Developmental dysplasia of the hip: a systematic literature review of the genes related with its occurrence

Endoscopic Shelf Acetabuloplasty Combined With Hip Arthroscopic Labral Repair, Cam Osteoplasty, and Capsular Plication Enables Elite Athletes With Acetabular Dysplasia to Return to Sport: A Case Series

OBJECTIVE

To investigate clinical outcomes and return to sport timeline for athletes with acetabular dysplasia after endoscopic shelf acetabuloplasty (ESA).

DESIGN

A retrospective review.

SETTING

Wakamatsu Hospital of the University of Occupational and Environmental Health, Japan between 2012 and 2019.

PATIENTS

Fifteen elite athletes (median age: 20 years) of 253 patients undergoing ESA, arthroscopic labral repair/reconstruction, cam osteochondroplasty, and capsular plication. The mean follow-up period was 27.8 months after surgery.

MAIN OUTCOME MEASURES

Patient-reported outcome scales (PROSs), including the modified Harris Hip Score, Nonarthritic Hip Score, International Hip Outcome Tool 12, Hip Outcome Score-Sports, and Vail Hip Score.

RESULTS

After ESA, all 15 elite athletes were able to return to sport effectively and compete at a preoperative level. The mean time between the operation and the first practice was 6.5 months, while the mean time between the ESA procedure and the first game was 9.6 months. Approximately 27.8 months after surgery, PROS outcomes improved significantly with no hips requiring emergency revision surgery at the final follow-up. At a mean of 47.1 months after surgery, 7 athletes decided to retire from their sport. Up to 71.1 months after surgery, the additional 8 patients continued to compete in their sport at an elite level.

CONCLUSIONS

ESA enables elite athletes with acetabular dysplasia to return to competition at a mean of 9.6 months postsurgery. The ESA procedure is an effective and promising method of treating elite athletes with acetabular dysplasia.

LEVEL OF EVIDENCE

IV.

Incidence of risk factors in developmental dysplasia of the hip: a retrospective study on 18,954 cases

BACKGROUND

DDH is 1 of the most important causes of childhood disability. A diagnosis of instability can be made in the neonatal period via the Ortolani and Barlow manoeuvres. However, clinical examination, although highly specific, has poor sensitivity as compared to ultrasound. There is controversy between the necessity of universal screening for dysplasia of all newborns or selective screening reserved for those with clinical signs of instability or known risk factors of DDH.

AIM

To analyse the risk factors of congenital hip dysplasia in a consecutive case series of children referred for diagnosis and treatment of DDH.

MATERIALS AND METHODS

This was a cross-sectional study on infants consecutively examined between January 2000 and December 2019 at the Marino Ortolani Centre in Ferrara, Italy. The first 3 types on Graf's classification were considered physiological (1A, 1B, 2A+), while the last 6 pathological (2A-, 2B, 2C, 2D, 3, 4).

RESULTS

18,954 infants met the inclusion criteria and were therefore considered eligible for the study. Of these 18,954 infants, 56% (n = 10,629) were females and 44% (n = 8325) were males. According to Graf classification, 34.9% (n = 6621) were 1A, 52.7% (n = 9999) were 1B, 4.0% (n = 753) were 2A+, 2.5% (n = 478) were 2A-, 1.5% (n = 284) were 2B, 1% (n = 196) were 2C, 1.3% (n = 243) were 2D, 1% (n = 193) were 3 and 1.0% (n = 187) were 4. The most significant risk factor was the female gender (OR 5.36; 95% CI, 4.63-6.20) followed by a family history (OR 2.35; 95% CI, 2.08-2.65), then skeletal pathologies (OR 2.04; 95% CI, 1.21-3.42), oligohydramnios (OR 1.75; 95% CI, 1.44-2.13), and finally breech presentation (OR 1.42: 95% CI, 1.27-1.60).

CONCLUSIONS

Based on our data, family history, musculoskeletal disease, oligohydramnios and breech presentation are the main risk factors for DDH development, as is the female sex.

Molecular mechanisms and genetic factors contributing to the developmental dysplasia of the hip

The most prevalent hip disease in neonates is developmental dysplasia of the hip (DDH). A timely and accurate diagnosis is required to provide the most effective treatment for pediatric patients with DDH. Heredity and gene variation have been the subject of increased attention and research worldwide as one of the factors contributing to the pathogenesis of DDH. Genome-wide association studies (GWAS), genome-wide linkage analyses (GWLA), and exome sequencing (ES) have identified variants in numerous genes and single-nucleotide polymorphisms (SNPs) as being associated with susceptibility to DDH in sporadic and DDH family patients. Furthermore, the DDH phenotype can be observed in animal models that exhibit susceptibility genes or loci, including variants in CX3CR1, KANSL1, and GDF5. The dentification of noncoding RNAs and de novo gene variants in patients with DDH-related syndrome has enhanced our understanding of the genes implicated in DDH. This article reviews the most recent molecular mechanisms and genetic factors that contribute to DDH.

Impact of endoplasmic reticulum stress on chondrocyte apoptosis in rat model of DDH

Developmental dysplasia of the hip (DDH) is a developmental disorder characterized by acetabular dysplasia leading to early osteoarthritis. This study examines the role of endoplasmic reticulum stress (ERS) in chondrocyte apoptosis and cartilage degeneration within a DDH model. In the rat model of DDH, created using a swaddling technique, significant deformities in the femoral head and acetabulum were observed, alongside an upregulation of matrix metalloproteinase-13 in acetabular cartilage. We also noted increased levels of apoptosis and ERS-related factors in the acetabular cartilage of DDH models. Additionally, rat chondrocytes exposed to high-magnitude cyclic tensile strain (CTS, 1 Hz, 10% equibiaxial strain) in vitro exhibited elevated ERS and increased apoptosis. Importantly, treatment with the ERS inhibitor 4-phenylbutyric acid effectively suppressed apoptosis induced by CTS in chondrocytes. Our findings suggest that ERS contributes to the upregulation of apoptosis-related factors in chondrocytes within the DDH model, indicating the potential of ERS modulation as a therapeutic approach for DDH-related cartilage degeneration.

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.

Early detection and risk factors of congenital hip dislocation in Morocco

Congenital dislocation of the hip is a malformation of the lower limbs that could be complicated by a disabling physical handicap with long-term psychological and social repercussions if detected late. This study aims to describe the screening for congenital hip dislocation and to investigate the association between the occurrence of this anomaly and possible risk factors in Morocco. The study was based on the exploitation of the records of children treated at the trauma and orthopedics department of the Mohammed VI University Hospital in Marrakech, Morocco. It concerned 160 cases with a 5-year follow-up from January 2016 to March 2021. The results of the study showed that 56.7% of the affected children had a bilateral dislocation and 25.8% of the cases had a left-sided dislocation. The malformation occurred more frequently in females 69.2%. A familial disposition to the malformation was found in about 22% of the cases. The diagnosis was late (at walking age) in 61% of children following the onset of lameness with or without pain in 91% of children. In 41.87% of the hips, the reduction was surgical, with 28% failure dominated by acetabular dysplasia in 11%. The risk factors for congenital hip dislocation identified in our setting were dominated by sex, primiparity, consanguineous marriage, and the presence of a family history of dislocation. Communication of risk factors specific to our setting to healthcare personnel will allow them to guide the diagnosis and increase vigilance in the at-risk population for management that prevents the development of complications.

Residual acetabular dysplasia after Pavlik harness treatment for Graf type II hips

Purpose

To evaluate the residual acetabular dysplasia in Graf type II hips after Pavlik harness treatment with a radiographic follow-up at 2 years of age.

Methods

We retrospectively reviewed the developmental dysplasia of the hip patients who were treated with the Pavlik harness between March 2018 and February 2022. Patients with Graf type II hip dysplasia who had at least one radiographic follow-up after 2 years of age were included. The following information, sex, laterality, affected side, age at harness initiation, treatment duration, α angle, and the morphology of bony roof, was collected and studied. We evaluated the radiographic acetabular index at the last follow-up and defined the value of greater than 2 standard deviations as residual acetabular dysplasia.

Results

A total of 33 patients (53 hips) met the criteria. The mean initial α angle was 53.4°; the mean age at Pavlik harness initiation was 10.9 weeks. The mean treatment duration was 10 weeks. The mean α angle at the last ultrasound follow-up was 64.9°. The mean age of the last radiographic follow-up was 2.6 years, and 26 hips had a residual acetabular dysplasia with acetabular indexes greater than 2 standard deviations above the mean. The morphology of the acetabular bony rim (odds ratio = 4.333, P = 0.029) and age of initial treatment <12 weeks (odds ratio = 7.113, P = 0.014) were seen as significant predictors for a higher acetabular index more than 2 years of age.

Conclusions

A notable incidence of residual acetabular dysplasia after Pavlik harness treatment in Graf type II hips, wherein the acetabular bony roof with a blunt rim at the end of treatment and initial age after 12 weeks were independent predictors associated with residual acetabular dysplasia.

Levels of evidence

Therapeutic studies, IV.

Developmental dysplasia of the hip: A systematic review of susceptibility genes and epigenetics

BACKGROUND

Developmental dysplasia of the hip (DDH) is a complex developmental deformity whose pathogenesis and susceptibility-related genes have yet to be elucidated. This systematic review summarizes the current literature on DDH-related gene mutations, animal model experiments, and epigenetic changes in DDH.

METHODS

We performed a comprehensive search of relevant documents in the Medline, Scopus, Cochrane, and ScienceDirect databases covering the period from October 1991 to October 2021. We analyzed basic information on the included studies and summarized the DDH-related mutation sites, animal model experiments, and epigenetic changes associated with DDH.

RESULTS

A total of 63 studies were included in the analysis, of which 54 dealt with the detection of gene mutations, 7 presented details of animal experiments, and 6 were epigenetic studies. No genetic mutations were clearly related to the pathogenesis of DDH, including the most frequently studied genes on chromosomes 1, 17, and 20. Most gene-related studies were performed in Han Chinese or North American populations, and the quality of these studies was medium or low. GDF5 was examined in the greatest number of studies, and mutation sites with odds ratios > 10 were located on chromosomes 3, 9, and 13. Six mutations were found in animal experiments (i.e., CX3CR1, GDF5, PAPPA2, TENM3, UFSP2, and WISP3). Epigenetics research on DDH has focused on GDF5 promoter methylation, three microRNAs (miRNAs), and long noncoding RNAs. In addition, there was also a genetic test for miRNA and mRNA sequencing.

CONCLUSIONS

DDH is a complex joint deformity with a considerable genetic component whose early diagnosis is significant for preventing disease. At present, no genes clearly involved in the pathogenesis of DDH have been identified. Research on mutations associated with this condition is progressing in the direction of in vivo experiments in animal models to identify DDH susceptibility genes and epigenetics analyses to provide novel insights into its pathogenesis. In the future, genetic profiling may improve matters.

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.

Developmental Dysplasia of the Hip: Guide for the Pediatric Primary Care Provider

Developmental dysplasia of the hip (DDH) is the most common congenital abnormality in newborns. Untreated DDH can cause significant impairments, including chronic hip pain, osteoarthritis, limb length discrepancy, altered gait, and joint contractures. Treatment outcomes are significantly worse with increasing delay in presentation, making early screening and detection critical. The purpose of this review is to provide a comprehensive guide for the pediatric primary care provider on the cause, diagnosis, and management of DDH. Screening practices, physical examination, imaging modalities, and treatment will be discussed. A missed hip dislocation in a walking-age child is a devastating but preventable event; pediatric primary care providers should have a high index of suspicion for DDH and promptly refer any patient with concerning findings to a pediatric orthopedic surgeon. [Pediatr Ann. 2022;51(9):e346-e352.].

Anatomical characteristics and potential gene mutation sites of a familial recurrent patellar dislocation

Background

Recurrent patellar dislocation is the result of anatomical alignment and imbalance of restraint of bone and soft tissue. We investigate the anatomical characteristics of the knee joint in a family of patients with recurrent patella dislocation, and to screen the possible pathogenic genes in this family by whole exome sequencing in 4 patients and 4 healthy subjects, so as to provide theoretical basis for the pathogenesis of this disease.

Methods

The data related to patella dislocation were measured by imaging data. The peripheral blood DNA of related family members was extracted for the whole exome sequencing, and then the sequencing results were compared with the human database. By filtering out synonymous variants and high-frequency variants in population databases, and then integrating single nucleotide non-synonymous variants of family members, disease-causing genes were found.

Results

All patients in this family have different degrees of abnormal knee anatomy, which is closely related to patella dislocation. The sequencing results of patients and normal persons in this patella dislocation family were compared and analyzed, and the data were filtered through multiple biological databases. Find HOXB9 (NM_024017.4:c.404A>G:p.Glu135Gly),COL1A1(NM_000088.3:c.3766G>A:p.Ala1256Thr),GNPAT(NM_014236.3:c1556A>G:p.Asp519Gly),NANS(NM_018946.3:c.204G>C:p.Glu68Asp),SLC26A2(NM_000112.3:c.2065A>T:p.Thr689Ser) are nonsynonymous variants (MISSENSE). Through Sanger sequencing, the identified mutations in HOXB9 and SLC26A2 genes were only present in samples from patients with recurrent patellar dislocation.

Conclusions

The patients with recurrent patellar dislocation had markedly abnormal knee anatomy in this family. HOXB9 gene and SLC26A2 gene were found to be the possible pathogenic genes or related genes for patella dislocation.

Comprehensive bioinformatics analysis of susceptibility genes for developmental dysplasia of the hip

Developmental dysplasia of the hip (DDH) is a multifactorial disease, which occurs under environmental and genetic influence. The etiopathogenesis of DDH has not been fully explained. As research progresses, many candidate genes have been found to be closely related to the occurrence of DDH. In this study, we comprehensively examined 16 susceptibility genes of DDH using bioinformatics. COL1A1 encodes the pro-alpha1 chains of type I collagen, which is the major protein component of the bone extracellular matrix (ECM). The genes displaying the most statistically significant co-expression link to COL1A1 are ASPN, TGFB1, DKK1, IL-6, TENM3 and GDF5. DKK1, FRZB and WISP3 are components of the Wnt signaling pathway. CX3CR1 and GDF5 regulate chondrogenesis through the canonical Wnt signaling pathway. ASPN could induce collagen mineralization through binding with collagen and calcium. Integrated bioinformatics analysis indicates that ECM, Wnt signaling pathway and TGF-β signaling pathway are involved in the occurrence of DDH. These provide a basis for further exploring the pathogenesis of DDH.

Clinical and Genetic Features of Chinese Adult Patients With Chronic Non-Bacterial Osteomyelitis: A Single Center Report

Objectives

Chronic non-bacterial osteomyelitis (CNO) is a rare polygenic autoinflammatory bone disease. We aimed to characterize the clinical manifestations and gene variants of Chinese adult patients with CNO.

Methods

By reviewing data of all CNO patients being diagnosed and followed up at the Center for Adult Autoinflammation Diseases, Department of Rheumatology, Peking Union Medical College Hospital, clinical and genetic features of these patients were evaluated and concluded.

Results

The median age of disease onset was 19 (6-64) years old, and adult-onset was observed in 6 (60%) patients. The mean time of diagnosis delay was 92 ± 78 months. The common symptoms were bone pain (10, 100%), fever (9, 90%), and arthritis (6, 60%). In total, there were 54 skeletal lesions, and each patient had no less than 2 lesions. The most frequently affected sites included lower limbs (20.5%), mandible, vertebrae and pelvis (17.5%, separately). Variants of 4 genes were detected in our study including COL1A1, PSTPIP1, LRP5 and CLCN7. In seven patients who were treated with combination therapy containing tumor necrosis factor (TNF) α inhibitors, five (55.6%) had a complete response and 2 (44.4%) had a partial response.

Conclusion

This is the first and largest case series of CNO in the Chinese adult patients. Four novel genetic mutations potentially associated with CNO were identified. Notably, CNO should be considered in the differential diagnosis of adult patients with long disease course and recurrent multifocal osteomyelitis of unknown cause, and these patients might benefit from combination therapy containing TNFα inhibitors.

Integrative Analysis of MicroRNA and mRNA Sequencing Data Identifies Novel Candidate Genes and Pathways for Developmental Dysplasia of Hip

OBJECTIVE

Our aim is to explore the candidate pathogenesis genes and pathways of developmental dysplasia of hip (DDH).

DESIGN

Proliferating primary chondrocytes from hip cartilage were used for total RNA extraction including 5 DDH patients and 5 neck of femur fracture (NOF) subjects. Genome-wide mRNA and microRNA (miRNA) were then sequenced on the Illumina platform (HiSeq2500). Limma package was used for difference analysis of mRNA expression profiles. edgeR was used for difference analysis of miRNA expression profiles. miRanda was used to predict miRNA-target genes. The overlapped DDH associated genes identified by mRNA and miRNA integrative analysis were further compared with the differently expressed genes in hip osteoarthritis (OA) cartilage.

RESULTS

Differential expression analysis identified 1,833 differently expressed mRNA and 186 differently expressed miRNA for DDH. Integrative analysis of mRNA and miRNA expression profiles identified 175 overlapped candidate genes (differentially expressed genes, DEGs) for DDH, such as VWA1, TMEM119, and SCUBE3. Further gene ontology enrichment analysis detected 111 candidate terms for DDH, such as skeletal system morphogenesis (P = 4.92 × 10^-5) and skeletal system development (P = 8.85 × 10^-5). Pathway enrichment analysis identified 14 candidate pathways for DDH, such as Hedgehog signaling pathway (P = 4.29 × 10^-5) and Wnt signaling pathway (P = 4.42 × 10^-2). Among the identified DDH associated candidate genes, we also found some genes were detected in hip OA including EFNA1 and VWA1.

CONCLUSIONS

We identified multiple novel candidate genes and pathways for DDH, providing novel clues for understanding the molecular mechanism of DDH.

MiR-4303 relieves chondrocyte inflammation by targeting ASPN in osteoarthritis

Background

Osteoarthritis (OA) is a severe articular cartilage disease whose pathogenesis involves the inflammation of chondrocytes. MicroRNAs (miRNAs) are considered to be effective inflammation regulators. However, the regulatory mechanism of miRNAs in osteoarthritis needs to be further elucidated. In this paper, we aim to investigate the underlying mechanisms by which miR-4303 regulates osteoarthritis.

Methods

RT-qPCR is performed to detect the mRNA expression levels of miR-4303, ASPN, PDIA3, PIK3CA, and TRAF3. CCK-8 assay and EdU assay are carried to assess chondrocyte viability. The protein expression levels of ASPN, PCNA, Ki-67, CyclinA1, CyclinB1, CyclinD2, p27, Bax, Bcl-2, cleaved caspase-3, and Cleaved caspase-9 were measured by western blot. FACs is performed to detect the cell cycle and apoptosis of chondrocyte. ELISA is conducted to assess the levels of TNF-β, IL-1β and IL-6 in the supernatant of chondrocytes. The potential binding sites of miR-4303 and ASPN are predicted by the miRDB database and confirmed by the dual-luciferase reporter gene assay.

Results

Our findings illustrated that miR-4303 was down-regulated in arthritic tissues and LPS-induced chondrocytes; miR-4303 overexpression rescued the decrease in cell viability, cell cycle arrest and apoptosis induced by LPS. Furthermore, miR-4303 overexpression inhibited the release of inflammatory factors in LPS-induced chondrocytes, miR-4303 relieved chondrocyte inflammation via targeting ASPN.

Conclusion

MiR-4303 serves as a prognostic biomarker and relieves chondrocyte inflammation via targeting ASPN. Our findings provide novel prognostic biomarkers in predicting the progression and prognosis of osteoarthritis.

PAPPA2 Promote the Proliferation of Dermal Papilla Cells in Hu Sheep (Ovis aries) by Regulating IGFBP5

Hu sheep (Ovis aries) is a rare white sheep breed, with four different types of lambskin patterns that have different values. However, the genetic mechanisms underlying different types of pattern formation remains unclear. This research aimed to characterize the molecular mechanism of differentially expressed gene PAPPA2 affecting the pattern type of Hu sheep's lambskin at the cellular level. Thus, RT-qPCR, EdU and Cell Cycle detection were used to explore the effect of PAPPA2 and IGFBP5 (a protein that can be hydrolyzed by PAPPA2) on the proliferation of dermal papilla cells (DPCs) after overexpression or interference with PAPPA2 and IGFBP5. The expression level of PAPPA2 in straight DPCs was 4.79 ± 1.84 times higher than curved. Overexpression of PAPPA2 promoted the proliferation of DPCs and also increased the expression of IGFBP5. Conversely, overexpression of IGFBP5 reduced the proliferation of DPCs. However, the proliferation of DPCs was restored by co-overexpression of PAPPA2 and IGFBP5 compared with overexpression of IGFBP5 alone. Thus, PAPPA2 can affect the proliferation of DPCs through regulating IGFBP5 and then participate in lambskin pattern determination. Overall, we preliminarily clarified the critical role played by PAPPA2 during the formation of different pattern in Hu sheep lambskin.

"Lessons from Rare Forms of Osteoarthritis"

Osteoarthritis (OA) is one of the most prevalent conditions in the world, particularly in the developed world with a significant increase in cases and their predicted impact as we move through the twenty-first century and this will be exacerbated by the covid pandemic. The degeneration of cartilage and bone as part of this condition is becoming better understood but there are still significant challenges in painting a complete picture to recognise all aspects of the condition and what treatment(s) are most appropriate in individual causes. OA encompasses many different types and this causes some of the challenges in fully understanding the condition. There have been examples through history where much has been learnt about common disease(s) from the study of rare or extreme phenotypes, particularly where Mendelian disorders are involved. The often early onset of symptoms combined with the rapid and aggressive pathogenesis of these diseases and their predictable outcomes give an often-under-explored resource. It is these "rarer forms of disease" that William Harvey referred to that offer novel insights into more common conditions through their more extreme presentations. In the case of OA, GWAS analyses demonstrate the multiple genes that are implicated in OA in the general population. In some of these rarer forms, single defective genes are responsible. The extreme phenotypes seen in conditions such as Camptodactyly Arthropathy-Coxa Vara-pericarditis Syndrome, Chondrodysplasias and Alkaptonuria all present potential opportunities for greater understanding of disease pathogenesis, novel therapeutic interventions and diagnostic imaging. This review examines some of the rarer presenting forms of OA and linked conditions, some of the novel discoveries made whilst studying them, and findings on imaging and treatment strategies.

Genetic Study of IL6, GDF5 and PAPPA2 in Association with Developmental Dysplasia of the Hip

Background: Developmental dysplasia of the hip (DDH) is one of the most prevalent skeletal disorders. DDH is considered a pathologic condition with polygenic background, but environmental and mechanic factors significantly contribute to its multifactorial etiology. Inheritance consistent with autosomal dominant type has also been observed. Single-nucleotide polymorphisms (SNPs) in various genes mostly related to formation of connective tissue are studied for a possible association with DDH. Methods: We genotyped three SNPs, rs1800796 located in the promoter region of the IL6 gene, rs143383 located in the 5′ untranslated region (UTR) of the GDF5 gene and rs726252 located in the fifth intron of the PAPPA2 gene. The study consisted of 45 subjects with DDH and 85 controls from all regions of Slovakia. Results: Association between DDH occurrence and studied genotypes affected by aforementioned polymorphisms was confirmed in the case of rs143383 in the GDF5 gene (p = 0.047), where the T allele was over-expressed in the study group. Meanwhile, in the matter of IL6 and PAPPA2, we found no association with DDH (p = 0.363 and p = 0.478, respectively). Conclusions: These results suggest that there is an association between DDH and GDF5 polymorphisms and that the T allele is more frequently presents in patients suffering from DDH.

Current Evidence about Developmental Dysplasia of the Hip in Pregnancy

In adults, developmental dysplasia of the hip (DDH) represents a spectrum of disorders. It is commonly found in women in routine orthopedic practice. Hip dysplasia is a leading precursor of joint laxity; when untreated, it can contribute to chronic modifications, such as thickening of the pulvinar and ligamentum teres (which can also elongate), hypertrophy of the transverse acetabular ligament, and osteoarthritis. DDH is presumed to be associated with alterations in pelvic morphology that may affect vaginal birth by the reduction in the transverse diameter of the pelvic inlet or outlet. Here, we provide an overview of the current knowledge of pregnancy-associated DDH. We primarily focused on how a surgical DDH treatment might influence the pelvic shape and size and the effects on the mechanism of birth. We presented the female pelvis from the standpoint of bone and ligament morphology relative to a pelvic osteotomy. Then, we described whether the pregnancy was impacted by previous surgical DDH treatments, performed from infancy to adulthood. In conclusion, hip dysplasia is not associated with high-risk complications during pregnancy or with increased difficulty in vaginal delivery.

Phenotypic Plasticity Conferred by the Metastatic Microenvironment of the Brain Strengthens the Intracranial Tumorigenicity of Lung Tumor Cells

Lung cancer is the leading cause of cancer-related deaths and is the primary source of brain metastases. Despite great advances in the study of the genetics and etiology of lung cancer in previous decades, the identification of the factors and mechanisms underlying the brain metastasis of lung tumors is still an open question. In this study, the results of bioinformatic conjoint analysis revealed that the metastatic microenvironment in the brain conferred lung tumor cell phenotypic plasticity, characterized by neural cell-like and embryonic–stem cell-like features. Meanwhile, the metabolic phenotype of the educated tumor cells underwent transition characterized by oxygen-related metabolism. The results of the experiments demonstrated that the downregulation of HOXB9 weakened the tumorigenicity of lung tumor cells. Bioinformatic prediction analysis also determined that many cell cycle-associated factors were potentially transcribed by HOXB9. Collectively, the results of this study suggested that under the influence of the metastatic environment of the brain, lung tumor cells seemed to acquire phenotypic plasticity characterized by neural cell-like features, and this transition may be associated with the aberrant upregulation of HOXB9.

Model construction and application for automated measurement of CE angle on pelvis orthograph based on MASK-R-CNN algorithm

Developmental dysplasia of the hip (DDH) is a common orthopedic disease. A simple and cost-effective scientific tool for assisting the early diagnosis of DDH is urgently needed. This study proposed a new artificial intelligence (AI) model for automated measure of the CE angle to aid the diagnosis of DDH by modifying the Mask R-CNN algorithm.13228 anteroposterior pelvic x-ray images were collected from the PACS system of the second Hospital of Jilin University, of which 104 images were randomly selected as test data. The rest of x-ray images were labelled and preprocessed for model development. The new AI model was the constructed based modified Mask R-CNN model to detect key points for CE angle measurement. The performance of AI model on measuring CE angle was verified by comparing with three attending orthopaedic doctors. The mean CE angles on left and right pelvis measured by the AI model was 29.46 ± 6.98°and 27.92 ± 6.56°, respectively, while the mean CE angle measured by the three doctors was 29.85 ± 6.92°and 27.75 ± 6.45°, respectively. AI model displayed a higly consistency with the doctors in measuring CE angles. Besides, AI model showed a much high efficiency in term of measuring time-consumption. In this study, we successfully constructed a new effective model for measuring CE angle by identifying key points, which provided a new intelligent measurement tool for orthopedic image measurement and evaluation.