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.

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.

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.

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.

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.

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.

Weighted diagnostic criteria for developmental dysplasia of the hip.

OBJECTIVE: To establish clinical diagnostic criteria for developmental dysplasia of the hip (DDH) that model the practices of expert clinicians. STUDY DESIGN: Of 23 clinical criteria for the diagnosis of DDH, ranked in order of diagnostic importance by international consensus, the 7 most highly ranked were placed in all possible combinations to create unique case vignettes. Twenty-six experts rated 52 vignettes for the presence of DDH. We modeled the data to determine which of the 7 criteria were associated with a clinician's opinion that the vignette represented DDH. From the resulting regression coefficients, for each vignette we calculated a probability of DDH. An independent panel rated the same vignettes using a visual analog scale response. We correlated the visual analog scale ratings with probabilities derived from the model. RESULTS: Our model identified 4 of 7 criteria as predictive of DDH (P < .001): Ortolani/Barlow test (ß = 3.26), limited abduction (ß = 1.48), leg length discrepancy (ß = 0.74), and first-degree family history of DDH (ß = 1.39). There was substantial correlation between the probability of DDH predicted by the model and that derived from an independent expert panel (r = 0.73; P < .001). CONCLUSION: Weighted clinical criteria for inferring the likelihood of DDH produced consistent results in the judgment of 2 separate groups of experts. Using these weights, nonexperts could establish the probability of DDH in a manner approaching the practice of clinical experts.

Cross-country comparison of victimisation-related injury admission in children and adolescents in England and Western Australia.

BACKGROUND: A single, standardised measure of victimisation-related (VR) injury admission in hospital administrative datasets could allow monitoring of preventive and response strategies and international comparisons of policy. Consistency of risk factors and incidence rates for a measure of victimisation-related injury in different countries with similar access to healthcare services would provide indirect evidence for measure validity. METHODS: Cohorts were derived from hospital administrative data for children aged less than 18 years who were admitted for acute injury to hospitals in England or Western Australia (WA) in 2000 to 2008. We compared the effects of age, sex and deprivation on the annual incidence of acute admission for VR injury defined by a cluster of ICD-10 codes reflecting characteristics that should alert clinicians to consider victimisation as a cause of injury. Four subcategories comprised codes specifically indicating child maltreatment, assault, undetermined cause, or adverse social circumstances. RESULTS: The incidence of VR injury followed a similar 'J'-shaped association with age in both countries with increasing rates from 10 years onwards and peaks in infancy and in 16-17 year-olds. In both countries, rates increased with deprivation. Girls had lower rates than boys except in the 11-15 age group where girls had higher rates than boys in WA but not in England. Adjusted incidence rates were similar in both countries for children aged 3 to 15 years old, but were higher in WA compared with England in children under 3 years old and in those aged 16-17 years. Higher rates in WA in 16-17 year-olds were explained by more admissions coded for the subcategories of adverse social circumstances, and to a lesser extent, assault, than in England. Children less than 3 years old were more often coded specifically for maltreatment in WA than in England. CONCLUSIONS: The similarities in risk factors and in the adjusted rates of victimisation-related injury admission in both countries suggest that the VR cluster of ICD-10 codes is measuring a similar underlying problem. Differential use of coding subcategories highlights the need to use the entire VR cluster for comparisons across settings.

Variations in the use of diagnostic criteria for developmental dysplasia of the hip.

BACKGROUND: Wide variation exists in reported prevalence estimates and management standards of developmental dysplasia of the hip (DDH). Discrepancies in diagnosticians' opinions may explain some of this variation. QUESTIONS/PURPOSES: We sought to determine (1) the consistency with which pediatric orthopaedic surgeons rate the importance of diagnostic criteria for DDH, and (2) whether there were geographic differences in how the diagnostic criteria were rated by surgeons. METHODS: One hundred ninety-seven of 220 members of the European Paediatric Orthopaedic Society and 100 of 148 members of the British Society of Children's Orthopaedic Surgery treating children with DDH participated in this cross-sectional study across 35 countries (15 regions). Each rated 37 items in four domains that specialists previously had identified as the most important features associated with DDH in early infancy. We determined consistency using the intraclass correlation coefficient (ICC; two-way random-effects model) interpreted as poor (0-0.40), acceptable (0.41-0.74), or good (≥ 0.75). RESULTS: Poor consistency among surgeons was found in rating the 37 diagnostic criteria (ICC, 0.33; 95% CI, 0.24-0.45). Consistency was poor for three domains (patient characteristics/history: ICC, 0.29; 95% CI, 0.16-0.58; ultrasound: ICC, 0.26; 95% CI, 0.14-0.52; radiography: ICC, 0.34; 95% CI, 0.12-0.95) and acceptable for one (clinical examination: ICC, 0.50; 95% CI, 0.33-0.73). Surgeons in particular regions appeared to have a concept of DDH diagnosis that distinguished them from specialists of other regions; consistency in eight regions was greater (ICC ≥ 0.40) than consistency among all 15 regions. CONCLUSIONS: The consistency of specialists in rating diagnostic criteria for DDH was lower than expected, and there was considerable geographic variation in terms of how specialists assigned importance ratings of the diagnostic criteria; these findings are somewhat counterintuitive, given the frequency with which this condition is diagnosed. These inconsistencies could explain, partly, the widely differing prevalence estimates and management standards of DDH.

Osteonecrosis complicating developmental dysplasia of the hip compromises subsequent acetabular remodeling.

BACKGROUND: Osteonecrosis of the femoral head secondary to treatment of developmental dysplasia of the hip (DDH) affects acetabular remodeling but the magnitude of this effect is unclear. QUESTIONS/PURPOSES: Using four measures of acetabular development, we (1) determined whether acetabular remodeling differed in hips with and without osteonecrosis; and (2) determined the impact of severity of osteonecrosis contributing to acetabular remodeling. METHODS: We retrospectively reviewed 95 patients (118 hips) treated for DDH by closed or open reduction with or without femoral osteotomy between 1992 and 2006. We evaluated serial radiographs from the time when a stable reduction had been achieved. In 902 radiographs taken over 19 years, we measured the acetabular index and three other indices of hip development. Patients were followed for a mean of 8 years (range, 1-19 years). At last followup, 86 of the 118 hips (73%) had osteonecrosis according to the criteria by Bucholz and Ogden. RESULTS: The acetabular index improved with time in all hips but the magnitude of improvement was larger in hips without osteonecrosis. The adjusted mean acetabular index at 14 years was 17° for hips with osteonecrosis (95% CI, 15°-18°) and 10° for hips without osteonecrosis (95% CI, 7°-13°). The lateral centering ratio improved after reduction to a normal value less than 0.85 in both groups but the rate of change with 0.06 versus 0.05 was higher in hips with osteonecrosis. The superior centering ratio was worse at all times in hips with osteonecrosis with a mean difference of 0.04. If only radiographic changes of Grades II and greater were considered osteonecrosis, the mean adjusted acetabular index at 14 years was 17.7° (15.6°-19.7°) for hips with osteonecrosis and 12.4° (10.3°-14.4°) for hips without osteonecrosis. CONCLUSIONS: Although radiographic indices improved consistently with time in hips without osteonecrosis, hips with osteonecrosis had abnormal indices of acetabular remodeling throughout followup. Osteonecrosis of the femoral head inhibited acetabular remodeling. LEVEL OF EVIDENCE: Level III, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Reliability of Bucholz and Ogden classification for osteonecrosis secondary to developmental dysplasia of the hip.

BACKGROUND: Osteonecrosis is perhaps the most important serious complication after treatment of developmental dysplasia of the hip (DDH). The classification by Bucholz and Ogden has been used most frequently for grading osteonecrosis in this context, but its reliability is not established and unreliability could affect the validity of studies reporting the outcome of treatment. QUESTIONS/PURPOSE: We established the interrater and intrarater reliabilities of this classification and analyzed the frequency and nature of disagreements. METHODS: Three pediatric hip surgeons, a musculoskeletal pediatric radiologist, and three orthopaedic trainees graded 39 radiographs (hips) according to the Bucholz and Ogden classification, blinded to any clinical data. Ratings were repeated after 2 weeks. Interrater reliability and intrarater reliability were determined using the simple kappa statistic. Grading was compared among raters, the nature and frequency of disagreements established, and subgroup analyses performed. RESULTS: Interrater reliability was 0.34 (95% CI = 0.28, 0.40) for all raters, and 0.31 (0.20 to 0.43) for the three surgeons. The best interrater reliability was observed between the radiologist and a surgeon with a kappa of 0.51 (0.30, 0.72). Intrarater reliability estimates ranged from 0.44 to 0.69. Raters disagreed regarding the grade of osteonecrosis in 26 of 39 hips (67%), with seven of 26 disagreements (27%) involving confusion between Grades I and II. CONCLUSIONS: The interrater reliability was lower than expected, considering the raters' experience. Distinguishing between Grades I and II was the most frequently observed problem. We believe that the low reliability was a result of an ambiguous classification scheme rather than the variability among the raters. Outcome studies of DDH based on this classification should be interpreted with caution. We recommend the development of a new classification with better prognostic ability. LEVEL OF EVIDENCE: Level III, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

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.

The presence of an ossific nucleus does not protect against osteonecrosis after treatment of developmental dysplasia of the hip.

BACKGROUND: Osteonecrosis (ON) is a major complication after treatment of developmental dysplasia of the hip (DDH). Several studies have explored the absence of the femoral head ossific nucleus at the time of hip reduction as a risk factor for the development of ON, but findings have been inconsistent. QUESTIONS/PURPOSES: We therefore determined the incidence of ON in children who underwent reduction of a dislocated hip in the presence or absence of the ossific nucleus. PATIENTS AND METHODS: We retrospectively reviewed the radiographs of 105 hips in 89 patients treated for DDH at the age of 18 months or younger. Radiographs were graded for the presence of the ossific nucleus at the time of hip reduction and for the presence of ON, as graded by the Bucholz and Ogden classification, for patients at a mean age of 10 years. We used log-binomial regression to estimate if the presence of the ossific nucleus was associated with a lower incidence of ON. RESULTS: We identified ON in 37 of the 105 hips (35%). The incidence of ON at 10 years was 40% in the absence of the ossific nucleus and 32% in the presence of the ossific nucleus (adjusted relative risk, 0.86; 95% confidence interval, 0.36-1.81). When only radiographic changes of Grade II and greater were considered ON, the risk was still not increased (relative risk, 1.26; 95% confidence interval, 0.62-2.56). CONCLUSION: Patients with an ossific nucleus at the time of hip reduction showed a slight tendency toward better outcomes. The ossific nucleus did not protect for ON. LEVEL OF EVIDENCE: Level III, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Standardized diagnostic criteria for developmental dysplasia of the hip in early infancy.

BACKGROUND: Clinicians use various criteria to diagnose developmental dysplasia of the hip (DDH) in early infancy, but the importance of these various criteria for a definite diagnosis is controversial. The lack of uniform, widely agreed-on diagnostic criteria for DDH in patients in this age group may result in a delay in diagnosis of some patients. QUESTIONS/PURPOSES: Our purpose was to establish a consensus among pediatric orthopaedic surgeons worldwide regarding the most relevant criteria for diagnosis of DDH in infants younger than 9 weeks. MATERIAL AND METHODS: We identified 212 potential criteria relevant for diagnosing DDH in infants by surveying 467 professionals. We used the Delphi technique to reach a consensus regarding the most important criteria. We then sent the survey to 261 orthopaedic surgeons from 34 countries. RESULTS: The response rate was 75%. Thirty-seven items were identified by surgeons as most relevant to diagnose DDH in patients in this age group. Of these, 10 of 37 (27%) related to patient characteristics and history, 13 of 37 (35%) to clinical examination, 11 of 37 (30%) to ultrasound, and three of 37 (8%) to radiography. A Cronbach alpha of 0.9 for both iterations suggested consensus among the panelists. CONCLUSION: We established a consensus regarding the most relevant criteria for the diagnosis of DDH in early infancy and established their relative importance on an international basis. The highest ranked clinical criteria included the Ortolani/Barlow test, asymmetry in abduction of 20° or greater, breech presentation, leg-length discrepancy, and first-degree relative treated for DDH. LEVEL OF EVIDENCE: Level IV, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

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.

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.