Ultrasonography in developmental dysplasia of the hip

Developmental dysplasia of the hip and ultrasound reading by pediatric orthopedic surgeons: a pilot study

Ultrasound is an imaging modality utilized for early detection and follow-up of developmental dysplasia of the hip (DDH) in infants. Traditionally, pediatric orthopedic surgeons have relied on radiologists to perform ultrasound examinations and interpret the imaging. Today, however, many orthopedic surgeons are performing and interpreting ultrasound themselves. The purpose of this paper was to evaluate the reliability of pediatric orthopedic surgeons in interpreting ultrasound imaging of infant hips. This was a prospective observational pilot study. After reading an instructional handout about the Graf method of hip ultrasonography, eight pediatric orthopedic surgeons measured 28 hip ultrasound images to determine the alpha angle and percent femoral head coverage. On the basis of cited intraclass correlation coefficient cutoff values, interrater reliability was found to be 'good' for percent femoral head coverage and 'fair' for alpha angle. These findings are equivalent to findings of similar studies using radiologists as examiners. Pediatric orthopedic surgeons can interpret ultrasound exams for diagnosing DDH.

Long-term outcomes of total hip arthroplasty in patients with developmental dysplasia of the hip: a minimum 21-year follow-up

PURPOSE

Early osteoarthritis (OA) due to developmental dysplasia of the hip (DDH) is a known indication for total hip arthroplasty (THA). Though screening tools and joint-preserving procedures have been established successfully, there still is a relevant number of patients suffering DDH. Due to the lack of long-term outcome studies, we like to close this gap and present the results of a highly specialized center.

METHODS

The study included 126 patients, who were treated in our institution with primary THA for DDH between January 1997 and December 2000. At the time of final follow-up, at a mean of 23 years postoperatively, 110 patients (121 hips) were clinically evaluated using the Harris-Hip Score. In addition, complication and surgical revision rates were assessed. We collected surgery-related data like implant choice and special surgical features such as autologous acetabular reconstruction or femoral osteotomies. Additionally, the severity of preoperative DDH was measured radiographically according to Crowe classification.

RESULTS

There were 91 female (83%) and 19 male (17%) patients with an average age of 51 ± 9.5 years (range 21-65) included. Mean follow-up was 23 ± 1.3 years (21-25), with a minimum of 21 years being necessary for inclusion. Using revision for any indication as primary endpoint, the Kaplan-Meier survivorship was 98.3% at 10 years and 81.8% at final follow-up. The overall revision rate was 18% (22 cases), which were split up as follows: 20 (17%) implant failures (loosened or broken components), one (1%) periprosthetic infection and one (1%) periprosthetic fracture. Regarding complications, we observed nine (7%) dislocations and one case (1%) with severe heterotopic ossification that required surgical excision. The mean Harris-Hip score at latest follow-up was 78 ± 14 points (32-95).

CONCLUSIONS

Though implants and surgical techniques have improved over time, our results suggest THA in patients suffering DDH to be seriously challenging with relatively high overall complications in long-term observation and fair clinical outcome after 21 years postoperatively. There is evidence that prior osteotomy might be associated with a higher revision rate.

Implementing the AAOS Guidelines for Screening of Developmental Dysplasia of the Hip Before the Age of 6 Months in Taiwan

BACKGROUND

The prevalence of developmental dysplasia of the hip (DDH) has been considered to be low in East Asia, but this may be incorrect because of inconsistent diagnostic definitions and testing criteria. In 2015, the AAOS released guidelines for systematic screening for DDH in newborns. We implemented these guidelines and compared DDH incidence and outcomes before and after their implementation.

METHODS

We used a historic comparison cohort of newborns with DDH between July 2015 and May 2017 before guideline implementation (the preguideline group); their data were retrieved using electronic medical records. In this group, the newborns received general hip screening without systemic follow-up. The postguideline group included newborns who were screened for hip dysplasia and followed up per the AAOS guidelines between July 2017 and May 2019. Their data were prospectively collected. The primary outcome in the postguideline group was DDH incidence. Other outcomes included rates of referral, surgery, and complications, and DDH prognosis.

RESULTS

The preguideline and postguideline groups included 3534 and 2663 newborns, respectively, of whom 49 (1.1%) and 225 (8.4%), respectively, were referred to the pediatric orthopaedic clinic enrolled. In the postguideline group, 35 patients were diagnosed as having DDH (incidence: 1.3%, 95% CI: 0.8%-1.9%). Both the incidence and referral rates were significantly higher in the postguideline group than in the preguideline group. Furthermore, the mean age at referral was 6.7±10.06 months and 0.9±0.25 months in the preguideline and postguideline groups, respectively, indicating a potential for early treatment in the postguideline group. Finally, the female sex was identified as a risk factor for residual hip dysplasia at 6 months of age.

CONCLUSION

DDH incidence in East Asia seems comparable to that in Western countries. Implementing the AAOS guidelines increased the diagnosis rate and opportunity for early treatment initiation, thus potentially avoiding surgical intervention. Nevertheless, residual DDH may be detected in some patients at 6 months of age, particularly in female infants.

LEVEL OF EVIDENCE

Level IV.

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 < 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.

The infants who have mature hip on ultrasonography but have risk factors of developmental dysplasia of the hip are required radiographic examination

Objectives

This study aims to evaluate the short-term results of infants who were radiologically diagnosed with developmental dysplasia of the hip (DDH), but in whom hip development was normal ultrasonographically.

Patients and methods

Between January 2018 and September 2020, a total of 15 infants (2 males, 13 females; median age: 5 months; range, 4 to 6 months) who were diagnosed with DDH radiologically and treated were retrospectively analyzed. Hip ultrasonography was used for early diagnosis, treatment, and for follow-up in infants up to six months of age. While the ultrasonographic findings were normal, radiography was performed in infants between four to six months of age who were at risk for DDH.

Results

Fifteen patients (22 hips) were diagnosed with DDH radiologically and treated. Radiologic dysplasia continued in seven hips of five patients during short-term follow-up.

Conclusion

These results suggest that ultrasonographic hip maturation may not be consistent with normal hip development in infants, particularly in those who are at risk for DDH. In infants with DDH which is confirmed by radiography (less than 6 months of age), the diagnosis may be missed on ultrasonographic examination.

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.

Using Z-score to optimize population-specific DDH screening: a retrospective study in Hangzhou, China

BACKGROUND

DDH (Developmental Dysplasia of the Hip) screening can potentially avert many morbidities and reduce costs. The debate about universal vs. selective DDH ultrasonography screening in different countries revolves to a large extent around effectiveness, cost, and the possibility of overdiagnosis and overtreatment. In this study, we proposed and evaluated a Z-score enhanced Graf method to optimize population-specific DDH screening.

METHODS

A total of 39,710 history ultrasonography hip examinations were collected to establish a sex, side specific and age-based Z-scores model using the local regression method. The correlation between Z-scores and classic Graf types was analyzed. Four thousand two hundred twenty-nine cases with follow-up ultrasonographic examinations and 5284 cases with follow-up X-ray examinations were used to evaluate the false positive rate of the first examination based on the subsequent examinations. The results using classic Graf types and the Z-score enhanced types were compared.

RESULTS

The Z-score enhanced Graf types were highly correlated with the classic Graf's classification (R = 0.67, p < 0.001). Using the Z-scores ≥2 as a threshold could reduce by 86.56 and 80.44% the false positives in the left and right hips based on the follow-up ultrasonographic examinations, and reduce by 78.99% false-positive cases based on the follow-up X-ray examinations, respectively.

CONCLUSIONS

Using an age, sex and side specific Z-scores enhanced Graf's method can better control the false positive rate in DDH screening among different populations.

Importance of early diagnosis for developmental dysplasia of the hip: A 5-year radiological outcome study comparing the effect of early and late diagnosis

AIM

Australia utilises a selective ultrasound screening programme. The rate of late diagnosis of developmental dysplasia of the hip (DDH) in Australia is increasing. The aim of this study is to quantify the treatment required and compare the 5-year radiological outcomes between early and late diagnosis in children with DDH with frank dislocation.

METHODS

We performed a case-matched control study of children with frank DDH dislocations from 2000 to 2010 comparing three groups: children with an early diagnosis successfully treated in a Pavlik harness (SP), children with an early diagnosis who failed Pavlik harness treatment (FP) and children with a late diagnosis (LD). Minimum follow-up was 4 years.

RESULTS

A total of 115 hips were included. Patients in the LD group required significantly more open reductions (P < 0.001), acetabular osteotomies (P < 0.001) and femoral osteotomies (P < 0.001). LD was also associated with significantly higher rates of growth disturbance at 46.3%, compared to 20.6% in the FP group and 5% in the SP group (P < 0.001). Overall, there were excellent radiological outcomes in 58.5% of the LD group compared to 79.4% in the FP group and 100% in the SP group.

CONCLUSION

In Australia, high rates of LD in DDH persist in the context of selective ultrasound screening. While good radiological outcomes are achievable, a significantly greater level of surgical intervention is required and this is associated with significantly higher rates of growth disturbance. Optimisation of screening in Australia is vital.

Ultrasound Evaluation of Pediatric Orthopaedic Patients

Ultrasonography is a valuable tool that can be used in many capacities to evaluate and treat pediatric orthopaedic patient. It has the capability to depict bone, cartilaginous and soft-tissue structures, and provide dynamic information. This technique can be readily applied to a wide range of pediatric conditions, including developmental dysplasia of the hip, congenital limb deficiencies, fracture management, joint effusions, and many other musculoskeletal pathologies. There are many benefits of implementing ultrasonography as a regular tool. It is readily accessible at most centers, and information can be quickly obtained in a minimally invasive way, which limits the need for radiation exposure. Ultrasonography is a safe and reliable tool that pediatric orthopaedic surgeons can incorporate into the diagnosis and management of a broad spectrum of pathology.

Discrepancy between ultrasonographic and radiographic findings in patients treated for developmental dysplasia of the hip; hip maturation on ultrasonography may not be consistent with radiographic hip maturation

Currently, hip sonography is used for early diagnosis and for monitoring developmental dysplasia of the hip (DDH) treatment in many countries. An early pioneer of ultrasonography for early diagnosis of DDH was Graf. Based on the Graf approach, hip ultrasonography is more sensitive and specific than radiography for the diagnosis of DDH, because of its capability to show cartilaginous structures of the hip joint. The aim of this study was to compare radiographic and ultrasonographic findings in patients treated for DDH. This study included 88 infants (98hips) treated for DDH. Radiography was simultaneously used for treatment and follow-up evaluation in addition to ultrasonography after six months of age. A retrospective evaluation was made of the ultrasonographs and radiographs of these infants. Of the total 98 hips, 28 were normal both ultrasonographically and radiographically, and a pathologic hip was demonstrated in 32 hips both sonographically and radiographically. Hip ultrasonography showed abnormal development in 32 hips, while radiography showed abnormal development in 70 hips. In 38 hips, the findings were normal according to ultrasonography but pathological according to radiography. There were no hips that were normal radiographically but pathological sonographically. When radiography is accepted as the standard imaging method in our study patients, the sensitivity and specificity of hip ultrasonography were determined as 45.7% [95% confidence interval (CI): 41.5-45.7] and 100% (95% CI: 89.4-100), respectively. These findings suggest that hip maturation apparent on ultrasonography may not be consistent with radiographic hip development in infants treated for DDH.

Developmental dysplasia of the hip: real world data from a retrospective analysis to evaluate the effectiveness of universal screening

AIMS

Developmental dysplasia of the hip is an important cause of disability in children and young adult and it also has a significant socio-economic impact in our society. The main objective of our study is to evaluate, in our hospital, the effectiveness of a universal ultrasound screening protocol and to assess the general knowledge about the theme of pediatricians and neonatologists.

METHODS

Retrospective study of infants born from January 2016 to April 2019, evaluated with hip ultrasound (Graf method). Risk factors assessed were female gender, breech presentation at birth, positive family history and twin birth. For the secondary objective, an anonymous and validated questionnaire was distributed to all pediatricians and neonatologists.

RESULTS

Among the 4000 hips analyzed, on ultrasound examination, 98.8% hips resulted mature or immature but appropriate for age, while 1,2% hips were pathological. Analyzing the mature or immature hips, 2,4% were positive on clinical examination and 97,6% were negative. In relation to ultrasound pathological hips, 33,3% have positive clinical examination, while 66,7% negative. From the analysis of risk factors a significant association emerged between female sex, breech presentation and family history with the ultrasound pathological findings. The results of Survey showed that inadequate training about developmental dysplasia of the hip is done during medical school.

CONCLUSIONS

A universal ultrasound screening allowed us to identify developmental dysplasia of the hip in a number of children with normal clinical examination and no risk factors. Specific training courses should be implemented regarding Developmental Dysplasia of the Hip for neonatologists and pediatricians.

Is it difficult to obtain inter-observer agreement in the measurement of the beta angle in ultrasound evaluation of the paediatric hip?

Introduction

The aim of this study was to determine the differences and consistencies in the morphological and angular interpretations of standard USG images. Therefore, it was aimed to show the correlations of orthopaedic doctors with different periods of experience in hip ultrasound measurements taken with the Graf method.

Materials and methods

The study included 210 infants randomly selected from those who presented at our hospital for DDH screening. A total of 6 ultrasound images were taken for each hip. These images were evaluated by  two paediatric orthopaedic professors, two orthopaedic specialists and two orthopaedic residents. The correlations of these measurements between all the doctors were evaluated statistically.

Results

In beta angle evaluation, agreement between all the evaluators was at the level of 0.054. No agreement was seen between the two residents or between the two specialists (p = 0.003, p = 0.998, p = 0.998, respectively). Agreement between the two professors was determined at the level of 0.508 (p < 0.001). Agreement was determined at the level of 0.066 between the specialists and the residents. No agreement was observed between the specialists and the professors or between the professors and the residents (p = 0.014, p = 0.098, p = 0.737, respectively).

Conclusions

It can be concluded that greater emphasis on the beta angle, the cartilage labrum, and more detailed explanations of this subject in the resident training program will achieve standardisation on this subject, and this is in direct proportion to clinical experience.

Level of evidence

IV

Ultrasound Is an Alternative to X-ray for Diagnosing Developmental Dysplasia of the Hips in 6-Month-Old Children

BACKGROUND

Infants previously treated for developmental dysplasia of the hips (DDH) are routinely imaged with ultrasound initially and reimaged with an anteroposterior (AP) pelvis X-ray at 6 months of age to assess for dysplasia. It has become convention to transition from ultrasound to AP X-ray at 6 months of age, but no study has demonstrated that ultrasound is inadequate at this age.

QUESTION/PURPOSE

The purpose of this study was to confirm that ultrasound for the 6-month DDH evaluation is a feasible alternative to the standard X-ray.

PATIENTS AND METHODS

Thirty-one 5- to 7-month-old infants undergoing AP pelvis X-ray related to previous Pavlik harness treatment for DDH or to a history of breech presentation were prospectively enrolled. All patients were imaged with an AP pelvis X-ray and bilateral hip ultrasounds. Three senior orthopedic surgeons unfamiliar with the patient histories evaluated both types of imaging for standard measures of hip dysplasia, including acetabular index (AI), alpha angle, and bony rim percent coverage of the femoral head. Pearson correlation coefficients were calculated for the X-ray and ultrasound measures.

RESULTS

Good quality ultrasound images were obtained in all patients, despite the presence of the ossific nucleus in 66% of the hips. All three reviewers correctly diagnosed the one dislocated hip via both X-ray and ultrasound. There were no false negatives on ultrasound, and none of the patients with negative ultrasounds required treatment during the mean 26 months of follow up. An increased AI on X-ray was correlated with lower percent coverage of the femoral head on ultrasound.

CONCLUSIONS

Ultrasound is a technically feasible DDH imaging modality that can be used as an alternative to X-ray for 6-month-olds.

Poorer radiological outcome after delayed diagnosis and treatment in human position in Fettweis plaster cast in 93 unstable hip joints type D, III and IV according to Graf

PURPOSE

In this study the course of unstable hips after successful treatment with Fettweis plaster of Paris (POP) is examined. Special focus will be given to age at beginning of treatment and initial hip type.

METHODS

The development of 93 unstable hips treated between November 2001 and April 2015 was examined. Inclusion criteria were: 1) unstable hips with successful treatment with Fettweis POP; 2) presence of two pelvic radiographs (12 to 24 months and 24 to 48 months). We analyzed: 1) the initial ultrasound hip type according to Graf; 2) the average age at first and second radiograph; 3) the Tönnis classification: normal findings (< 1 SD), slightly (1 SD to 2 SD) and severely dysplastic hips (> 2 SD).

RESULTS

In all, there were 14 hips type D, 41 hips type III and 38 hips type IV. Mean age of the first radiograph was 13.9 months and of the second 28.5 months. The first radiograph showed: (< 1 SD): 36, (1 SD to 2 SD): 34, (> 2 SD): 23 hips, the second radiograph: (< 1 SD): 33, (1 SD to 2 SD): 19, (> 2 SD): 30 hips. With subdivision at the start of treatment at age eight or fewer weeks 2/16 hips (12.5%) and with initiation of the treatment more than eight weeks 22/77 (26.0%) deteriorated. During the course between first and second radiograph a total of 35.7% of initial hip type D, 19.5% of type III and 23.7% of type IV deteriorated.

CONCLUSION

Radiograph controls after treatment with Fettweis POP show poorer outcome after delaying the start of treatment more than 8 weeks. These findings were independent of the initial ultrasound hip type. Regular radiograph controls of all hip types treated for unstable hips are justified to detect residual dysplasia.

LEVEL OF EVIDENCE

IV.

Clinical study of anterior hip ultrasound (van Douveren's method)-assisted Pavlik harness

PURPOSE

To investigate the use of anterior hip ultrasound (van Douveren's method)-assisted Pavlik harness in developmental dysplasia of the hip (DDH).

METHODS

Weekly anterior hip ultrasound scanning was performed in children with fixed Pavlik harness to detect whether hip reduction was achieved with the help of harness (the superior ramus of the pubis, the acetabulum, the femoral head, and the femoral neck being depicted in one plane indicated concentric reduction of the hip), and the stability of the reduction was checked by ultrasonography.

RESULTS

A total of 39 child patients and 51 dysplastic hips were successfully detected by anterior ultrasound, and stable reduction was achieved in 37 hips (15 Graf type D and 22 type III) right after the help of Pavlik harness, in seven hips (6 type III and 1 type IV) two weeks after the help of Pavlik harness; the remaining seven hips (2 type III and 5 type IV) failed to reach stable reduction after two weeks.

CONCLUSION

The anterior hip ultrasound (van Douveren's method) can be used to detect the reduction and stability of hip after Pavlik harness treatment in children with DDH. The majority of Graf type D and III hips can achieve a stable concentric reduction right after the help of Pavlik harness, while severely dislocated type IV hips have a low success rate for harness treatment, and abandonment of harness therapy should be considered in early stage.

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

OBJECTIVE

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

[An ultrasonographic study of the correlation between developmental dysplasia of the hip and congenital muscular torticollis in children]

OBJECTIVE

To investigate the significance of early screening of pediatric developmental dysplasia of the hip (DDH) and congenital muscular torticollis (CMT) using ultrasonography and establish a simultaneous screening model for pediatric DDH and CMT.

METHODS

From January, 2013 to January, 2016, a total of 5060 pediatric patients with suspected DDH and CMT underwent ultrasonic examinations. The diagnostic results of the two diseases were classified into different clinical types, and Chi-square test was used to analyze the one-way relationship between different types of DDH and CMT; correspondence analysis was used for multivariate analysis of the variables. Chi-square test was used to analyze the difference between the detection rates in suspected CMT patients and the normal population.

RESULTS

GrafIIa type DDH was associated with mass-type CMT in the children (χ²=331.800, P<0.001). DDH of GrafIIb, GrafIIc, Graf III, and Graf IV types were related with non-tumor type of CMT. The children with a suspected diagnosis of CMT showed a significantly higher detection rate of DDH than the normal subjects (χ²=321.889, P<0.001).

CONCLUSION

DDH is closely related with CMT. Early simultaneous screening of DDH and CMT can help to improve the early diagnosis rate of CMT in children.

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.

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

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.

The reliability of ultrasonography in developmental dysplasia of the hip: How reliable is it in different hands?

BACKGROUND

Developmental dysplasia of the hip (DDH) is the most common skeletal dysplasia. Two principal methods used in early diagnosis of DDH are clinical examination and ultrasonographic investigation. Dogruel et al. found a low specificity of clinical examination in patients with DDH. Additionally, Kamath et al. stated that ultrasonography performed by a radiologist in routine clinical practice is more reliable than physical examination performed by the average clinician. In clinical practice, the application and assessment of hip ultrasonography are completed by a single person. This assessment determines the followup of the patient. Thus, hip ultrasonography performed on the same person by different individuals under the same conditions will yield a more accurate assessment of the reliability of ultrasonographic assessment of DDH. Although inter-observer reliability was high in many previous studies of ultrasound image evaluation, reliability rates vary among studies of the application of ultrasonography.

MATERIALS AND METHODS

Inter-examiner reliability of hip ultrasonography was analyzed among four investigators who separately evaluated 100 hips (50 infants). The obtained bone structure angles α, cartilage structure angles β, and distribution of hip types were compared among the investigators. All infants were brought to the hospital for a healthy child followup examination, according to the country's health policy. Babies between 0 and 6 months were included in the study. Babies with any neuromuscular disorders, neural tube defects or any type of genetic anomalies were excluded from the study. The study was explained to the families of all infants and written informed consent was obtained.

RESULTS

There was a significant difference in the hip type determined by the investigators with respect to α and β angles (P < 0.01, P < 0.01, P = 0.002). The average alpha measurements of the first orthopedist, second orthopedist, first radiologist, and second radiologist were 67.38 ± 6.24, 65.60 ± 5.84, 65.44 ± 4.59, and 62.59 ± 4.50, respectively. The average beta measurements of the first orthopedist, second orthopedist, first radiologist, and second radiologist were 53.85 ± 8.86, 50.74 ± 7.80, 44.77 ± 6.30, and 44.39 ± 5.81, respectively. Agreement among the results obtained by the clinicians was investigated in dual comparisons. The relative agreement according to the alpha angle ranged from 3.6% to 44.5%, and the relative concordance according to the beta angle ranged from 0.9% to 45.3%. Agreement regarding hip typing was determined to range from 19.1% to 42.6%.

CONCLUSION

Sonographic evaluation of the hip appears to vary depending on the investigator.

To swaddle, or not to swaddle? Paleoepidemiology of developmental dysplasia of the hip and the swaddling dilemma among the indigenous populations of North America

OBJECTIVES

Clinical prevalence of developmental dysplasia of the hip (DDH) is high among modern indigenous populations of North America, yet no systematic study of the paleoepidemiology of this group exists. This study discusses the skeletal criteria, epidemiology, pathophysiology, and risk factors of DDH. A range of cases of DDH from an archaeological Native American population are described and the clinical and prehistoric prevalence of DDH among indigenous populations of North America are calculated and discussed within a biocultural perspective.

METHODS

Pelves of 390 adults from the Late Prehistoric (1490 B.P. ± 70) Buffalo site, West Virginia, were examined for DDH. Morphology of true and false acetabula was classified and other changes of the pelvis, lower limb, and spine were noted along with cranial deformation, providing evidence of infant restriction. Prevalence of DDH among living and archaeological indigenous peoples of North America were calculated and compared. Cranial deformation was assessed as evidence for swaddling.

RESULTS

DDH was identified in 18 adults from Buffalo, resulting in a minimum prevalence of 46.15 per 1,000, within the range reported in modern indigenous groups in North America. Most, but not all, of the DDH cases were associated with cranial deformation, but not all cases of cranial deformation were associated with DDH.

CONCLUSIONS

The etiology of DDH suggests that components of both genetic predisposition and swaddling practices have combined to create a high-risk environment for the development of DDH, contributing to high prevalence within archaeological populations, like Buffalo, and modern Indigenous groups of North America.

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.

Joined at the hip? A paleoepidemiological study of developmental dysplasia of the hip and its relation to swaddling practices among indigenous peoples of North America

OBJECTIVES

Clinical prevalence of developmental dysplasia of the hip (DDH) is the highest among modern indigenous populations of North America, yet no systematic study of the paleoepidemiology of this group exists. This study discusses the skeletal criteria, epidemiology, pathophysiology, and risk factors for DDH. A range of cases of DDH from an archaeological Native American population are described, and the clinical and prehistoric prevalence of DDH among indigenous populations of North America are calculated and discussed within a biocultural perspective.

METHODS

Pelves of 390 adults from the Late Prehistoric (1490 BP ± 70) Buffalo site, West Virginia were examined for DDH. Morphology of true and false acetabula was classified and other changes of the pelvis, lower limb, and spine were noted along with cranial deformation, providing evidence of infant restriction. Prevalence of DDH among living and archaeological indigenous peoples of North America were calculated and compared.

RESULTS

DDH was identified in eighteen adults from Buffalo, resulting in a prevalence of 46.15, within the range reported in modern indigenous groups in North America. However, there is a significant difference between the DDH prevalence in prehistory and today in the target population.

CONCLUSIONS

Indigenous peoples of North America have the highest reported global prevalence of DDH today and in prehistory. The etiology of DDH suggests that components of both genetic predisposition and swaddling practices have combined to create a high-risk environment for the development of DDH, contributing to its high prevalence within archaeological populations, like Buffalo, and modern Native American/Aboriginal groups within North America.

Image quality in real-time teleultrasound of infant hip exam over low-bandwidth internet links: a transatlantic feasibility study

Evolution of communication systems, especially internet-based technologies, has probably affected Radiology more than any other medical specialty. Tremendous increase in internet bandwidth has enabled a true revolution in image transmission and easy remote viewing of the static images and real-time video stream. Previous reports of real-time telesonography, such as the ones developed for emergency situations and humanitarian work, rely on high compressions of images utilized by remote sonologist to guide and supervise the unexperienced examiner. We believe that remote sonology could be also utilized in teleultrasound exam of infant hip. We tested feasibility of a low-cost teleultrasound system for infant hip and performed data analysis on the transmitted and original images. Transmission of data was accomplished with Remote Ultrasound (RU), a software package specifically designed for teleultrasound transmission through limited internet bandwidth. While image analysis of image pairs revealed statistically significant loss of information, panel evaluation failed to recognize any clinical difference between the original saved and transmitted still images.

The utility of ultrasonography for the diagnosis of developmental dysplasia of hip joint in congenital muscular torticollis

Objective

To determine whether a routine ultrasonography (US) is necessary for diagnosis of developmental dysplasia of hip (DDH), presenting with congenital muscular torticollis (CMT).

Methods

Cases of 133 patients (81 males, 52 females) diagnosed as CMT were reviewed, retrospectively. We reviewed the medical charts and diagnostic examination. We also assessed the coincidence of CMT and DDH, and investigated the clinical features of CMT related to DDH.

Results

Twenty (15.0%) patients out of 133 CMT patients were diagnosed as having DDH by US. Of whom, 8 patients were radiographically positive and 4 patients were both clinically and radiographically positive. Nine patients were treated with a harness and 1 of them needed closed reduction and casting. Out of 9 patients treated with a harness, only 4 were clinically positive. The difference and ratio of the sternocleidomastoid (SCM) muscle thickness between the normal and abnormal side was significantly greater in DDH patients (p=0.014). Further, receiver operating characteristic analysis showed when the SCM ratio is greater than 2.08 and the SCM difference is greater than 6.1 mm, the efficiency of US for the diagnosis of the DDH was found to be the best (p<0.05).

Conclusion

To evaluate DDH, physical examination showed low sensitivity and radiologic study has limitation for the child before 4 to 6 months of age. Therefore, we recommend that hip is screened by US for the diagnosis of DDH associated with CMT when physical examination is positive or CMT patients with large SCM difference and high SCM ratio.

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.

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.

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.

The epidemiology and demographics of hip dysplasia

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

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

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

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

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

Reliability of ultrasonographic measurements in suspected patients of developmental dysplasia of the hip and correlation with the acetabular index

BACKGROUND

Ultrasonography is accepted as a useful imaging modality in the early detection of developmental dysplasia of the hip (DDH). Early detection and early treatment of DDH prevents hip dislocation and related physical, social, economic, and psychological problems. The purpose of this study was to evaluate the reliability of ultrasonographic and roentgenographic measurements measured by seven different observers.

MATERIALS AND METHODS

The alpha angles of 66 hips in 33 patients were measured using the Graf method by seven different observers. Acetabular index degrees on plane roentgenograms were measured in order to assess the correlation between the ultrasonographic alpha angle and the radiographic acetabular index, which both show the bony acetabular depth, retrospectively.

RESULTS

The interclass correlation coefficient, measuring the interobserver reliability, was high and statistically significant for the ultrasonographic measurements. There was a negative correlation between the alpha angle and the acetabular index.

CONCLUSIONS

Ultrasonography, when applied properly, is a reliable technique between different observers, in the diagnosis and follow up of DDH. When assessed concomitantly with the roentgenographic measurements, the results are reliable and statistically meaningful.

The creation of a Pavlik "hemi-harness" for a singly irreducible hip in bilateral dysplastic hips

PURPOSE

The treatment of bilaterally dislocated hips with a Pavlik harness can have deleterious effects if one hip remains dislocated. We assess the success of potentially leaving the persistently dislocated hip free and the relocated hip in a "hemi-Pavlik" harness.

METHODS

In this report, we retrospectively review three cases of bilaterally dislocated hips in children who were treated with a Pavlik harness. Only one hip was effectively reduced by the harness and, in each case, half of the harness was cut away to create a "hemi-Pavlik" harness and the free side was operated on at a later date.

RESULTS

Initial follow-up has shown that the "hemi-Pavlik" harness is effective in maintaining reduction of one hip whilst leaving the other hip untreated, thus, avoiding the complications of prolonged use of the harness in an unreduced hip or having both hips dealt with operatively.

CONCLUSIONS

We suggest, in the early stages, that if only one side of the bilaterally displaced hips can be reduced, the non-reduced side should be left free and an elective procedure carried out at a later stage. In the early stages, a "hemi-Pavlik" harness is effective in treating the reducible hip and causes no treatment obstacles for the irreducible side.

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.

[Hip ultrasound screening in Germany. Results and comparison with other screening procedures]

General ultrasound screening programmes to determine DDH are still a matter of discussion due to a lack of evidence. To facilitate further discussions this review gives an overview of the international data and literature concerning the different screening policies taking into account the results of the German evaluation study from 1997 to 2002. General ultrasound screening programmes are established in Germany and Austria. The analysis of the German screening showed 535 cases of DDH with first operative procedure (age 10 weeks to 5 years) that were treated as inpatients: 66% underwent a closed reduction, 11% an open reduction and 23% an osteotomy of the acetabulum/femur. The number of children who had no ultrasound of the hip before diagnosis decreased from 22% in the first year to 8% in the last. The first ultrasound examination was without pathological findings in 12% of the cases. Capture-recapture estimates suggested that 52% of cases were reported, so that the incidence for first operation due to DDH was 0.26 per 1,000 live births in 1997. This is much lower than in other countries and 4/5 less than the time before screening with ultrasound in Germany. At most 42% of the cases might be preventable by an improvement of the screening programme, but at least 51% would not be prevented. The German ultrasound screening programme has proved to be effective. Improvement of economic efficiency is still possible. Therefore, the German programme with different screening times can be recommended.

Correlation of femoral head coverage and Graf alpha angle in infants being screened for developmental dysplasia of the hip

Ultrasonography has become accepted as a useful imaging modality in the early detection of developmental dysplasia of the hip (DDH). The purpose of this study was to investigate the extent to which ultrasonographic measurements of femoral head coverage correspond to the categories of hip maturity defined by Graf's angle alpha. The infants in this study (1,037 infants, 2,034 hips) were examined as part of an ultrasound screening program for detecting DDH. We found that femoral head coverage is positively correlated with alpha angle, and we also found upper and lower threshold values of femoral head coverage (51% and 39%), such that all hips having these values or beyond had mature or pathological development, respectively. For the detection of hips having mature development, this provided a specificity of 100% (by definition) and a sensitivity of 82.6%. For hips having pathological development, specificity was 100% and sensitivity was 79.2%.

The lack of evidence of the effect of selective ultrasound screening on the incidence of late developmental dysplasia of the hip in the Greater Glasgow Region

The aim of our study was to establish whether the use of ultrasound to screen babies with risk factors has reduced the number of children presenting late with developmental dysplasia of the hip. Screening based on selection by risk factors was introduced in 1997. The average annual incidence from 1992 to 1996 was 0.84 and from 1997 to 2001 was 0.57 per 1000 live births. This decline in incidence of late developmental dysplasia of the hip was not significant (P=0.088). Sixty-four children (82%) had nothing that could be perceived as a risk factor for the condition. Our study presents population-based findings and it is clear that selective screening is not working in our region. It is unlikely that there will be one solution that could be applied throughout the United Kingdom given the diversity in the access to healthcare facilities. Clear leadership and accountability are required if we are to make any progress towards abolishing this condition that causes a significant morbidity in young adults.

Clinical examination versus ultrasonography in detecting developmental dysplasia of the hip

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

Ultrasound 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.

Late presenting dislocation of sonographically stable hips

We report on seven developmental hip dislocations in five babies (age 6-22 months) in whom ultrasound had demonstrated reduced and stable hips. Four hips in three babies had been diagnosed as having clinical instability (Barlow positive) at birth, which had stabilized by the time of the scan (16-45 days). Femoral head coverage ranged from 36 to 56%. One hip had minimal sonographic laxity on stress examination. Hips that are reduced and stable sonographically at 2-6 weeks of age can subsequently dislocate. Any child with instability at birth should be reviewed with a pelvic radiograph at 4-6 months, even if an ultrasound scan appears to be normal.

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

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

Ultrasonography in screening for developmental dysplasia of the hip in newborns: systematic review

OBJECTIVE

To assess the accuracy and effectiveness of the screening of all newborn infants for developmental dysplasia of the hip (DDH) using ultrasound imaging, as is standard practice in some European countries but not in the United Kingdom, the United States, or Scandinavia.

DESIGN

Systematic review.

DATA SOURCES

Twenty three medical, economic, and grey literature databases (to March 2004), with no limitations of design or language; some references were provided by experts.

SELECTION OF STUDIES

Only diagnostic accuracy studies and comparative studies conducted in an unselected newborn population were eligible for the review. Two reviewers independently selected the studies and performed the quality assessment.

RESULTS

The review identified one diagnostic accuracy study, and this was of limited quality. In this study the reference standard was treatment up to age of 8 months or an abnormal ultrasound finding at age 8 months. Ultrasound screening had a sensitivity of 88.5% (95% confidence interval 84.1% to 92.1%), specificity of 96.7% (96.4% to 97.4%), a positive predictive value of 61.6% and a negative predictive value of 99.4%. Ten studies evaluated the impact of ultrasound in screening, but these too had various methodological weaknesses, limiting the reliability of their findings. Compared with clinical screening, general ultrasound screening in newborns may increase overall treatment rates, but ultrasound screening seems to be associated with shorter and less intrusive treatment.

CONCLUSIONS

Clear evidence is lacking either for or against general ultrasound screening of newborn infants for DDH. Studies that investigate the natural course of the disorder, the optimal treatment for DDH, and the best strategy for ultrasound screening are needed.

Assessment of the use of hip ultrasonography by Graf's method between 1 and 6 years of age

Ultrasonographic examinations of both hips of 133 children whose age ranged from 13 to 72 months were performed using the Graf's method. A standard plane which was mandatory prior to the hip typing could be obtained in 93, 91, 84, 79 and 66% of the sonograms for 13-24, 25-36, 37-48, 49-60 and 61-72 months age groups, respectively. The 61-72 months age group had the lowest percentage of valid sonograms and this difference was considered significant (P=0.001). It was concluded that plain radiography was still the gold standard imaging technique in developmental dysplasia of the hip, but hip ultrasonography by the Graf's method might be an alternative imaging technique in experienced hands for the evaluation of developmental dysplasia of the hip in children between 1 and 5 years of age.