips, and of these, 15 hips (1.78%) developed Graf type IIb dysplasia and underwent treatment. Patient characteristics that were found to be significant risk factors were swaddling use, female gender, breech delivery and positive family history. Given its low specificity, our findings suggest that clinical examination does not reliably detect ultrasonographically defined developmental dysplasia of the hip in infants being screened for this disease.

Ultrasound in the diagnosis of developmental dysplasia of the hip in newborns. The European approach. A review of methods, accuracy and clinical validity

Based on soft evidence that ultrasound screening tends to reduce the rate of late developmental dysplasia of the hip (DDH) and the need for surgical interventions, different screening strategies including universal or selective ultrasound screening have been established in several European countries and centres during the last decade. We performed an extensive search for articles on ultrasound diagnosis of developmental dysplasia of the hip over the last 26 years. A few studies reported an adequate repeatability for the static [Graf, Morin, modified Morin (Terjesen)] and for the combined static/dynamic methods [modified Graf (Rosendahl)], while no such reports were found for the dynamic (Harcke) ultrasound techniques. The effect of newborn ultrasound screening on late DDH have been addressed in two randomised trials (RCTs), both concluding that both selective and universal ultrasound screening tend to reduce the prevalence of subluxed or dislocated DDH, thus without reaching statistical significance. Finally, several observational studies have shown that morphologically normal hips tend to remain normal with or without a co-existing instability, and 97% of sonographically immature hips tend to normalise spontaneously within 3 months. Two studies report on a similar pattern for mildly dysplastic, but stable hips. From the data available we suggest that selective ultrasound screening is worthwhile in areas with a high prevalence of late cases, given a well-organised, high-quality service can be provided.

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.

Musculoskeletal sonography in the neonate and infant

Babies are ideal subjects for investigation by sonography. They are small and easily examined with the use of high-frequency transducers. Their unique status in US imaging tends to get lost amid the array of other available modalities, such as MRI and CT imaging. Some of the questions posed in pediatric musculoskeletal imaging that are routinely directed to other imaging modalities can be solved quickly at a lower cost by sonography in neonates and infants without sedation or any known clinical risk. These small children not only have thinner soft tissues but they have long bones and midline spine structures whose ends are largely composed of cartilage, which provides an early opportunity to examine these regions by US. And we cannot overestimate the value of new parents being able to stay next to their baby during imaging in a warm, friendly and non-threatening environment.

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.

Ultrasound for screening developmental dysplasia of the hip: a European perspective

PURPOSE OF REVIEW

For the past 20 years, sonography of the hip has become the imaging procedure of choice to diagnose hip maturation disorders in German-speaking countries. In Austria, hip sonography is a mandatory and essential feature of preventive public health measures; the "Mutter-Kind-Pass" has been the official medical identity card for mother and child since 1992 in Austria. This review summarizes the most recent literature dealing with ultrasound screening for developmental dysplasia of the hip in Europe.

RECENT FINDINGS

This article focuses on the results in recent articles about sonography screening of the hip joint in the first year of life.

SUMMARY

The continued development and refinement of the method, which is now standardized in German-speaking countries and hence can be taught in uniformly structured courses, has made sonography of the infant hip a gold standard for screening for developmental dysplasia of the hip in these countries.