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.

Feeling the clunk: Managing and attributing uncertainty in screening for developmental dysplasia of the hip in infancy.

The management of uncertainty in clinical practice has been an enduring topic of sociological scholarship. However, little of this addresses how uncertainty and non-knowledge are attributed to the self and other actors. We take the example of checking for developmental dysplasia of the hip (DDH), part of infant screening in UK primary care, to examine the 'double contingency' of attributions of uncertainty and ignorance. Our data come from interviews with parents and General Practitioners (GPs), and observations of the six-week check conducted as part of a study to develop a checklist to aid GPs' diagnostic and referral decisions. Parents' pervasive uncertainties about managing with a new-born infant place them in a trusting relation to biomedicine, in which knowledge about infant hips is delegated to the clinical team: most described themselves as not-knowing about DDH. GPs focus on the uncertainties of applying sensory and experiential knowledge of infant bodies, in a consultation with more diffuse aims than screening for DDH. A prototype checklist, developed by orthopaedic specialists, was an explicit attempt to reduce uncertainty around thresholds for referral. However, using the checklist surfaced multiple logics of uncertainty. It also surfaced attributions of uncertainty and non-knowledge to other actors: orthopaedic specialists' assumptions about GPs' uncertain technical knowledge; GPs' assumptions about orthopaedic specialists' ignorance of the primary care setting; and clinicians' assumptions about the role of parental ignorance. This 'double contingency' of attributions of other actors' non-knowledge is a salient additional dimension to the uncertainty that infuses biomedical practice.

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

While perinatal risk factors are widely used to help identify those at risk for developmental dysplasia of the hip (DDH) within the first 6 to 8 weeks of life, limited data exist about their association with radiographic evidence of dysplasia in childhood. The purpose of this study was to determine which perinatal risk factors are associated with acetabular dysplasia in children who are ≥2 years of age. METHODS: Pelvic radiographs were made in 1,053 children (mean age, 4.4 years [range, 2 to 7 years]) who had been assessed prospectively as having at least 1 of 9 widely accepted perinatal risk factors for DDH. Two radiologists who were blinded to patient risk factors, history, and age determined the acetabular index (AI). The primary outcome was defined as an AI >2 standard deviations from the Tönnis reference values ("severe" dysplasia). The secondary outcome was an AI of >20° at >2 years of age. The association between risk factors and outcomes was assessed using logistic regression. The effect of treatment in infancy was adjusted for in 37 hips. RESULTS: Twenty-seven participants (3%) showed "severe" hip dysplasia; 3 of these had received treatment for DDH in infancy. Girls were more likely to experience this outcome (odds ratio [OR] = 2.59; 95% confidence interval [CI] = 1.04 to 6.46; p = 0.04); no other examined risk factors were significant. The secondary outcome appeared in 146 participants (14%), 12 of whom had received treatment in infancy. We observed the following predictors for this outcome: female sex (OR = 1.77; 95% CI = 1.21 to 2.59; p = 0.003), breech presentation (OR = 1.74; 95% CI = 1.08 to 2.79; p = 0.02), and being a firstborn child, which had a protective effect (OR = 0.67; 95% CI = 0.46 to 0.96; p = 0.03). CONCLUSIONS: We identified a substantial number of cases that will require at least radiographic surveillance for mild and severe hip dysplasia; 92% had no prior diagnosis of DDH. Those who had been born breech were affected by this outcome even if ultrasonography of the hip had been normal at 6 to 8 weeks, suggesting a benefit from additional radiographic testing. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Mechanical Analysis of Explanted Telescopic Rods in the Management of Osteogenesis Imperfecta: A Multicenter Study.

BACKGROUND: Telescopic rods in the management of osteogenesis imperfecta fail frequently. This could be attributed to technical errors, rod design, and rod structure. We aimed to analyze the mechanical properties and tribology of explanted male and female components to identify effects of in vivo telescoping that may relate to observed patterns of successful telescoping or failure. METHODS: Recruitment took place at 3 of the 4 English centers for osteogenesis imperfecta. Twenty-five rods explanted for growth or failure during revision to a new rod were analyzed in terms of clinical indication and prerevision imaging to identify if there was a technical mode of failure. Laboratory analysis was performed using optical and scanning electrical microscopy, radiograph diffraction analysis, hardness test, bending test, and energy-dispersive x-ray spectroscopy. RESULTS: All implants tested were of high-grade stainless steel. Female components had inferior strength [mean Vickers hardness property (HV0.3) at 0.3 to 313 kg] in comparison to male components (HV0.3 406) due to different techniques of manufacture. Female rods also had a higher wear coefficient (7.89×10-12 m3/N/m3) than the male rods (6.46×10-12 m3/N/m3). Abrasive wear, shear deformation, scratches, and wear debris were identified in all rods. Male and female components displayed corrosion contributing to adhesive wear. Intraoperatively cut rods, particularly the female components, had irregular ends leading to more wear. CONCLUSIONS: Current manufacturing techniques result in inferior material strength in female components compared with males, which combined with wear patterns is likely to lead to implant failure. Intraoperative cutting of rods may increase risk of failure due to wear. Considering techniques to improve strength as well as design in new implants may lead to better outcomes. LEVELS OF EVIDENCE: Level IV-cross-sectional study.

Understanding physician behaviour in the 6-8 weeks hip check in primary care: a qualitative study using the COM-B.

OBJECTIVES: A compulsory hip check is performed on an infant at 6-8 weeks in primary care for the detection of developmental dysplasia of the hip (DDH). Missed diagnoses and infants incorrectly labelled with DDH remain an important problem. The nature of physician behaviour as a likely source of this problem has not been explored. The aims of this study were to make a behavioural diagnosis of general practitioners (GPs) who perform these hip checks, and identify potential behavioural change techniques that could make the hip checks more effective. DESIGN: Qualitative study with in-depth semistructured interviews of 6-8 weeks checks. We used the Capability, Opportunity, Motivation and Behaviour model in making a behavioural diagnosis and elicited factors that can be linked to improving the assessment. SETTING: Primary care. PARTICIPANTS: 17 GPs (15 female) who had between 5 and 34 years of work experience were interviewed. RESULTS: Capability related to knowledge of evidence-based criteria and skill to identify DDH were important behavioural factors. Both physical (clinic time and space) and social (practice norms), opportunity were essential for optimal behaviour. Furthermore, motivation related to the importance of the 6-8 weeks check and confidence to perform the check and refer appropriately were identified in the behavioural diagnosis. CONCLUSION: Aspects of capability, opportunity and motivation affect GPs' diagnosis and referral behaviours in relation to DDH. The findings from this work extend current knowledge and will inform the development of an intervention aimed at improving the diagnosis of DDH.

Patient-reported outcomes in young adults with osteonecrosis secondary to developmental dysplasia of the hip - a longitudinal and cross-sectional evaluation.

BACKGROUND: Osteonecrosis of the femoral head is a common complication in the treatment of developmental dysplasia of the hip (DDH). While functional outcomes of affected patients are good in childhood, it is not clear how they change during the transition to young adulthood. This study determined the relationship between osteonecrosis and hip function, physical function and health status in adolescents and young adults. METHODS: We performed a cross-sectional study of 169 patients with a mean age of 19.7 ± 3.8 years with and without osteonecrosis following an open or closed reduction (1995-2005). We also performed a separate longitudinal evaluation of an historical cohort of 54 patients with osteonecrosis, embedded in this sample. All completed patient-reported outcome measures in 2015/2016 to quantify hip function (maximum score 100); physical function (maximum score 100); and general health status (maximum score 1). We graded all radiographs for subtype of osteonecrosis (Bucholz-Ogden); acetabular dysplasia (centre-edge angle); subluxation (Shenton's line); and osteoarthritis (Kellgren-Lawrence). Analyses were adjusted for the number of previous surgical procedures on the hip and for the severity of residual hip dysplasia. RESULTS: In 149 patients (186 hips) with and without osteonecrosis, the mean differences (95% confidence interval) in hip function, physical function and quality of life were - 4.7 (- 10.26, 0.81), - 1.03 (- 9.29, 7.23) and 0.10 (- 1.15, 1.18), respectively. Adjusted analyses stratified across types of osteonecrosis showed that only patients with Bucholz-Odgen grade III had reduced hip function (p < 0.01) and physical function (p < 0.05) but no difference in health-related quality of life when compared to no osteonecrosis. CONCLUSION: Osteonecrosis secondary to DDH is a relatively benign disorder in adolescents and young adulthood. Affected patients demonstrated minimal physical disability, a normal quality of life but reduced hip function.

Congenital growth hormone deficiency associated with hip dysplasia and Legg-Calve-Perthes disease.

OBJECTIVE: Growth hormone deficiency (GHD) is usually treated with recombinant human GH (rhGH), and this has been rarely associated with hip disorders. We analysed the clinical data of patients with congenital GHD receiving rhGH who had associated hip dysplasia or Legg-Calve-Perthes disease (LCPD), with a view to determining whether the hip dysplasia was associated with the underlying disease or with rhGH treatment. DESIGN: We performed a retrospective analysis of paediatric and adolescent patients seen between 1992-2018 with congenital GHD and hip disorders. Data were collected through a review of the patients' medical records and included demographics, clinical and imaging data, and the time frame between the onset of the symptoms related to the hip disorders and the onset of GH treatment. RESULTS: Of the 13 patients with hip disorders, hip dysplasia was present in ten patients and LCPD in three. Hip dysplasia was diagnosed before rhGH was initiated in 50% of cases. These patients had bilateral hip dysplasia and isolated GHD. LCPD was diagnosed in one patient before rhGH was commenced and did not progress. In two patients, LCPD was diagnosed after rhGH was started and did temporarily progress in one of them, but rhGH was not discontinued because LCPD did not seem to be related to rhGH treatment. CONCLUSIONS: This study suggests that hip dysplasia could be a manifestation of an underlying GHD. Additionally, rhGH treatment may not necessarily be causative of LCPD.

Study protocol for evaluation of aid to diagnosis for developmental dysplasia of the hip in general practice: controlled trial randomised by practice.

INTRODUCTION: In the UK, a compulsory '6-week hip check' is performed in primary care for the detection of developmental dysplasia of the hip (DDH). However, missed diagnoses and infants incorrectly labelled with DDH remain a problem, potentially leading to adverse consequences for infants, their families and the National Health Service. National policy states that infants should be referred to hospital if the 6-week check suggests DDH, though there is no available tool to aid examination or offer guidelines for referral. We developed standardised diagnostic criteria for DDH, based on international Delphi consensus, and a 9-item checklist that has the potential to enable non-experts to diagnose DDH in a manner approaching that of experts. METHODS AND ANALYSIS: We will conduct a controlled trial randomised by practice that will compare a diagnostic aid against standard care for the hip check. The primary objective is to determine whether an aid to the diagnosis of DDH reduces the number of clinically insignificant referrals from primary care to hospital and the number of late diagnosed DDH. The trial will include a qualitative process evaluation, an assessment of professional behavioural change and a full health economic evaluation. We will recruit 152 general practitioner practices in England. These will be randomised to conduct the hip checks with use of the study diagnostic aid and/or as per usual practice. The total number of infants seen during a 15-month recruitment period will be 110 per practice. Two years after the 6-week hip check, we will measure the number of referred infants that are (1) clinically insignificant for DDH and (2) those that constitute appropriate referrals. ETHICS AND DISSEMINATION: This study has approval from the Health Research Authority (16/1/2020) and the Confidentiality Advisory Group (18/2/2020). Results will be published in peer-reviewed academic journals, disseminated to patient organisations and the media. TRIAL REGISTRATION NUMBER: NCT04101903; Pre-results.

Parents' expectations and experiences of the 6-week baby check: a qualitative study in primary care.

BACKGROUND: The Newborn and Infant Physical Examination (NIPE) programme requires all babies to have a comprehensive health check at 6-8 weeks of age. These are typically completed by GPs. Although person-centred care has achieved prominence in maternity care policy in recent years, there is limited empirical evidence on what parents and/or carers expect from the check, and how far experiences meet their needs. AIM:  To explore the expectations and experiences of parents attending their GP for a baby check. DESIGN & SETTING: A qualitative study was undertaken in primary care in London. METHOD: Content analysis was undertaken of transcripts of semi-structured interviews. Interviews were conducted with a total of 16 participants (14 mothers and two fathers) who had recently attended for a 6-week check for their baby. RESULTS: Despite the availability of plentiful sources of general advice on infants' health and development, a thorough check by a trusted GP was an important milestone for most parents. They had few specific expectations of the check in terms of what examinations were undertaken, but even experienced parents anticipated reassurance about their baby's normal development. Many also hoped for reassurance about their own parenting. Parents appreciated GPs who explained what they were doing during the examination; space to raise any concerns; and combined mother and baby checks. Referrals to secondary care were generally experienced as reassuring rather than a source of anxiety. CONCLUSION: The baby check meets needs beyond those of the NIPE screening programme. Protecting the time for a thorough consultation is important for parents at what can be a vulnerable time.

Predicting developmental dysplasia of the hip in at-risk newborns.

BACKGROUND: The development of developmental dysplasia of the hip can be attributed to several risk factors and often in combination with each other. When predicting the likelihood of developing this condition, clinicians tend to over and underestimate its likelihood of occurring. Therefore, the study aim is to determine among at-risk newborns how to best predict developmental dysplasia of the hip (DDH) within 8 weeks post-partum. METHODS: Prospective cohort study in secondary care. Patient population included newborns at-risk for DDH - we assessed 13,276 consecutive newborns for the presence of DDH risk factors. Only newborns with at least one of the predefined risk factors and those showing an abnormal examination of the hip were enrolled (n = 2191). For the development of a risk prediction model we considered 9 candidate predictors and other variables readily available at childbirth. The main outcome measure was ultrasonography at a median age of 8 weeks using consensus diagnostic criteria; outcome assessors were blinded. RESULTS: The risk model includes four predictors: female sex (OR = 5.6; 95% CI: 2.9-10.9; P <  0.001); first degree family history of DDH (OR = 4.5; 95% CI: 2.3-9.0; P <  0.001), birthweight > 4000 g (OR = 1.6; 95% CI: 0.6-4.2; P = 0.34), and abnormal examination of hip (OR = 58.8; 95% CI: 31.9, 108.5; P <  0.001). This model demonstrated excellent discrimination (C statistic = 0.9) and calibration of observed and predicted risk (P = 0.35). A model without the variable 'hip examination' demonstrated similar performance. CONCLUSION: The risk model quantifies absolute risk of DDH within 8 weeks postpartum in at-risk newborns. Based on clinical variables readily available at the point of childbirth, the model will enhance parental counselling and could serve as the basis for real time decisions prior to discharge from maternity wards.

Preoperative botulinum neurotoxin A for children with bilateral cerebral palsy undergoing major hip surgery: a randomized double-blind placebo-controlled trial.

AIM: To assess whether preoperative botulinum neurotoxin A (BoNT-A) affects pain after major hip surgery for children with bilateral cerebral palsy (CP). METHOD: This was a randomized, parallel arms, placebo-contolled trial. Children with hypertonic CP aged 2 to 15 years awaiting bony hip surgery at a tertiary hospital were randomized to receive either BoNT-A or placebo injections into the muscles of the hip on a single occasion immediately before surgery. The primary outcome was the paediatric pain profile (PPP), which was assessed at baseline and weekly for 6 weeks. Treatment allocation was by minimization. Participants, clinicians, and outcome assessors were masked to group assignment. RESULTS: Twenty-seven participants (17 males, 10 females; mean 8y 8mo [SD 3y 9mo], range 3y 4mo-15y 10mo) were allocated to BoNT-A and 27 participants (14 males, 13 females; mean 8y 11mo [SD 3y 5mo], range 4y 1mo-15y 2mo) to placebo. Mean (SD) PPP at 6 weeks for the BoNT-A group (n=24 followed up) was 10.96 (7.22) and for the placebo group (n=26) was 10.04 (8.54) (p=0.69; 95% confidence interval [CI] -4.82, 3.18). There were 16 serious adverse events in total during 6 months of follow-up (n=6 in BoNT-A group). INTERPRETATION: Use of BoNT-A immediately before bony hip surgery for reducing postoperative pain for children with CP was not supported. WHAT THIS PAPER ADDS: Botulinum neurotoxin A (BoNT-A) does not reduce postoperative pain following bony hip surgery. BoNT-A also does not affect postoperative quality of life.

NEUROTÓXINA A BOTULÍNICA PREOPERATORIA PARA NIÑOS CON PARÁLISIS CEREBRAL BILATERAL QUE VAN A SER SOMETIDOS A UNA CIRUGÍA MAYOR DE CADERA: UN ENSAYO ALEATORIO, DOBLE CIEGO, CONTROLADO CON PLACEBO: OBJETIVE: Evaluar si la neurotóxina A botulínica preoperatoria (BoNT-A) afecta el dolor después de una cirugía mayor de cadera en niños con parálisis cerebral bilateral (PC). MÉTODO: Este fue un ensayo aleatorio, con brazos paralelos, controlado con placebo. Los niños con PC hipertónica de 2 a 15 años de edad que esperaban una cirugía de cadera en un hospital terciario se escogieron al azar para recibir inyecciones de BoNT-A o de placebo en los músculos de la cadera una sola administración previa a la cirugía. El resultado primario fue el perfil de dolor pediátrico (PPP, siglas en ingles), que se evaluó al inicio del estudio y semanalmente durante 6 semanas. La asignación del tratamiento fue por minimización. Tanto los participantes, como los clínicos y evaluadores de resultados, eran desconocidos para la asignación de grupo. RESULTADOS: Veintisiete participantes (17 varones y 10 mujeres; medios 8 años 8 meses) [Desviación Estandar SD 3 años 9 meses], rango 3 años 4 meses-15 años 10 meses) se les administro BoNT-A y 27 participantes (14 varones y 13 mujeres; media 8 años 11 meses [SD 3 años 5 meses], rango 4 años 1 mes - 15 años 2 meses) a placebo. La PPP media (SD) a las 6 semanas para el grupo de BoNT-A (n = 24 seguidas) fue de 10,96 (7,22) y para el grupo de placebo (n = 26) fue de 10,04 (8,54) (p = 0,69; intervalo de confianza del 95% [CI, siglas en ingles] -4,82, 3,18). Hubo 16 eventos adversos graves en total durante 6 meses de seguimiento (n = 6 en el grupo BoNT-A). INTERPRETACIÓN: El uso de BoNT-A inmediatamente antes de la cirugía de cadera con el fin de reducir el dolor postoperatorio en niños con PC no fue consistente.

NEUROTOXINA BOTULÍNICA A PRÉ-OPERATÓRIA PARA CRIANÇAS COM PARALISIA CEREBRAL BILATERAL SUBMETIDAS A GRANDE CIRURGIA DE QUADRIL: UM ESTUDO RANDOMIZADO, DUPLO-CEGO, CONTROLADO POR PLACEBO: OBJETIVO: Avaliar se a neurotoxina botulínica tipo A (BTA) pré-operatória A afeta a dor após grande cirurgia de quadril em crianças com paralisia cerebral bilateral (PC). MÉTODO: Este foi um estudo randomizado, com braços paralelos e controlado por placebo. Crianças com PC espástica com idade entre 2 a 15 anos aguardando cirurgia óssea de quadril em um hospital terciário foram randomizadas para receber ou BTA ou injeções de placebo nos músculos do quadril em uma única ocasião imediatamente antes da cirurgia. O desfecho primário foi o perfil de dor pediátrica (PDP), que foi avaliado na linha de base e semanalmente por 6 semanas. A alocação de tratamento foi por minimização. Os participantes, clínicos e avaliadores de resultados foram cegados quanto a atribuição de grupo. RESULTADOS: Vinte e sete participantes (17 homens, 10 mulheres; média de 8 anos e 8 meses [DP 3 anos e 9 meses], com idade entre 3 anos e 4 meses à 15 anos e 10 meses) foram alocados para o grupo BTA e 27 participantes (14 homens, 13 mulheres; média de 8 anos e 11 meses [DP 3 anos e 5 meses], com idade entre 4anos e 1mês à 15anos e 2 meses) foram alocados no grupo placebo. A média (DP) do PDP às 6 semanas para o grupo BTA (n = 24) foi de 10,96 (7,22) e para o grupo placebo (n = 26) foi de 10,04 (8,54) (p = 0,69; intervalo de confiança de 95% [IC] -4,82, 3,18). Houve 16 eventos adversos sérios no total durante 6 meses de acompanhamento (n = 6 no grupo BTA). INTERPRETAÇÃO: O uso da BTA imediatamente antes da cirurgia óssea do quadril para reduzir a dor pós-operatória em crianças com PC não foi apoiado.

Research priorities in children requiring elective surgery for conditions affecting the lower limbs: a James Lind Alliance Priority Setting Partnership.

OBJECTIVE: To identify and prioritise research questions concerning the elective surgical management of children with conditions affecting the lower limb by engaging patients, carers and healthcare professionals. DESIGN: A modified nominal group technique. SETTING: UK. PARTICIPANTS: 388 individuals (29 patients, 155 parents/carers, 204 healthcare professionals) were recruited through hospital clinics, patient charities and professional organisations and participated in the initial prioritisation survey; 234 individuals took part in the interim prioritisation survey. 33 individuals (3 patients, 9 parents/carers, 11 healthcare professionals, 7 individuals representing the project's steering group and 3 James Lind Alliance (JLA) facilitators) attended the final face-to-face workshop to rank the top 10 research priorities. INTERVENTIONS: Surveys were distributed using various media resources such as newsletters, internet messaging boards and the 'Paediatric Lower Limb Surgery Priority Setting Partnership (PSP) website. Printed copies of the questionnaire were also made available to families in outpatient clinics. OUTCOME MEASURES: Survey results, top 10 and top 26 priority rankings RESULTS: The process took 18 months to complete (July 2017-January 2019); 388 people generated 1023 questions; a total of 801 research questions were classified as true uncertainties. Following the JLA methodology, 75 uncertainties were developed from the initial 801 questions. Twenty six of those were selected through a second survey and were taken to the final face-to-face workshop where the top 10 research priorities were selected. The top10 priorities included questions on cerebral palsy, common hip conditions (ie, Perthes' disease and developmental dysplasia of the hip) as well as rehabilitation techniques and methods to improve shared decision-making between clinicians and patients/families. CONCLUSIONS: This is the first JLA PSP in children's orthopaedic surgery, a particularly under-researched and underfunded area. We have identified important research topics which will guide researchers and funders and direct their efforts in future research.

Genome-wide association study of developmental dysplasia of the hip identifies an association with GDF5.

Developmental dysplasia of the hip (DDH) is the most common skeletal developmental disease. However, its genetic architecture is poorly understood. We conduct the largest DDH genome-wide association study to date and replicate our findings in independent cohorts. We find the heritable component of DDH attributable to common genetic variants to be 55% and distributed equally across the autosomal and X-chromosomes. We identify replicating evidence for association between GDF5 promoter variation and DDH (rs143384, effect allele A, odds ratio 1.44, 95% confidence interval 1.34-1.56, P = 3.55 × 10-22). Gene-based analysis implicates GDF5 (P = 9.24 × 10-12), UQCC1 (P = 1.86 × 10- 10), MMP24 (P = 3.18 × 10-9), RETSAT (P = 3.70 × 10- 8) and PDRG1 (P = 1.06 × 10- 7) in DDH susceptibility. We find shared genetic architecture between DDH and hip osteoarthritis, but no predictive power of osteoarthritis polygenic risk score on DDH status, underscoring the complex nature of the two traits. We report a scalable, time-efficient recruitment strategy and establish for the first time to our knowledge a robust DDH genetic association locus at GDF5.

Timing of surgical intervention for developmental dysplasia of the hip: a randomised controlled trial (Hip 'Op).

BACKGROUND: Developmental dysplasia of the hip (DDH) is a very common congenital disorder, and late-presenting cases often require surgical treatment. Surgical reduction of the hip may be complicated by avascular necrosis (AVN), which occurs as a result of interruption to the femoral head blood supply during treatment and can result in long-term problems. Some surgeons delay surgical treatment until the ossific nucleus (ON) has developed, whereas others believe that the earlier the reduction is performed, the better the result. Currently there is no definitive evidence to support either strategy. OBJECTIVES: To determine, in children aged 12 weeks to 13 months, whether or not delayed surgical treatment of a congenitally dislocated hip reduces the incidence of AVN at 5 years of age. The main clinical outcome measures were incidence of AVN and the need for a secondary surgical procedure during 5 years' follow-up. In addition, to perform (1) a qualitative evaluation of the adopted strategy and (2) a health economic analysis based on NHS and societal costs. DESIGN: Phase III, unmasked, randomised controlled trial with qualitative and health economics analyses. Participants were randomised 1 : 1 to undergo either early or delayed surgery. SETTING: Paediatric orthopaedic surgical centres in the UK. PARTICIPANTS: Children aged 12 weeks to 13 months with DDH, either newly diagnosed or following failed splintage, and who required surgery. We had a target recruitment of 636 children. INTERVENTIONS: Surgical reduction of the hip performed as per the timing allocated at randomisation. MAIN OUTCOME MEASURES: Primary outcome - incidence of AVN at 5 years of age (according to the Kalamchi and MacEwen classification). Secondary outcomes - need for secondary surgery, presence or absence of the ON at the time of primary treatment, quality of life for the main carer and child, and a health economics and qualitative analysis. RESULTS: The trial closed early after reaching < 5% of the recruitment target. Fourteen patients were randomised to early treatment and 15 to delayed treatment. Implementation of rescue strategies did not improve recruitment. No primary outcome data were collected, and no meaningful conclusions could be made from the small number of non-qualitative secondary outcome data. The qualitative work generated rich data around three key themes: (1) access to, and experiences of, primary and secondary care; (2) the impact of surgery on family life; and (3) participants' experiences of being in the trial. LIMITATIONS: Overoptimistic estimates of numbers of eligible patients seen at recruiting centres during the planning of the trial, as well as an overestimation of the recruitment rate, may have also contributed to unrealistic expectations on achievable patient numbers. FUTURE WORK: There may be scope for investigation using routinely available data. CONCLUSIONS: Hip 'Op has highlighted the importance of accurate advance information on numbers of available eligible patients, as well as support from all participating investigators when conducting surgical research. Despite substantial consultation with parents of children in the planning stage, the level of non-participation experienced during recruitment was much higher than anticipated. The qualitative work has emphasised the need for appropriate advice and robust support for parents regarding the 'real-life' aspects of managing children with DDH. TRIAL REGISTRATION: Current Controlled Trials ISRCTN76958754. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 63. See the NIHR Journals Library website for further project information.

Association between the ossific nucleus and osteonecrosis in treating developmental dysplasia of the Hip: updated meta-analysis.

BACKGROUND: A meta-analysis concluded that there was no effect of the femoral head ossification and the incidence of osteonecrosis in the treatment of developmental dysplasia of the hip (DDH), unless only osteonecrosis grades II-IV were considered. The meta-analysis, limited due to the small number of studies available at that time, identified a need for an update as further research emerges. We observed a trend in recent years towards delaying treatment of DDH in the absence of an ossified nucleus. Numerous new publications on this topic encouraged us to update the 2009 meta-analysis. METHODS: We performed a systematic review of the literature from 1967 to 2016 and included studies that reported on the treatment of DDH, the ossific nucleus and osteonecrosis. Two independent reviewers evaluated all articles. We performed a meta-analysis with the main outcome defined as the development of osteonecrosis of the femoral head at least two years after closed or open reduction. RESULTS: Of four prospective and ten retrospective studies included in the systematic review, 11 studies (1,021 hips) met the inclusion criteria for the meta-analysis. There was no significant effect of the ossific nucleus on the development of all grades of osteonecrosis (relative risk, 0.88; 95% confidence interval, 0.56-1.41) or osteonecrosis grades II-IV (0.67; 0.41-1.08). In closed reductions, the ossific nucleus halved the risk for developing osteonecrosis grades II-IV (0.50; 0.26-0.94). CONCLUSIONS: Based on current evidence there does not appear to be a protective effect of the ossific nucleus on the development of osteonecrosis. In contrast to the previous meta-analysis, this update demonstrates that this remains the case irrespective of the grade of osteonecrosis considered relevant. This updated meta-analysis is based on twice as many studies with a higher quality of evidence.

The most relevant diagnostic criteria for developmental dysplasia of the hip: a study of British specialists.

BACKGROUND: Developmental dysplasia of the hip (DDH) is the most common orthopaedic disorder in newborns. Despite this considerable variation in practice exists. The aim of this study was to determine the clinical relevance and a ranking order for the diagnostic criteria in DDH amongst paediatric orthopaedic surgeons practicing in the UK. METHOD: One hundred members of the British Society of Children's Orthopaedic Surgery (BSCOS) were asked to rate the importance of 37 criteria useful in the diagnosis of DDH in newborns, using a 10 cm visual analogue scale. We determined the consistency among specialists in rating the criteria with the intraclass correlation coefficient (ICC) and compared the results to a group of international peers. RESULTS: Ortolani/Barlow tests, asymmetry in abduction ≥20° and a first-degree relative treated for DDH ranked among the top ten. Participants demonstrated poor consistency in rating the 37 criteria (ICC 0.39; 95% CI 0.29, 0.52), but for clinical examination criteria alone their consistency improved (ICC 0.52; 0.35, 0.75). The importance ratings of members of BSCOS and members of the European Paediatric Orthopaedic Society differed for 15/37 (41%) criteria (p <0.05). CONCLUSIONS: Members of BSCOS had a preference for criteria relating to clinical examination and ultrasound.

Diagnostic yield of sonography in infants with suspected hip dysplasia: diagnostic thinking efficiency and therapeutic efficiency.

OBJECTIVE: The purpose of this study is to determine the impact of sonographic information on surgeons' diagnostic thinking and decision making in the management of infants with a possible diagnosis of developmental dysplasia of the hip (DDH). SUBJECTS AND METHODS: Five experienced orthopedic surgeons examined 66 hips of infants who were referred for a possible diagnosis of DDH and reported for each hip a confidence level about the diagnosis of DDH using a visual analog scale (VAS) before and after hip sonography was obtained. In addition, they reported a management plan. We determined the efficiency in diagnostic thinking by calculating the mean gain in diagnostic confidence as the percentage change in VAS scores and the impact of sonography on the management plan (therapeutic efficiency). RESULTS: Sonography led to a change in diagnosis in 52% (34/66) of hips. The management plan changed in 32% (21/66) of hips. The mean gain in reported diagnostic confidence was 19.4% (95% CI, 17.3-21.5%), but it was 46.0% (95% CI, 30.5-60.8%) in cases where the management changed as a result of sonography (difference, 37.7%; p < 0.0001). The greatest yield of sonography was found in hips showing limited abduction. Sonography obviated further follow-up in 23% (15/66) of cases. CONCLUSION: Sonography refined the diagnostic thinking of clinicians and led to a change in diagnosis in 52% of cases. Management plans changed in 32% of cases.