Real-time ultrasound in the diagnosis of congenital dislocation and dysplasia of the hip

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.

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.

Concentric Circles: A New Ultrasonographic Sign for the Diagnosis of Normal Infantile Hip Development

Ultrasound (US) of the infant hip is used to diagnose developmental dysplasia of the hip (DDH). We present a new sonographic sign that describes the periphery of the femoral head and the acetabulum as two concentric circles.During 2008−2019, 3650 infants were referred for diagnosis of DDH. All underwent a clinical and US examination. We recorded the femoral head as the inner circle, within a fixed external circle, which was identified as the acetabulum. We analysed the clinical signs and risk factors. The US sign of two concentric circles was normal in 3522 infants and was classified as normal hip development. The alpha angle was >60° in 3449 (95%) infants. For the remaining 73 (5%) infants, the alpha angle was 50−60° and underwent further follow-up examination until the alpha angle was normalised. In 128 babies (3.5%), we detected the disruption of the concentric circle sign; the femoral head was found outside the acetabulum, which appeared with an upward sloping roof and the alpha angle was <50°. These infants had DDH and received appropriate treatment. Infants with a concentric circle sign and normal alpha angle are normal, whereas those with a disrupted sign are considered as having DDH.

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.

Developmental disorders of the hip treated at the Clinic for Orthopaedic Diseases – in a period of 10 years (2009-2018)

Developmental hip dysplasia includes a wide range of conditions such as subluxation, dislocation, hip instability, and teratological hip. The diagnosis  was confirmed by clinical examination, ultrasound  examination and anterior-posterior view radiograph  (AP). Treatment  varied  depending on the patient's age and the degree of dysplasia: Pavlik harness, closed reduction, open reduction  and corrective osteotomies. In this  study 242 patients were included, of whom  198 were female  patients and 44 male. All of the patients were treated with conservative treatment- closed reducation and spica casting. Left-sided dislocations were  more common than right sided dislocations with predominance in the female patients. The main treatment in follow-up patients was closed reduction with or without adductor muscle tenotomy   (m. add. longus). In cases with  unsuccessful attempt  of closed reduction, open reduction  was performed with or without adductor muscle tenotomy. Depending on the residual dysplasia, patients were additionally treated with pelvic osteotomies    (Salter 's inominate  osteotomy), varus derotation osteotomy, valgus osteotomy, proximal femoral resection, and  trochanter major  transposition. 167 patients were treated with closed reduction  and 3 with open reduction. The remaining patients were treated with closed reduction and additional surgery or with open reduction and additional surgery. Out of all treated patients, only 10 patients had recurrent dislocation of the hip, 7 female and 3 male patients. Closed reduction was performed again on two patients, and open reduction of the hip was performed on one patient. The average  age  of  patients was  21.5 months. By presenting the cases in a period of 10 years, it was conclud  that most  cases were  diagnosed later. Also, the standard closed reduction treatment  was successful even after the first year in said  patients. Depending on the residual dysplasia of the hip, in order to achieve better congruence of the joint, additional surgeries were  performed.

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.

What is the Interobserver Reliability of an Ultrasound-enhanced Physical Examination of the Hip in Infants? A Prospective Study on the Ease of Acquiring Skills to Diagnose Hip Dysplasia

BACKGROUND

Developmental dysplasia of the hip (DDH) is the most common disorder found in newborns. The consequences of DDH can be mitigated with early diagnosis and nonoperative treatment, but existing approaches do not address the current training deficit in making an early diagnosis.

QUESTION/PURPOSE

Can ultrasound be taught to and used reliably by different providers to identify DDH in neonates?

METHODS

This was a prospective observational study of a series of neonates referred for an evaluation of their hips. An experienced clinician trained three second examiners (a pediatric orthopaedic surgeon, an orthopaedic resident, and a pediatrician) in performing an ultrasound-enhanced physical examination. The 2-hour training process included video and clinical didactic sessions aimed to teach examiners to differentiate between stable and unstable hips in newborns using ultrasound. The experienced clinician was a pediatric orthopaedic surgeon who uses ultrasound regularly in clinical practice. Materials required for training include one ultrasound device. A total of 227 infants (454 hips) were examined by one of the three second examiners and the experienced clinician (gold standard) to assess reliability. Of the 454 hips reviewed, there were 18 dislocations, 24 unstable hips, and 63 dysplastic hips, and the remainder had normal findings. The cohort was composed of a series of patients younger than 6 months referred to a specialty pediatric orthopaedic practice.

RESULTS

Ultrasound-enhanced physical examination of the hip was easily taught, and the results were reliable among different levels of providers. The intraclass correlation coefficient between the gold-standard examiner and the other examiners for all hips was 0.915 (p = 0.001). When adjusting for only the binary outcome of normal versus abnormal hips, the intraclass correlation coefficient was 0.97 (p = 0.001). Thus, the agreement between learners and the experienced examiner was very high after learners completed the course.

CONCLUSION

After a 2-hour course, physicians were able to understand and reliably examine neonatal children using ultrasound to assess for DDH. The success of the didactic approach outlined in this study supports the need for ultrasound-enhanced examination training for the diagnosis of DDH in orthopaedic surgery and pediatric residency core curriculums. Training programs would best be supported through established residency programs. Expansion of training more residents in the use of ultrasound-enhanced physical examinations would require a study to determine its efficacy. This finding highlights the need for further research in implementing ultrasound-enhanced physical examinations on a broader scale.

LEVEL OF EVIDENCE

Level II, diagnostic study.

Screening of Newborns and Infants for Developmental Dysplasia of the Hip: A Systematic Review

BACKGROUND

Developmental dysplasia of hip (DDH) is a common disorder of childhood and has a good prognosis when treated at an early age. In spite of being a significant concern, many children with DDH are not picked early and present late at walking age. In our country, it is presumed to be due to absence of a national policy for screening of DDH. Screening programmes including the combination of clinical and radiological methods in different ways have been suggested. However, the exact method of screening is controversial.

PURPOSE

To analyze effectiveness and cost-effectiveness of various screening methods for DDH.

STUDY DESIGN

Systematic review.

METHODS

This review was conducted in accordance with PRISMA guidelines. Medline database was explored for original case series and randomized clinical trials. Inclusion criteria were English language, screening for DDH in neonates, sample size more than 500, and studies with minimum duration of one year.

RESULTS

Thirty-four studies were selected to write the manuscript. This included 23 studies looking for effectiveness of a screening programme and 11 studies comparing various outcomes of different screening strategies. A trend favoring universal ultrasound screening was observed.

CONCLUSION

The literature supports universal ultrasound screening and has proved its cost-effectiveness. However, considering the logistic and financial challenges in our country, immediate implementation of universal ultrasound screening seems impractical. In the absence of any current guidelines for screening for DDH in India, we suggest professional organizations involved in the care of children and public health policy-makers to come together to develop national screening guidelines for DDH.

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.

Neonatal hip ultrasound: tangent to lateral roof angle correlates better with stability than alpha angle according to Graf or percentage femoral head coverage

The aim of this study was to determine the relationship of tangent to the lateral roof angle (TLRA), Graf's alpha angle and percentage femoral head cover (PHC) and to observed stability, and to establish intraobserver and interobserver errors for measurement of alpha angle and TLRA. In total, 2235 babies referred to the hip review clinic over a period of 8  years. Intraobserver and interobserver errors were calculated from readings of 383 hip images by an experienced paediatric radiologist and a trainee. Taking TLRA <70° as abnormal resulted in sensitivity for unstable right hips of 88% compared with 77% for alpha angle <60° (P  =  0.002) and 81% for PHC <60% (P  =  0.028) and specificity of TLRA 89%, alpha angle 90% (P  =  0.07) and PHC 83% (P  <  0.001). Corresponding figures for left hips are sensitivity of TLRA 99%, alpha angle 91% (P  <  0.001) and PHC 96% (P  =  0.013), and specificity TLRA 86%, alpha angle 83% (P  =  0.001) and PHC 67% (P  <  0.001). Mean intraobserver errors for alpha angle were 1.85° and 1.81° for consultant and trainee compared to 2.54 and 2.55 for TLRA. Mean interobserver errors were 2.22 for alpha angle and 3.42 for TLRA. TLRA, a new parameter, correlated better with observed stability with significant improvement in sensitivity in both hips and specificity in left hips compared with Graf's alpha angle, and significantly improved sensitivity and specificity in both hips compared with percentage femoral head cover.

Pavlik harness and Frejka pillow: compliance affects results of outpatient treatment

PURPOSE OF THE STUDY

Outpatient treatment of hip dysplasia in newborns has excellent results. A combination of general screening with early treatment with a functional abduction device works well. Treatment with the Frejka pillow and the Pavlik harness is frequently used in our region. The aim of the study is to compare efficiency and treatment duration, related to the brace used, and to prove that the choice of an abduction device implies parental compliance with the treatment protocol.

MATERIALS AND METHODS

Data of 286 treated children were analyzed. The diagnosis was made in the first weeks of life by clinical and sonographic examinations during general screening. The choice of treatment device was expert dependent and was involved by many variables. The experience, type of clinical finding and sonographic pathology according to Graf, availability of a treating facility, and the potential cooperation of individual parents were major parameters. The Frejka pillow was used to treat 145 children and the Pavlik harness was used in 137 children. The treatment duration and percentage of infants lost from follow-up in relation to the device used was documented.

RESULTS

The success rate of outpatient treatment was 98.6%. In six patients, the type of device had to be changed during the treatment period. Physiological sonographic findings were achieved in all hips by the end of the treatment. The Frejka pillow was used as the preferred device in milder stable dysplastic hips, while unstable and decentered hips were treated more frequently with the Pavlik harness. Treatment lasted, on average, 95 days and 119 days in the Frejka and in the Pavlik group, respectively; there was no statistical significance in treatment duration of comparable sonographic pathologies. We observed statistically greater parental non-compliance with the treatment protocol in the Pavlik harness group (p = 0.0279; OR 2.7; 95% CI 1.07; 8.5).

CONCLUSIONS

Neither of the abduction devices was inferior with regard to treatment efficiency. We found that parental cooperation was an important factor during screening and treatment. The treatment decision and the choice of the brace must be made with full consent of the parents, keeping in mind that comfort during the nursing care may have a significant influence on compliance with the treatment protocol.

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.

Diagnosis and treatment of developmental dysplasia of the hip: A current practice of paediatric orthopaedic surgeons

BACKGROUND

Developmental dysplasia of the hip (DDH) is one of the prevalent musculoskeletal conditions in young adults and is a leading cause of hip osteoarthrosis in this age group. The optimum age for surgical intervention when needed is not well established in the literature and the lack of management guidelines and standard practice of DDH leads to different practices worldwide. This study aims to investigate the current practice of paediatric orthopaedic surgeons in diagnosing and treating DDH worldwide and identify points of agreement and disagreement.

METHODS

A cross-sectional study utilizing an online questionnaire was designed to examine the different points of view and current practice of paediatric orthopaedic surgeons worldwide regarding DDH diagnosis and treatment.

RESULTS

Ninety-one surgeons responded, with an overall response of 45.5%. The vast majority of respondents use ultrasonography in children less than 3 months of age and pelvic radiography in over 3 months to diagnose DDH. Pavlik harness is the most popular DDH treatment for children younger than 6 months. For older children, closed reduction with hip spica cast is the most preferable treatment. The maximum duration of first-line treatment has a broad range. The treatment of bilateral DDH varies widely among surgeons.

CONCLUSION

This study shows clearly that paediatric orthopaedic surgeons do not agree on the diagnosis and treatment protocol of DDH, hence different approaches to this common disease are practised. The lack of an international guideline should motivate paediatric orthopaedic surgeons to discuss and formulate a uniform and evidence-based protocol for the diagnosis and treatment of DDH.

Changes in femoral head size and growth rate in young children with severe developmental dysplasia of the hip

BACKGROUND

Developmental dysplasia of the hip (DDH) is known to result in smaller femoral head size in toddlers; however, alterations in femoral head size and growth have not been documented in infants.

OBJECTIVE

To determine with ultrasound (US) whether femoral head size and growth are altered in infants (younger than 1 year of age) with severe DDH.

MATERIALS AND METHODS

We identified all patients at our tertiary care children's hospital from 2002 to 2014 who underwent US for DDH. We included studies with at least one hip with severe DDH, defined as <25% coverage of the femoral head, and excluded teratological DDH. We constructed a control group of randomized patients with normal US studies. Two pediatric radiologists blinded to diagnosis measured bilateral femoral head diameter. Inter-reader variability and femoral head diameter difference between dislocated and contralateral normal femoral heads were evaluated. Mean femoral head diameters were compared across types of hip joint; femoral head growth rates per month were calculated.

RESULTS

Thirty-seven children with DDH (28 female) were identified (median age: 33 days). The control group contained 75 children (47 female) with a median age of 47 days. Fifty-three of the 74 hips in the study group had severe DDH. Twenty-four children with DDH had completely dislocated hips (nine bilateral, five with contralateral severe subluxations). Thirteen other children had severe subluxation, two bilaterally. There was good inter-reader agreement in the normal femoral head group and moderate agreement in the severe DDH group. In the study group, severe DDH femoral head diameter was significantly smaller than their contralateral normal hip. Severe DDH femoral head diameter was significantly smaller than normal femoral head diameter in the control group. The severe DDH femoral head growth rate was slightly less but not significantly slower than normal femoral head growth rate in the study group.

CONCLUSION

On US during infancy, femoral head size is significantly reduced in severe cases of DDH.

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.

Congenital Dislocation or Developmental Dysplasia of the newborn hip?

The role of universal primary ultrasound screening for detection of developmental dysplasia of the hip of the newborn remains controversial in Britain. Two infants in whom ultrasonography was reported to show no evidence of developmental dysplasia in the newborn period, but who later presented with acetabular dysplasia and subluxation requiring surgery, are presented.

Effect of increase in birth weight in a newborn on hip ultrasonography

Exposure to the pressure experienced by higher birth weight babies during the intrauterine period might cause hip dysplasia. The aim of this study is to determine the effect of birth weight in newborns on hip ultrasonography when the paternal and maternal risk factors are excluded. A total of 701 babies born at 38-42 gestational weeks were included in the study. Hip ultrasonography was performed within 7 days following birth using the Graf technique in the babies without risk factors for developmental dysplasia of the hip. Images obtained were controlled with respect to conformity to the Graf method and angular measurements were performed. According to the α and β angle values obtained, type 1A and 1B hips were categorized as mature; type 2A hips were categorized as immature; and type 2C, D, 3A, 3B, and 4 hips were categorized as pathological hips. The results obtained were analyzed for the effect of birth weight on the angular values and hip typing. The birth weight of the babies was 338,488 ± 48,241 g (2030-6124 g). It was determined that the birth weight had no effect on the values of α and β angles in the male babies (P=0.21, 0.76). It was determined that increasing birth weight decreased the α angle value (P=0.001) and caused no difference in the β angle value (P=0.057) in the female babies. It was found that birth weight had no effect on hip typing in both female and male babies (P=0.060, 0.22). Increases in birth weights caused decreases in ultrasonographic α angles only in female babies.

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

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

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

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

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

Is congenital talipes equinovarus a risk factor for pathological dysplasia of the hip? : a 21-year prospective, longitudinal observational study

There is controversy whether congenital foot abnormalities are true risk factors for pathological dysplasia of the hip. Previous United Kingdom screening guidelines considered congenital talipes equinovarus (CTEV) to be a risk factor for hip dysplasia, but present guidelines do not. We assessed the potential relationship between pathological dysplasia of the hip and fixed idiopathic CTEV. We present a single-centre 21-year prospective longitudinal observational study. All fixed idiopathic CTEV cases were classified (Harrold and Walker Types 1 to 3) and the hips clinically and sonographically assessed. Sonographic Graf Type III, IV and radiological irreducible hip dislocation were considered to be pathological hip dysplasia. Over 21 years there were 139 children with 199 cases of fixed idiopathic CTEV feet. Sonographically, there were 259 normal hips, 18 Graf Type II hips, 1 Graf Type III hip and 0 Graf Type IV hip. There were no cases of radiological or sonographic irreducible hip dislocation. Fixed idiopathic CTEV should not be considered as a significant risk factor for pathological hip dysplasia. This conclusion is in keeping with the current newborn and infant physical examination guidelines in which the only risk factors routinely screened are family history and breech presentation. Our findings suggest CTEV should not be considered a significant risk factor in pathological dysplasia of the hip.

The "ischial limb": a landmark on anterior ultrasound scanning used to assess reduction in developmental dysplasia of the hip

BACKGROUND

Early recognition of failure of reduction during abduction splinting in developmental dysplasia of the hip (DDH) is essential to avoid inappropriate prolonged damaging harness use. Graf ultrasound scanning (USS) is an accepted gold standard for assessing neonatal hip dysplasia but cannot verify reduction in the abducted position of a neonatal hip in a Pavlik harness. We describe a new anatomic landmark of the hip using anterior USS-the "ischial limb," correlate this to the position of the femoral head in reduced and dislocated positions, and assess the application of this in the assessment of DDH.

METHODS

A porcine model was used to identify anatomic, radiologic, and ultrasonic features comparable to the human neonatal hip. A pilot clinical study was conducted of 50 neonates (11M:39F) treated for DDH in Pavlik harness, utilizing weekly anterior USS to determine the concentricity of femoral head reduction relative to the ischial limb and whether this could identify any failures to achieve reduction.

RESULTS

The animal model identified an ultrasound landmark, termed the ischial limb that represents the ossification zone of the ischial contribution to the tri-radiate acetabular cartilage, and approximates to the center of the acetabulum. Anterior USS clearly demonstrated this ischial limb in clinical practice and its relation to the femoral head in all dysplastic hips (n=79). Immediate concentric reduction was observed in 11 patients, more gradual reduction over 3 weeks in 37 patients, and failure to achieve stable reduction was verified in 2 patients. The technique was reproducible in 100% of patients (n=50). Mean additional clinic time was 5 minutes per visit.

CONCLUSIONS

The ischial limb, identified on anterior hip USS, delineates the position of the tri-radiate cartilage. This technique efficiently assesses hip reduction during Pavlik harness treatment and can differentiate between failure to achieve reduction or maintain a stable reduction at an earlier stage than conventional US methods.

LEVEL OF EVIDENCE

Development of diagnostic criteria on basis of consecutive patients: level 2 evidence.

Verification of hip reduction using anterior ultrasound scanning during Pavlik harness treatment of developmental dysplasia of the hip

AIM

Ultrasound scanning (USS) is used for diagnosis and surveillance in developmental dysplasia of the hip (DDH). Lateral coronal scanning is performed with the hip flexed, in neutral adduction. In this position an unstable hip may dislocate, failing to demonstrate a reducible hip, leading to abandonment of harness treatment. Anterior ultrasound permits imaging of the flexed abducted hip in harness. This study evaluates the role of anterior & lateral USS in determining duration of treatment and reduction in DDH.

METHOD

Between 1997 & 2010, 233 patients requiring harness treatment received lateral USS, with dislocated & dysplastic hips re-imaged fortnightly. From 2005, anterior USS was used additionally to assess reduction in harness.

RESULTS

One-hundred and eighteen patients (167 hips) received lateral USS, 115 (160 hips) received both. In the lateral cohort, 103 (140 hips) were treated successfully, mean duration 66.2 days (95% CI 60.2-72.1), with 15 (26 hips) failures (15.5%), mean 30 (CI 95% 19.3-40.6). In the anterior cohort, 107 (150 hips) were treated successfully, mean 53.3 (95% CI 49.8-56.7), with 8 (10 hips) failures (6.25%), mean 35.3 (CI 95% 25.5-44.9). Children receiving an anterior USS had a shorter duration of treatment (p = 0.011) and no difference in failures (p = 0.21).

CONCLUSIONS

A reduced duration of treatment for Graf 3 hips was observed. Anterior ultrasound allows earlier recognition of hips that fail to stabilize, via two observed modes of failure; failure of hip reduction and failure to stabilize after reduction.

Use of ultrasonography in developmental dysplasia of the hip

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Musculoskeletal screening: developmental dysplasia of the hip

Developmental dysplasia of the hip (DDH) is common because it is present in 1 of 100 newborns. Failure to diagnose DDH and treat in infancy can result in significant long-term disability. Early diagnosis can be accomplished through a quick but careful physical examination of all newborns. Further selective screening by ultrasound is indicated for those children with risk factors for DDH, which include family history, breech presentation, and unstable hip examination at the initial newborn examination. Continued examination of the hip at all routine well-child checkups is mandatory through the first year of life because late presenting DDH may occur. Treatment with a Pavlik harness is not typically instituted in the neonate because many unstable hips stabilize without intervention, but it is indicated in children older than 2 weeks with hip instability. Ultrasound screening for infants with risk factors for DDH is recommended at age 6 weeks. Pavlik harness treatment for children with unstable hips or significant dysplasia on ultrasound is continued until the hips stabilize and show concentric reduction on imaging. With time, diagnosis and treatment evolve to accommodate the growing child. Infants who fail to respond to nonoperative management may require more extensive interventions. At any time when treatment is initiated, a DDH specialist should be involved in the patient's care. If DDH is recognized early, treatment is less invasive, and long-term effects are minimized.

Strategies to improve nonoperative childhood management

Early diagnosis is of paramount importance to favorably alter the natural history of DDH. Most cases of dysplasia can be diagnosed by careful history taking and physical examination. Imaging modalities, such as ultrasonography, have increased our ability to detect subtleties not appreciated by means of physical examination or plain radiography. Although the evaluation of children with risk factors for DDH is important, most dysplasia occurs in girls who have no other risk factors. For all infants, a competent newborn physical examination using the Ortolani maneuver is the most useful procedure to detect hip instability. Early treatment of an unstable hip with a Pavlik harness or similarly effective orthosis is effective, safe, and strongly advised.

Screening for developmental dysplasia of the hip in Hong Kong

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

The relationship between mode of delivery and developmental dysplasia of the hip in breech infants

This prospective cohort study aimed to investigate the relationship between developmental dysplasia of the hip and mode of delivery in 571 consecutive breech infants using a modified Graf’s static morphological method to grade the severity of dysplasia.

In this group, 262 infants were born by planned Caesarian section, 223 by emergency section and 86 vaginally. Taking all grades of hip dysplasia into account (Graf types II, III and IV), there was no statistical difference in the incidence of dysplasia between the groups (elective section 8.4%, emergency section 8.1% and vaginal delivery 7.0%). However, when cases with Graf type II dysplasia, which may represent physiological immaturity, were excluded, the rate of type III and IV hips, which we consider to be clinically relevant, increased in the vaginally delivered group (4.7%) compared with the elective section group (1.1%), with a relative risk of approximately 1:4 (95% confidence interval 1.03 to 15.91). No difference was observed between the emergency and elective section groups, or between the emergency section and vaginally delivered groups.

This study supports previous published work, with the added value that the diagnoses were all confirmed by ultrasound.

Is ultrasound screening for DDH in babies born breech sufficient?

PURPOSE

To review our incidence of developmental dysplasia of the hip (DDH) in breech infants referred for ultrasound screening and to determine if subsequent follow-up radiographs are necessary in these patients with normal clinical and ultrasound examinations.

METHODS

A review of the clinical data and imaging studies of all children with the risk factor of breech presentation that were referred for orthopedic evaluation over a 5-year period was conducted. All patients were examined by a fellowship-trained pediatric orthopedic surgeon and all ultrasounds were done at approximately 6 weeks of age by an experienced ultrasonographer. Ultrasounds were evaluated using the dynamic method as described by Harcke. As per our protocol, all patients with normal screening ultrasounds were brought back for a final clinical examination and radiographic check at 4-6 months. Acetabular dysplasia was indicated by radiographic parameters-if there was severe blunting of the sourcil, abnormal acetabular index for age, or if there was significant asymmetry of acetabular indices side-to-side-in the setting of clinical parameters-if there was greater than 10° difference in side-to-side abduction or symmetric abduction of less than 60°.

RESULTS

Three hundred patients with the risk factor of breech presentation were included. Thirty-four patients had clinically unstable hips; 266 had clinically stable hips and were screened by ultrasound. Sixty-four percent were female and 36% were male. Twenty-seven percent of these breech patients had abnormal screening ultrasounds and were subsequently treated. Of the remaining 73% with normal ultrasounds, who were returned per protocol at a mean of 5 months, 29% had evidence of dysplasia and underwent treatment. The diagnosis of dysplasia following a normal ultrasound was based on both radiographic and clinical parameters. Of the hips treated with a Pavlik harness, 62% had acetabular indices at least two standard deviations from the age-corrected average versus 26% of patients not treated. The average length of follow-up was 10 months.

CONCLUSIONS

Retrospectively, we found that, at approximately 6 weeks of age, ultrasound screening of breech patients with clinically stable hips produces an incidence of DDH of 27%. In those patients with a normal ultrasound, 29%, at 4-6 months radiographic follow-up, were found to have dysplasia requiring treatment. This data supports breech as the most important risk factor for hip dysplasia and we, therefore, recommend careful and longitudinal evaluation of these patients with: a careful newborn physical examination, an ultrasound at age 6 weeks, and an anteroposterior (AP) pelvis and frog lateral radiograph at 6 months, as the risk of subsequent dysplasia is too high to discharge patients after a normal ultrasound.

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

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

Neonatal foot deformities and their relationship to developmental dysplasia of the hip

In a prospective study over 11 years we assessed the relationship between neonatal deformities of the foot and the presence of ultrasonographic developmental dysplasia of the hip (DDH). Between 1 January 1996 and 31 December 2006, 614 infants with deformities of the foot were referred for clinical and ultrasonographic evaluation. There were 436 cases of postural talipes equinovarus deformity (TEV), 60 of fixed congenital talipes equinovarus (CTEV), 93 of congenital talipes calcaneovalgus (CTCV) and 25 of metatarsus adductus.

The overall risk of ultrasonographic dysplasia or instability was 1:27 in postural TEV, 1:8.6 in CTEV, 1:5.2 in CTCV and 1:25 in metatarsus adductus.

The risk of type-IV instability of the hip or irreducible dislocation was 1:436 (0.2%) in postural TEV, 1:15.4 (6.5%) in CTCV and 1:25 (4%) in metatarsus adductus. There were no cases of hip instability (type IV) or of irreducible dislocation in the CTEV group.

Routine screening for DDH in cases of postural TEV and CTEV is no longer advocated. The former is poorly defined, leading to the over-diagnosis of a possibly spurious condition. Ultrasonographic imaging and surveillance of hips in infants with CTCV and possibly those with metatarsus adductus should continue.

A reappraisal of the Ortolani examination in children with developmental dysplasia of the hip

The Ortolani maneuver is currently accepted as an accurate test to detect developmental dislocation of the hip. However, the clinical sign does not always correlate with the findings seen on ultrasound. The ultrasound-documented position of the femoral head was correlated with the result of the clinical Ortolani examination to better understand the value and validity of the Ortolani test. Two populations were compared: hips with a positive Ortolani sign and hips with a negative Ortolani sign but with an ultrasound-documented dislocated hip. In the Ortolani-positive group, there were 45 patients (53 affected hips), and in the Ortolani-negative group, there were 24 patients (25 dislocated hips). Position of the femoral head at rest, side of involvement, and sex showed no significant difference between the Ortolani-positive and -negative groups. Mean age of patients in the Ortolani-positive group was less (mean, 28 days) and was statistically different (P < 0.05) from those in the Ortolani-negative group (mean, 91 days). In conclusion, dislocated hips that show similar femoral head movement can produce an Ortolani-positive examination in a younger patient and an Ortolani-negative examination in an older patient. The classic clinical method described by Ortolani for detecting hip dislocation in which the thigh of the affected hip is abducted and the femoral head was thought to be reducing into the acetabulum can be erroneous. All Ortolani-positive hips were abnormal, as the sensation characteristic of a positive Ortolani examination may be felt without full reduction and, in some cases, with no reduction, as documented by ultrasound.

Ultrasound screening in developmental hip dysplasia: do all scanned hips need to be followed up?

Many ways of detecting hip instability in the newborn infant exist, including a history of risk factors, clinical examination and ultrasound. We investigated our practice of 'at risk' screening using subjective, dynamic and static, ultrasound, followed by radiographic evaluation at 12 months. We found that the average age at presentation was 71 days, with the most common reason for referral being a clicking hip. None of the hips deemed stable under review deteriorated, and all those considered normal at first visit had a normal radiograph at 12 months. Abnormal radiographs were found in all the other groups.

Ultrasound measurements in the management of unstable hips treated with the pavlik harness: reliability and correlation with outcome

The purposes of this study were to determine the interobserver and intraobserver reliability of ultrasound measurements in unstable neonatal hips treated with the Pavlik harness and to determine whether ultrasound measurements correlate with radiological outcome at 6 months. Sixty-four babies treated from birth with the Pavlik harness for neonatal hip instability were scanned at 2 and 6 weeks. The alpha and beta angles of Graf, the combined (H) angle of Hosny, and the femoral head coverage (FHC) were measured by 3 observers and remeasured by each observer on a minimum of 50 scans. From 248 scans, 792 sets of measurements were made. Hips were categorized as normal, abnormal, or borderline for each parameter; and interobserver and intraobserver repeatability coefficients and Kappa values were calculated. The alpha angle had the smallest interobserver range (17 degrees), the H angle range was 21 degrees, and the beta angle 28 degrees. Kappa values were best for the FHC and beta angle (0.66-0.8). The mean acetabular index (AI) of all hips at 6 months was 26 degrees (SD, 4.9). The AI was 30 degrees or greater in 24 hips (18 babies) despite prolonged splintage in 9 hips (6 babies). A stepwise linear regression analysis showed that the FHC at 6 weeks was predictive of AI at 6 months (regression coefficient -0.27; 95% confidence interval -0.42 to -0.12; P<0.001). We recommend the FHC as being reproducible, useful, and predictive of outcome in neonatal hips treated for instability.

The significance of at-risk factors in ultrasound surveillance of developmental dysplasia of the hip. A ten-year prospective study

Of the 34,723 infants born between 1 June 1992 and 31 May 2002, the hips of 2578 with clinical instability or at-risk factors for developmental dysplasia of the hip were imaged by ultrasound. Instability of the hip was present in 77 patients, of whom only 24 (31.2%) had an associated risk factor. From the 'at-risk' groups, the overall risk of type-III dysplasia, instability and irreducibility was 1:15 when family history, 1:27 when breech delivery and 1:33 when foot deformity were considered as risk factors. Of those hips which were ultrasonographically stable, 88 had type-III dysplasia. A national programme of selective ultrasound screening of at-risk factors for the diagnosis of hip dislocation or instability alone cannot be recommended because of its low predictive value (1:88). However, the incidence of type-III dysplasia and hip dislocation or dislocatability in the groups with clinical instability, family history, breech position and possibly postural foot deformity as risk factors could justify a programme of selective ultrasound imaging.

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

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

Imaging methods used for children with hip dysplasia

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

Longitudinal study of normal hip development by ultrasound

In the management of a newborn's hips, ultrasonography has proven to be useful. The progression of measurements at different ages in normal hips has not been thoroughly investigated. The purpose of this prospective study was to assess the longitudinal development of clinically stable hips. Forty newborns (80 hips) were assessed by ultrasonography at birth and at 6 and 12 weeks of age. Femoral head coverage (FHC), alpha angles, and beta angles were measured. The results showed a significant change in values between the three points in time for all measurements (P < 0.001). The mean FHC progressed from 58.4% to 65.6% to 69.3%, the mean alpha angle from 70.2 degrees to 76.8 degrees to 80.3 degrees , and the mean beta angle from 52.1 degrees to 45.7 degrees to 42.9 degrees . In clinically stable hips, the FHC and alpha and beta angles change significantly over time; therefore, it is important to consider the child's age when interpreting ultrasound images.

Instability of the neonatal hip: the role of early or late splintage

From January 1992 to December 1997, 59 dislocatable hips (37 children), confirmed by ultrasound, were splinted by Pavlik bracing within 2 weeks of birth. The majority were splinted within 1 week. From January 1998 to December 1999, 16 dislocatable hips (11 children) were evaluated by ultrasound and were not initially splinted but were followed up by serial ultrasound. They were splinted if they did not spontaneously stabilise on ultrasound. None of those patients treated by immediate splintage between 1992 and 1997 have subsequently required surgical intervention. Two of the infants treated between 1998 and 1999 (12% of the hips) later required a surgical procedure on the hip joint or proximal femur (p=0.049, Fisher's exact test). Nine out of 16 hips required splintage at a later date. We would not advocate delayed observation by ultrasound of unstable hips after 2 weeks of age. A clinically unstable hip should be assessed by ultrasound within 2 weeks of birth. If it is unstable on ultrasound, it should be splinted for 6 weeks. There is no need to wean off the splint.

Comparison of three distraction methods and conventional radiography for early diagnosis of canine hip dysplasia

Two radiographic distraction techniques (one employing a wooden lath and, the other, a PennHip distractor), an ultrasonographic distraction method and conventional radiographic Fédération Cynologique Internationale (FCI) hip score were evaluated in eight-month-old Labrador retrievers to determine the most reliable method for predicting radiographic FCI hip score at the age of one year. With reference to the FCI hip score, sensitivity and specificity of the PennHip method were 100 per cent and 54 per cent; sensitivity and specificity of the lath technique were 85 per cent and 71 per cent; whereas they were 62 per cent and 67 per cent for the ultrasonographic method. For all distraction methods, the positive predictive value (PPV) was moderate and the negative predictive value (NPV) was high. Sensitivity, specificity, PPV and NPV were 100 per cent for the FCI hip score. It is concluded that, at the age of eight months, FCI hip score is the most reliable method for predicting FCI hip score at the age of one year in the colony of dogs investigated. Both the PennHip and lath method were also clinically reliable techniques in predicting true negatives. The ultrasonographic distraction method was moderately reliable.

Neonatal hip screening

CONTEXT

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

STARTING POINT

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

WHERE NEXT

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

Review article: diagnostic ultrasonography: applications in orthopaedic surgery

Diagnostic ultrasonography of musculoskeletal diseases in the United States has been used most often for detection of rotator cuff tears or developmental dysplasia of the hip. Diagnostic ultrasonography also is useful in imaging the periarticular soft tissues about the knee, hip, ankle, occult pediatric fractures, muscle injury, bone healing, and foreign bodies. Recent technologic improvements have made this imaging modality increasingly more accurate while providing significant benefits over traditional modalities such as magnetic resonance imaging, particularly regarding cost, patient satisfaction, and ease of usage. Increasing use in the future of diagnostic ultrasonography for musculoskeletal conditions is likely as acceptance grows. This review focuses on recent, practical applications of diagnostic ultrasonography of the musculoskeletal system.

Ultrasonography of the infant hip: the significance of provokable instability with normal morphology

The hips of infants 2- to 4-weeks-old were investigated with ultrasonography. In all cases, ultrasonography verified morphologically normal hips; however, either a bilateral or unilateral instability of the hip could be provoked as demonstrated by ultrasonography. The first series of 27 infants (41 hips) were treated with abduction splint (Frejkas pillow) for 16 weeks. The second series of 28 infants (44 hips) were left untreated. All infants had repeat ultrasonography at 2 and 16 weeks and radiographs at 16 weeks. At 2 weeks, provokable instability was still seen in 10 hips in the treated group and 12 hips in the untreated group. At 16 weeks, all hips were ultrasonographically stable. The morphology was evaluated by alpha and beta angles by ultrasonography and also acetabular index by radiographs at 16 weeks. In all cases, normal hip development was noted with no differences between the two groups. Therefore, sonographically, instability in morphologically normal or immature hips has no clinical significance.

Ultrasound screening of the infant's hip: introduction of a new combined angle

This study evaluates the most widely used sonographic measurements for judging an infant's hip morphology. The alpha and beta angles of Graf, the bony coverage percentage of Morin and a new combined angle were analysed. This latter angle records the direction of the whole acetabulum (cartilagenous and bony) as one unit. One-hundred sonograms were examined independently by two observers to calculate the interobserver and intraobserver limits of agreement. The new combined angle proved to be the most reproducible measurement. Graf's alpha angle was the second most reliable measurement followed by the bone coverage percentage. The relationship between the combined angle and alpha angle was statistically significant with a correlation coefficient of 0.70 (P<0.001).

Sonographic investigation of anatomical specimens of infant hip joints

The anatomical foundations of infant hip sonography techniques are ill-defined. We investigated anatomical specimens of infant hip joints in a water bath, with Graf's and Terjesen's methods. Acetabular position was varied in defined increments, with respect to the ultrasound beam. The alpha angles and the femoral head coverage were measured. Plastic acetabular casts were sawn along the sonographic section planes, and the cut sections compared with the sonographic sections. For images to be obtained, which were analysable by the two methods, the ultrasound beam had to intersect with the acetabular inlet plane at defined angles. The acetabular notch had to be anteriorly rotated from the ultrasound beam plane by at least 20 degrees. Beam entry within a 50 degrees sector posterior to the perpendicular on the inlet plane gave analysable images. The alpha angles and femoral head coverage were much affected by coronal-plane transducer tilt. Caudad tilts were associated with lesser values, a fact that should be borne in mind in clinical ultrasound investigations.

Diagnosing childhood acetabular dysplasia using the lateral margin of the sourcil

The purpose of this study was to evaluate the lateral edge of the acetabulum and locate the most accurate marking point on a plain radiograph when measuring the acetabular index (AI) and the center-edge (CE) angle. We studied the radiographs of 53 patients with unilateral developmental dysplasia of the hip (DDH), all of whom were treated by closed reduction. In addition to plain radiographs, eight patients had magnetic resonance imaging (MRI) studies, 16 had three-dimensional computed tomography (3-DCT) studies, and six underwent arthrographic studies. We found that the most lateral bony margin of the acetabular roof on plain radiograph represents the anterolateral portion of the acetabulum. The lateral end of the sourcil indicates the lateral margin of the mid-superior portion of the acetabulum. To reduce intra- and interobserver errors, we suggest that when measuring the AI and the CE angle, physicians clearly indicate in the medical records which of the two marking points was used.