An in-depth analysis of young adults with osteonecrosis secondary to developmental dysplasia of the hip who underwent total hip arthroplasty.

BACKGROUND: Patients with osteonecrosis of the femoral head secondary to DDH frequently require total hip arthroplasty (THA), but it is not well understood which factors necessitate this requirement. We determined the incidence of THA in patients who have osteonecrosis secondary to DDH and factors associated with need for THA. METHODS: We included patients who received closed or open reductions between 1995 and 2005 with subsequent development of osteonecrosis. We determined osteonecrosis according to Bucholz and Ogden; osteoarthritis severity (Kellgren-Lawrence), subluxation (Shenton's line); neck-shaft angle; and acetabular dysplasia (centre-edge and Sharp angles). We also recorded the number of operations of the hip in childhood and reviewed case notes of patients who received THA to describe clinical findings prior to THA. We assessed the association between radiographic variables and the need for THA using univariate logistic regression. RESULTS: Of 140 patients (169 hips), 22 patients received 24 THA (14%) at a mean age of 21.3 ± 3.7 years. Associated with the need for THA were grade III osteonecrosis (OR 4.25; 95% CI 1.70-10.77; p = 0.0019), grade IV osteoarthritis (21.8; 7.55-68.11; p < 0.0001) and subluxation (8.22; 2.91-29.53; p = 0.0003). All patients who required THA reported at least 2 of: severe pain including at night, stiffness, and reduced mobility. Acetabular dysplasia and number of previous operations were not associated with the need for THA. CONCLUSIONS: We identified a 14% incidence of THA by age 34 years in patients with osteonecrosis secondary to DDH. Grade III osteonecrosis (global involvement femoral head and neck) was strongly associated with THA, emphasising the importance to avoid osteonecrosis when treating DDH.

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.

The incidence of late-detected developmental dysplasia of the hip and its functional outcomes: a 17-year cohort study using selective ultrasound screening.

BACKGROUND AND PURPOSE: We aimed to establish the incidence of late-detected developmental dysplasia of the hip (DDH) with a selective ultrasound (US) examination over 17 years using the femoral head coverage (FHC) as a US measurement. The secondary aim was to establish the everyday function using patient-reported outcome measures (PROMs). PATIENTS AND METHODS: The incidence of late-detected DDH was based on 60,844 children. Patients diagnosed for the first time after 3 months and before the age of 8 years were included. In the second part of the study, consent to participate was mandatory. PROMIS-25 Pediatric, PROMIS-25 Parent, and EQ-5D-5L were used according to the patient's age to assess everyday function. RESULTS: The incidence of late-detected DDH was 0.48/1,000. The median age at diagnosis was 8 months (range 4-41 months), with a tendency to require repeated treatment with open surgery if DDH was diagnosed later. Most children reported no or minor health problems with a mean of 18 years' follow-up. CONCLUSION: We found that selective US examination of the hips by measuring the FHC is a reliable method to examine newborns for DDH resulting in a low incidence of late-detected DDH amounting to 0.48/1,000 newborn children.

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.

Incidence of Neonatal Developmental Dysplasia of the Hip and Late Detection Rates Based on Screening Strategy: A Systematic Review and Meta-analysis.

Importance: Universal ultrasonographic screening for developmental dysplasia of the hip (DDH) has gained increasing popularity despite the lack of benefit in terms of reducing the rates of late-detected cases (age ≥12 weeks) in randomized clinical trials. Objective: To report the reported incidence of DDH in the English scientific literature and compare rates of late-detected cases in settings with different DDH screening strategies. Data Sources: PubMed, Scopus, and Web of Science databases were searched on November 25 and 27, 2021. No time filters were used in the search. Study Selection: All observational studies reporting the incidence of early-detected or late-detected (age ≥12 weeks) DDH were included. Non-English reports were excluded if the abstract did not include enough information to be included for analysis. Data Extraction and Synthesis: The number of newborns screened and the detection rates were extracted. Meta-analysis calculated the pooled incidence of DDH per 1000 newborns with 95% CIs using a random- or fixed-effects model. This study is reported according to the PRISMA and MOOSE guidelines. Main Outcomes and Measures: The main outcome measures were early detection, early treatment, late detection, and operative treatment incidences. Results: A total of 1899 studies were identified, 203 full texts were assessed, and 76 studies with 16 901 079 infants were included in final analyses. The early detection rate was 8.4 (95% CI, 4.8-14.8) infants with DDH per 1000 newborns with clinical screening, 4.4 (95% CI, 2.4-8.0) infants with DDH per 1000 newborns with selective ultrasonographic screening, and 23.0 (95% CI, 15.7-33.4) infants with DDH per 1000 newborns with universal ultrasonographic screening. Rates for nonoperative treatment were 5.5 (95% CI, 2.1-14) treatments per 1000 newborns with clinical screening, 3.1 (95% CI, 2.0-4.8) treatments per 1000 newborns with selective ultrasonographic screening, and 9.8 (95% CI, 6.7-14.4) treatments per 1000 newborns with universal ultrasonographic screening. The incidence of late-detected DDH was 0.5 (95% CI, 0.2-1.5) infants with DDH per 1000 newborns with clinical screening, 0.6 (95% CI, 0.3-1.3) infants with DDH per 1000 newborns with selective ultrasonographic screening, and 0.2 (95% CI, 0.0-0.8) infants with DDH per 1000 newborns with universal ultrasonographic screening. The corresponding incidences of operative treatment were 0.2 (95% CI, 0.0-0.9) operations per 1000 newborns with clinical screening, 0.5 (95% CI, 0.4-0.7) operations per 1000 newborns with selective ultrasonographic screening, and 0.4 (95% CI, 0.2-0.7) operations per 1000 newborns with universal ultrasonographic screening. Conclusions and Relevance: This meta-analysis found that early detection rates and nonoperative treatments were higher with universal screening. The late detection and operative treatment rates with universal screening were similar to those among selectively and clinically screened newborns. Based on these results, universal screening may cause initial overtreatment without reducing the rates of late detection and operative treatment.

Cold Weather as a Risk Factor for Late Diagnosis and Surgery for Developmental Dysplasia of the Hip.

BACKGROUND: Newborn hip screening aims to prevent the late diagnosis of and subsequent surgical procedures for developmental dysplasia of the hip (DDH). Weather may affect how parents swaddle their babies in early life, but weather has never been formally regarded as a risk factor in hip screening. This study investigates the association between the incidence of surgically treated DDH and the outdoor temperature. METHODS: Surgical procedures for late-diagnosed DDH were investigated in 12 birth-year cohorts (1999 to 2010) using the Taiwan National Health Insurance Research Database. The number of children who underwent a DDH-related surgical procedure between 6 months and 5 years of age per total live births was evaluated as an outcome of hip screening. Trend and regression analyses were used to determine the association between the incidence of surgically treated DDH and birth year, birth month, and the temperature during the birth month and first 3 months of life. RESULTS: The mean incidence of surgically treated DDH was 0.48 per 1,000 live births (1,296 surgically treated patients per 2,712,002 live births). The incidence of surgically treated DDH among babies born in winter months (0.70 per 1,000) was significantly higher than that among babies born in summer months (0.32 per 1,000), and it was significantly correlated with mean temperature in the first 3 months of life (r2 = 0.91; p < 0.0001) and birth month (r2 = 0.68; p < 0.001). Multivariable regression revealed that external temperature in the first 3 months of life was the most significant factor (ß = -0.034 [95% confidence interval, -0.042 to -0.022]; p < 0.001) for the incidence of surgically treated DDH (adjusted r2 = 0.485). The trend of seasonal differences remained the same throughout the study years following implementation of the hip-screening policy. CONCLUSIONS: As the incidence of surgically treated DDH is the ultimate outcome of newborn hip screening, cold weather should be regarded as a risk factor and should be incorporated into future screening programs. Weather patterns of different geographical areas should be studied to determine if children born in the winter are at an increased risk for requiring a surgical procedure for DDH, and newborn hip-screening programs should be revised accordingly. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Descripción de pacientes con displasia del desarrollo de cadera en Hospital Clínico Herminda Martin, Chillán, entre los años 2020-2021 / Description of patients with developmental dysplasia of the hip at the Hospital Clínico Herminda Martin, Chillán, between the years 2020-2021

Introducción: La displasia del desarrollo de la cadera (DDC), una patología multifactorial más prevalente en el sexo femenino, afecta a lactantes, y el diagnóstico y tratamiento oportuno permiten evitar consecuencias posteriores, morbimortalidad significativa y una carga en salud importante. Objetivo: Conocer la realidad local en relación con el diagnóstico y tratamiento de la DDC, describiendo demográficamente a los pacientes evaluados por médicos especialistas, específicamente traumatólogos infantiles del Hospital Clínico Herminda Martin (HCHM) en Chillán. Materiales y métodos: Se llevó a cabo un estudio descriptivo transversal de una cohorte de pacientes evaluados mediante radiografías en el HCHM por sospecha de DDC, entre junio de 2020 y julio de 2021. Se recopilaron variables como sexo, tipo de compromiso del desarrollo de la cadera y tratamiento utilizado. Resultados: De 146 pacientes evaluados, el 83.6% correspondían al sexo femenino, mientras que el 16.4% eran del sexo masculino. En cuanto a los tratamientos ortopédicos, el 82.7% fueron mujeres y el 17.2% hombres, siendo las correas de Pavlik el tratamiento más utilizado. Solo 7 pacientes requirieron tratamiento quirúrgico. Discusión: Los resultados obtenidos se respaldan en la evidencia internacional, reflejando realidades similares a la situación local. La relevancia de este estudio radica en la falta de una base de datos nacional o local actualizada sobre la patología, sumado a la ventaja de informar acerca de los tratamientos disponibles y la adherencia a ellos. Esto permite reflejar el comportamiento de la población local durante los años 2020-2021. Las limitaciones incluyen el seguimiento, debido a restricciones por la pandemia y la falta de datos previos.

Introduction: Developmental dysplasia of the hip (DDH), a multifactorial pathology more prevalent in females, affects infants, where timely diagnosis and treatment avoid subsequent consequences, significant morbidity, and mortality, as well as the health burden it generates. Objective: To understand the local reality regarding the diagnosis and treatment of DDH by describing the demographic characteristics of patients evaluated by medical specialists, specifically child traumatologists from the Hospital Clínico Herminda Martin (HCHM) in Chillán. Materials and Methods: A cross-sectional descriptive study was conducted on a cohort of patients evaluated through radiographs at HCHM due to suspected DDH between June 2020 and July 2021. Variables collected included sex, type of hip development compromise, and treatment used. Results: Out of 146 patients, 83.6% were female and 16.4% were male. In terms of orthopedic treatments, 82.7% were females, and 17.2% were males, with Pavlik straps being the most used orthopedic treatment. Only 7 patients underwent surgical treatment. Discussion: The obtained results align with international evidence, reflecting realities similar to the local situation. The study's significance lies in the absence of an updated national or local database on the pathology. Additionally, it provides insights into available treatments and patient adherence, offering a snapshot of the local population's behavior during 2020-2021. Limitations include patient follow-up challenges due to pandemic restrictions and the lack of pre-existing data.

Differences in knee joint degeneration between primary hip osteoarthritis and hip osteoarthritis secondary to hip developmental dysplasia: A propensity score-based analysis.

OBJECTIVES: This study aimed to investigate differences in lower limb alignment and the prevalence of knee osteoarthritis (OA) among patients with primary hip osteoarthritis (PHOA) versus those with hip osteoarthritis secondary to developmental dysplasia of the hip (DDH-OA). METHODS: We compared 83 patients who underwent primary total hip arthroplasty for unilateral PHOA or DDH-OA after performing propensity score matching. The prevalence of knee OA and lower limb alignment were evaluated on preoperative plain radiographs. RESULTS: The prevalence of knee OA on the ipsilateral side was significantly higher in the PHOA group than in the DDH-OA group (p =.019), whereas there was no difference between the groups on the contralateral side (p = .631). Lower-limb alignment was more valgus on the ipsilateral side in the DDH-OA group than the PHOA group, whereas it was not significantly different on the contralateral side between groups. CONCLUSION: The prevalence of knee OA and lower-limb malalignment on the ipsilateral side of hip OA were different for PHOA and DDH-OA patients. Shifting the mechanical axis of lower limbs might be associated with the prevalence of knee OA and lower limb malalignment in the presence of unilateral hip OA.

Developmental dysplasia of the hip and associated risk factors in Saudi children: A retrospective study.

BACKGROUND: Studies investigating the association between developmental dysplasia of the hip (DDH) and risk factors in Saudi Arabia are rare. OBJECTIVE: Investigate the association between DDH and several risk factors among Saudi children. METHODS: The medical records of 82 children born in or admitted to King Abdul Aziz Medical City in Riyadh, Saudi Arabia with clinical suspicion of hip dislocation (HD) were included. The association between DDH and the following risk factors was investigated: age < 3 y, female-gender, twinning, first-born child, C-section, breech presentation, prematurity, positive family history and presence of associated abnormalities. RESULTS: HD was confirmed in 73 (89%) children (Positive HD) and excluded in 9 (11%) children (Negative HD). Eleven (13.4%) children were excluded from the positive cases as it was confirmed that they have paralytic hip dislocation not DDH. DDH was confirmed in 62 children (75.6%). The Chi square test (χ2) and odds ratios (OR) revealed that the positive family history, female-gender, age < 3 years, and presence of associated abnormalities had significant associations with the presence of DDH with P values and OR equal 0.00 (16.4), 0.002 (3.1), 0.005 (2.6), and 0.04 (1.9) respectively. Breech presentation, twinning, first-born children, prematurity, and C-section were not associated with DDH with P values and OR equal 0.93 (1.1), 0.46 (0.4), 0.11 (0.4), 0.08 (0.3), and 0.002 (0.3) respectively. CONCLUSIONS: Positive family history, female-gender, age < 3 years, and presence of associated abnormalities had approximately 16, 3, 2.5, and 2 times increased risk for DDH.

Periacetabular Osteotomy for Developmental Dysplasia of the Hip and Femoroacetabular Impingement: A Study Using the U.K. Non-Arthroplasty Hip Registry (NAHR) Data Set.

BACKGROUND: Periacetabular osteotomy (PAO) is a well-recognized procedure for the treatment of hip dysplasia in young adults and can be used for the surgical management of femoroacetabular impingement (FAI) with acetabular retroversion. The aim of this study was to use a national database to assess the outcomes of PAO for developmental dysplasia of the hip (DDH) and for FAI. METHODS: All patients in whom an isolated PAO had been performed between January 2012 and February 2019 were identified in the Non-Arthroplasty Hip Registry (NAHR). Their outcomes were assessed using the EuroQol-5 Dimensions (EQ-5D) index and the International Hip Outcome Tool (iHOT)-12 preoperatively and then at 6 months, 12 months, and 2 years postoperatively. RESULTS: Six hundred and thirty (630) PAOs were identified, with 558 (89%) performed for DDH and 72 (11%) performed for FAI. Most patients (90%) were female. The mean age in the DDH group (31.2 years) was significantly higher (p < 0.0001) than that in the FAI group (26.5 years). There were no other significant between-group demographic differences. Preoperatively and at each follow-up time-period, iHOT-12 scores were better in the DDH group than in the FAI group; however, only the preoperative scores differed significantly. There was significant improvement between the preoperative and 6-month iHOT-12 and EQ-5D index scores in both the DDH and the FAI group. This improvement was maintained at 12 months postoperatively, by which time almost 90% of the patients had achieved the minimum clinically important difference (MCID) in their iHOT-12 score. CONCLUSIONS: This study shows that PAO is a successful surgical intervention for DDH and FAI in the short term, with significant improvement in patient-reported outcome scores that is maintained up to 2 years postoperatively. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Developmental dysplasia of the hip.

Developmental dysplasia of the hip encompasses a range of hip abnormalities in which the femoral head and acetabulum fail to develop and articulate anatomically. Developmental dysplasia of the hip is a clinically important condition, with a prevalence of 1-2/1000 in unscreened populations and 5-30/1000 in clinically screened populations. The pathology is incongruence between the femoral head and the acetabulum, which can be caused by an abnormally shaped femoral head, acetabulum, or both. This results in a spectrum of different hip abnormalities. The precise aetiology behind developmental dysplasia of the hip is unclear, but there are a number of established risk factors. In the UK, universal clinical examination of newborns and 6-8-week-old babies is performed under the national UK newborn screening programme for developmental dysplasia of the hip (part of the Newborn and Infant Physical Examination). The physical examination of the newborn hip involves initial inspection of the infant for any of the clinical features of developmental dysplasia of the hip, followed by hip stability tests (Barlow's and Ortolani's tests). Hip ultrasound is the gold standard diagnostic and monitoring tool for developmental dysplasia of the hip in newborns and infants under 6 months of age, or until ossification of the femoral head. Some mild cases of developmental dysplasia of the hip (and the immature hip) resolve without requiring intervention; however, there are a number of treatments, both non-operative and operative, that may be used at various stages of this condition.

Genetic variant of COL11A2 gene is functionally associated with developmental dysplasia of the hip in Chinese Han population.

OBJECTIVES: Developmental dysplasia of the hip (DDH) is a common skeletal disorder. This study was conducted to demonstrate the association between DDH and a polymorphism rs9277935 of COL11A2 gene. RESULTS: A significant difference in genotype distribution in a recessive model (TT+GT vs. GG) between two groups (P=0.017) was demonstrated. Analysis in female patients showed significantly greater frequency of minor allele G(0.49 vs. 0.43, p=0.024) and significantly higher distribution of GG genotype (p=0.006). DDH patients were found to have significantly lower COL11A2 expression than controls. Moreover, DDH patients with rs9277935 genotype TT have a significantly increased expression of COL11A2 than those with genotype GG. COL11A2 demonstrated chondrogenic properties in vitro. CONCLUSION: Polymorphism rs9277935 of gene COL11A2 is a functional variant regulating the expression and the chondrogenic properties of COL11A2 in DDH in Chinese Han population. METHODS: A case-control candidate gene association study was conducted in 945 patients (350 radiologically confirmed DDH patients and 595 healthy controls). Difference of COL11A2 expression in hip joint tissue was compared between the patients and the controls. Allelic difference in Col11a2 expression by rs9277935 was assessed with luciferase activity. Chondrogenic effects of Col11a2 signaling on BMSCs were also determined in vitro.

Incidence rate and risk factors for radiographic hip osteoarthritis in Japanese men and women: a 10-year follow-up of the ROAD study.

OBJECTIVE: To investigate the incidence and progression rate of radiographic hip osteoarthritis (OA) and its risk factors in Japanese men and women using a large-scale population of a nationwide cohort study, Research on Osteoarthritis/osteoporosis Against Disability (ROAD). METHODS: From the baseline survey of the ROAD study, 2,975 participants (1,043 men and 1,932 women) aged 23-94 years (mean, 70.2 years) living in urban, mountainous, and coastal communities were followed up with hip radiography at 3, 7, and 10 years (mean follow-up, 7.1 years). Radiographs were scored using the Kellgren/Lawrence (K/L) grading system, and radiographic hip OA was defined as K/L ≥ 2. The incidence and progression rate of hip OA were examined. Acetabular dysplasia was defined as a central-edge angle <20°. Cox's proportional hazard model was used to assess risk factors for incident and progressive radiographic hip OA. RESULTS: The incidence rate of radiographic hip OA was 5.6/1,000 person-years and 8.4/1,000 person-years in men and women, respectively. The progression rate of hip OA was 2.2/1,000 person-years and 6.0/1,000 person-years in men and women, respectively. The significant risk factors for incident hip OA were age, obesity, and acetabular dysplasia at baseline (hazard risk [HR] 1.05, 95% confidence interval [CI] 1.03-1.08; 1.78, 1.10-2.75; 2.06, 1.30-3.17, respectively). The significant risk factors for progressive hip OA were baseline hip pain and acetabular dysplasia (HR 5.68, 95%CI 1.07-22.61; 14.78, 3.66-56.06, respectively). CONCLUSION: Continued longitudinal surveys of the ROAD study will contribute to knowledge about and potential prevention of incident and progressive hip OA.