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

Impact of the coronavirus disease 2019 pandemic on ultrasound screening of developmental dysplasia of the hip and follow-up imaging: a report from southeastern Turkey

Objective

To investigate the effect of coronavirus disease 2019 restrictions on ultrasound (US) screening of developmental dysplasia of the hip (DDH) in a children’s hospital.

Methods

The records of US screening of DDH were retrospectively evaluated in the pandemic period (April 2020 to July 2021) and the pre-pandemic period (January 2019 to February 2020). The monthly US number, sex, radiologist number, and age at the initial examination were recorded.

Results

A total of 6107 US scans were performed during the pre-pandemic period, which significantly decreased to 3340 during the pandemic. The number of monthly US scans performed did not change between the pre-pandemic (142.7/month) and pandemic (128.2/month) periods. The number of delayed examinations in the total population did not significantly change between the two periods. However, the number of delayed examinations in patients with abnormal hips was significantly increased during the pandemic compared with that in the pre-pandemic period.

Conclusions

Coronavirus disease 2019 restrictions decreased the US screening rate of DDH by almost half, but the number of US scans performed by each radiologist was unchanged. The compliance with follow-up recommendations was reduced by half, which may lead to an increase in the incidence of delayed and untreated DDH cases.

Accuracy of New Deep Learning Model-Based Segmentation and Key-Point Multi-Detection Method for Ultrasonographic Developmental Dysplasia of the Hip (DDH) Screening

Hip joint ultrasonographic (US) imaging is the golden standard for developmental dysplasia of the hip (DDH) screening. However, the effectiveness of this technique is subject to interoperator and intraobserver variability. Thus, a multi-detection deep learning artificial intelligence (AI)-based computer-aided diagnosis (CAD) system was developed and evaluated. The deep learning model used a two-stage training process to segment the four key anatomical structures and extract their respective key points. In addition, the check angle of the ilium body balancing level was set to evaluate the system’s cognitive ability. Hence, only images with visible key anatomical points and a check angle within ±5° were used in the analysis. Of the original 921 images, 320 (34.7%) were deemed appropriate for screening by both the system and human observer. Moderate agreement (80.9%) was seen in the check angles of the appropriate group (Cohen’s κ = 0.525). Similarly, there was excellent agreement in the intraclass correlation coefficient (ICC) value between the measurers of the alpha angle (ICC = 0.764) and a good agreement in beta angle (ICC = 0.743). The developed system performed similarly to experienced medical experts; thus, it could further aid the effectiveness and speed of DDH diagnosis.

3D-printed pelvis model is an efficient method of osteotomy simulation for the treatment of developmental dysplasia of the hip

Developmental dysplasia of the hip (DDH) is a congenital or developmental deformation of the hip joint, which may require a high number of surgical interventions. It has been indicated that 3D printing may be used to simulate a fractured pelvis to facilitate the fixation of plates during the surgical procedure. In the present double-blinded randomized clinical trial, the utility of the 3D-printed pelvis model, comprising 3D reconstruction, reverse engineering and rapid prototyping, in the treatment of DDH was evaluated with 3D CT as control. The value of the 3D-printed pelvis model in the surgical management and development of a strategy for an individualized operation for DDH using osteotomy simulation was also assessed. The results indicated that use of the 3D-printed pelvis model increased the success rate of the operation with a shortened surgery time and post-operative recovery time for DDH patients. In addition, the application of the 3D-printed pelvis model allowed for more efficient surgical management of DDH than 3D CT and promoted post-operative recovery of the DDH patients. Pre-operative planning using the 3D-printed pelvis model was feasible for DDH patients. Furthermore, few patients exhibited delayed incision healing, wound infection or nonunion in the DDH group with osteotomy simulation using the 3D-printed pelvis model or 3D-CT. In conclusion, the present study indicated that the 3D-printed pelvis model, including 3D reconstruction, reverse engineering and rapid prototyping, constitutes an efficient tool for pelvic osteotomy simulation, which improves personalized pre-operative planning by providing a visual and accurate osteotomy model for patients with DDH (Chinese Trial Registry No. KCT0012374).

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.

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

BACKGROUND

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICAL RELEVANCE

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

The effect of gestational age on sonographic screening of the hip in term infants

Several authors have suggested that the final five weeks of gestation are a critical period for the development of the hip. In order to test the hypothesis that gestational age at birth may influence the development of the hip joint, we analysed the sonographic findings in 1992 hips (in 996 term newborns) with no risk factor for developmental dysplasia of the hip. The 996 infants were born at a mean gestational age of 39 weeks (37 to 41).

The mean bony roof angle (α), cartilage roof angle (β) and the distribution of the type of hip were compared between the 37th, 38th, 39th, 40th and 41st birth week groups. There was a significant difference in the distribution of type of hip between the different birth week groups (p < 0.001), but no significant difference between the α angles of all groups (p = 0.32). There was no correlation between birth week and roof angle (p = 0.407 and p = 0.291, respectively) and no significant correlation between birth weight and roof angle (p = 0.735 and p = 0.132, respectively).

The maturity of the infant hip, as assessed sonographically, does not appear to be affected by gestational age, and the fetal development of the acetabular roof appears to plateau from 37 weeks.

Cite this article: Bone Joint J 2013;95-B:266–70.

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

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

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Does probe frequency influence diagnostic accuracy in newborn hip ultrasound?

Ultrasonography of the hip has gained wide acceptance as reliable method for diagnosing developmental hip dysplasia in infants. This blinded study was conducted to investigate the influence of two linear probes with different frequency on diagnostic accuracy and reproducibility. In 206 consecutive newborns, the bony roof angle (α-angle) and cartilage roof angle (β-angle) were assessed by three investigators according to Graf. The hips were measured twice both with a 7.5 MHz and a 12 MHz linear transducer (Sonoline G60S(®) ultrasound system; Siemens, Erlangen, Germany). Each investigator evaluated his sonograms 6 weeks later. Depending on the mean values for α-angle and β-angle, the hips were classified. Reproducibility of the Graf classification was not found to be influenced. In two of three investigators, we observed significant improvement concerning variation of the β-angle with the 12 MHz probe. The use of high-resolution transmitters may improve diagnostic accuracy in ultrasonography of the newborn's hip.

Developmental dysplasia of the hip: impact of sonographic newborn hip screening on the outcome of early treated decentered hip joints-a single center retrospective comparative cohort study based on Graf's method of hip ultrasonography

PURPOSE/BACKGROUND/INTRODUCTION: The aim of this study was to retrospectively evaluate the impact of neonatal sonographic hip screening using Graf's method for the management and outcome of orthopaedic treatment of decentered hip joints with developmental dysplasia of the hip (DDH), using three decades (1978-2007) of clinical information compiled in a medical database.

METHODS

Three representative cohorts of consecutive cases of decentered hip joints were selected according to different search criteria and inclusion and exclusion parameters: (1) cohort 1 (1978-1982; n = 80), without sonographic screening; (2) cohort 2.1 (1994-1996; n = 91), with nationwide established general sonographic screening according to the Graf-method; (3) cohort 2.2 (2003-2005; n = 91), with sonographic screening including referred cases for open reduction from non-screened populations. These three cohorts were compared for the following parameters: age at initial treatment, successful closed reduction, necessary overhead traction, necessary adductor-tenotomy, rate of open reduction, rate of avascular necrosis (AVN) and rate of secondary acetabuloplasty.

RESULTS

The age at initial treatment was reduced from 5.5 months in the first cohort to 2 months in the two subsequent two cohorts and the rate of successful closed reduction increased from 88.7 to 98.9 and 95.6%, respectively. There was a statistically significant improvement in six out of seven parameters with sonographic hip screening; only the rate of secondary acetabuloplasty did not improve significantly.

CONCLUSION

Compared to the era before the institution of a sonographic hip screening programme according to the Graf-method in Austria in 1992, ultrasound screening based-treatment of decentered hip joints has become safer, shorter and simpler: "safer" means lower rate of AVN, "shorter" means less treatment time due to earlier onset and "simpler" means that the devices are now less invasive and highly standardized.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

[Developmental dysplasia of the hip]

At one month, the acetabular depth from a standard lateral coronal section is 4.6 ± 1.0mm. The correlation between experienced and junior radiologists is high (kappa 0.795). A treshhold of 6mm with a Δ (difference between right and left) less than 1.5mm provides a sensitivity of 100% for the detection of DDH at one month. Universal US screening at one month of all high-risk infants in 2009 resulted in a reduction of delayed diagnosis of DDH (zero girls, two boys) in Ille-et-Vilaine due to continuous medical education of general radiologists.

Reproducibility of different screening classifications in ultrasonography of the newborn hip

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Evaluation of a training program for general ultrasound screening for developmental dysplasia of the hip in preventive child health care

BACKGROUND

A research study in the Netherlands showed that general ultrasound (US) screening was cost-effective in the detection of developmental dysplasia of the hip (DDH). This study was followed by a pilot implementation study. Part of this pilot implementation study is to investigate whether professionals of the infant health care (IHC) system, with no previous US experience, would be able to perform US of the hip.

OBJECTIVE

This study looks at health care worker ability to classify US images into a modified Graf system.

MATERIALS AND METHODS

After theoretical and practical training, seven nurses and physicians of the participating IHC centers reported their findings on sonographic images of 80 children. This was repeated five months later. From the two evaluation moments the intraobserver agreement and the interobserver agreement was determined.

RESULTS

The average estimated interobserver Cohen's kappa for both sessions was for nurses 0.6 and for physicians 0.5. The second evaluation showed a decrease from an average of 4.3% missed cases per screener to 2.3% and an increase of an average of 5% false positives per screener to 9.1%.

CONCLUSION

The inter- and intra-observer agreement is comparable to similar studies in which the participants had a professional background in US examination. The level of agreement of the trainees in the perspective of the screening process was considered sufficient for the pilot implementation project.

Parenthood and immunomodulation in patients with multiple sclerosis

Little is known about the influence of immunomodulation on parenthood, in particular paternity in multiple sclerosis (MS). The objective was to determine whether there is an increased risk for pregnancies initiated by MS-parents under disease modifying therapies (DMT). We investigated the clinical outcome of pregnancies fathered by MS-patients under DMT by nationwide questionnaire and within our own outpatient clinic. Additionally, we compared the birth weight of children from MS-fathers exposed to DMT, MS-mothers without DMT, MS-mothers under interferon-beta (IFN beta) at the time of conception and healthy controls (HCs). DMT was reported for 32 paternities of 46 children; 30 under IFN beta, 12 under glatiramer acetate, 2 under natalizumab, 1 under methotrexate and 1 under combined azathioprine- and IFN beta-1b-treatment. Six (13%) pregnancies ended in early spontaneous abortions; of the 40 children of MS-fathers under DMT, 2 (5%) were preterm, 1 (2.5%) had a spinal lipoma and 3 (7.5%) had moderate hip dysplasia, of whom 2 were siblings whose mother had severe hip dysplasia. Mean birth weight of newborns from MS-fathers under DMT was not significantly reduced compared to HCs. Comparing birth weight of newborns of MS-mothers versus MS-fathers, we found a significant difference to the disadvantage of MS-mothers with or without IFN beta-treatment. No statistical difference in birth weight of IFN beta-exposed versus untreated MS-mothers was observed. Despite the small numbers, our available data suggest safe paternity by MS-patients. IFN beta-treatment of mothers does not seem to have an impact on birth weight, however, MS may contribute to a reduced birth weight.

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

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

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.

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

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

Parametric 3D hip joint segmentation for the diagnosis of developmental dysplasia

In this paper, we present a segmentation method for the hip joint from 3D ultrasound data. The proposed approach starts from a well-known energy formulation of the segmentation problem, and employs the extended local structure tensor as image feature in order to incorporate gray level and texture information in a common framework. Using the Kullback-Leibler distance as an intrinsic dissimilarity measure, the energy minimization is performed by estimating the optimal parameters of the sphere and paraboloid that best approximate the femoral head and acetabulum, respectively. A 2D level set segmentation of the iliac bone and an easy user interaction step allow for the introduction of the necessary constraints to make the energy minimization feasible. Experimental results over several data volumes show this approach to be capable of successfully approximating the anatomy of the hip joint by simple geometrical surfaces.

Neonatal incidence of hip dysplasia: ten years of experience

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

LEVEL OF EVIDENCE

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

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

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

LEVEL OF EVIDENCE

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

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

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

Sonography of hip dysplasia

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

Ultrasound screening for developmental dysplasia of the hip

BACKGROUND

Clinical examination of newborns has been shown to be inadequate for the early detection of developmental dysplasia of the hip (DDH). It is debatable whether US examination is a valid alternative.

OBJECTIVE

To contribute further knowledge to the natural history of DDH; to examine the distribution of hip morphology as classified by Graf according to sex and risk factors in an unselected Italian population; to propose a temporal pattern of US screening of all newborns to detect DDH.

MATERIALS AND METHODS

All newborns (n=8,896) sequentially delivered in the Maternal and Child Health Hospital of Milan underwent US examination in the first week of life and, when findings were within normal limits, in the third month of life. Subjects categorised at birth as Graf type 2a with alpha angle between 50 degrees and 52 degrees, underwent a further US examination at the end of the first month of life. Subjects with ambiguous findings at the 3-month examination were re-examined at the end of the fourth month of life. All infants with abnormal hips abandoned the screening process and underwent treatment. RESULTS. Overall, 56 cases of DDH were identified: 34 in the first week of life examination, 10 at 1 month; 10 at 3 months and 2 at 4 months. CONCLUSIONS. A two-step US screening of newborns is recommended: at the end of the first month and within the fourth month of life.