Epidemiological investigation and ultrasonic diagnosis of developmental dysplasia of the hip in Chinese infants: A large multi-center cohort study

Two genetic variants in the HIBCH and FTCDNL1 genes are associated with susceptibility to developmental dysplasia of the hips among the Han Chinese population of Southwest China

BACKGROUND

Developmental dysplasia of the hip (DDH) is a common cause of childhood disability, and the incidence of DDH shows significant familial aggregation. As the genetic factors of DDH remain unknown, the correlation between five candidate single nucleotide polymorphisms (SNPs) and DDH was evaluated in the Han Chinese population of Southwest China.

METHODS

A case‒control association study was conducted in 276 patients with DDH and 318 healthy controls. SNP genotyping in the case and control groups was performed by SNPshot and multiple PCR. SNPs were genotyped in the case and control groups by multiplex PCR. The relationship between DDH and candidate SNPs was evaluated using the χ2 test.

RESULTS

The genotype distributions of rs291412 in HIBCH and rs769956 in FTCDNL1 were different between the case and control groups (P < 0.05). After genetic model analysis, logistic regression analysis revealed that the C allele of rs291412 had a protective effect on DDH (OR = 0.605, P = 0.010) and that the G allele of rs769956 was a risk factor (OR = 2.939, P = 0.010).s.

CONCLUSION

These SNPs could be associated with susceptibility to DDH but larger population-based studies should confirm the current results.

Life Course Epidemiology of Hip Osteoarthritis in Japan: A Multicenter, Cross-Sectional Study

BACKGROUND

The incidence of developmental dysplasia of the hip (DDH) in Japanese newborns has reduced drastically following a primary prevention campaign initiated around 1972 to 1973; this perinatal education campaign promoted maintaining the hips of newborns in the naturally flexed-leg position. The purpose of the present study was to describe the life course epidemiology of hip osteoarthritis (OA) in adolescent and adult patients and to assess its association with exposure to the primary prevention campaign for DDH.

METHODS

We included new patients with hip OA diagnosed from January 1, 2022, to December 31, 2022, at 12 core hospitals (8 special-function hospitals and 4 regional medical care support hospitals). The trend in the percentage of hips with a history of DDH treatment in childhood was estimated with use of a centered moving average using the birth year of the patient. We compared the prevalence of severe subluxation (Crowe type II, III, or IV) between patients with secondary hip OA due to hip dysplasia who were born in or before 1972 and those who were born in or after 1973.

RESULTS

Overall, 1,095 patients (1,381 hips) were included. The mean age at the time of the survey was 63.5 years (range, 15 to 95 years). A total of 795 patients (1,019 hips; 73.8% of hips) were diagnosed with secondary OA due to hip dysplasia. Approximately 13% to 15% of hips among patients born from 1963 to 1972 had a history of DDH treatment in childhood; however, the percentage decreased among patients born in or after 1973. The prevalence of severe subluxation (Crowe type II, III, or IV) among patients born in or after 1973 was 2.4%, which was significantly less than that among patients born in or before 1972 (11.1%; odds ratio, 0.20; p < 0.001).

CONCLUSIONS

As of 2022, secondary hip OA due to hip dysplasia is still responsible for most new cases of adolescent and adult hip OA seen in core hospitals in Japan. However, the perinatal education campaign initiated 50 years ago, which utilized a population approach and advocated for maintaining the hips of newborns in the naturally flexed-leg position, may have improved the environmental factors of DDH, as indicated by the apparently reduced need for treatment of DDH in childhood and the associated severe subluxation. This may result in a reduced need for challenging hip surgery later in life.

LEVEL OF EVIDENCE

Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

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.

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.

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.

Developmental retardation of femoral head size and femoral head ossification in mild and severe developmental dysplasia of the hip in infants: a preliminary cross-sectional study based on ultrasound images

Background

For infants up to 6 months, ultrasound (US) screening of developmental dysplasia of the hip (DDH) is recommended. This cross-sectional study investigated the developmental data of femoral head size and femoral head ossification in mature infant hips and the impact of mild and severe DDH on femoral head development based on US images.

Methods

We reviewed all hip US studies performed from January 2018 to December 2019 to evaluate DDH in infants younger than 6 months at West China Hospital, Sichuan University. The femoral head diameter (FHD) and femoral head ossification center type of each hip were recorded. A total of 1,037 normal participants with 2,074 mature hips and 367 DDH participants with 456 dysplastic hips were included in this study.

Results

For normal mature hips (Graf I), the FHD of mature male hips was significantly larger than that of female hips from the age of 2 months to 6 months (all P values <0.01), and the femoral head ossification center of males occurred significantly later than that of females at the same age from 3 months to 6 months (all P values <0.05). Compared with the matched mature hips, the FHDs of Graf IIa (-), IIb, IIc, and D, III or IV hips were significantly smaller (1.64 vs. 1.72 cm, 1.75 vs. 1.79 cm, 1.65 vs. 1.73 cm, 1.51 vs. 1.71 cm, respectively; all P values <0.05), and the occurrence of the femoral head ossification center was delayed in Graf IIa (-) and D, III or IV hips (both P values <0.05). However, no significant developmental retardation of the femoral head was observed in Graf IIa (+) hips.

Conclusions

We identified a relatively normal range for the development of infants' hips from 1 month old to 6 months old and found significant developmental retardation of the femoral head in Graf IIa (-), IIb, IIc, and D, III or IV hips. This is a preliminary study of the developmental impact of DDH on the femoral head, and we will continue the follow-up study after treatment.

Knowledge and Practices Related to Hip-Healthy Swaddling for Newborns Among Maternity Nurses

OBJECTIVE

To assess the self-reported knowledge, education, and practices related to hip-healthy swaddling of newborns among nurses, how they teach this technique to parents, and the relationships among these factors.

DESIGN

Descriptive cross-sectional exploratory survey.

SETTING

Academic women and children's hospital with an average of 4,500 annual births.

PARTICIPANTS

One hundred four registered maternity nurses who work primarily in the maternity unit.

METHODS

At three staff meetings, we surveyed maternity nurses to determine their knowledge, education, and practices related to hip-healthy swaddling and how they teach this technique to parents. We analyzed results using descriptive statistics and chi-square and Fisher's exact tests.

RESULTS

Of the 156 nurses in the maternity unit, 104 attended three staff meetings and completed the survey. Among the participants, 18.9% (18/95; 9 participants did not respond) were unable to identify the correct hip swaddling position. Overall, 64.2% (61/95; 9 participants did not respond) reported that they received education on general swaddling technique, yet 14.8% (9/61) of these participants were unable to identify the correct hip-healthy swaddling position. Among the participants, 99.0% (103/104) reported that nurses teach parents how to swaddle infants rather than other health care providers; 12.5% (13/104) of participants responded that medical doctors provide training as well. Overall, 67.0% (69/103; 1 participant did not respond) reported that they taught parents in >75% of parent interactions.

CONCLUSION

Our results illustrate a gap in knowledge about hip-healthy swaddling among the maternity nurses who participated in this survey and a need for further education.

Fluoride increases the susceptibility of developmental dysplasia of the hip via increasing capsular laxity triggered by cell apoptosis and oxidative stress in vivo and in vitro

The etiology of developmental dysplasia of the hip (DDH) is multifactorial, including breech presentation and hip capsular laxity. In particular, hip laxity is the main contributor to DDH by changing the ratio and distribution of collagens. Also, fluoride (F) affects collagens from various tissue besides bone and tooth. To investigate the association of DDH and excessive F intake, we conducted this research in lab on cell and animal model simultaneously. We established animal model of combination of DDH and F toxicity. The incidence of DDH in each group was calculated, and hip capsules were collected for testing histopathological and ultrastructural changes. The primary fibroblasts were further extracted from hip capsule and treated with F. The expression of collagen type I and III was both examined in vivo and in vitro, and the level of oxidative stress and apoptosis was also tested identically. We revealed that the incidence of DDH increased with F concentration. Furthermore, the oxidative stress and apoptosis levels of hip capsules and fibroblasts both increased after F exposure. Therefore, this study shows that excessive F intake increases susceptibility to DDH by altering hip capsular laxity in vivo and in vitro respectively. We believe that F might be a risk factor for DDH by increasing hip laxity induced by triggering fibroblast oxidative stress and apoptosis.

Outcomes of ultrasound-monitored treatment of divelopmental dysplasia of the hip graf type II

Introduction: The management of developmental dysplasia of the hips (DDH) type Graf IIa is still controversial. This study aims to examine the outcomes of ultrasound-monitored Pavlik harness treatment, as well as the effects of associated factors, such as gender, side of DDH, the age at the treatment start, and laterality on the treatment outcomes in different Graf type II subtypes. Methods: A cohort retrospective investigation was performed on 88 ultrasound-screened infants or 125 hips diagnosed with Graf type II dysplasia during a six-month period at a single institution, the University Clinic for Orthopedic Surgery, Skopje. Subsequently, 47 infants (18 boys, 29 girls) or 73 hips who underwent Pavlik harness treatment with at least one follow-up throughout treatment monitoring were included in this study. Results: The treatment success rate of the right DDH Graf type IIa (-) was higher (70.8%) compared to the rate of success (50%) in the treatment of left Graf type IIa (-) hips. The mean age of the infants at the treatment start in successfully treated Graf type IIa (-) hips was lower (9.12 ± 2.27 weeks) compared to the age of the infants with treatment failure at the last follow-up (11.33 ± 3.06 weeks), P = 0.04. Conclusion: The age of treatment initiation and the side of DDH were the most relevant factors related to the treatment outcome. Infants with maturational deficit hips, Graf type IIa (-), should undergo early initiated, carefully guided, and monitored Pavlik harness treatment.