2D/4D Finger Length Ratio in the Screening of Developmental Dysplasia of the Hip.

OBJECTIVE: To investigate whether there is a relationship between the 2nd finger and 4th finger length measurement ratios and developmental dysplasia of the Hip (DDH). STUDY DESIGN: Cross-sectional observational study. Place and Duration of the Study: Department of Orthopaedics and Traumatology, Meram Faculty of Medicine Hospital, Konya, Turkiye, from January 2020 to May 2023. METHODOLOGY: Infants were screened for DDH with Graff method for the ultrasounds of both hips. Lengths of the 2nd and 4th fingers of both hands were measured and recorded. Patients with additional risk factors for developmental dysplasia of the hip (breech birth, family history, oligohydramnios, swaddling) were excluded. RESULTS: Two hundred and fifty-six babies were screened including 55.1% (n = 141) girls and 44.9% (n = 115) boys. Their mean age was 2.51 ± 0.80 months. The average lengths were 31.73 ± 3.05 mm, for the left 2nd finger and 34.26 ± 3.48 mm for the left 4th finger. In the hip USG measurements, the mean alpha angles were 62.91 ± 3.12° for the right hip and, 63.20 ± 3.55° for the left hip. Eighteen (7%) of babies who underwent hip ultrasound (USG) had unilateral or bilateral DDH. Among these cases, 2.7% (n = 7) had right, 2.3% (n = 6) had left, and 2% (n = 5) had bilateral DDH. There was no statistically significant correlation between the ratios of right 2/4 finger lengths and the right alpha angle (rs = 0.051; p = 0.421). There was a statistically positive and statistically significant correlation between the ratios of left 2/4 finger lengths and the left alpha angle (rs = 0.154; p = 0.013). CONCLUSION: Only the left-hand finger ratio among the parameters in the model had a statistically significant effect on DDH. Therefore, the left hand 2D/4D finger length may be of value in screening for DDH. KEY WORDS: Developmental dysplasia of the hip, Second to fourth finger digit ratio, Ring finger, Digit ratios.

Who performs neonatal hip assessment: is there a cause for concern?

OBJECTIVE: The UK falls behind other European countries in the early detection of developmental dysplasia of the hip (DDH) and screening strategies differ for early detection. Clinical detection of DDH is challenging and recognised to be dependent on examiner experience. No studies exist assessing the number of personnel currently involved in such assessments.Our objective was to review the current screening procedure by studying a cohort of newborn babies in one teaching hospital and assess the number of health professionals involved in neonatal hip assessment and the number of examinations undertaken during one period by each individual. METHODS: This was a retrospective observational study assessing all babies born consecutively over a 14-week period in 2020. Record of each initial baby check was obtained from BadgerNet. Follow-up data on ultrasound or orthopaedic outpatient referrals were obtained from clinical records. RESULTS: 1037 babies were examined by 65 individual examiners representing 9 different healthcare professional groups. The range of examinations conducted per examiner was 1-97 with a median of 5.5 examinations per person. 49% of individuals examined 5 or less babies across the 14 weeks, with 18% only performing 1 examination. Of the six babies (0.48%) treated for DDH, one was picked up on neonatal assessment. CONCLUSION: In a system where so many examiners are involved in neonatal hip assessment, the experience is limited for most examiners. Currently high rates of late presentation of DDH are observed locally, which are in accordance with published national experience. The potential association merits further investigation.

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.

Congenital dislocation of the knee complicated with bilateral hip dislocation: a case report and literature review.

BACKGROUND: Congenital dislocation of the knee is characterised by excessive knee extension or dislocation and anterior subluxation of the proximal tibia, and this disease can occur independently or coexist with different systemic syndromes. Nevertheless, significant controversy surrounds treating this disease when combined with hip dislocation. This paper presents a case of a 4-month-old patient diagnosed with bilateral hip dislocation combined with this disease. The study discusses the pathophysiology, diagnosis, and treatment methods and reviews relevant literature. CASE PRESENTATION: We reported a case of a 4-month-old female infant with congenital dislocation of the right knee joint, which presented as flexion deformity since birth. Due to limitations in local medical conditions, she did not receive proper and effective diagnosis and treatment. Although the flexion deformity of her right knee joint partially improved without treatment, it did not fully recover to normal. When she was 4 months old, she came to our hospital for consultation, and we found that she also had congenital dislocation of both hip joints and atrial septal defect. We performed staged treatment for her, with the first stage involving surgical intervention and plaster orthosis for her congenital dislocation of the right knee joint, and the second stage involving closed reduction and plaster fixation orthosis for her congenital hip joint dislocation. Currently, the overall treatment outcome is satisfactory, and she is still under follow-up observation. CONCLUSIONS: Early initiation of treatment is generally advised, as nonsurgical methods prove satisfactory for mild cases. However, surgical intervention should be considered in cases with severe stiffness, unresponsive outcomes to conservative treatment, persistent deformities, or diagnoses and treatments occurring beyond the first month after birth.

Causes of late-presenting developmental dislocation of the hip beyond 12 months of age: A pilot study.

Background & objectives: Developmental dysplasia of the hip (DDH), when detected early, can usually be managed effectively by simple methods. A delayed diagnosis often makes it a complex condition to treat. Late presentation of DDH is fairly common in developing countries, and there is scarcity of literature regarding the epidemiology and reason for late presentation. Through this study, we attempted to identify the reasons for late presentation of DDH in children more than 12 months of age. Methods: Fifty four children with typical DDH and frank dislocation of hip in whom treatment was delayed for 12 months or more were included. Parents were interviewed with a pre-structured questionnaire and data were collected for analysis with Microsoft Excel 2016 and SPSS version 26. Results: Diagnostic delay was the most common reason for late presentation and was observed in 52 children (96.2%). The mean age at diagnosis was 24.7 months. The mean age at treatment was 37.3 months with a mean delay of 12.5 months from diagnosis and 22.1 months from initial suspicion. Physician-related factors contributed 55.3 per cent, while family and social issues accounted for 44.7 per cent of overall reasons for diagnostic and treatment delays. Interpretation & conclusions: Late presentation of DDH in walking age is common. Physician- and family-related factors accounted for most of these cases. Failure or inadequate hip screening at birth by the attending physician is a common reason for late diagnosis. The family members were unaware about the disorder and developed suspicion once child started walking with an abnormal gait.

Identification of A Novel Variant of Filamin A Destroying the Attraction Between Benzene Rings and Sulfhydryl in Developmental Dysplasia of the Hip.

Developmental dysplasia of the hip (DDH), characterized by acetabular deformity that manifests from loose ligaments to complete dislocation of the hip, can cause notable pain and dysfunction and lead to hip dislocation, secondary fractures, scoliosis, and osteoarthritis of hip. Variants in FLNA may produce a spectrum of malformations in multiple organs, especially the skeleton. This study aimed to identify the genetic etiologies of DDH patients and provide genetic testing information for further diagnosis and treatment of DDH. We recruited a Chinese woman with DDH and her family members. Whole-exome sequencing was used to identify the patient's genetic etiologies. Protein models were used to analyze the pathogenic mechanism of the identified variants. A novel variant (c.3493T>G, p.C1165G) of FLNA was detected. The structural models of the mutant FLNA protein indicated that the variant would lose its sulfhydryl side chain and destroy the attraction between benzene rings and sulfhydryl. We reported a novel variant (c.3493T>G, p.C1165G) of FLNA in a Chinese woman with DDH. Our research outcome enriches the gene pool for hip dysplasia and emphasizes the pathogenicity of sulfhydryl side chain disruption in FLNA.

Hip sonography according to Graf: practical notes for the student, the examiner and the reviewer.

Since the publication of Professor Reinhard Graf's work in 1980, Graf's technique has become the gold standard for screening Developmental Dysplasia of the Hip (DDH) in many European and non-European countries. Despite the fact that it is supported by robust literature evidence, there is criticism about its reliability and reproducibility, questioning severalaspects of the diagnostic procedure. There is, however, concern, based on recent literature, about the quality and reliability of the published data, which may, in many cases, be based on inadequate scans, and therefore any conclusions drawn have to be questioned. The aim of this review is to demonstrate the most important aspects of Graf's technique, to clarify the potential sources of confusion and to flag up the most common errors and mistakes made, either during the ultrasound examination, or during the reporting procedure. Furthermore, this review can be used as a guide for reviewers and editors and should help to enhance the quality control of publications on this subject.

Prevalence of developmental dysplasia of the hip (DDH) in infants: a systematic review and meta-analysis.

OBJECTIVE: To estimate the prevalence of developmental dysplasia of the hip (DDH) in infants with a systematic review and meta-analysis. METHOD: A literature search was conducted in April 2023, using databases such as Cochrane Library, PubMed, MEDLINE, CNKI, and SinoMed, without language restrictions. Eligible studies included cross-sectional studies reporting the prevalence of DDH among infants aged 0-12 months. Two independent reviewers manually selected and coded the studies, with any disagreements resolved by a third reviewer. Meta-analysis was performed using a random-effects model to calculate the prevalence of DDH. Regression analysis examined the trend of DDH prevalence, and stratification analysis explored heterogeneity between studies. RESULTS: A total of 65 studies involving 3 451 682 infants were included in the meta-analysis. None of the studies were classified as high quality, four were medium-to-high quality, 50 were low-to-medium quality, and eight were low quality. The pooled prevalence of DDH was 1.40% (95% CI: 0.86 to 2.28, I2=100%), and prevalence of dysplasia, subluxation, and dislocation was 1.45% (95% CI: 0.93 to 2.24, I2=97%), 0.37% (95% CI: 0.22 to 0.60, I2=94%), and 0.21% (95% CI: 0.13 to 0.34, I2=92%), respectively. Notably, the overall prevalence has a slight upward trend in the last three decades (ß=0.24, p=0.35), but the dysplasia was downward trend (ß=-0.48, p<0.01). Girls have higher risk of DDH than boys (1.46% vs 0.66%; Q=5.83, df=1, p=0.02). There were no significant differences based on gender, country, setting, or screening technique. CONCLUSION: The prevalence of DDH among infants is approximately one in a 100, with girls being at higher risk. Though the prevalence of dysplasia has decreased, there is a slight upward trend in overall DDH. Therefore, routine screening for DDH in infants is recommended to prevent more serious developmental problems.

Investigation of Igf-1, Igf-Bp3 and Igf-Bp5 levels in umbilical cord blood of infants with developmental dysplasia of the hip.

BACKGROUND: IGF-1 (insulin-like growth factor-1) is an important regulator of bone formation. Its deficiency has been associated with fetal growth disorders and hip dysplasia. The aim of this study was to evaluate whether IGF-1, IGF-BP3 (insulin like growth factorbinding protein 3), and IGF-BP5 levels in the umbilical cord blood can be predictive for early diagnosis of DDH. METHODS: Umbilical cord blood samples were collected from 860 mothers with pregnancies at high risk for DDH between October 2020 and January 2021. Mothers at 37-42 weeks of gestation, with risk factors for DDH, who delivered healthy infants were included. Blood samples were collected during delivery. Each eligible infant was medically followed up and underwent a hip ultrasound in the postnatal 2nd or 3rd month. Infants diagnosed with DDH were matched with a healthy cohort in terms of sex, birth weight, maternal age, and gestational week, and the IGF-1, IGF-BP3 and IGF-BP5 levels were studied and compared. RESULTS: Evaluation was made of 20 infants diagnosed with DDH and 60 healthy infants. Of the total 80 infants, 72.5% were female.The umbilical cord blood levels of IGF-1 and IGF-BP3 were similar in both groups. The IGF-BP5 values were significantly lower in the DDH patient group. Except for DDH diagnosis, the other categorical variables of the study did not appear to influence the levels of any of the IGFs. DISCUSSION: Umbilical blood samples could potentially help diagnose DDH. The levels of IGF-BP5 were shown to be significantly lower in infants with DDH.

Preterm birth does not increase the risk of developmental dysplasia of the Hip: a systematic review and meta-analysis.

BACKGROUND: The purpose of this systematic review was to appraise the literature on the association between preterm birth and developmental dysplasia of the hip (DDH). METHODS: Medline, Embase, Scopus, and Web of Science databases were queried for all studies pertaining to DDH and preterm birth. Data were imported and analyzed in Revman5 and Comprehensive Meta-Analysis (CMA) for pooled prevalence estimation. RESULTS: Fifteen studies were included in the final analysis. There were 759 newborns diagnosed with DDH in these studies. DDH was diagnosed in 2.0% [95%CI:1.1-3.5%] of the premature newborns. Pooled incidence rate of DDH was not statistically different between those groups (2.5%[0.9%-6.8%] vs. 0.7%[0.2%-2.5%] vs. 1.7%[0.6%-5.3%];Q = 2.363,p = 0.307). CONCLUSIONS: In this systematic review and meta-analysis, we did not find preterm birth to be a significant risk factor for DDH. Data suggests that female sex and breech presentation are associated with DDH in preterm infants, but the data is scarce in the literature.

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.

Known risk factors of the developmental dysplasia of the hip predicting more severe clinical presentation and failure of Pavlik harness treatment.

PURPOSE: Developmental dysplasia of the hip (DDH) varies from mild instability of the hip to subluxation or total dislocation of the joint. Well-known risk factors of DDH include pre-natal breech position, female sex, positive family history, hip side, primiparity and the mode of delivery. Aim of the present study was to further evaluate known risk-factors of DDH, find associations with more severe dysplasia (characterized with Ortolani positivity) and find risk factors of failure of the Pavlik harness treatment. MATERIAL AND METHODS: All children with the diagnosis of DDH treated in Tampere University hospital in the years 1998-2018 were retrospectively identified for the study and the data was collected from the medical records. Teratological dislocations (n = 3) were excluded from the analysis. Total of 945 patients were included. RESULTS: Breech presentation was strongly associated with Ortolani positivity (p < 0.001). Breech presentation was not associated with ending up for spica casting and/or operative treatment (p = 0.291) despite the association with Ortolani positivity. Ortolani positivity (p = 0.002), positive family history (p = 0.013) and girl sex (p = 0.029) were associated with ending up for spica casting and/or operative treatment. CONCLUSION: Breech presentation seems to increase the risk of Ortolani positive DDH. However, these infants are likely to recover with initially started Pavlik harness treatment, as it was not associated with elevated risk for undergoing more robust treatments. Positive family history and girl sex are associated with the most severe cases of developmental dysplasia of the hip, and it may predispose to the failure of the Pavlik harness treatment.

Diagnostic accuracy of a deep learning model using YOLOv5 for detecting developmental dysplasia of the hip on radiography images.

Developmental dysplasia of the hip (DDH) is a cluster of hip development disorders and one of the most common hip diseases in infants. Hip radiography is a convenient diagnostic tool for DDH, but its diagnostic accuracy is dependent on the interpreter's level of experience. The aim of this study was to develop a deep learning model for detecting DDH. Patients younger than 12 months who underwent hip radiography between June 2009 and November 2021 were selected. Using their radiography images, transfer learning was performed to develop a deep learning model using the "You Only Look Once" v5 (YOLOv5) and single shot multi-box detector (SSD). A total of 305 anteroposterior hip radiography images (205 normal and 100 DDH hip images) were collected. Of these, 30 normal and 17 DDH hip images were used as the test dataset. The sensitivity and the specificity of our best YOLOv5 model (YOLOv5l) were 0.94 (95% confidence interval [CI] 0.73-1.00) and 0.96 (95% CI 0.89-0.99), respectively. This model also outperformed the SSD model. This is the first study to establish a model for detecting DDH using YOLOv5. Our deep learning model provides good diagnostic performance for DDH. We believe our model is a useful diagnostic assistant tool.

[Definition of hip dysplasia in 2023 : Signs of macro and micro instability]. / Definition der Hüftdysplasie im Jahr 2023 : Zeichen der Makro- und Mikroinstabilität.

BACKGROUND: Hip dysplasia is a complex static-dynamic pathology leading to chronic joint instability and osteoarthritis. Because our understanding of the underlying pathomorphologies of hip dysplasia, both on the macro and micro levels, has evolved, an updated definition is needed. QUESTION: What is the definition of hip dysplasia in 2023? METHODS: By summarizing and reviewing relevant literature, we provide an up-to-date definition of hip dysplasia with a guide to appropriately making the diagnosis. RESULTS: In addition to the pathognomonic parameters, supportive and descriptive indicators, as well as secondary changes are used to fully characterize instability inherent in hip dysplasia. The primary diagnostic tool is always the plain anteroposterior pelvis radiograph, which can be supplemented by additional investigations (MRI of the hip with intraarticular contrast agent; CT) if necessary. CONCLUSION: The complexity, subtlety, and diversity of the pathomorphology of residual hip dysplasia requires careful, multilevel diagnosis and treatment planning in specialized centers.

Radiographic markers of hip dysplasia in young adults: predictive effect of factors in early life.

ABSTRAC: BACKGROUND AND OBJECTIVES: Acetabular dysplasia in young adults occurs, despite screening for developmental hip dysplasia (DDH) in the neonatal period. We aimed to examine how early life factors predict radiographic measurements of acetabular dysplasia at 18-19 years of age. METHODS: From a previous randomized trial (n = 12,014; 1988-90) evaluating the role of hip ultrasound in newborn screening of DDH, 4469 participants (2193 males) were invited to a follow-up 18 years later (2007-09), of which 2370 (53% attendance; 932 males) met. We examined associations between early life factors and four radiographic measurements for acetabular dysplasia at skeletal maturity. Hierarchical regressions, with addition of variables observed/measured consecutively in time, were analyzed using mixed effects models considering hip as the unit in the analyses. The study is approved by the Regional Ethics Committee. RESULTS: In total, 2340 participants (921 boys), mean age 18.7 years, (SD 0.6) had hip radiographs performed at follow-up and were included. Early life factors significantly predicting radiographic acetabular dysplasia at age 18-19-years included female gender, breech, low acetabular inclination (alpha) angle and sonographic instability, abduction treatment, as well as the velocity of growth during childhood. A positive family history of DDH was not associated with acetabular dysplasia at skeletal maturity. CONCLUSION: The acetabular inclination (alpha) angle as measured on ultrasound at birth turned out to be a significant predictor of dysplasia at 18-19 years of age. The discordant role of a positive family history in early versus adult hip dysplasia is intriguing, warranting further studies on the genetic mechanisms of DDH.

Developmental Dysplasia of the Hip From Birth to Adolescence: Clear Indications and New Controversies.

It is important to be knowledgeable about the latest information on the diagnosis and the evidence-based management of developmental hip dysplasia and dislocation from birth through adolescence. The focus should be on the effect of the problem; normal growth and development of the hip joint; and the pathoanatomy, natural history, and long-term outcomes of developmental dysplasia of the hip, hip subluxation, and dysplasia. Many controversies exist in the management of this complex spectrum of disorders.

Is prematurity a risk factor for developmental dysplasia of the hip? A systematic review and meta-analysis.

Developmental dysplasia of the hip (DDH) is the most common orthopedic disorder in newborns. Early recognition and diagnosis are critical to prevent long-term complications. While several risk factors have been established, the association between prematurity and DDH remains unclear. Our analysis sought to analyze the literature exploring the relationship between prematurity and DDH. Articles evaluating the relationship between prematurity and DDH published between 1 January 2000 and 1 February 2022 were queried, with 11 studies included for analysis. Overall, a total of 8720 patients were included. The gestational age ranged from 23 to 36 weeks for preterm and ≥37 weeks for term births. Seven studies agreed that gestational age did not have a significant impact on DDH. Pooled analysis of available data demonstrated no significant difference in DDH among preterm and term infants (OR, 1.11; 95% CI, 0.82-1.51; P = 0.49). Sub-group analysis of two studies reporting data on very preterm (≤32 weeks) and term infants revealed no significant difference in the occurrence of DDH (OR, 4.58; 95% CI, 0.09-244.78; P = 0.45). Four studies found early gestational age is associated with a significantly higher incidence of mature hips compared to late preterm or term babies. Similarly, pooled analysis demonstrated significantly lower Graf classification among preterm infants (OR, 0.13; 95% CI, 0.03-0.61; P = 0.009). Based on the current literature, our analysis found that prematurity is not strongly associated with DDH. Furthermore, early gestational age was associated with a significantly higher incidence of mature hips measured by Graf classification.

Whole exome sequencing of 28 families of Danish descent reveals novel candidate genes and pathways in developmental dysplasia of the hip.

Developmental dysplasia of the hip (DDH) is a common condition involving instability of the hip with multifactorial etiology. Early diagnosis and treatment are critical as undetected DDH is an important cause of long-term hip complications. Better diagnostics may be achieved through genetic methods, especially for patients with positive family history. Several candidate genes have been reported but the exact molecular etiology of the disease is yet unknown. In the present study, we performed whole exome sequencing of DDH patients from 28 families with at least two affected first-degree relatives. Four genes previously not associated with DDH (METTL21B, DIS3L2, PPP6R2, and TM4SF19) were identified with the same variants shared among affected family members, in more than two families. Among known association genes, we found damaging variants in DACH1, MYH10, NOTCH2, TBX4, EVC2, OTOG, and SHC3. Mutational burden analysis across the families identified 322 candidate genes, and enriched pathways include the extracellular matrix, cytoskeleton, ion-binding, and detection of mechanical stimulus. Taken altogether, our data suggest a polygenic mode of inheritance for DDH, and we propose that an impaired transduction of the mechanical stimulus is involved in the etiopathological mechanism. Our findings refine our current understanding of candidate causal genes in DDH, and provide a foundation for downstream functional studies.

Epidemiology of Developmental Dysplasia of the Hip: Analysis of Japanese National Database.

BACKGROUND: Developmental dysplasia of the hip (DDH) is a cluster of hip development disorders that affects infants. The incidence of DDH-related dislocation (DDH-dislocation) is reportedly 0.1-0.3%; however, the nationwide incidence of DDH-dislocation in Japan has not been previously reported. The primary aim of this study was to report the nationwide incidence of DDH-dislocation in Japan using the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB), and to examine its regional variation across Japan. METHODS: This was a retrospective birth cohort study using the NDB. Data on patients born between 2011 and 2013 and assigned DDH-dislocation-related disease codes during 2011-2018 were extracted. Among these, patients who underwent treatment for DDH-dislocation between 2011 and 2018 were defined as patients with DDH-dislocation. RESULTS: Across the 2011, 2012, and 2013 birth cohorts, 2,367 patients were diagnosed with DDH-dislocation, yielding the nationwide incidence of 0.076%. Region-specific incidence rates were almost similar across Japan. Secondary analyses revealed that 273 (11.5%) patients were diagnosed at the age of ≥1 year. The effect of birth during the cold months on the incidence of DDH-dislocation was significant (relative risk [RR] = 1.89, 95% confidence interval [CI]: 1.75-2.06). The risk of DDH-dislocation among girls was approximately seven times higher than that among boys. CONCLUSION: This is the first study to report the nationwide incidence of DDH-dislocation in Japan, which was estimated at 0.076%. The regional variation was trivial and unlikely to be clinically significant. Thus, the incidence rates were approximately equal across all regions in Japan.

Early Investigation and Bracing in DDH Impacts Maternal Wellbeing and Breastfeeding.

BACKGROUND: The outcomes of Pavlik Harness (PH) management for Developmental Dysplasia of the Hip (DDH) are equivalent regardless of the initiation timing, if it is within the first 6 weeks of life. A PH may be a physical barrier to breastfeeding, which is important for nutrition, immunity, and normal child development. The diagnosis of DDH and early management with a PH may also negatively affect the maternal psychosocial wellbeing and the infant-maternal relationship. The purpose of this study is to investigate the impact of the diagnosis of DDH and the management with a PH has on maternal wellbeing and maintenance of breastfeeding, compared with being screened for but not diagnosed with DDH. METHODS: A retrospective cohort of the mothers of infants who were diagnosed with DDH and treated with a PH brace was compared with the mothers of infants who were screened for DDH only. The Hip Worries Inventory and Edinburgh Postnatal Depression Scale were completed by the mothers in both groups. The PH group also completed an in-house questionnaire specific to PH and breastfeeding. RESULTS: Eighty completed surveys were included, 50 from the treatment group. The mean age of the PH initiation was 6.2 weeks. The modified Hip Worries Inventory score was higher in the treatment group, with a mean difference (MD) of 9.7 out of 50 (95% confidence interval, CI, 6.8, 12.5). The MD of the Edinburgh Postnatal Depression Scale was 2.0 out of 30 (CI -0.5, 4.5). Although there was no difference in the breastfeeding ease before and after the PH initiation (MD-0.2, CI-0.7, 0.2), 83% of mothers found breastfeeding more difficult with a PH and 11% of mothers stopped breastfeeding earlier than planned because of the PH. CONCLUSIONS: Mothers of infants with DDH worry more about their child's hips and the PH. Screening alone may contribute to maternal psychological dejection and negative thoughts. The presence of a PH makes breastfeeding more difficult. LEVEL OF EVIDENCE: Retrospective comparative study, level III.