Examination of the infant hip with real-time ultrasonography

The Feasibility of Prenatal Ultrasonic Screening for Developmental Dysplasia of the Hip

BACKGROUND

developmental dysplasia of the hip (DDH) is a condition characterized by abnormal hip development in infancy. Early diagnosis allows for effective treatment, while late presentation often necessitates complex surgical interventions. Current recommendations advise screening between the 6th and 8th week postnatal using an ultrasound, typically employing the Graf method. However, there is no universal consensus on whether ultrasound screening significantly increases treatment likelihood compared to clinical examination-guided ultrasound. This study aims to explore the feasibility of prenatal ultrasound for the early identification of DDH risk.

METHODS

This prospective observational study involved 100 pregnant women undergoing fetal hip ultrasounds during the second and third trimesters. Using the modified Graf method, alpha and beta angles were calculated on the fetus. Postnatally, alpha and beta angles were compared with the prenatal values.

RESULTS

Prenatal ultrasound at the 24th week showed inconclusive results because of the difficulty in identification of Graf landmarks, while ultrasound at the 34th week proved to be a reliable and safe method for the quantitative determination of alpha and beta angles. Significant correlations were found between prenatal and postnatal alpha and beta angles. Moreover, significant differences in prenatal alpha and beta values were observed in patients developing mature/immature hips postnatally.

CONCLUSIONS

Prenatal diagnostics show promise for predicting infant hip development. Further research is warranted to validate correlation strength and clinical applicability.

Risk factors for a false negative Ortolani and Barlow examination in developmental dysplasia of the hip

INTRODUCTION

Although universal screening by neonatal clinical examination with Ortolani and Barlow manoeuvres is widely adopted, its role as a sole screening tool is controversial due to its poor sensitivity and failure in identifying hip joints that eventually require surgical intervention.

HYPOTHESIS

This study aims to identify risk factors for a false negative Ortolani and Barlow examination in neonatal screening for DDH. The hypothesis is that risk factors for developmental dysplasia of the hips could similarly be risk factors for a false negative Ortolani and Barlow examination.

MATERIAL AND METHODS

In the 14-year retrospective cohort study, all newborn infants born in a single institution from 1st January 1999 to 31st December 2013 were screened clinically with the Ortolani/Barlow manoeuvre by a neonatologist. Infants with positive risk factors, despite a normal clinical examination, were then scheduled for bilateral hip ultrasound in the first three months of life and evaluated according to the Graf's method, Harcke's method of dynamic ultrasound screening and Terjesen's method of evaluation for femoral head coverage.

RESULTS

A total of 164 infants with normal Ortolani and Barlow examinations were scheduled for bilateral hip ultrasound due to the presence of risk factors. Amongst these, 32 (19.5%) infants were evaluated to have an abnormal hip on ultrasound. Breech position was the only statistically significant risk factor for a false negative Ortolani/Barlow examination (14/34, 41.2% vs. 18/112, 13.8%; p<0.001).

DISCUSSION

Sonographic hip examinations are recommended for all infants with breech presentation even if they have a normal Ortolani and Barlow examination.

LEVEL OF EVIDENCE

III; case-control study.

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.

Pubofemoral distances correlate to acetabular morphology and sonological instability in screening for hip dysplasia

Aims

The present study seeks to investigate the correlation of pubofemoral distances (PFD) to α angles, and hip displaceability status, defined as femoral head coverage (FHC) or FHC during manual provocation of the newborn hip < 50%.

Methods

We retrospectively included all newborns referred for ultrasound screening at our institution based on primary risk factor, clinical, and PFD screening. α angles, PFD, FHC, and FHC at follow-up ultrasound for referred newborns were measured and compared using scatter plots, linear regression, paired t-test, and box-plots.

Results

We included 2,735 newborns, of whom 754 received a follow-up hip ultrasound within six weeks of age. After exclusion, 1,500 hips were included for analysis. Sex distribution was 372 male and 380 female, and the mean age at examination was 36.6 days (4 to 87). We found a negative linear correlation of PFD to α angles (p < 0.001), FHC (p < 0.001), and FHC during provocation (p < 0.001) with a 1 mm increase in PFD corresponding to a -2.1° (95% confidence interval (CI) -2.3 to -1.9) change in α angle and a -3.4% (95% CI -3.7 to -3.0) change in FHC and a -6.0% (-6.6 to -5.5) change in FHC during provocation. The PFD was significantly higher with increasing Graf types and in displaceable hips (p < 0.001).

Conclusion

PFD is strongly correlated to both α angles and hip displaceability, as measured by FHC and FHC during provocation, in ultrasound of newborn hips. The PFD increases as the hips become more dysplastic and/or displaceable.

Universal Ultrasound Screening for Developmental Dysplasia of the Hip Among Infants in Community Settings in Japan: A Scoping Review

Introduction

Early identification of developmental dysplasia of the hip (DDH) is necessary to minimize its negative effects. Ultrasound screening is useful for detecting DDH in hospitals. Awareness about community-based screening systems is low in Japan. Despite established nationwide home visiting services and child health checkups in the country, more than 10% of DDH patients are diagnosed at the age of ≥1 year. This review aimed to clarify the status of universal ultrasound screening for DDH among infants in community settings in Japan.

Methods

The electronic databases of Igaku Chuo Zasshi, MEDLINE, CHINAL, ERIC, and APA PsycInfo were searched for articles published between 2002 and 2022. Articles were evaluated with the reach, effectiveness, adoption, implementation, and maintenance framework.

Results

In total, 148 articles were identified. Two articles were manually added, and 67 articles were excluded through abstract reviews, of which 20 were duplicates. Finally, 18 articles were included in the analysis. There are two types of universal ultrasound screening in community settings: municipality-led and hospital-led. Since 1992, municipality-led screening has been conducted during public infant health checkups in five municipalities. Six hospitals implemented ultrasound screening. The participation rate was around 90%. The Graf method is typically used for this purpose. The prevalence of abnormal hips was 3.6%-16.6%. Owing to limited human resources and skills in ultrasound, all studies mentioned the necessity of a universal screening system for the early detection of DDH.

Conclusion

Embedding universal ultrasound screening in community health checkup systems enables collaboration between healthcare professionals and caregivers to improve health inequities and ensure early detection of DDH cases.

Community-Based Hip Screening for Up to Four-Month-Old Infants and Health Guidance for Their Caregivers in Japan: A Nation-Wide Survey

Early detection of developmental dysplasia of the hip (DDH) in children is crucial. Due to COVID-19, maternal and child health services have been suspended temporarily, increasing the risk of late detection of DDH. This study aimed to reveal Japan's current situation regarding community hip screening for newborns and infants and to provide health guidance for caregivers regarding DDH. A web-based, nationwide cross-sectional survey was conducted between February and March 2023 (n = 1737). One public health nurse overseeing maternal and child health per municipality responded to the 2022 municipality hip screening system. Among the 436 municipalities that responded (response rate: 25.1%), 97.5% implemented hip screening within 4 months, and approximately 60% performed it during newborn home visits, while only 2.3% conducted hip ultrasound screening. Perfect checking of the risk factors for DDH during newborn home visits and training opportunities for home visitors must be improved. Educational programs regarding DDH for home visitors and caregivers are needed to prevent the late diagnosis of DDH. Furthermore, collaboration between pediatric orthopedic surgeons and nurses is crucial for developing effective community-based hip-screening systems by bridging the evidence and practice gap in the early detection of DDH.

Paediatric hip ultrasound

Aims

The aim of this study was to investigate the agreement in interpretation of the quality of the paediatric hip ultrasound examination, the reliability of geometric and morphological assessment, and the relationship between these measurements.

Methods

Four investigators evaluated 60 hip ultrasounds and assessed their quality based the standard plane of Graf et al. They measured geometric parameters, described the morphology of the hip, and assigned the Graf grade of dysplasia. They analyzed one self-selected image and one randomly selected image from the ultrasound series, and repeated the process four weeks later. The intra- and interobserver agreement, and correlations between various parameters were analyzed.

Results

In the assessment of quality, there a was moderate to substantial intraobserver agreement for each element investigated, but interobserver agreement was poor. Morphological features showed weak to moderate agreement across all parameters but improved to significant when responses were reduced. The geometric measurements showed nearly perfect agreement, and the relationship between them and the morphological features showed a dose response across all parameters with moderate to substantial correlations. There were strong correlations between geometric measurements. The Graf classification showed a fair to moderate interobserver agreement, and moderate to substantial intraobserver agreement.

Conclusion

This investigation into the reliability of the interpretation of hip ultrasound scans identified the difficulties in defining what is a high-quality ultrasound. We confirmed that geometric measurements are reliably interpreted and may be useful as a further measurement of quality. Morphological features are generally poorly interpreted, but a simpler binary classification considerably improves agreement. As there is a clear dose response relationship between geometric and morphological measurements, the importance of morphology in the diagnosis of hip dysplasia should be questioned.

The effect of selective ultrasound screening on the incidence of late presentation of developmental hip dysplasia-a meta-analysis

Different screening strategies for developmental dysplasia of the hip (DDH) exist. Despite screening efforts, cases of late presentation continue to occur, often necessitating surgery. This systematic review and meta-analysis assess the effect of newborn selective ultrasound screening for DDH on the incidence of late presentation in infants and children, compared to a universal ultrasound strategy. A systematic search across Medline and EMBASE databases was performed between January 1950 and February 2021. A consensus-based evaluation of abstracts led to retrieval of relevant full text, original articles or systematic reviews in English only. These were assessed according to agreed eligibility criteria, and their reference lists were reviewed to identify additional eligible publications. Following final consensus on included publications, data was extracted, analysed and reported as per PRISMA and Prospero (CRD42021241957) guidelines. The 16 eligible studies consisted of 2 randomised controlled trials and 14 cohort studies, published between 1989 and 2014, with a total of 511,403 participants. In total, 121,470 (23.8%) received a neonatal hip ultrasound, of whom 58,086 and 63,384 were part of a selective or a universal ultrasound screening strategy, respectively. The difference in the proportion of late presentation between the universal and selective strategies was 0.0904 per 1,000 (P = 0.047). The time effect, i.e. the difference between early and late presentation defined respectively, as less than and more than 3 months of age, regardless of screening strategy, was not significant (P = 0.272). Although there was variability in study design and reporting, the quality of the evidence, based on the critical appraisal skills programme appraisal tools, was generally good. Compared to universal ultrasound screening for DDH, selective screening resulted in a slightly higher rate of late presentation. Uniformity in design and reporting of DDH studies and a cost-effectiveness analysis are needed.

The management of developmental dysplasia of the hip in children aged under three months : a consensus study from the British Society for Children's Orthopaedic Surgery

AIMS

A national screening programme has existed in the UK for the diagnosis of developmental dysplasia of the hip (DDH) since 1969. However, every aspect of screening and treatment remains controversial. Screening programmes throughout the world vary enormously, and in the UK there is significant variation in screening practice and treatment pathways. We report the results of an attempt by the British Society for Children's Orthopaedic Surgery (BSCOS) to identify a nationwide consensus for the management of DDH in order to unify treatment and suggest an approach for screening.

METHODS

A Delphi consensus study was performed among the membership of BSCOS. Statements were generated by a steering group regarding aspects of the management of DDH in children aged under three months, namely screening and surveillance (15 questions), the technique of ultrasound scanning (eight questions), the initiation of treatment (19 questions), care during treatment with a splint (ten questions), and on quality, governance, and research (eight questions). A two-round Delphi process was used and a consensus document was produced at the final meeting of the steering group.

RESULTS

A total of 60 statements were graded by 128 clinicians in the first round and 132 in the second round. Consensus was reached on 30 out of 60 statements in the first round and an additional 12 in the seond. This was summarized in a consensus statement and distilled into a flowchart to guide clinical practice.

CONCLUSION

We identified agreement in an area of medicine that has a long history of controversy and varied practice. None of the areas of consensus are based on high-quality evidence. This document is thus a framework to guide clinical practice and on which high-quality clinical trials can be developed.Cite this article: Bone Joint J 2023;105-B(2):209-214.

Evaluation of the labrum on postoperative magnetic resonance images: a predictor of acetabular development in developmental dysplasia of the hip

INTRODUCTION

Residual acetabular dysplasia of the hip after open reduction can complicate the treatment of developmental dysplasia of the hip (DDH) due to the potential need for corrective surgery. This retrospective study aimed to determine the predictive factors for acetabular development using postoperative radiographs and magnetic resonance imaging (MRI).

METHODS

We retrospectively investigated 74 hips of patients with DDH who underwent open reduction after reaching walking age and were followed up radiologically until skeletal maturity. We evaluated the cartilaginous acetabulum and labrum using a new method that measures the cartilaginous and labral landmarks on coronal and axial MR T2*-weighted images in patients aged 5 years. The mean age at the time of surgery was 22 months and that at the final survey was 20 years. Severin classification was determined at the final follow-up. Groups with good (53 hips) and poor (21 hips) outcomes were compared using the postoperative radiographic and MRI parameters recorded at 5 years of age. Factors predicting acetabular development were identified using univariate and multiple logistic analyses.

RESULTS

There were no significant differences in the bony-acetabular index (AI) and centre-edge (CE) angle between the good and poor outcome groups. However, the poor outcome group had significantly larger cartilaginous- and labral-AIs but significantly smaller cartilaginous- and labral-CE angles than the good outcome group (both p < 0.05). Multiple logistic regression analysis showed that labral-AI and labral-CE angle were predictors of acetabular development after open reduction for DDH, and their optimal cut-offs were 4° (77% sensitivity, 76% specificity) and 37° (68% sensitivity, 85% specificity), respectively.

DISCUSSION

Normal cartilaginous acetabulum development occurs in childhood, and evaluation using only radiographs is difficult. However, labral-AI ⩾4° and labral-CE angle <37° on MRI at 5 years of age offer useful indications for corrective surgery in patients with DDH.

Progress in screening strategies for neonatal developmental dysplasia of the hip

Developmental dysplasia of the hip (DDH) is the most common congenital disease of the musculoskeletal system in newborns and encompasses a disease spectrum ranging from a stable hip with a mildly dysplastic acetabulum to complete hip dislocation. Systematic screening for infant DDH has been performed for several decades all over the world and has contributed greatly to the early detection, diagnosis and treatment of DDH. However, some cases of delayed diagnosis still occur among the screened population, or conversely, overdiagnosis or overtreatment occasionally occurs. Furthermore, screening strategies for DDH are still controversial. The aim of our study was to analyze the current literature on DDH screening, paying particular attention to DDH screening strategies and their effectiveness. We searched the DDH screening literature from 1958 to 2021 in MEDLINE and other databases using PubMed. In this study, we reviewed the history of DDH screening and the progress of screening strategies and discussed the controversies regarding clinical and ultrasound screening methods with particular emphasis on the current opinions. Given the existing scientific evidence and changes in newborn DDH screening practices, universal ultrasound screening seems to be the best option for preventing late-detected cases and can be recommended as a favorable prevention strategy.

Factors for selective ultrasound screening in newborns with developmental dysplasia of the hip (DDH)

Background

Hip ultrasound screening for DDH provides better sensitivity compared to physical examination. Due to a lower prevalence and limited resources, selective hip ultrasound in newborns at risk could be considered a proper screening protocol in Thailand and Asian countries.

Objective

This study was aimed to evaluate risk factors and define criteria for selective screening.

Methods

A case-control study was conducted in 2020. All newborns with hip ultrasound screening were included. Cases were defined as newborns with abnormal hip ultrasounds, while controls were those with normal studies. Inter and intra-rater reliability were evaluated. All factors were analyzed using univariate and multivariate logistic regression. The model performance was tested by Hosmer-Lemeshow goodness of fit. Internal validity was performed by the split data method. Area under the receiver operating characteristic (ROC) curve was estimated.

Results

Ninety-five newborns (29 cases and 66 controls) were included. Eighty percent of cases and 58% of controls were female. The gestational age was 36.6 and 37.7 weeks in case and control, respectively. Female, breech presentation, positive Ortolani test, positive Barlow test, and limited hip abduction were significant factors with odds ratio of 2.82, 5.12, 34.21, 69.64, and 5.48, respectively. The final model included breech presentation, positive Ortolani test, and positive Barlow test. The model cut-off value 15.02 provided sensitivity (93.10%) and specificity were (80.30%). The area under the ROC curve was 0.9308. The split data remained significant internal validity for all factors with p-value &lt; 0.05.

Conclusion

Careful history taking and physical examination are essential to identify the risk factors for DDH. Newborns with breech presentation, positive Ortolani test and positive Barlow test should be screened by hip ultrasound.

Splinting for the non-operative management of developmental dysplasia of the hip (DDH) in children under six months of age

BACKGROUND

Developmental dysplasia of the hip (DDH) describes the abnormal development of a hip in childhood, ranging from complete dislocation of the hip joint to subtle immaturity of a hip that is enlocated and stable within the socket. DDH occurs in around 10 per 1000 live births, though only one per 1000 are completely dislocated. There is variation in treatment pathways for DDH, which differs between hospitals and even between clinicians within the same hospital. The variation is related to the severity of dysplasia that is believed to require treatment, and the techniques used to treat dysplasia.

OBJECTIVES

To determine the effectiveness of splinting and the optimal treatment strategy for the non-operative management of DDH in babies under six months of age.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, seven other electronic databases, and two trials registers up to November 2021. We also checked reference lists, contacted study authors, and handsearched relevant meetings abstracts.

SELECTION CRITERIA

Randomised controlled trials (RCTs), including quasi-RCTs, as well as non-RCTs and cohort studies conducted after 1980 were included. Participants were babies with all severities of DDH who were under six months of age. Interventions included dynamic splints, static splints or double nappies (diapers), compared to no splinting or delayed splinting.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, extracted data and performed risk of bias and GRADE assessments. The primary outcomes were: measurement of acetabular index at years one, two and five, as determined by radiographs (angle): the need for operative intervention to achieve reduction and to address dysplasia; and complications. We also investigated other outcomes highlighted by parents as important, including the bond between parent and child and the ability of mothers to breastfeed.

MAIN RESULTS

We included six RCTs or quasi-RCTs (576 babies). These were supported by 16 non-RCTs (8237 babies). Five studies had non-commercial funding, three studies stated 'no funding' and 14 studies did not state funding source. The RCTs were generally at unclear risk of bias, although we judged three RCTs to be at high risk of bias for incomplete outcome data. The non-RCTs were of moderate and critical risk of bias. We did not undertake meta-analysis due to methodological and clinical differences between studies; instead, we have summarised the results narratively. Dynamic splinting versus delayed or no splinting Four RCTs and nine non-RCTs compared immediate dynamic splinting and delayed dynamic splinting or no splinting. Of the RCTs, two considered stable hips and one considered unstable (dislocatable) hips and one jointly considered unstable and stable hips. No studies considered only dislocated hips. Two RCTs (265 babies, very low-certainty evidence) reported acetabular index at one year amongst stable or dislocatable hips. Both studies found there may be no evidence of a difference in splinting stable hips at first diagnosis compared to a strategy of active surveillance: one reported a mean difference (MD) of 0.10 (95% confidence interval (CI) -0.74 to 0.94), and the other an MD of 0.20 (95% CI -1.65 to 2.05). Two RCTs of stable hips (181 babies, very low-certainty evidence) reported there may be no evidence of a difference between groups for acetabular index at two years: one study reported an MD of -1.90 (95% CI -4.76 to 0.96), and another study reported an MD of -0.10 (95% CI -1.93 to 1.73), but did not take into account hips from the same child. No study reported data at five years. Four RCTs (434 babies, very low-certainty evidence) reported the need for surgical intervention. Three studies reported that no surgical interventions occurred. In the remaining study, two babies in the dynamic splinting group developed instability and were subsequently treated surgically. This study did not explicitly state if this treatment was to achieve concentric reduction or address residual dysplasia. Three RCTs (390 babies, very low-certainty evidence) reported no complications (avascular necrosis and femoral nerve palsy). Dynamic splinting versus static splinting One RCT and five non-RCTs compared dynamic versus static splinting. The RCT (118 hips) reported no occurrences of avascular necrosis (very low-certainty evidence) and did not report radiological outcomes or need for operative intervention. One quasi-RCT compared double nappies versus delayed or no splinting but reported no outcomes of interest. Other comparisons No RCTs compared static splinting versus delayed or no splinting or staged weaning versus immediate removal.

AUTHORS' CONCLUSIONS

There is a paucity of RCT evidence for splinting for the non-operative management of DDH: we included only six RCTs with 576 babies. Moreover, there was considerable heterogeneity between the studies, precluding meta-analysis. We judged the RCT evidence for all primary outcomes as being of very low certainty, meaning we are very uncertain about the true effects. Results from individual studies provide limited evidence of intervention effects on different severities of DDH. Amongst stable dysplastic hips, there was no evidence to suggest that treatment at any stage expedited the development of the acetabulum. For dislocatable hips, a delay in treatment onset to six weeks does not appear to result in any evidence of a difference in the development of the acetabulum at one year or increased risk of surgery. However, delayed splinting may reduce the number of babies requiring treatment with a harness. No RCTs compared static splinting with delayed or no splinting, staged weaning versus immediate removal or double nappies versus delayed or no splinting. There were few operative interventions or complications amongst the RCTs and the non-randomised studies. There's no apparent signal to indicate a higher frequency of either outcome in either intervention group. Given the frequency of this disease, and the fact that many countries undertake mandatory DDH screening, there is a clear need to develop an evidence-based pathway for treatment. Particular uncertainties requiring future research are the effectiveness of splinting amongst stable dysplastic hips, the optimal timing for the onset of splinting, the optimal type of splint to use and the need for 'weaning of splints'. Only once a robust pathway for treatment is established, can we properly assess the cost-effectiveness of screening interventions for DDH.

Ultrasound techniques for the detection of developmental dysplasia of the hip: a systematic review and meta-analysis

BACKGROUND

Developmental dysplasia of the hip (DDH) encompasses a broad spectrum of hip pathologies, including femoral or acetabular dysplasia, hip instability, or both. According to the medical literature, ultrasonography is the most reliable diagnostic method for DDH. Several techniques for the assessment of hips in newborns and infants, using ultrasonography, have been described.

OBJECTIVE

To compare the accuracy of the Graf technique and other diagnostic techniques for DDH.

DESIGN AND SETTING

A systematic review of studies that analyzed ultrasound techniques for the diagnosis of DDH within an evidence-based health program of a federal university in São Paulo (SP), Brazil.

METHODS

A systematic search of relevant literature was conducted in the PubMed, EMBASE, Cochrane Library, CINAHL, and LILACS databases for articles published up to May 5, 2020, relating to studies evaluating the diagnostic accuracy of different ultrasound techniques for diagnosing DDH. The QUADAS 2 tool was used for methodological quality evaluation.

RESULTS

All hips were analyzed using the Graf method as a reference standard. The Morin technique had the highest rate of sensitivity, at 81.12-89.47%. The Suzuki and Stress tests showed 100% specificity. The Harcke technique showed a sensibility of 18.21% and specificity of 99.32%.

CONCLUSION

All the techniques demonstrated at least one rate (sensibility and specificity) lower than 90.00% when compared to the Graf method. The Morin technique, as evaluated in this systematic review, is recommended after the Graf method because it has the highest sensitivity, especially with the three-pattern classification of 89.47%.

REGISTRATION NUMBER

Identifier: CRD42020189686 at the International Prospective Register of Systematic Reviews (identifier: CRD42020189686).

Acetabular depth, an early predictive factor of acetabular development: MRI in patients with developmental dysplasia of the hip after open reduction

Early prediction of future acetabular development is important to determine an additional surgery for developmental dysplasia of the hip (DDH). The purpose of this study was to investigate the predictive factors of acetabular development using MRI. We retrospectively investigated dislocated 40 hips and 34 normal hips in 37 pediatric patients (9 males and 28 females) with DDH who underwent open reduction after walking age. We evaluated the cartilaginous acetabulum and labrum of the patients using coronal MRI T2*-weighted images at 5 years of age. The mean age at the time of surgery was 22 months, and the mean age at the final survey was 19 years. We divided patients into two groups in accordance with the Severin classification at the final follow-up. Groups with good outcomes (affected 26 hips and unaffected 27 hips) and poor outcomes (14 hips and 7 hips) were compared using the MRI parameters on each side. Predictive factors of acetabular development were identified using univariate and multiple logistic regression analyses. Using multiple logistic regression analysis, labral acetabular roof depth and labral hip center distance at 5 years of age represented predictors after open reduction (odds ratio 0.27, P = 0.035; odds ratio 3.4, P = 0.028, respectively) on the affected side, and bony hip center distance represented a predictor on the unaffected side (odds ratio 2.6, P = 0.049). Acetabular development in the unaffected side could be predicted by bony assessment, while acetabular development in the affected side had to be assessed by labrum using MRI.

Practice Essentials of Imaging in Early Diagnosis of DDH

INTRODUCTION

Developmental dysplasia of hip joint (DDH) is a dynamic progressive pathology which can tilt either way. The term strictly applies to primary dysplasia, where etiology is not clearly known. Secondary dysplasia can be due multiple causes, such as neuromuscular disorders, connective tissue disorders or skeletal syndromes.

METHODS

The etiology being multifactorial, it needs a multidisciplinary team to address the issue at hand. The management starts antenatally with a detailed history of any risk factors and a dedicated ultrasound of the foetus, since forewarned is forearmed. At birth, a paediatrician having a keen sense of DDH will perform Barlow's or Ortolani's manoeuvre and can be the first one to sound the alarm in the event of positive findings. How and when a Radiologist needs to step in will depend on inter-departmental discussions between the paediatrician and the orthopedician.

RESULTS

In the presence of positive clinical screening tests, and non-availability of ultrasound, a preliminary X ray pelvis AP view including both hip joints should be the requisitioned in a child of any age, particularly, if belonging to the high-risk group. If ultrasound is available, a screening exam till 6 months of age is recommended to rule out DDH.

DISCUSSIONS

India is known for its vast numbers and little babies with occult diseases are the first to bear the brunt of conditions which have very few symptoms to start with. DDH is one such condition which most unfortunately expresses itself as a symptom only when it's too late, i.e., most often when the child begins to walk. Ultrasound is the modality of choice in neonates; however, since India is a country of modest means, in majority of the regions, radiographs still remain the first line of investigation.

Ultrasound as a diagnostic tool for femoral head containment disorders in children between one and 12 years of age

PURPOSE

Ultrasound has been used to diagnose hip dysplasia in neonates and to screen until the end of their first year. For older children, femoral head containment disorders such as developmental dysplasia of the hip, Legg-Calvé-Perthes disease or cerebral palsy are usually diagnosed with plain radiographs. The aim of the present study was to evaluate ultrasound in comparison with radiographic imaging in children up to age 12 years and to determine reference values for sonographic containment parameters.

METHODS

Hip ultrasound and radiographic imaging were acquired on the same day and then compared. As a reference, normal acetabular angle and acetabulum head index were determined on radiographs. Lateral cartilage distance (LCD), lateral head distance (LHD) and femoral head extrusion angle (HA) were measured on ultrasound images.

RESULTS

We included 96 patients with 167 healthy hips in the study. A total of 55 patients were female and 41 male. The mean age was 5.2 years (sd 3.3; 1.0 to 11.9). LCD_ultrasound, LHD_ultrasound and HA_ultrasound correlated significantly with radiographic parameters. The following ultrasound values were calculated as limits for impending loss of containment: LCD_ultrasound ≥ 6.5 mm, LHD_ultrasound ≥ 3.3 mm and HA_ultrasound ≥ 27.6°.

CONCLUSION

Ultrasound is a simple, radiation-free diagnostic tool to detect femoral head containment disorders, even in children older than one year. This study provides reference values for hip ultrasound in children up to 12 years.

LEVEL OF EVIDENCE

III.

Anterior hip ultrasound: A useful technique in developmental dysplasia of the hips

Introduction: Infant developmental dysplasia of the hips arises when there is an interruption to normal joint development, usually present at birth but may be a later development. It has a wide spectrum of severity with potentially disastrous long-term complications if left untreated. Incidence is highly variable, often being attributed to differences of opinion in definition and diagnosis; however, there is consensus that ultrasound be used in screening and management. Topic Description: The anterior hip ultrasound technique is underutilised but is of value due to the additional confidence it provides regarding joint stability. Discussion: The ability to relate the acquired ultrasound image to hip anatomy and a technical appreciation of the technique are crucial to successful use. The method is described and its use within previous literature briefly outlined. Using pictorial ultrasound imaging examples to demonstrate the technique, we aim to highlight the anterior approach as a useful addition to ultrasound assessment of infant developmental dysplasia of the hips. Conclusion: Knowledge and understanding of different techniques is essential for practitioners involved in the diagnosis and management of this multifaceted and vigorously debated condition.

Effectiveness of different types of ultrasonography screening for developmental dysplasia of the hip: A meta-analysis

BACKGROUND

Infant hip screening for early detection of developmental dysplasia of the hip (DDH) is essential as early detection can enable less invasive treatments and achieve better long-term results. A previous meta-analysis assessed about 10,000 infants per group, which is insufficient for evaluating the effect of different infant hip screening strategies on early detection and treatment of DDH. Therefore, we conducted a systematic review and meta-analysis using both randomized controlled trials and cohort studies to determine the effects of universal hip ultrasonography screening (UHUS) and selective hip ultrasonography screening (SHUS) on the incidence of late-diagnosed DDH.

METHODS

A literature search of PubMed, EMBASE, and Cochrane databases was performed. The summary odds ratio (OR) with 95% confidence interval (CI) was calculated using fixed-effects models.

RESULTS

Meta-analysis of five studies that met the eligibility criteria revealed a significant difference in late-diagnosed DDH (OR 0.44, 95% CI 0.23-0.83) between infants screened using UHUS (n = 29,070) and those screened using SHUS (n = 30,442) in a fixed-effects model without heterogeneity among studies. In the subgroup analysis, meta-analysis of the randomized controlled trials showed no significant difference in late-diagnosed DDH (OR 0.52, 95% CI 0.20-1.39) between infants screened using UHUS (n = 11,453) and those screened using SHUS (n = 12,077) in a fixed-effects model with low heterogeneity among studies (I = 0.9%). However, meta-analysis of the cohort studies showed a significant difference in late-diagnosed DDH (OR 0.38, 95% CI 0.17-0.89) between infants screened using UHUS (n = 17,617) and those screened using SHUS (n = 18,345) in a fixed-effects model with low heterogeneity among studies. Sensitivity analysis revealed that the impact of each study on the summary results was not significant. There was no publication bias in our meta-analysis.

CONCLUSIONS

Our meta-analysis suggests that a statistically significant decrease in the incidence of late-diagnosed DDH is possible when UHUS is adopted compared with SHUS. Our study provides information about the effects of different infant hip screening strategies on the incidence of late-diagnosed DDH, which can help decide upon which strategy to apply.

Recommendations for early diagnosis of Developmental Dysplasia of the Hip (DDH): working group intersociety consensus document

This consensus document has been prepared by a multidisciplinary group of experts (Paediatricians, Radiologists, Paediatric Orthopaedics) and it is mainly aimed at paediatricians, hospitals and primary care providers. We provide recommendations for the early diagnosis and treatment of Developmental Dysplasia of the Hip (DDH) and indications on its management.

Pearls and Pitfalls of Hip Ultrasound

Failure to appreciate key anatomic features and suboptimal sonographic technique lead to incorrect assessment of the key elements of developmental dysplasia of the hip: position, stability, and morphology. In this article, we address common errors, identify sonographic features critical for accurate image interpretation, and address measurement variability.

A Bibliometric Analysis of Citation Classics in the Journal of Ultrasound in Medicine

OBJECTIVES

A bibliometric analysis of articles in the Journal of Ultrasound in Medicine (JUM) identified the journals' most impactful articles.

METHODS

A bibliometric analysis of citation classics that were published in the JUM from its inception in 1982 to 2019 was performed. All citation classics, defined as articles cited 100 or more times, were evaluated for the number of citations, citations per year, publication year, subspecialty, design, and country of origin. Characteristics were compared before and after 1998 by the Mann-Whitney test for unpaired data and 2-sample z tests of sample proportions. The Kruskal-Wallis test for nonparametric continuous data was used to compare the median number of citations per year by decade of publication.

RESULTS

A total of 7868 articles were published in the JUM between 1982 and 2019; 54 (0.7%) were citation classics. The median citation classics year of publication was 1998 (interquartile range [IQR], 1991-2003). Most citation classics originated from the United States (36 of 54 [66.7%]), were observational (47 of 54 [87%]), and were related to obstetric and gynecologic topics (16 of 54 [29.6%]). Citation classics after 1998 received significantly more citations per year (9.3 versus 4.7; P < .001), with no other differences noted. The median number of citations per year increased for each decade, with medians of 4 citations (IQR, 3.6-4.7) in 1982 to 1991 and 11.2 citations (IQR, 9-13.9) in 2002 to 2012 (P < .001).

CONCLUSIONS

This list provides insight into the most influential articles that were published in the JUM. Most citation classics were observational, were from the United States, and covered obstetric and gynecologic topics. Citation classics received more citations per year after 1998.

Abduction treatment in stable hip dysplasia does not alter the acetabular growth: results of a randomized clinical trial

Background The effect of bracing over natural history of stable dysplastic hips is not well known. This multicenter randomized trial aimed at objectifying the effect of abduction treatment versus active surveillance in infants of 3 to 4 months of age. Methods Patients were randomized to either Pavlik harness or active surveillance group. Ultrasound was repeated at 6 and 12 weeks post randomization. The primary outcome was the degree of dysplasia using the Graf α-angle at 6 months of age. The measurement of the acetabular index (AI) on plain pelvis X-rays was used to identify persistent dysplasia after 9 months and walking age (after 18 months). Findings The Pavlik harness group (n = 55) and active surveillance group (n = 49) were comparable for predictors of outcome. At 12 weeks follow-up the mean α-angle was 60.5° ± 3.8° in the Pavlik harness group and 60.0° ± 5.6° in the active surveillance group. (p = 0.30). Analysis of secondary outcomes (standard of care) showed no treatment differences for acetabular index at age 10 months (p = 0.82) and walking age (p = 0.35). Interpretation Pavlik harness treatment of stable but sonographic dysplastic hips has no effect on acetabular development. Eighty percent of the patients will have a normal development of the hip after twelve weeks. Therefore, we recommend observation rather than treatment for stable dysplastic hips.

Orthopedic and ultrasound assessment of hip stability of newborns referred by pediatricians with suspected Developmental Dysplasia

OBJECTIVE

to evaluate newborns with suspected hip instability, referred by pediatricians to a tertiary orthopedic service.

METHODS

newborns from a public university maternity hospital, with suspected instability or risk factors for hip dysplasia, were referred to the Department of Orthopedics and Anesthesiology, Ribeirão Preto/SP, where we evaluated them clinically and through ultrasound examinations of the hips. Once we found dysplasia, we initiated treatment, and in cases in which there was only hip immaturity and normal clinical examination, we performed clinical and ultrasound observation and review at two or three months of age.

RESULTS

we examined 448 newborns, with female predominance and average age at first evaluation of 27 days. The main cause of referral was pelvic presentation at delivery. In 8% there was a positive Ortolani sign and in 12.5%,. At orthopedic examination, 405 (90.5%) patients were normal, 8.5% had hip click and 1.1% had positive Ortolani test. At ultrasound, 368 (89.5%) had immaturity, 26 (6.3%) had moderate dysplasia and in 17 (4.1%) patients the hips were frankly dysplastic. All cases with positive Ortolani sign showed dysplasia at ultrasound.

CONCLUSION

there was an excess diagnosis of hip instability in the pediatrician evaluation, which, however, allowed the patient a second assessment, in a more specialized environment and with more technological resources.

Imaging of developmental dysplasia of the hip: ultrasound, radiography and magnetic resonance imaging

Developmental dysplasia of the hip (DDH) describes a broad spectrum of developmental abnormalities of the hip joint that are traditionally diagnosed during infancy. Because the development of the hip joint is a dynamic process, optimal treatment depends not only on the severity of the dysplasia, but also on the age of the child. Various imaging modalities are routinely used to confirm suspected diagnosis, to assess severity, and to monitor treatment response. For infants younger than 4 months, screening hip ultrasound (US) is recommended only for those with risk factors, equivocal or positive exam findings, whereas for infants older than 4-6 months, pelvis radiography is preferred. Following surgical hip reduction, magnetic resonance (MR) imaging is preferred over computed tomography (CT) because MR can not only confirm concentric hip joint reduction, but also identify the presence of soft-tissue barriers to reduction and any unexpected postoperative complications. The routine use of contrast-enhanced MR remains controversial because of the relative paucity of well-powered and validated literature. The main objectives of this article are to review the normal and abnormal developmental anatomy of the hip joint, to discuss the rationale behind the current recommendations on the most appropriate selection of imaging modalities for screening and diagnosis, and to review routine and uncommon findings that can be identified on post-reduction MR, using an evidence-based approach. A basic understanding of the physiology and the pathophysiology can help ensure the selection of optimal imaging modality and reduce equivocal diagnoses that can lead to unnecessary treatment.

Correlations between ultrasonographic and subsequent radiographic findings of developmental dysplasia of the hips

Purpose

The study aimed to investigate the utility of ultrasonographic (US) findings in predicting the subsequent radiographic parameters of developmental dysplasia of the hips.

Methods

In this 12-year retrospective cohort study, all new-born infants with a positive clinical examination or risk factors were included. They were scheduled for hip ultrasonography in the first 3 months, and subsequent radiographs at 1 year of life. The US images were evaluated using the Graf classification, Harcke’s dynamic screening method, and Terjesen’s femoral head coverage method. The radiographic images were evaluated using the acetabular index and femoral head position. The overall US or radiographic findings were considered abnormal if they were classified as abnormal for any of their respective parameters. The overall US and radiographic parameters were correlated.

Results

A total of 160 patients were included. The overall US and radiographic parameters showed no statistically significant difference (P=0.050). The sensitivity, specificity, and accuracy of the overall US parameters were 57.1%, 84.9%, and 81.3%, respectively. All three individual US parameters showed no statistically significant differences, with the overall radiographic findings and acetabular index (P>0.05). However, they showed a statistically significant difference, with the position of the femoral head (P<0.001), with the US parameters having an excellent negative predictive value of 100% for identifying an abnormal femoral head position.

Conclusion

The current study suggests that US findings evaluated in the first 3 months of life showed no statistically significant difference with radiographic findings evaluated at 1 year of life. The US parameters showed an excellent negative predictive value for abnormal femoral head position on radiographs.

Does Late Hip Dysplasia Occur After Normal Ultrasound Screening in Breech Babies?

BACKGROUND

Recent literature has raised concern regarding the occurrence of late dysplasia after normal screening in breech babies. One paper states a late dysplasia incidence of 29%. This finding is in contrast with other published work, which suggests breech presentation is predictive of spontaneous stabilization of the unstable neonatal hip. We decided to identify the rate of late dysplasia after normal screening in our patient cohort and also to investigate the use of a prophylactic abduction diaper.

METHODS

During the study period of December 2012 to June 2014, breech babies referred to the screening program at our institution were identified. Ninety babies were prospectively enrolled into the study and randomized to either the observational arm or prophylactic treatment with the Healthy Hip Diaper (HALO, Minnetonka, MN). All babies had a normal initial clinical examination and ultrasound. Regular follow-up including clinical and ultrasound examination was undertaken culminating in pelvic x-rays performed at 13±1 months. A total of 63% of patients elected against their randomization to prophylactic treatment, 28% opted for prophylactic treatment against their randomization to observation only, meaning a total of 40% of babies proceeded against their initial randomization. In total, 75% of recruited babies completed follow-up. Dysplasia was defined as an acetabular index >2 SD from the mean sex, age, and side-specific values.

RESULTS

The overall rate of radiographic dysplasia at 13 months was 7.4%. The rate was 5% in those using a Healthy Hip Diaper and 8.3% in those under observation only. This was not a statistically significant difference. Two patients required operative intervention, one requiring capsulorraphy with acetabuloplasty, the other requiring an arthrogram. Overall compliance with the abduction diaper was low.

CONCLUSIONS

We conclude that late radiographic dysplasia does occur after normal clinical and ultrasound screening in breech babies, although not to the same extent as recently published data. We cannot recommend prophylactic abduction devices for breech babies who have a normal hip ultrasound at 6 weeks of age. Consideration must be given to further clinical and radiographic follow-up for hip dysplasia when the risk factor of breech presentation is present.

LEVEL OF EVIDENCE

Level II-prospective comparative trial.

The earliest timing of ultrasound in screening for developmental dysplasia of the hips

Purpose

The current study aimed to evaluate the results of ultrasound screening for developmental dysplasia of the hips (DDH) done at various weeks of life, to determine the earliest time that ultrasound screening can be performed reliably.

Methods

In this 17-year cohort study, all neonates who underwent ultrasound screening prior to the 12th week of life with subsequent follow-up radiography done at 1 year of life were included. The ultrasound images were evaluated according to the Graf classification, Harcke’s dynamic ultrasound screening method, and Terjesen’s femoral head coverage method. The radiographic images were evaluated according to the acetabular index and the femoral head position. The accuracy and correlation between the ultrasound findings from various weeks of life with the radiographic findings at 1 year of life were evaluated.

Results

A total of 348 neonates were included in the study, of whom 92 had abnormal ultrasound findings and 42 had abnormal radiographic findings at 1 year. Significant differences were identified between the findings of ultrasound screening examinations performed prior to the fourth week of life (day 21 and before) and the radiographic findings at 1 year of life (P<0.05). In contrast, no significant differences were identified when ultrasound screening was performed between the fourth and 12th weeks of life (day 22 and beyond) (P>0.05). The accuracy of ultrasound screening was 79.2% or higher when performed during or after the fourth week of life (day 22 and beyond).

Conclusion

The earliest that ultrasound screening for DDH can be performed reliably is during the fourth week of life (day 22 and beyond).

Predicting acetabular growth in developmental dysplasia of the hip following open reduction after walking age

BACKGROUND

Acetabular dysplasia of the hip following open reduction can complicate the treatment of developmental dysplasia of the hip (DDH). The purposes of this retrospective study were to investigate the long-term results of open reduction performed via an extensive anterolateral approach for DDH after walking age and to predict acetabular development using postoperative radiographs and arthrograms.

METHODS

From 1973 to 2001, we performed open reduction for 131 hips in 119 pediatric patients with DDH after failed closed reduction. Of these, 85 hips of 73 patients who underwent arthrography at 5 years old were followed-up radiologically until skeletal maturity. Mean age at the time of surgery was 17 ± 4.6 months (range, 10-33 months), and mean age at final survey was 19 ± 5.7 years (range, 14-33 years). Mean follow-up time was 17.7 ± 5.8 years (range, 13-32 years). Groups with satisfactory outcomes (66 hips) and unsatisfactory outcomes (19 hips) according to the Severin classification were compared. Factors predicting acetabular development were identified using univariate and multiple logistic analyses.

RESULTS

Univariate analysis showed a significant between-group difference in acetabular index (AI) at 2 months postoperatively, and in center-edge (CE) angle, cartilaginous AI (CAI), and cartilaginous CE angle at 5 years old (p < 0.05 each). In multiple logistic regression analysis, CAI at 5 years old represented a predictor of acetabular development after open reduction for DDH (odds ratio, 1.81; 95% confidence interval (CI), 1.04-3.13; p < 0.05). Area under the receiver operating characteristic curve for CAI at 5 years old was 0.93 (95%CI, 0.85-1.0), and the optimal cut-off was 10° (81.8% sensitivity, 92% specificity).

CONCLUSIONS

A CAI ≥10° on hip arthrograms at 5 years old may offer a useful indicator of the need for corrective surgery following open reduction after walking age.

Ultrasound of the infant hip: manual fixation is equivalent to Graf's technique regarding image quality-a randomized trial

Background

In Middle Europe ultrasonography is the standard method used to screen for developmental dysplasia of the hip in infants. Our aim was to determine whether manual fixation of the child is equivalent to Graf’s technique regarding image quality.

Methods

This randomized trial was conducted at a free-standing general pediatric outpatient clinic in Vienna, Austria. Healthy infants in the 1st and between the 6th and 8th week of life with no hip malalignment were included. After randomization, Group 1 was examined using Graf’s fixation device and participants in Group 2 were fixated on the examination couch by their parents. In a second step, all images underwent a blinded evaluation.

Results

A total of 117 babies (Group 1: n = 62, Group 2: n = 54, excluded: n = 1) were examined and 230 images (Group 1: n = 122, Group 2: n = 108) were evaluated, of which 225 were sonographically normal. Two images, showing a type IIa right hip and a type IIa + left hip respectively, were excluded. One participant had to be excluded as the respective images showed two pathologic hip joints. Two images in Group 1 and three in Group 2 were not evaluable. No statistical association between image quality (11 quality criteria and overall evaluability) and fixation technique (0.12 ≤ p ≤ 1.0 or constant) was found.

Conclusions

Considering sonographically normal hip joints, we found no evidence that manual fixation differed from Graf’s technique regarding image quality. In future studies, hip pathologies should be included and discomfort of infants and parents during the examination should be addressed.

Trial registration

German Clinical Trials Register, ID: DRKS00015694), registered retrospectively on October 7th, 2018.

Patchy increased echogenicity: a sonographic sign of femoral head necrosis following reduction and casting for developmental dysplasia of the hip

A developmental dysplasia of the hip (DDH) case treated by closed reduction and casting and subsequently confirmed to have avascular necrosis (AVN) was retrospectively noted to have an abnormal pattern of echogenicity in the femoral head on sonograms obtained within 1.5 months of surgery. Patchy increased echogenicity in parts of the unossified cartilage replaced the normal pattern of central coalescence of vessels described with development of the ossification center. An additional case with similar findings confirms this should be considered a sign of evolving AVN following closed reduction.

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

Aims

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

Patients and Methods

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

Results

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

Conclusion

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

Hip Sonography: 20 Years Experience and Results

Hip sonography in the “Graf technique” is an important tool to detect early DDH cases and dysplastic hips in the German speaking countries, although hip sonography is still controversially discussed in the English speaking countries. The reason may be different techniques with different classification and outcome. Exact anatomical identification, measurement technique, typing, difference between instability and elasticity with a reproducible “standard plane” is absolutely necessary to make hip ultrasound (US) comparable and reliable.

US screening had reduced open reductions in Germany to 1:4000, in Austria to 0.23 per thousand. Because of the early screening and earlier less aggressive treatment, the overall costs could be reduced by 1/3 in comparison to the pre-ultrasound area.

US screening seems to prevent many, but not all operations and can be recommended as an important tool for prevention.

Clicky hip alone is not a true risk factor for developmental dysplasia of the hip

AIMS

A clicky hip is a common referral for clinical and sonographic screening for developmental dysplasia of the hip (DDH). There is controversy regarding whether it represents a true risk factor for pathological DDH. Therefore a 20-year prospective, longitudinal, observational study was undertaken to assess the relationship between the presence of a neonatal clicky hip and pathological DDH.

PATIENTS AND METHODS

A total of 362 infants from 1997 to 2016 were referred with clicky hips to our 'one-stop' paediatric hip screening clinic. Hips were assessed clinically for instability and by ultrasound imaging using a simplified Graf/Harcke classification. Dislocated or dislocatable hips were classified as Graf Type IV hips.

RESULTS

The mean age at presentation was 13.8 weeks (12.8 to 14.7). In all 351 out of 362 children (97.0%) had Graf Type I hips (normal) that required no treatment. Nine children (2.5%) had Graf Type II hips but all resolved to Graf Type I hips on follow-up scans. One child (0.3%) had Graf Type III hip dysplasia and one child (0.3%) had an irreducible hip dislocation. The two pathological hips were associated with unilateral limited hip abduction. Mean referrals increased from 12.9 to 23.3 each year (p = 0.002) from the first decade of the study to the second, driven by increasing primary care referrals (5.5 versus 16.7 per year, p < 0.001).

CONCLUSION

Most clicky hips required no treatment other than reassurance to parents. Clicky hips with a normal hip examination should be considered a variant of normal childhood and not a risk factor for DDH. However, an abnormal hip examination including unilateral limited hip abduction should prompt urgent further investigations. Cite this article: Bone Joint J 2017;99-B:1533-6.

The pubo-femoral distance decreases with Pavlik harness treatment for developmental dysplasia of the hip in newborns

OBJECTIVE

To evaluate the evolution of the ultrasonographic pubo-femoral distance (PFD) before and after Pavlik harness treatment for developmental dysplasia of the hip (DDH) in newborns.

PATIENTS AND METHODS

Twenty-five patients (16.7 ± 10.4 days; 19 females, six males) diagnosed with DDH and treated using the Pavlik harness were included. Eighteen patients had bilateral, and seven unilateral DDH, with a total of 43 dysplastic hips. The seven non-dysplastic hips in unilateral cases were used for comparison. The PFD was measured in the coronal and axial planes with the hip flexed to approximately 90°, before and after an average of 93 days of treatment. The femoral head coverage was assessed in the coronal plane, and correlated with PFD values.

RESULTS

In dysplastic hips, the mean PFD decreased from 6.1 ± 1.8 mm to 3.0 ± 0.7 mm in the axial (adjusted difference, 2.9 mm; p < 0.01), and from 5.9 ± 2.0 to 3.0 ± 0.6 mm in the coronal plane (adjusted difference 2.7 mm; p < 0.01). The femoral head coverage increased from 30.8 to 62.1%, and the mean differences of femoral head coverage and PFD were significantly correlated (p < 0.001). There was no difference between treated dysplastic and non-dysplastic hips. There was high intra- and inter-observer agreement for PFD measurements.

CONCLUSION

The PFD decreased significantly after DDH treatment using the Pavlik harness in newborns, and showed significant correlation with the femoral head coverage improvement. PFD might be a reliable tool for monitoring DDH treatment in newborns treated using the Pavlik harness.

Diagnosing developmental dysplasia of the hip using the Graf ultrasound method: risk and protective factor analysis in 11,820 universally screened newborns

The essential role of ultrasound examinations in diagnosis and treatment of developmental dysplasia of the hip (DDH) is widely accepted while the weighting and correlation of protective factors and perinatal risk for DDH still give rise to debate. Our aim was to investigate the impact of single and twofold combined risk and protective factors on the newborns' hip maturity, assessed with the Graf ultrasound method. Therefore, data sets of 11,820 universally screened newborns were analyzed. Univariate and logistic regression analyses were performed to correlate risk and protective factors with mature or immature but appropriate for age and pathologic hip types. Thereby, female gender (OR 4.07 (95% CI 3.01-5.51), p < 0.001), breech presentation (4.98 (3.71-6.71), p < 0.001), and positive family anamnesis (5.05 (3.49-7.31), p < 0.001) as well as the combination of female gender with high birth weight (3.51 (2.45-5.03), p < 0.001) could be identified as independent predictive risk factors. Only low birth weight (0.27 (0.11-0.66), p = 0.004) could be identified as a single protective factor, while no combination of protective factors was significant.

CONCLUSION

The significance and the informative value of risk and protective factor combinations, e.g., for selective ultrasound surveys, are limited. Early universal ultrasound screening using the Graf method is advised to timely detect hip immaturity and pathologies and to provide the optimal approach for mature or immature but appropriate for age and pathologic hips. What is Known: • Ultrasound screening is essential for diagnosis and treatment of DDH in time while the weighting and correlation of protective factors and perinatal risk and their role for the ultrasound screening protocol still give rise to debate. What is New: • The effects of single risk and protective factors for DDH do not cumulate or counteract, resulting in a limited value of a selective screening protocol based on risk and protective factors. • A universal screening protocol using the Graf ultrasound method is recommended.

Hip ultrasonography in clinical practice

The current practice of hip ultrasonography for developmental dysplasia of the hip (DDH) is based on more than three decades of experience. During this time, professional medical organizations in the United States have addressed both the clinical practice and imaging aspects of early detection of DDH. Current evidence-based clinical practice recommendations come from the American Academy of Pediatrics and the American Academy of Orthopaedic Surgeons. Consensus imaging recommendations come from the American Institute of Ultrasound in Medicine, the American College of Radiology, Society for Pediatric Radiology and the Society of Radiologists in Ultrasound. In this review the author compares and contrasts the current guidelines and offers additional practice tips for those providing comprehensive hip ultrasound services to infants.

The most-cited articles in pediatric imaging: a bibliometric analysis

INTRODUCTION

The number of citations that an article has received reflects its impact on the scientific community. The purpose of our study was to identify and characterize the 51 most-cited articles in pediatric imaging.

EVIDENCE ACQUISITION

Based on the database of Journal Citation Reports, we selected 350 journals that were considered as potential outlets for pediatric imaging articles. The Web of Science search tools were used to identify the most-cited articles relevant to pediatric imaging within the selected journals.

EVIDENCE SYNTHESIS

The 51 most-cited articles in pediatric imaging were published between 1952 and 2011, with 1980-1989 and 2000-2009 producing 15 articles, each. The number of citations ranged from 576-124 and the number of annual citations ranged from 49.05-2.56. The majority of articles were published in pediatric and related journals (N.=26), originated in the USA (N.=23), were original articles (N.=45), used MRI as imaging modality (N.=27), and were concerned with the subspecialty of brain (N.=34). University College London School of Medicine (N.=6) and School of Medicine University of California (N.=4) were the leading institutions and Reynolds EO (N.=7) was the most voluminous author.

CONCLUSIONS

Our study presents a detailed list and an analysis of the most-cited articles in the field of pediatric imaging, which provides an insight into historical developments and allows for recognition of the important advances in this field.

Pavlik harness treatment for pathological developmental dysplasia of the hip: meeting the standard?

In the UK, the Pavlik harness is generally the accepted treatment technique for the treatment of neonatal and infant pathological developmental dysplasia of the hip. In 2013, the success rate of the Pavlik harness became an outcome measure from the British Society of Children's Orthopaedic Surgery for appraisal and revalidation with the GMC for paediatric orthopaedic surgery. The standard set requires an 80% success rate, with less than 20% requiring surgery. This study evaluated the outcomes of Pavlik harness treatment in neonates/infants with 'pathological hips' diagnosed by ultrasound imaging in a district general hospital setting. In a 10-year prospective observational longitudinal cohort study, modified Graf type III and IV hips (excluding those presenting with irreducible hip dislocation) were classified as pathological and splinted. A total of 2826 neonates/infants underwent ultrasound assessment in the paediatric orthopaedic 'screening clinic'. Neonates and infants were referred as 'at-risk' or as clinically unstable by the Paediatric Department and by general practitioners. Thirty-one Graf type III and 95 Graf type IV hips were identified and treated with a Pavlik harness. One Graf type III (30/31=success rate 96.8%) and three clinically unstable Graf type IV hips progressed to irreducible hip dislocations (92/95=96.8%). The success rate of the Pavlik harness in Graf type III and IV dysplasia was 96.8%, with 3.2% requiring surgery because of progression of the condition, confirming acceptable results for this technique in a district general hospital setting.

Ultrasound Examination of Pediatric Musculoskeletal Diseases and Neonatal Spine

Ultrasound (US) is a simple, non-invasive imaging modality which allows high-resolution imaging of the musculoskeletal (MSK) system. Its increasing popularity in pediatrics is due to the fact that it does not involve radiation, has an ability to visualize non-ossified cartilaginous and vascular structures, allows dynamic imaging and quick contralateral comparison. US is the primary imaging modality in some pediatric MSK conditions like infant hip in developmental dysplasia (DDH), hip joint effusion, epiphyseal trauma and evaluation of the neonatal spine. US is the modality of choice in infants with DDH, both in the initial evaluation and post-treatment follow-up. US has a sensitivity equivalent to MRI in evaluation of the neonatal spine in experienced hands and is a good screening modality in neonates with suspected occult neural tube defects. In other MSK applications, it is often used for the initial diagnosis or in addition to other imaging modalities. In trauma and infections, US can often detect early and subtle soft tissue abnormalities and a quick comparison with the contralateral side aids in diagnoses. Dynamic imaging is crucial in evaluating congenital instabilities and dislocations, soft tissue and ligamentous injuries, epiphyseal injuries and fracture separations. High-resolution imaging along with color Doppler (CD) is useful in the characterization of soft tissue masses. This article reviews the applications of US in pediatric MSK with emphasis on conditions where it is a primary modality. Limitations of US include inability to penetrate bone, hence, limited diagnosis of intraosseous pathology and operator dependency.

Intraoperative assessment of closed reduction for developmental dislocation of the hip using 3-dimensional fluoroscopy

BACKGROUND

Postoperative imaging for operatively treated developmental dislocation of the hip typically uses computed tomography or a magnetic resonance imaging (MRI). Neither imaging modality offers the ability to intervene intraoperatively. The 3-dimensional (3D) C-arm provides an attractive alternative providing immediate intraoperative feedback on the quality of a hip reduction. Our primary research question was to determine whether 3D fluoroscopy could assess hip position after closed reduction and spica casting. Secondary questions included whether reduction was maintained postoperatively when compared with postoperative MRI, and to determine the radiation dose received by the infant.

METHODS

We retrospectively identified 16 patients from 2010 to 2013 who underwent closed reduction and spica casting for a developmentally dislocated hip who underwent both intraoperative 3D fluoroscopy and postoperative MRI imaging. Scans were retrieved and assessed by a blinded pediatric orthopaedic fellow. Assessment of hip reduction was graded based on the modified Shenton line of the pelvis in axial plane images. Effective radiation doses between imaging modalities were compared using an anthropomorphic phantom.

RESULTS

All hips were reduced on 3D fluoroscopic images. Comparing the intraoperative 3D scans with the postoperative MRI images all 16 hips were in the same position. At 12 weeks all hips were reduced and no signs of subluxation were identified on the plain anteroposterior radiograph. 3D fluoroscopy achieved the lowest effective dose of radiation per study measuring 0.3 mSv compared with 0.5 mSv for low-dose CT and 0.48 mSv for 60 seconds of live fluoroscopy.

CONCLUSIONS

Accurate assessment of the quality of hip reduction is possible in the axial plane using 3D fluoroscopy with no significant loss of reduction in the early postoperative period. When comparing the effective radiation exposure to limited-cut computed tomography protocols, 3D fluoroscopy offers a low-dose alternative that may facilitate cost savings and early discharge.

LEVEL OF EVIDENCE

Diagnostic studies-investigating a diagnostic test; study of nonconsecutive patients with consistently applied gold standard; level III.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Do normal hips dislocate?

There have been a small number of case reports describing late normal-hip dislocations in children who were later diagnosed with developmental dysplasia of the hip. Here, we contest the assumption that normal hips can dislocate. We argue that (as in our case) the ultrasound scans in all published case reports on late dislocated normal hips did not show results that were entirely normal and therefore, so far, there has been no convincing evidence of a dislocation of a normal hip. We also want to highlight the importance of meticulous ultrasound and clinical assessments of high-risk children by an experienced orthopaedic surgeon.

Natural history of hip instability in infants (without subluxation or dislocation): a three year follow-up

BACKGROUND

The natural history of hip instability (without subluxation or dislocation) and treatment in infants remain controversial. We performed a retrospective cohort case-only study with blinded, prospectively collected data to assess normalization of the acetabular index in consecutive untreated infant hips with sonography instability.

METHODS

Consecutive hips meeting inclusion criteria were followed by sonography/radiography and data analyzed using tabular and regression models.

RESULTS

In 48 hips, acetabular index measured by radiography normalized within 3 years of age without treatment. Normalization by age occurred: 7 months in 35%, 12 months in 67%, 18 months in 75%, 24 months in 81%, and 36 months in 100%. Two patterns of normalization of the acetabular index were observed: group I showed ossification in a physiological range of normal by 7 months of age, and group II had delayed ossification with later normalization of the acetabular index measurement. Breech presentation (p =0.013) and cesarean delivery (p =0.004) statistically directly correlated with a later normalization.

CONCLUSIONS

The natural history of infant hip instability (without subluxation or dislocation), which is reduced at rest and unstable with stress as diagnosed by the Harcke method of sonography, has spontaneous normalization of the acetabular index within 3 years of age. We suggest three patterns of acetabular ossification in unstable infants' hips: (I) normal ossification, (II) delayed ossification with normalization of the acetabular index by age 3 years, and (III) defective secondary centers of ossification with an upward tilt of the lateral acetabular rim in adolescence.