Predicting developmental dysplasia of the hip in at-risk newborns

Risk factors of developmental dysplasia of the hip in infants: A meta-analysis based on cohort studies

INTRODUCTION

Developmental dysplasia of the hip (DDH) is a prevalent condition in children. Currently, the exact etiology of DDH remains uncertain. The objective of this study was to conduct a meta-analysis to investigate the risk factors associated with DDH in infants. The findings would provide a theoretical foundation for targeted early screening and diagnosis.

HYPOTHESIS

Several indicators, such as gender, intrauterine position, family history of DDH, gestational age, delivery mode, amniotic fluid levels, swaddling, parity, fetus number, combined musculoskeletal deformities, birth weight, and physical examination results, may serve as risk factors for DDH.

MATERIALS AND METHODS

Cohort studies investigating the risk factors of DDH in infants through logistic regression analysis were searched in the Wanfang, VIP citation, China National Knowledge Infrastructure (CNKI), China Biology Medicine disc, Excerpta Medica Database (Embase), PubMed, and Cochrane Library databases up to May 2023. After extracting the data from eligible literature and assessing them using the Newcastle-Ottawa Scale (NOS), articles were selected based on pre-established inclusion and exclusion criteria.

RESULTS

A total of eleven literature reports covering 979,757 infants were included in this meta-analysis. The publication bias did not significantly influence the results. The incidence rate of DDH was 47.99‰ among infants with risk factors compared to 3.21‰ in the general population. Risk factors for DDH included being female (OR=6.97, 95% CI: 5.18-9.39, p<0.001), breech delivery (OR=4.14, 95% CI: 3.09-5.54, p<0.001), positive family history (OR=4.07, 95% CI: 2.20-7.52, p<0.001), cesarean section (OR=1.11, 95% CI: 1.01-1.21, p=0.032), oligohydramnios (OR=3.93, 95% CI: 1.29-12.01, p=0.016), swaddling (OR=6.74, 95% CI: 1.25-36.31, p=0.026), firstborn status (OR=1.84, 95% CI: 1.49-2.53, p<0.001), combined musculoskeletal malformations (OR=2.27, 95% CI: 1.58-3.27, p<0.001), and physical signs of DDH (OR=8.71, 95% CI: 2.44-31.07, p=0.001). Premature delivery (OR=0.91, 95% CI: 0.88-0.95, p<0.001) was a protective factor for DDH. The relationship between multiple pregnancies (OR=0.58, 95% CI: 0.33-1.02, p=0.060) and low birth weight (OR=0.62, 95% CI: 0.14-2.76, p=0.529) in relation to DDH remained uncertain.

DISCUSSION

This meta-analysis shows that female, breech delivery, positive family history, cesarean section, firstborn status, oligohydramnios, swaddling and combined musculoskeletal malformations are associated with DDH. Premature delivery appeared to be a protective factor against DDH. Nevertheless, the other factors need more research to reach more conclusive results.

LEVEL OF EVIDENCE

III; meta-analysis.

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.

Environmental and Genetic Risk Factors in Developmental Dysplasia of the Hip for Early Detection of the Affected Population

Diagnosis of developmental dysplasia of the hip (DDH) mostly relies on physical examination and ultrasound, and both methods are operator-dependent. Late detection can lead to complications in young adults. Current evidence supports the involvement of environmental and genetic factors, such as single nucleotide variants (SNVs). Incorporating genetic factors into diagnostic methods would be useful for implementing early detection and management of affected individuals. Our aim was to analyze environmental factors and SNVs in DDH patients. We included 287 DDH cases and 284 controls. Logistic regression demonstrated an association for sex (OR 9.85, 95% CI 5.55-17.46, p = 0.0001), family history (OR 2.4, 95% CI 1.2-4.5, p = 0.006), fetal presentation (OR 3.19, 95% CI 1.55-6.54, p = 0.002), and oligohydramnios (OR 2.74, 95%CI 1.12-6.70, p = 0.026). A model predicting the risk of DDH including these variables showed sensitivity, specificity, PPV, and NPV of 0.91, 0.53, 0.74, and 0.80 respectively. The SNV rs1800470 in TGFB1 showed an association when adjusted for covariables, OR 0.49 (95% CI 0.27-0.90), p = 0.02. When rs1800470 was included in the equation, sensitivity, specificity, PPV and NPV were 0.90, 0.61, 0.84, and 0.73, respectively. Incorporating no-operator dependent variables and SNVs in detection methods could be useful for establishing uniform clinical guidelines and optimizing health resources.

Why all newborn hip screening programs have same results-a mini review

All newborns are screened for developmental dysplasia of the hip (DDH), but countries have varying screening practices. The aim of this narrative mini review is to discuss the controversies of the screening and why it seems that all screening programs are likely to have same outcome. Different screening strategies are discussed alongside with other factors influencing DDH in this review. Universal ultrasound (US) has been praised as it finds more immature hips than clinical examination, but it has not been proven to reduce the rates of late-detected DDH or surgical management. Universal US screening increases initial treatment rates, while selective US and clinical screening have similar outcomes regarding late detection rates than universal US. This can be explained by the extrinsic factor affecting the development of the hip joint after birth and thus initial screening during the early weeks cannot find these cases.  Conclusion: It seems that DDH screening strategies have strengths and limitations without notable differences in the most severe outcomes (late-detected cases requiring operative treatment). Thus, it is important to acknowledge that the used screening policy is a combination of values and available resources rather than a decision based on clear evidence.

Birthweight correlates to pubo-femoral distances and α angles in hip ultrasound of newborns at 6 weeks of age: a retrospective cohort study

BACKGROUND AND PURPOSE

There is inconsistency in the literature regarding the relationship between increased birthweight and risk of developmental dysplasia of the hip (DDH). We aimed to investigate the correlation between birthweight and pubo-femoral distance (PFD), as well as Graf's α angle in newborns undergoing hip ultrasound examination at 6 weeks of age.

PATIENTS AND METHODS

Basic newborn characteristics and ultrasound measurements were retrospectively collected during a 1-year study period. We excluded multiple births, newborns born at less than 37 gestational weeks, and incomplete information. Simple and multiple linear regression analyses were performed to evaluate the correlation of birthweight and PFD, and, second, birthweight and α angles including a stratified regression analysis investigating the potential effect modification of sex.

RESULTS

707 newborns (1,414 hips) were included. Mean birthweight was significantly higher for male newborns (P < 0.001). Increased birthweight was positively correlated to PFD values (crude coefficient 0.21, 95% confidence interval [CI] 0.10-0.32) and the correlation was still present after adjusting for sex, family history, and breech presentation (adjusted coefficient 0.18, CI 0.07-0.29). The stratified α angle model for the males was significant for both the crude coefficient (-0.73, CI -1.28 to -0.19) and the adjusted (-0.59, CI -1.15 to -0.03), and also for the females (crude coefficient -1.14, CI -1.98 to -0.31 and adjusted coefficient -1.15, CI -1.99 to -0.31).

CONCLUSION

We found that increased birthweight positively correlated to PFD, and negatively correlated to α angle, but this was not of clinical significance.

Universal in-house neonatal hips ultrasonography screening in the United Arab Emirates

OBJECTIVES

To investigate if the incidence of developmental dysplasia of the hip (DDH) differs considering the geographical origin, clinical picture, or presence of risk factors in homogenous cohort of neonates born in Mediclinic Al Jowhara hospital, Al Ain, United Arab of Emirates (UAE).

METHODS

Universal ultrasonography hips screening of the neonates in the maternity ward of Mediclinic Al Jowhara hospital, Al Ain, UAE, was carried out using the Graf method. The average age of the neonates was 3 days. Two groups were formed for comparison: I) the Gulf Cooperation Council (GCC) group (n=169, 47.7%), and II) the non-GCC group (n=185, 52.3%).

RESULTS

The incidence of DDH was 1.7%. It was higher among neonates from the GCC region (2.9%) and significantly higher among girls from this region (6.3%). The incidence of immature hips (type IIa) was 9% and was similar regardless of origin or gender.

CONCLUSION

Neonates from the GCC region, girls in particular, have a higher incidence of DDH. These results highlight the emergency to establish a national ultrasonography DDH screening program.

The Influence of Risk Factors in the Early Detection of Developmental Dysplasia of the Hip in a Country with Limited Material Resources

Developmental dysplasia of the hip (DDH) is a condition that includes a wide spectrum of anomalies ranging from simple instability with ligamentous hyperlaxity to the complete displacement of the femoral head outside the abnormally developed cotyloid cavity. Early detection and initiation of treatment allow "restitutio ad integrum" healing, which has raised the medical community's interest in early diagnosis. However, in countries with limited material resources, where echographic screening is not performed, efforts are being made to increase the sensitivity of clinical screening. Thus, the concept of "hip at risk" is taking shape worldwide. This is the normal clinical hip, but associated with one or more risk factors. We conducted a retrospective study for the period 2010-2015 with patients who presented in the ambulatory clinic of the St. John Children's Clinical Hospital, Galati. The study included 560 patients, who were all examined clinically and sonographically, according to the Graf method, by a senior orthopedic doctor with competence in hip sonography. The data obtained from the anamnesis, clinical examination, and ultrasound examination were recorded in the DDH file. The goal of the statistical analysis of the group of patients was to find a correlation between DDH and the risk factors used in the clinical detection of this pathology. In the studied group, four risk factors were identified that have an increased association with DDH: female sex, pelvic presentation, limitation of coxo-femoral abduction, and congenital clubfoot; thus, the conclusion of the study is that patients who have at least one of the listed risk factors should be examined sonographically as quickly as possible. The early ultrasound examination will allow the identification of the disease and the initiation of treatment.

Sample size requirements are not being considered in studies developing prediction models for binary outcomes: a systematic review

BACKGROUND

Having an appropriate sample size is important when developing a clinical prediction model. We aimed to review how sample size is considered in studies developing a prediction model for a binary outcome.

METHODS

We searched PubMed for studies published between 01/07/2020 and 30/07/2020 and reviewed the sample size calculations used to develop the prediction models. Using the available information, we calculated the minimum sample size that would be needed to estimate overall risk and minimise overfitting in each study and summarised the difference between the calculated and used sample size.

RESULTS

A total of 119 studies were included, of which nine studies provided sample size justification (8%). The recommended minimum sample size could be calculated for 94 studies: 73% (95% CI: 63-82%) used sample sizes lower than required to estimate overall risk and minimise overfitting including 26% studies that used sample sizes lower than required to estimate overall risk only. A similar number of studies did not meet the ≥ 10EPV criteria (75%, 95% CI: 66-84%). The median deficit of the number of events used to develop a model was 75 [IQR: 234 lower to 7 higher]) which reduced to 63 if the total available data (before any data splitting) was used [IQR:225 lower to 7 higher]. Studies that met the minimum required sample size had a median c-statistic of 0.84 (IQR:0.80 to 0.9) and studies where the minimum sample size was not met had a median c-statistic of 0.83 (IQR: 0.75 to 0.9). Studies that met the ≥ 10 EPP criteria had a median c-statistic of 0.80 (IQR: 0.73 to 0.84).

CONCLUSIONS

Prediction models are often developed with no sample size calculation, as a consequence many are too small to precisely estimate the overall risk. We encourage researchers to justify, perform and report sample size calculations when developing a prediction model.

Validation of parameters recommended for secondary screening for developmental dysplasia of the hip in Japan

BACKGROUND

Based on the Japanese Pediatric Orthopaedic Association's guidelines, secondary screening and imaging including ultrasonography and radiography, are recommended in infants with limited hip abduction (<70°) or in those with multiple risk factors including the following: asymmetrical skin creases, a family history of developmental dysplasia of the hip, female sex, and pelvic position at delivery. However, there is still little information regarding the usefulness of this guideline. The objective of this study was to investigate the association between the risk factors and developmental dysplasia of the hip diagnosed using ultrasound and radiography.

METHODS

A total of 356 infants (67 boys and 289 girls) underwent secondary ultrasonographic and radiological screening for developmental dysplasia of the hip in our hospital. Risk factors were documented from their medical records. The recommended item score, which we defined as an integrated value of the recommended item, was calculated for each patient. The limitation of hip abduction alone was a criterion for secondary screening; therefore, we defined the scores as follows: the limitation of hip abduction scored 2 points and other recommended scores were assigned 1 point. If the recommended item score was 2 points or more, we classified the infants as high-risk.

RESULTS

A total of 280 of 356 infants were included in the high-risk group, which showed a higher ratio of cases with abnormal imaging findings than the low-risk group. According to the multivariate logistic regression analyses among the recommended items, being female, skin asymmetry, and limb limitation were identified as independent risk factors for imaging abnormality and the need for Pavlik harness treatment.

CONCLUSIONS

The recommended items for secondary screening based on the Japanese Pediatric Orthopaedic Association's guidelines could be useful for screening infants in need of treatment.

The cost effectiveness of potential risk factors for developmental dysplasia of the hip within a national screening programme

Aims

Early detection of developmental dysplasia of the hip (DDH) is associated with improved outcomes of conservative treatment. Therefore, we aimed to evaluate a novel screening programme that included both the primary risk factors of breech presentation and family history, and the secondary risk factors of oligohydramnios and foot deformities.

Methods

A five-year prospective registry study investigating every live birth in the study’s catchment area (n = 27,731), all of whom underwent screening for risk factors and examination at the newborn and six- to eight-week neonatal examination and review. DDH was diagnosed using ultrasonography and the Graf classification system, defined as grade IIb or above or rapidly regressing IIa disease (≥4^o at four weeks follow-up). Multivariate odds ratios were calculated to establish significant association, and risk differences were calculated to provide quantifiable risk increase with DDH, positive predictive value was used as a measure of predictive efficacy. The cost-effectiveness of using these risk factors to predict DDH was evaluated using NHS tariffs (January 2021).

Results

The prevalence of DDH that required treatment within our population was 5/1,000 live births. The rate of missed presentation of DDH was 0.43/1000 live births. Breech position, family history, oligohydramnios, and foot deformities demonstrated significant association with DDH (p < 0.0001). The presence of breech presentation increased the risk of DDH by 1.69% (95% confidence interval (CI) 0.93% to 2.45%), family history by 3.57% (95% CI 2.06% to 5.09%), foot deformities by 8.95% (95% CI 4.81% to 13.1%), and oligohydramnios nby 11.6% (95 % CI 3.0% to 19.0%). Primary risk factors family history and breech presentation demonstrated an estimated cost-per-case detection of £6,276 and £11,409, respectively. Oligohydramnios and foot deformities demonstrated a cost-per-case detected less than the cost of primary risk factors of £2,260 and £2,670, respectively.

Conclusion

The inclusion of secondary risk factors within a national screening programme was clinically successful as they were more cost and resource-efficient predictors of DDH than primary risk factors, suggesting they should be considered in the national guidance.

Cite this article: Bone Jt Open 2023;4(4):234–240.

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

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

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

Background

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

Objective

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

Methods

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

Results

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

Conclusion

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

Impact of Multiple Factors on the Incidence of Developmental Dysplasia of the Hip: Risk Assessment Tool

Background and Objectives: Developmental dysplasia of the hip (DDH) is one of the most common musculoskeletal conditions in children. If not treated, it leads to disability, gait abnormalities, limb shortening, and chronic pain. Our study aims to determine the impact of multiple risk factors on the incidence of DDH and to develop an interactive risk assessment tool. Materials and Methods: We conducted a retrospective cohort study in the Outpatient Clinic for Children of the Medical University of Warsaw Hospital. The Graf classification system was used for universal ultrasonographic screening. In total, 3102 infants met the eligibility criteria. Results: The incidence of DDH in the study group was 4.45%. The incidence of DDH in the Warsaw population, Poland, during the study period was 3.73 to 5.17 (95% CI). According to the multivariate analysis, the risk factors for DDH were birth weight (OR = 2.17 (1.41−3.32)), week of delivery (OR = 1.18 (1.00−1.37)), female sex (OR = 8.16 (4.86−13.71)), breech presentation (OR = 5.92 (3.37−10.40)), physical signs of DDH (25.28 (8.77−72.83)) and positive family history in siblings (5.74 (2.68−12.31)). Our results support the recent hypothesis that preterm infants (<37 weeks) have a lower rate of DDH. Conclusions: A multivariate logistic regression predictive model was used to build the risk calculator. The DDH risk calculator will be evaluated in a prospective validation study.

The Global Research Trends and Hotspots on Developmental Dysplasia of the Hip: A Bibliometric and Visualized Study

Background: Developmental dysplasia of the hip (DDH) is a common musculoskeletal disorder in newborns and also one of the most common causes of hip arthritis in women. Many topics concerning DDH still remain controversial, and the global research trend in this field has not been well-studied yet. The aim of the present study was to illustrate the overall knowledge structure, development trends, and research hotspots of DDH.

Methods: The publications related to DDH from 1998 to 2020 were identified from the Web of Science Core Collection (WOSCC). Three bibliometric tools were used to conduct visualization and knowledge maps. Annual trends of publications, contributions of countries, institutions, authors, funding agencies and journals, and clustering of keywords were analyzed.

Results: A total of 2,691 publications were included. The annual number of DDH publications showed an increasing trend worldwide. The United States has made the greatest contribution, with the largest number of publications and the highest H-index. The most prolific institutions were Shanghai Jiao Tong University, Children's Hospital of Philadelphia, and Shriners Hospital for Children. Professors Tönnis D, Harris WH, Crowe JF, Graf R, and Salter RB have made great achievements in this field. However, the collaboration between international institutions or researchers was relatively low and mainly conducted in European and American countries. All the keywords could be divided into five clusters: hip osteoarthritis study, hip replacement study, hip ultrasound study, osteotomy surgery study, and etiology study. A trend of balanced and diversified development existed in these clusters. Keywords with the ongoing bursts, including clinical outcome, risk factor, femoroacetabular impingement, predictor, arthroscopy, morphology, and anteversion may continue to be the research hotspots in the near future.

Conclusions: There will be an increasing number of publications on DDH research, and the United States stay ahead in this field. International collaboration needs to be further strengthened. The information can provide helpful references for researchers to explore hot issues or target a specific field of DDH.

Predictors of Hip Dysplasia at 4 Years in Children with Perinatal Risk Factors

While perinatal risk factors are widely used to help identify those at risk for developmental dysplasia of the hip (DDH) within the first 6 to 8 weeks of life, limited data exist about their association with radiographic evidence of dysplasia in childhood. The purpose of this study was to determine which perinatal risk factors are associated with acetabular dysplasia in children who are ≥2 years of age.