Determining the reliability of the Graf classification for hip dysplasia

Does This Infant Have a Dislocated Hip?: The Rational Clinical Examination Systematic Review

Importance

Delayed diagnosis of a dislocated hip in infants can lead to complex childhood surgery, interruption to family life, and premature osteoarthritis.

Objective

To evaluate the diagnostic accuracy of clinical examination in identifying dislocated hips in infants.

Data Sources

Systematic search of CINAHL, Embase, MEDLINE, and the Cochrane Library from the inception of each database until October 31, 2023.

Study Selection

The 9 included studies reported the diagnostic accuracy of the clinical examination (index test) in infants aged 3 months or younger and a diagnostic hip ultrasound (reference test). The Graf method of ultrasound assessment was used to classify hip abnormalities.

Data Extraction and Synthesis

The Rational Clinical Examination scale was used to assign levels of evidence and the Quality Assessment of Diagnostic Accuracy Studies tool was used to assess bias. Data were extracted using the individual hip as the unit of analysis; the data were pooled when the clinical examinations were evaluated by 3 or more of the included studies.

Main Outcomes and Measures

Sensitivity, specificity, and likelihood ratios (LRs) of identifying a dislocated hip were calculated.

Results

Among infants screened with a clinical examination and a diagnostic ultrasound in 5 studies, the prevalence of a dislocated hip (n = 37 859 hips) was 0.94% (95% CI, 0.28%-2.0%). There were 8 studies (n = 44 827 hips) that evaluated use of the Barlow maneuver and the Ortolani maneuver (dislocate and relocate an unstable hip); the maneuvers had a sensitivity of 46% (95% CI, 26%-67%), a specificity of 99.1% (95% CI, 97.9%-99.6%), a positive LR of 52 (95% CI, 21-127), and a negative LR of 0.55 (95% CI, 0.37-0.82). There were 3 studies (n = 22 472 hips) that evaluated limited hip abduction and had a sensitivity of 13% (95% CI, 3.3%-37%), a specificity of 97% (95% CI, 87%-99%), a positive LR of 3.6 (95% CI, 0.72-18), and a negative LR of 0.91 (95% CI, 0.76-1.1). One study (n = 13 096 hips) evaluated a clicking sound and had a sensitivity of 13% (95% CI, 6.4%-21%), a specificity of 92% (95% CI, 92%-93%), a positive LR of 1.6 (95% CI, 0.91-2.8), and a negative LR of 0.95 (95% CI, 0.88-1.0).

Conclusions and Relevance

In studies in which all infant hips were screened for developmental dysplasia of the hip, the prevalence of a dislocated hip was 0.94%. A positive LR for the Barlow and Ortolani maneuvers was the finding most associated with an increased likelihood of a dislocated hip. Limited hip abduction or a clicking sound had no clear diagnostic utility.

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.

Paediatric hip ultrasound

Aims

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

Methods

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

Results

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

Conclusion

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

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.

Analysis of the results of hip ultrasonography in 48 666 infants and efficacy studies of conservative treatment

PURPOSE

This study aimed to investigate the detection rate of developmental dysplasia of the hip (DDH) by ultrasound. To obtain the distribution characteristics of the different types (I-IV) and the role of ultrasound in the evaluation of infants with DDH (type IIc and above) receiving conservative treatment.

METHODS

A retrospective analysis was performed. The chi-square test was used for comparisons between count-data groups. Two-sided tests were used for all analyses. The results of ultrasound follow-up after conservative treatment are described.

RESULTS

Among the 48 666 infants examined, the detection rates were as follows: type I, 95.42%; IIa, 3.18%; IIb, 0.91%; IIc, 0.22%; D, 0.01%; III, 0.14%; and IV, 0.12%. There were 4456 hips with IIa and above, more left (54.65%) than right (45.35%) hips, and more females (82.60%) than males (17.40%). The detection rate of type IIa and above was 4.58%, and that of type IIb and above was 1.40%. After the treatment, the α value increased, and β value decreased. The cure rate of the less-than-42-days group was higher than that of the other groups.

CONCLUSION

The ultrasound detection rate of DDH is high. DDH was more likely to occur on the left side and in females. It is recommended that the infants should be treated within 42 days.

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

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

The evaluation of ultrasonographic hip measurement differences among physicians according to the Graf method in newborns

Background/Aim: Hip ultrasonography (USG) is the most important diagnostic method in developmental hip dysplasia in newborns. However, a disadvantage of the ultrasonography method is that there can be measurement differences among doctors measuring the same hip. We aimed to investigate the causes and solutions of this situation. We further strived to measure the hip ultrasonography performed by different physicians using the Graf method and comparing the obtained values. Methods: Hip USGs of newborns admitted to Malatya Turgut Ozal University Faculty of Medicine Hospital between Jan. 8, 2020 and Jan. 5,.2021 were measured and classified using the Graf method. The study type is consistent with retrospective cohort studies. Newborns aged 0-22 weeks without any additional pathology were included in the study. A radiologist and two orthopedists measured and interpreted the images separately in accordance with the Graf method. The first hip measurements (R1) were made by the radiologist (R) with the USG device, and they were classified according to alpha and beta angles; two printouts were made. The first orthopedic specialist (OS1) and the second orthopedic specialist (OS2) made their measurements with printouts. Subsequently, the results from the physicians were compared. Results: A statistically significant difference was found between R1-OS2 (P < 0.001) and OS1-OS2 (P < 0.001) in terms of the Graf classifications. No statistically significant difference was found between R1 and OS1 in terms of the Graf classification (P = 0.562). A statistically significant difference was found between R1-OS2 (P < 0.001) and OS1-OS2 (P = 0.048) angles (alpha and beta) measurements. While R1 and OS1 measurements were compatible with each other, OS2 measurements were found to be inconsistent. Conclusion: We think that there may be differences in angle measurements and the Graf classification among physicians who perform hip ultrasonography in newborns, and the most important way to correct this is through regular participation of physicians in subject-specific trainings.

Study on multiplanar measurements of infant hips with three-dimensional ultrasonography

PURPOSE

An automatic evaluation technology based on artificial intelligence and three-dimensional ultrasonography (3D US) is proposed for hip US inspection plane selection. This study aimed to evaluate the consistency of the α angle as measured using 3D US to select the section plane and two-dimensional ultrasonography (2D US) to manually select the Graf image, as well as to explore the feasibility of diagnosing developmental dysplasia of the hip (DDH) using 3D US and reconstruction technology.

METHODS

A total of 216 infant hips were included and assessed by doctors using 3D US layer-by-layer. The researchers used a computer to identify the coronal images that met the Graf standard and then compared the α_X values obtained with the α_G values measured artificially by 2D US.

RESULTS

Compared with 2D US, 3D US more clearly showed the relative positions of the ilium, ischia, and pubis. The measured α value of the optimal section obtained by 3D US showed good agreement with the measured α value of the standard Graf section.

CONCLUSION

The artificial intelligence and 3D US-based automatic evaluation technology for section selection and inspection for DDH showed good agreement with the Graf method based on standard sections.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Development of an electronic navigation system for elimination of examiner-dependent factors in the ultrasound screening for developmental dysplasia of the hip in newborns

To develop an electronic navigation system to increase reliability and comparability in the ultrasound screening of developmental dysplasia of the hip (DDH). The impact of the navigation system on transducer positioning and on sonographic measurements according to Graf was analyzed. Twenty hips in newborns were examined sonographically using a new navigation system capable of detecting the transducer and pelvis position in order to calculate the relative tilt in the frontal, axial, and sagittal-plane. In each newborn an ultrasound image was obtained conventionally according to Graf and a second image using the sonographic navigation system. Relative roll and pitch angles and sonographic measurements were analyzed using paired T-tests and Levene-tests. Relative tilt angles in the conventional group ranged from − 8.9° to 14.3° (frontal-plane) and − 23.8° to 14.2° (axial-plane). In the navigation-assisted group ranges from − 3.0° to 3.5° and − 2.8° to 4.5° were observed. Variances were significantly lower in the navigation-assisted group (p < 0.001 and p = 0.004 respectively). The navigation system allowed for a significant reduction of relative tilt angles between the transducer and the newborn pelvis, thus supporting an optimal transducer positioning. This is a promising approach to improve reproducibility and reliability in the ultrasound screening for DDH.

Interpreting neonatal hip sonography: intraobserver and interobserver variability

The purpose of this study is to state the reliability of neonatal hip ultrasound interpretation, defining the intra and interoperator variability in the evaluation of the scans. We considered a sample of 2071 scans (coming from 798 patients who attended the screening programme for hip dysplasia), which were interpreted by the operator who obtained and read the images at the screening time and then by a different operator who saw the images for the first time. Both the intra and interoperator variability of α and β angles' values resulted statistically not significative (intraclass correlation coefficient > 0.8) and determining a class shift (according to the Graf's classification) in a nonstatistically significative number of cases (agreement percentage >91% and Cohen's κ >0.8). Hip sonography can reliably detect hip dysplasia and the intra and interoperator variability in the interpretation of the exam is NS when the examination is correctly executed.

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

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

A Systematic Review and Meta-analysis on the Reproducibility of Ultrasound-based Metrics for Assessing Developmental Dysplasia of the Hip

BACKGROUND

The purposes of this study were to (1) perform a systematic review of articles that reported agreement or reproducibility in repeated diagnosis of developmental dysplasia of the hip (DDH) using ultrasound imaging, (2) estimate the reproducibility in the available dysplasia metrics, and (3) compare reproducibility of the available dysplasia metrics.

METHODS

A systematic review of the Medline and Embase databases was performed by using a search strategy formulated from our research question: "For infants at risk of DDH, are US imaging-based diagnoses reproducible?" Two reviewers independently identified articles for inclusion in the systematic review, and then assessed the quality of the included studies using the Guidelines for Reporting Reliability and Agreement Studies guideline. Variability and agreement-related statistics in the included studies were extracted and included in a meta-analysis for summarizing the available statistics. The reproducibility of the available dysplasia metrics was compared, with a Bonferroni correction made to adjust for multiple comparisons.

RESULTS

Twenty eight studies were included in the systematic review. Overall, the quality of the included studies was moderate (average, 10.7/15; range, 6 to 12). Graf's alpha angle had the lowest interexamination variability of the metrics assessed, followed by Graf's beta angle (the variability of the alpha angle was 10% lower than the variability of the beta angle, P<0.05). However, despite Graf's angles having lower variability compared with other dysplasia metrics, their actual variability was still problematically high. This finding was supported by the low intraclass correlation and Kappa coefficient values reported in the included studies. There was also evidence to suggest that the reproducibility in DDH diagnosis has potentially worsened over time.

CONCLUSIONS

Overall, we found high variability and low agreement in all reported dysplasia metrics. Furthermore, in the last 3 decades, the repeatability of dysplasia metrics has not markedly improved and may even have declined, indicating a genuine need for improving repeatability and reliability of ultrasound-based DDH diagnosis.

LEVEL OF EVIDENCE

Level III-systematic review of level III studies.

Values for bony acetabular roof angle and percentage femoral head cover in a selective ultrasound neonatal hip-screening programme: effect of age, sex and side

Published maturation curves for bony acetabular roof or α angle (AA) and percentage femoral head cover (FHC) with age are sparse. We aimed to determine typical values for AA and FHC in 2236 infants referred to a selective ultrasound screening programme. There was increase in the values of first measurement of AA and FHC related to the logarithm of age. Males had greater values than females (P<0.001) and right hips had greater values than left (P<0.001) for both measurements. Significant side differences have not been reported previously. Treatment decisions should be made on the basis of sex, side and age-specific data.

Screening in Developmental Dysplasia of the Hip (DDH)

Screening for Developmental Dysplasia of the Hip (DDH) is a controversial subject. Screening may be by universal neonatal clinical examination (Ortolani or Barlow manoeuvres) with the addition of sonographic imaging of the hip (selective 'at risk' hips or universal screening in the neonate). In the UK, the NIPE guidelines recommend universal neonatal clinical assessment of the hip joints, a General Practitioner 6-8 week clinical 'hip check' and assessment clinically with sonographic imaging at 4-6 weeks for certain 'at risk' hips for pathological DDH. The effectiveness and difficulties arising from the UK current screening policy (clinical and sonographic) are highlighted. The purpose of the review was to assess the risk factors and efficacy of diagnostic methods in DDH, based on longitudinal cohort studies of 10 years or more.

CONCLUSION

Hip screening in DDH does not meet most of the World Health Organisation's criteria for an effective screening programme and should only be considered as surveillance due to its low sensitivity and positive predictive value (PPV). There is a significant risk of over diagnosis and over treatment. There is no International consensus on screening in DDH. Pathological DDH is mainly a female condition and 'at risk'/General Practitioner screening identifies few pathological cases in male subjects. The General Practitioner 6-8 week 'hip check' has a very low PPV for pathological DDH and is of doubtful value in screening and diagnosis. Unilateral limitation of hip abduction is a time dependent and useful clinical sign in the diagnosis of pathological DDH. The majority of the previously considered 'at risk' factors are not true risk factors with little or no association with pathological DDH.

Higher Pavlik Harness Treatment Failure Is Seen in Graf Type IV Ortolani-positive Hips in Males

BACKGROUND

Patients with developmental dysplasia of the hip (DDH) whose hips are dislocated but reducible (Ortolani positive) are more likely to experience Pavlik harness treatment failure than are patients with dysplastic and reduced but dislocatable (Barlow positive) hips. However, data regarding factors associated with failure are limited and conflicting.

QUESTIONS/PURPOSES

We asked: (1) What is the frequency of Pavlik harness treatment failure among Ortolani-positive hips, Barlow-positive hips, and dysplastic hips? (2) What are the factors predictive of failure of Pavlik harness treatment for Ortolani-positive hips?

METHODS

In this retrospective study we identified 150 patients who underwent the Pavlik harness method for treatment of DDH between August 2011 and July 2015. Six patients initially treated at an outside facility, four patients with associated conditions, and three who pursued treatment elsewhere were excluded. A total of 137 patients (215 hips) with a median age at the time of Pavlik placement of 30 days (range, 4-155 days) were included. Of the 215 hips, 78 (36.3%) were Ortolani positive, 60 (27.9%) were Barlow positive, and 77 (35.8%) were stable, with the diagnosis of dysplasia made on ultrasound. All patients were treated with the Pavlik harness method. The primary outcome was failure of the Pavlik harness to achieve and maintain concentric hip reduction assessed by examination and ultrasound. All patients were followed after completion of Pavlik treatment for a minimum of 2 months (mean, 3 months; range, 2-4 months). In addition, 90% (122 of 137) of the patients were followed for a minimum of 6 months. Patient-specific data including family history, breech versus cephalic presentation at birth, age, sex, laterality, and hip abduction were recorded. Ultrasound data at the time of diagnosis included Graf classification, alpha angle, and percentage of femoral head coverage.

RESULTS

The Pavlik harness method failed in 27% (21 of 78) of hips that were Ortolani positive, 8% (six of 77) with dysplasia, and 5% (three of 60) that were Barlow positive. After controlling for potential confounding variables, such as range of hip abduction, male sex (adjusted odds ratio [OR], 6.9; 95% CI, 2.0-24.2; p = 0.002) and Graf Type IV ultrasound classification (dislocated hip with alpha angle less than 43° and labrum displaced downward) (OR, 4.4; 95% CI, 1.3-15.4; p = 0.019) were identified as independent predictors of failure of Pavlik treatment among Ortolani-positive hips.

CONCLUSIONS

Ultrasound imaging of the hip should be part of the initial assessment for Ortolani-positive hips, as the ultrasound classification was found to have prognostic implications. Parents of male infants with Graf Type IV hips should be counseled regarding the higher risk of Pavlik failure. Future well-designed prospective controlled studies are necessary to establish whether alternative strategies to the Pavlik harness might improve the early outcomes of DDH in males with Graf Type IV hips.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Reliability of Computer-Assisted and Manual Measurement Methods for Assessment of Graf Type 1 and Type 2 Hip Sonograms

OBJECTIVES

The purpose of this study was to investigate the interobserver, intraobserver, and intermethod reliability of computer-assisted digital and manual measurements of hip sonograms.

METHODS

Seventy-four hip sonograms were evaluated in this retrospective study. Five evaluators measured digital images and manual paper printouts according to the Graf method (Arch Orthop Trauma Surg 1984; 102:248-255). Interobserver and intraobserver reliability rates were calculated. Reliability criteria were graded on a numeric scale.

RESULTS

The interobserver reliability of both computer-based and manual methods for alpha angle measurements was good to excellent, but the interobserver reliability was fair to poor for beta angle measurements. Intraobserver reliability was varied. Alpha angle measurements by both manual and computer-based methods had high concordance with each other, whereas beta angle measurements had low concordance. The intermethod variability did not differ between observers.

CONCLUSIONS

The alpha angle measurements had high concordance with each other for both manual and computer-based methods, whereas the beta angle measurements had low concordance. This information should be taken into account in clinical practice. Overall, the two measurement methods were reliable and consistent with each other.

Imaging update on developmental dysplasia of the hip with the role of MRI

OBJECTIVE

The purpose of this article is to review developmental dysplasia of the hip (DDH), a well-described entity previously evaluated with a standard multimodality imaging algorithm, typically consisting of ultrasound and radiography depending on patient age.

CONCLUSION

MRI is increasingly used because it is a noninvasive imaging modality that offers excellent anatomic detail, enabling the differentiation of ossified and unossified components of the hip. The radiologist should be aware of the increasing role of MRI and recognize the critical MRI findings of DDH.

Diagnostic yield of sonography in infants with suspected hip dysplasia: diagnostic thinking efficiency and therapeutic efficiency

OBJECTIVE

The purpose of this study is to determine the impact of sonographic information on surgeons' diagnostic thinking and decision making in the management of infants with a possible diagnosis of developmental dysplasia of the hip (DDH).

SUBJECTS AND METHODS

Five experienced orthopedic surgeons examined 66 hips of infants who were referred for a possible diagnosis of DDH and reported for each hip a confidence level about the diagnosis of DDH using a visual analog scale (VAS) before and after hip sonography was obtained. In addition, they reported a management plan. We determined the efficiency in diagnostic thinking by calculating the mean gain in diagnostic confidence as the percentage change in VAS scores and the impact of sonography on the management plan (therapeutic efficiency).

RESULTS

Sonography led to a change in diagnosis in 52% (34/66) of hips. The management plan changed in 32% (21/66) of hips. The mean gain in reported diagnostic confidence was 19.4% (95% CI, 17.3-21.5%), but it was 46.0% (95% CI, 30.5-60.8%) in cases where the management changed as a result of sonography (difference, 37.7%; p < 0.0001). The greatest yield of sonography was found in hips showing limited abduction. Sonography obviated further follow-up in 23% (15/66) of cases.

CONCLUSION

Sonography refined the diagnostic thinking of clinicians and led to a change in diagnosis in 52% of cases. Management plans changed in 32% of cases.

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.

Weighted diagnostic criteria for developmental dysplasia of the hip

OBJECTIVE

To establish clinical diagnostic criteria for developmental dysplasia of the hip (DDH) that model the practices of expert clinicians.

STUDY DESIGN

Of 23 clinical criteria for the diagnosis of DDH, ranked in order of diagnostic importance by international consensus, the 7 most highly ranked were placed in all possible combinations to create unique case vignettes. Twenty-six experts rated 52 vignettes for the presence of DDH. We modeled the data to determine which of the 7 criteria were associated with a clinician's opinion that the vignette represented DDH. From the resulting regression coefficients, for each vignette we calculated a probability of DDH. An independent panel rated the same vignettes using a visual analog scale response. We correlated the visual analog scale ratings with probabilities derived from the model.

RESULTS

Our model identified 4 of 7 criteria as predictive of DDH (P < .001): Ortolani/Barlow test (β = 3.26), limited abduction (β = 1.48), leg length discrepancy (β = 0.74), and first-degree family history of DDH (β = 1.39). There was substantial correlation between the probability of DDH predicted by the model and that derived from an independent expert panel (r = 0.73; P < .001).

CONCLUSION

Weighted clinical criteria for inferring the likelihood of DDH produced consistent results in the judgment of 2 separate groups of experts. Using these weights, nonexperts could establish the probability of DDH in a manner approaching the practice of clinical experts.

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.

Is it worthwhile to screen the hip in infants born with clubfeet?

PURPOSE

There is some disagreement about whether idiopathic congenital talipes equinovarus (CTEV) increases the risk of neonatal developmental dysplasia of the hip (DDH). This study aimed to investigate the incidence of DDH in our infants with idiopathic CTEV.

METHODS

We conducted an observational cohort study over a three-year period to assess the relationship between idiopathic CTEV and DDH. All neonates younger than six weeks with idiopathic CTEV who were treated in our medical centre were admitted to this study. Each subject underwent hip ultrasound examination using the Graf method at the age of six weeks. DDH was diagnosed when a hip was type IIa(-) or worse according to the Graf classification of sonographic hip type.

RESULTS

A total of 184 patients were diagnosed with idiopathic CTEV and underwent hip sonography. In total, seven hips of five individuals underwent treatment (four girls and one boy). The results indicated that 2.7% of babies (five of 184) with idiopathic CTEV had DDH. However, we did not find any statistically significant difference (p = 0.5776) in the Pirani scores between the DDH group and group with normal hips.

CONCLUSIONS

This study revealed that the idiopathic CTEV group had a greater incidence of DDH in comparison with the general population. It is recommended that hip sonography be undertaken particularly in patients with idiopathic CTEV.

Reliability of Bucholz and Ogden classification for osteonecrosis secondary to developmental dysplasia of the hip

BACKGROUND

Osteonecrosis is perhaps the most important serious complication after treatment of developmental dysplasia of the hip (DDH). The classification by Bucholz and Ogden has been used most frequently for grading osteonecrosis in this context, but its reliability is not established and unreliability could affect the validity of studies reporting the outcome of treatment.

QUESTIONS/PURPOSE

We established the interrater and intrarater reliabilities of this classification and analyzed the frequency and nature of disagreements.

METHODS

Three pediatric hip surgeons, a musculoskeletal pediatric radiologist, and three orthopaedic trainees graded 39 radiographs (hips) according to the Bucholz and Ogden classification, blinded to any clinical data. Ratings were repeated after 2 weeks. Interrater reliability and intrarater reliability were determined using the simple kappa statistic. Grading was compared among raters, the nature and frequency of disagreements established, and subgroup analyses performed.

RESULTS

Interrater reliability was 0.34 (95% CI = 0.28, 0.40) for all raters, and 0.31 (0.20 to 0.43) for the three surgeons. The best interrater reliability was observed between the radiologist and a surgeon with a kappa of 0.51 (0.30, 0.72). Intrarater reliability estimates ranged from 0.44 to 0.69. Raters disagreed regarding the grade of osteonecrosis in 26 of 39 hips (67%), with seven of 26 disagreements (27%) involving confusion between Grades I and II.

CONCLUSIONS

The interrater reliability was lower than expected, considering the raters' experience. Distinguishing between Grades I and II was the most frequently observed problem. We believe that the low reliability was a result of an ambiguous classification scheme rather than the variability among the raters. Outcome studies of DDH based on this classification should be interpreted with caution. We recommend the development of a new classification with better prognostic ability.

LEVEL OF EVIDENCE

Level III, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Standardized diagnostic criteria for developmental dysplasia of the hip in early infancy

BACKGROUND

Clinicians use various criteria to diagnose developmental dysplasia of the hip (DDH) in early infancy, but the importance of these various criteria for a definite diagnosis is controversial. The lack of uniform, widely agreed-on diagnostic criteria for DDH in patients in this age group may result in a delay in diagnosis of some patients.

QUESTIONS/PURPOSES

Our purpose was to establish a consensus among pediatric orthopaedic surgeons worldwide regarding the most relevant criteria for diagnosis of DDH in infants younger than 9 weeks.

MATERIAL AND METHODS

We identified 212 potential criteria relevant for diagnosing DDH in infants by surveying 467 professionals. We used the Delphi technique to reach a consensus regarding the most important criteria. We then sent the survey to 261 orthopaedic surgeons from 34 countries.

RESULTS

The response rate was 75%. Thirty-seven items were identified by surgeons as most relevant to diagnose DDH in patients in this age group. Of these, 10 of 37 (27%) related to patient characteristics and history, 13 of 37 (35%) to clinical examination, 11 of 37 (30%) to ultrasound, and three of 37 (8%) to radiography. A Cronbach alpha of 0.9 for both iterations suggested consensus among the panelists.

CONCLUSION

We established a consensus regarding the most relevant criteria for the diagnosis of DDH in early infancy and established their relative importance on an international basis. The highest ranked clinical criteria included the Ortolani/Barlow test, asymmetry in abduction of 20° or greater, breech presentation, leg-length discrepancy, and first-degree relative treated for DDH.

LEVEL OF EVIDENCE

Level IV, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

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.

Diagnosis and treatment of developmental dysplasia of the hip in the Netherlands: national questionnaire of paediatric orthopaedic surgeons on current practice in children less than 1 year old

PURPOSE: There is no consensus in the literature regarding the diagnosis and treatment of developmental dysplasia of the hip (DDH). We designed a national questionnaire to assess the various opinions and current practice of paediatric orthopaedic surgeons in the Netherlands regarding the diagnosis and treatment of DDH in children less than 1 year old. METHODS: The questionnaire was sent to all members of the Dutch Paediatric Orthopaedic Society (DPOS). It discusses different methods and criteria used in the diagnosis of DDH, the use of different therapies and the use of different imaging techniques to evaluate the result of treatment. RESULTS: With 38 responders, the overall response rate to the survey was 67%. Most surgeons use clinical, radiographic and/or ultrasound examination for the diagnosis. The starting point of treatment is usually on the mild part of the DDH spectrum. The Pavlik harness is most popular in the treatment of dislocated hips, whereas in dysplastic hips, most surgeons use a rigid splint. The duration of treatment has a wide range and evaluation of the effect of treatment is predominantly done by radiography. CONCLUSIONS: The diagnosis and treatment of DDH in the Netherlands has as much diversity as the literature has recommendations about this subject. The lack of consensus on many aspects of DDH diagnosis and treatment should form the basis for a discussion among Dutch paediatric orthopaedic surgeons. Using the available evidence, it should be possible to formulate a more uniform protocol for the diagnosis and treatment of DDH.

Ultrasound screening for developmental dysplasia of the hip in the newborn: a population-based study in the Maribor region, 1997-2005

AIM

Ultrasound imaging has become an accepted tool for accurate diagnosis of developmental dysplasia of the hip (DDH) and for its management. The aim of the present study was to evaluate the results of the general neonatal hip screening program in Maribor between 1997 and 2005 in comparison with earlier reported results for our region, where this program was introduced in 1985.

PATIENTS AND METHODS

Of the total number of 17,846 newborns born in our maternity hospital, 17,393 were included in the study during the nine-year period. All hips were examined by ultrasonography within the first week of life. Data for 2.5% of newborns were not available. The incidence of sonographic hip types according to the Graf method was analyzed, together with the sex distribution, lateralization of hip pathology and treatment recommendations.

RESULTS

A total of 34,786 hips were evaluated sonographically: 84.9% of hips were mature at first examination (Graf types Ia and Ib), 14.1% were immature (Graf type IIa) and 1.1% were pathological (Graf types IIc or worse). In the group of pathological hips, girls were more frequently affected than boys (3.9:1) and the left hip was more frequently affected than the right (1.2:1). The incidence of hip types IIc or worse decreased sevenfold throughout the observation period, from 2.1 in 1997 to 0.3 in 2005. This distribution of hip types resulted in an average treatment rate of 18 newborns per 1000 live borns, down from 42 treated hips per 1000 newborns in 1997 to 6 hips per 1000 in 2005. During this nine-year period, only 19 children required surgical treatment for DDH before the age of three years.

CONCLUSION

In our region, general ultrasound hip screening of newborns for DDH seems to be effective in reducing the overall treatment rate. The number of surgical procedures has remained stable during the past nine-year screening period and is lower than in the pre-ultrasound era.

Associated risk factors in children who had late presentation of developmental dysplasia of the hip

PURPOSE

The purpose of this study was to assess the role of clinical examination, associated risk factors and plain radiograph of the pelvis in children who had late presentation of DDH.

METHODS

We report on a 7-year prospective study, in children who had late presentation of developmental dysplasia of the hip (DDH). For this purpose, 740 hips in 370 referred children, age range 3-7 months (mean 3.44 months) were clinically and radiologically assessed, and the associated risk factors recorded.

RESULTS

Female sex, first born, positive family history and breech presentation were confirmed as risk factors for DDH. Significant findings were an increased risk for vaginal delivery over caesarean section for breech presentation (P = 0.002). There was an increased risk for caesarean section in the absence of breech presentation. Multiple births and preterm births had a reduced risk. For breech presentation, the risk of DDH was estimated to be at least 1.6% for girls and 3.4% for boys; a combination of factors increased the risk. Limitation of abduction (43.2%) and asymmetry of the groin skin folds (72.7%) were found to be the two most common clinical findings associated with DDH. Bilateral acetabular dysplasia is more common than unilateral dysplasia. Foot deformities were rarely encountered in children with acetabular dysplasia.

CONCLUSIONS

The percentage of first-born babies who had DDH is lower than reported in the literature (34%), but still shows significant risk. We did find that bilateral acetabular dysplasia is more common than unilateral dysplasia. Torticollis and foot deformities are rarely found to be associated with DDH. All these findings needs further evaluation in children who had surgical treatment for DDH, to see if they are different from dysplastic groups. Limitation of abduction is an important clinical finding, but is not always associated with DDH. Asymmetry of the skin folds in the groin were found to be an important clinical finding associated with DDH for all age groups. As clinical examination depends on many factors, and most DDH cases are of the dysplastic type, it is mandatory to depend on further diagnostic tools for confirmation of DDH.