The significance of at-risk factors in ultrasound surveillance of developmental dysplasia of the hip. A ten-year prospective study

Validation of parameters recommended for secondary screening for developmental dysplasia of the hip in Japan

BACKGROUND

Based on the Japanese Pediatric Orthopaedic Association's guidelines, secondary screening and imaging including ultrasonography and radiography, are recommended in infants with limited hip abduction (<70°) or in those with multiple risk factors including the following: asymmetrical skin creases, a family history of developmental dysplasia of the hip, female sex, and pelvic position at delivery. However, there is still little information regarding the usefulness of this guideline. The objective of this study was to investigate the association between the risk factors and developmental dysplasia of the hip diagnosed using ultrasound and radiography.

METHODS

A total of 356 infants (67 boys and 289 girls) underwent secondary ultrasonographic and radiological screening for developmental dysplasia of the hip in our hospital. Risk factors were documented from their medical records. The recommended item score, which we defined as an integrated value of the recommended item, was calculated for each patient. The limitation of hip abduction alone was a criterion for secondary screening; therefore, we defined the scores as follows: the limitation of hip abduction scored 2 points and other recommended scores were assigned 1 point. If the recommended item score was 2 points or more, we classified the infants as high-risk.

RESULTS

A total of 280 of 356 infants were included in the high-risk group, which showed a higher ratio of cases with abnormal imaging findings than the low-risk group. According to the multivariate logistic regression analyses among the recommended items, being female, skin asymmetry, and limb limitation were identified as independent risk factors for imaging abnormality and the need for Pavlik harness treatment.

CONCLUSIONS

The recommended items for secondary screening based on the Japanese Pediatric Orthopaedic Association's guidelines could be useful for screening infants in need of treatment.

Does This Infant Have a Dislocated Hip?: The Rational Clinical Examination Systematic Review

Importance

Delayed diagnosis of a dislocated hip in infants can lead to complex childhood surgery, interruption to family life, and premature osteoarthritis.

Objective

To evaluate the diagnostic accuracy of clinical examination in identifying dislocated hips in infants.

Data Sources

Systematic search of CINAHL, Embase, MEDLINE, and the Cochrane Library from the inception of each database until October 31, 2023.

Study Selection

The 9 included studies reported the diagnostic accuracy of the clinical examination (index test) in infants aged 3 months or younger and a diagnostic hip ultrasound (reference test). The Graf method of ultrasound assessment was used to classify hip abnormalities.

Data Extraction and Synthesis

The Rational Clinical Examination scale was used to assign levels of evidence and the Quality Assessment of Diagnostic Accuracy Studies tool was used to assess bias. Data were extracted using the individual hip as the unit of analysis; the data were pooled when the clinical examinations were evaluated by 3 or more of the included studies.

Main Outcomes and Measures

Sensitivity, specificity, and likelihood ratios (LRs) of identifying a dislocated hip were calculated.

Results

Among infants screened with a clinical examination and a diagnostic ultrasound in 5 studies, the prevalence of a dislocated hip (n = 37 859 hips) was 0.94% (95% CI, 0.28%-2.0%). There were 8 studies (n = 44 827 hips) that evaluated use of the Barlow maneuver and the Ortolani maneuver (dislocate and relocate an unstable hip); the maneuvers had a sensitivity of 46% (95% CI, 26%-67%), a specificity of 99.1% (95% CI, 97.9%-99.6%), a positive LR of 52 (95% CI, 21-127), and a negative LR of 0.55 (95% CI, 0.37-0.82). There were 3 studies (n = 22 472 hips) that evaluated limited hip abduction and had a sensitivity of 13% (95% CI, 3.3%-37%), a specificity of 97% (95% CI, 87%-99%), a positive LR of 3.6 (95% CI, 0.72-18), and a negative LR of 0.91 (95% CI, 0.76-1.1). One study (n = 13 096 hips) evaluated a clicking sound and had a sensitivity of 13% (95% CI, 6.4%-21%), a specificity of 92% (95% CI, 92%-93%), a positive LR of 1.6 (95% CI, 0.91-2.8), and a negative LR of 0.95 (95% CI, 0.88-1.0).

Conclusions and Relevance

In studies in which all infant hips were screened for developmental dysplasia of the hip, the prevalence of a dislocated hip was 0.94%. A positive LR for the Barlow and Ortolani maneuvers was the finding most associated with an increased likelihood of a dislocated hip. Limited hip abduction or a clicking sound had no clear diagnostic utility.

The Risk of Developmental Dysplasia of the Hip in Premature Infants with Breech Presentation at Birth

OBJECTIVE

This article evaluates the risk (defined here as incidence per 1,000 infants) of developmental dysplasia of the hip (DDH) in premature infants undergoing hip ultrasound (HUS) for breech presentation only compared with other indications.

STUDY DESIGN

Retrospective study of infants born between January 1, 2009 and December 31, 2018 at <37 weeks' gestation with a HUS obtained in the first year of life, at Nationwide Children's Hospital, the only available facility for pediatric radiology and orthopaedic services in central Ohio. We calculated risk differences and odds ratios of DDH by the indication of HUS.

RESULTS

From 2,397 infants reviewed, 89% underwent HUS for breech presentation only. The local incidence of DDH for infants undergoing HUS for breech-only indication was 15 per 1,000 compared with 155 per 1,000 for infants undergoing HUS for other indications. The odds ratio of DDH diagnosis was 12.1 (95% confidence interval: 7.5, 19.6) for infants undergoing HUS for an indication other than breech presentation only relative to infants undergoing HUS for the indication of breech presentation only.

CONCLUSION

The risk of DDH diagnosis in premature infants undergoing HUS for breech presentation is much lower than those undergoing HUS for clinical concerns and other risk factors. Screening these infants with physical examination may be sufficient.

KEY POINTS

· Breech presentation is the most common indication for hip ultrasound in premature infants.. · The risk of DDH is lower in premature infants with breech presentation compared with premature infants with other clinical concerns.. · The risk of DDH is higher in infants born at 33 to 36 weeks of gestation compared with those born at an earlier gestation..

Developmental Dysplasia of the Hip Is Not Associated with Breech Presentation in Preterm Infants

OBJECTIVES

The aim of the study is to (1) determine the incidence of developmental dysplasia of the hip (DDH) in preterm infants born prior to 35 completed weeks' gestation in a breech presentation, and (2) evaluate if the association between breech presentation and DDH in full-term infants holds for premature infants.

STUDY DESIGN

This study design comprises retrospective review of infants born between January 1, 2008, and December 31, 2017, at <35 weeks' gestation and admitted to the NICU. Infants had hip ultrasounds at 4 to 6 weeks' corrected age if they were born in a breech presentation with a stable hip examination. We excluded infants born in a presentation other than breech or vertex, had no documentation of presentation at birth, or if they died within the first year.

RESULTS

We included 1,533 infants. Preterm infants <35 weeks' gestation born in the breech versus vertex position had an incidence of DDH of 0.47% (2/428) and 0.36% (4/1,105), respectively. There was no significant difference in the incidence of DDH between infants born in the breech versus vertex position (Chi-square and Fisher's exact tests). The sensitivity, specificity, and positive and negative predictive values of breech presentation in detecting DDH were 33, 72, 0.47, and 99.6%, respectively.

CONCLUSION

There is no association between breech presentation and DDH in preterm infants <35 weeks' gestation. Obtaining hip ultrasounds on preterm infants <35 weeks' gestation born in the breech presentation with a normal hip examination is not recommended.

KEY POINTS

· Breech position is a risk factor for DDH in term newborns.. · Preterm infants are often in the breech position until 37 weeks' gestation.. · This study shows that breech presentation is not a risk factor for DDH in preterm infants..

The cost effectiveness of potential risk factors for developmental dysplasia of the hip within a national screening programme

Aims

Early detection of developmental dysplasia of the hip (DDH) is associated with improved outcomes of conservative treatment. Therefore, we aimed to evaluate a novel screening programme that included both the primary risk factors of breech presentation and family history, and the secondary risk factors of oligohydramnios and foot deformities.

Methods

A five-year prospective registry study investigating every live birth in the study’s catchment area (n = 27,731), all of whom underwent screening for risk factors and examination at the newborn and six- to eight-week neonatal examination and review. DDH was diagnosed using ultrasonography and the Graf classification system, defined as grade IIb or above or rapidly regressing IIa disease (≥4^o at four weeks follow-up). Multivariate odds ratios were calculated to establish significant association, and risk differences were calculated to provide quantifiable risk increase with DDH, positive predictive value was used as a measure of predictive efficacy. The cost-effectiveness of using these risk factors to predict DDH was evaluated using NHS tariffs (January 2021).

Results

The prevalence of DDH that required treatment within our population was 5/1,000 live births. The rate of missed presentation of DDH was 0.43/1000 live births. Breech position, family history, oligohydramnios, and foot deformities demonstrated significant association with DDH (p < 0.0001). The presence of breech presentation increased the risk of DDH by 1.69% (95% confidence interval (CI) 0.93% to 2.45%), family history by 3.57% (95% CI 2.06% to 5.09%), foot deformities by 8.95% (95% CI 4.81% to 13.1%), and oligohydramnios nby 11.6% (95 % CI 3.0% to 19.0%). Primary risk factors family history and breech presentation demonstrated an estimated cost-per-case detection of £6,276 and £11,409, respectively. Oligohydramnios and foot deformities demonstrated a cost-per-case detected less than the cost of primary risk factors of £2,260 and £2,670, respectively.

Conclusion

The inclusion of secondary risk factors within a national screening programme was clinically successful as they were more cost and resource-efficient predictors of DDH than primary risk factors, suggesting they should be considered in the national guidance.

Cite this article: Bone Jt Open 2023;4(4):234–240.

A comparison of different selective ultrasound screening strategies for developmental dysplasia of the hip

To analyze whether the addition of risk-based criteria to clinical examination-based selective ultrasound screening would increase the rates of early detected cases of developmental dysplasia of the hip (DDH) and decrease the rate of late detected cases. A systematic review with meta-analysis was performed. The initial search was performed in the PubMed, Scopus, and Web of Science databases in November 2021. The following search terms were used: (hip) AND (ultrasound) AND (luxation or dysplasia) AND (newborn or neonate or congenital). A total of 25 studies were included. In 19 studies, newborns were selected for ultrasound based on both risk factors and clinical examination. In six studies, newborns were selected for ultrasound based on only clinical examination. We did not find evidence indicating that there are differences in the incidence of early- and late-detected DDH, or in the incidence of nonoperatively treated DDH between the risk-based and clinical examination-based groups. The pooled incidence of operatively treated DDH was slightly lower in the risk-based group (0.5 (95% confidence interval (CI) 0.3 to 0.7)) compared with the clinical examination group (0.9 per 1,000 newborns, (95% CI 0.7 to 1.0)). The use of risk factors in conjunction with clinical examination in the selective ultrasound screening of DDH might lead to fewer operatively treated cases of DDH. However, more studies are needed before stronger conclusions can be drawn.

Prediction of Late Dysplasia Based on Ultrasound and Plain X-Ray at 6 Months

BACKGROUND

Developmental dysplasia of the hip represents a spectrum of deformity. Residual dysplasia at 2 years of age is associated with an increased risk for osteoarthritis and functional limitations. We compared the prognostic value of 6-month imaging modalities and aimed to identify optimal diagnostic metrics for the prediction of residual dysplasia.

METHODS

After IRB approval, patients who underwent Pavlik treatment between 2009 and 2018 with 2-year follow-up were identified. Sonographs [ultrasound (US)] and radiographs (x-ray) were obtained at 6-month and 2-year-old visits. Dysplasia at 2 years was defined as an acetabular index (AI) >24 degrees. Receiver operating characteristic curves were constructed to quantitatively compare the prognostic ability of US and x-ray-based measures at 6 months. Youden's index [(YI) (values range from 0 (poor test) to 1 (perfect test)] was used to evaluate existing cutoffs at 6 months of age (normal measurements: alpha angle (AA) ≥60 degrees, femoral head coverage (FHC) ≥50%, and AI <30 degrees) relative to newly proposed limits.

RESULTS

Fifty-nine patients were included, of which 28.8% of patients (95% CI: 17.3 to 40.4%) had acetabular dysplasia at 2 years. After adjusting for sex, AA [Area under the Curve (AUC): 80] and AI (AUC: 79) at 6 months of age were better tests than FHC (AUC: 0.77). Current diagnostic cutoffs for AA (YI: 0.08), AI (YI: 0.0), and FHC (YI: 0.06) at 6 months had poor ability to predict dysplasia at 2 years. A composite test of all measures based on proposed cutoffs (AA ≥73 degrees, FHC > 62% and AI ≤24 degrees) was a better predictor of dysplasia at 2 years (Youden's index (YI): 0.63) than any single metric.

CONCLUSIONS

The rate of residual dysplasia remains concerning. The 6-month x-ray and US both play a role in the ongoing management of the developmental dysplasia of the hip. The prediction of dysplasia is maximized when all metrics are considered collectively. Existing parameters were not accurate; We recommend the following cutoffs: AA ≥73 degrees, FHC > 62%, and AI ≤24 degrees. These cutoffs must be validated.

LEVEL OF EVIDENCE

Prognostic Level II.

Surgical procedures in infants with early diagnoses of developmental dysplasia of the hip. A prospective 4-year follow-up study

Background

Dysplastic hips infants may normalize spontaneously without any intervention due to the natural growth. However, some infants need one or more surgical interventions to achieve stable and non-dysplastic hips. The purpose of this study is to determine the proportion of infants diagnosed with DDH before the age of 6 months undergoing surgical procedures of the hip(s) before the age of four years and to determine the number and types of surgical procedures in each infant.

Methods

A prospective and consecutive study of all infants aged 0-6 months diagnosed with dysplasia of the hips in the combined paediatric orthopaedic and radiologic examination in the Region of Southern Denmark 2013-2017. From medical records, we obtained information about all surgical procedures in the hips including open or closed reductions, arthrographies, tenotomies, and pelvic osteotomies before the age of 4 years.

Results

Overall, 281 infants with hip dysplasia were included. The median age at first examination was 48 days. In 254 (90%) of the infants, the hips resolved spontaneously, and 27 (10%) needed one or more surgical interventions. Overall, the 27 infants had 47 surgical intervention as 12 infants had more than one intervention. One infants had five surgical interventions. The most frequent surgical procedures were closed reduction and arthrography with or without adductor tenotomy (58%) and pelvic osteotomy (27%). Among infants with surgical interventions, 23 (8.2%) had unstable hips, and four (1.4%) had stable hips. All four infants with stable hips had an arthrography and none required a pelvic osteotomy.

Discussion

This study supports the propensity for spontaneous normalization early dysplasia of the hips in infants. Only a small proportion of the infants needed surgical interventions to achieve stable and non-dysplastic hips.

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.

Morphological Analysis of Hip Joint of Patients Suffering From Recurrent Patella Dislocation

The purpose was to investigate morphological changes of the hip joint in patients with recurrent dislocation of the patella combined with trochlear dysplasia. There was a retrospective analysis of 148 patients and 150 control subjects. The selection of participants was randomized. Hip and knee data for all participants were obtained from X-ray or computed tomography measurements. Nine values, that is, central edge angle (CEA), acetabulum index angle (AIA), femoral neck-shaft angle, sharp angle, the depth of the acetabulum, femoral anteversion angle (FAA), anterior acetabular section angle (AASA), posterior acetabular section angle (PASA), and sulcus angle, were measured to evaluate differences between the control group and the patient group and analyze the correlation of the sulcus angle in patients to FAA and CEA. Patients with recurrent dislocation of the patella had less acetabular coverage and are more likely to develop developmental dysplasia of the hip than the hips of patients with normal knees. For the patient group, three values, that is, CEA (27.68 ± 5.25 vs. 34.30 ± 3.51 degrees, p < 0.001), AASA (57.14 ± 6.17 vs. 63.08 ± 7.23 degrees, p < 0.001), and PASA (89.53 ± 6.51 vs. 99.63 ± 5.94 degrees, p < 0.001), were decreased. The sharp angle (43.77 ± 3.23 vs. 39.28 ± 3.19 degrees, p < 0.001), AIA (11.52 ± 4.41 vs. 3.73 ± 2.51 degrees, p < 0.001), and FAA (24.68 ± 3.44 vs. 18.49 ± 3.55 degrees, p < 0.001) were increased. The acetabulum became shallower in-depth (7.05 ± 2.18 vs. 10.45 ± 1.61 mm, p < 0.001). There was a weak correlation between the sulcus angle and CEA (r =  - 0.302, p < 0.001) and FAA (r = 0.212, p = 0.022). Recurrent patellar dislocation combined with trochlear dysplasia may be associated with the hip morphology. Developmental disorders of the knee joint, and hip joint should be considered in the treatment of patients with recurrent dislocation of the patella.

Is foot deformity associated with developmental dysplasia of the hip?

Aims

To assess if congenital foot deformity is a risk factor for developmental dysplasia of the hip (DDH).

Methods

Between 1996 and 2012, 60,844 children were born in Sør-Trøndelag county in Norway. In this cohort study, children with risk factors for DDH were examined using ultrasound. The risk factors evaluated were clinical hip instability, breech delivery, a family history of DDH, a foot deformity, and some syndromes. As the aim of the study was to examine the risk for DDH and foot deformity in the general population, children with syndromes were excluded. The information has been prospectively registered and retrospectively analyzed.

Results

Overall, 494 children (0.8%) had DDH, and 1,132 (1.9%) a foot deformity. Of the children with a foot deformity, 49 (4.3%) also demonstrated DDH. There was a statistically significant increased association between DDH and foot deformity (p < 0.001). The risk of DDH was highest for talipes calcaneovalgus (6.1%) and club foot (3.5%), whereas metatarsus adductus (1.5%) had a marginal increased risk of DDH.

Conclusion

Compared with the general population, children with a congenital foot deformity had a significantly increased risk for DDH and therefore we regard foot deformity as a true risk factor for DDH.

Cite this article: Bone Joint J 2020;102-B(11):1582–1586.

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.

Imaging of developmental dysplasia of the hip: ultrasound, radiography and magnetic resonance imaging

Developmental dysplasia of the hip (DDH) describes a broad spectrum of developmental abnormalities of the hip joint that are traditionally diagnosed during infancy. Because the development of the hip joint is a dynamic process, optimal treatment depends not only on the severity of the dysplasia, but also on the age of the child. Various imaging modalities are routinely used to confirm suspected diagnosis, to assess severity, and to monitor treatment response. For infants younger than 4 months, screening hip ultrasound (US) is recommended only for those with risk factors, equivocal or positive exam findings, whereas for infants older than 4-6 months, pelvis radiography is preferred. Following surgical hip reduction, magnetic resonance (MR) imaging is preferred over computed tomography (CT) because MR can not only confirm concentric hip joint reduction, but also identify the presence of soft-tissue barriers to reduction and any unexpected postoperative complications. The routine use of contrast-enhanced MR remains controversial because of the relative paucity of well-powered and validated literature. The main objectives of this article are to review the normal and abnormal developmental anatomy of the hip joint, to discuss the rationale behind the current recommendations on the most appropriate selection of imaging modalities for screening and diagnosis, and to review routine and uncommon findings that can be identified on post-reduction MR, using an evidence-based approach. A basic understanding of the physiology and the pathophysiology can help ensure the selection of optimal imaging modality and reduce equivocal diagnoses that can lead to unnecessary treatment.

Profile of Patients Diagnosed with Developmental Dysplasia of the Hip

Objective  To describe the profile of patients with developmental dysplasia of the hip (DDH) diagnosed by physical and ultrasound examination, with the implementation of a protocol for the treatment and follow-up of DDH.

Methods  A cross-sectional study with DDH patients born between January 2014 and December 2016, in the city of Pelotas, Southern Brazil. Ethnicity, gender, birth weight, fetal presentation, affected side of the hip, gestational age, maternal age and family history were considered. The data on the medical records were compared with the characteristics of the general population described on the Brazilian National Information System on Live Births (Sistema de Informação sobre Nascidos Vivos [SINASC]).

Results  A total of 33 DDH patients were identified, mostly female, with a four-fold higher probability of having the condition ( p  < 0.001); the left was the most affected side. No statistically significant association was found regarding the following factors: birth weight, gestational age, ethnicity, and maternal age. The newborns in breech presentation had a 15-fold higher probability of presenting DDH ( p  < 0.001). A total of 21 newborns required immediate treatment of the hips, since the ultrasound showed a Graf classification of IIb or higher, or the radiography showed dislocation in DDH patients older than 6 months of age.

Conclusion  Screening for DDH is essential in all newborns; physical examinations revealing alterations must be complemented with ultrasound imaging to avoid the delayed diagnosis of the condition.

Examining the effectiveness of examination at 6-8 weeks for developmental dysplasia: testing the safety net

OBJECTIVE

The 'GP check' at 6-8 weeks forms part of the selective surveillance system for developmental dysplasia of the hip (DDH) in the UK. It is imperative to pick up DDH within the first months of life to allow for non-invasive treatment and the avoidance of surgery. We aim to investigate the effectiveness of hip examination at 6-8 weeks.

METHODS

This is a longitudinal observational study including all infants born in our region in the 5 years following 2006. Early presentation was defined as diagnosis within 14 weeks of birth and late presentation after 14 weeks. Treatment records for early and late DDH as well as referrals for ultrasound (US) following examination at 6-8 weeks were analysed. Attendance of the examination at 6-8 weeks in those patients who went on to present with a late DDH was also analysed.

RESULTS

23 112 live births occurred during the study period. There were 141 confirmed cases of DDH. 400 referrals for US were received following examination at 6-8 weeks; 6 of these had a positive finding of DDH. 27 patients presented after 14 weeks and were classified as late presentations. 25 of these patients had attended examination at 6-8 weeks and no abnormality had been identified.

CONCLUSIONS

The sensitivity of examination at 6-8 weeks was only 19.4%, its specificity was 98% and it had a positive predictive value of 1.5%. For many years the check at 6-8 weeks has been thought of as a means to identify those children not identified as neonates; however, we found that four out of five children with DDH were not identified by the check at 6-8 weeks. Unfortunately, we conclude that the presumed safety net of the examination in its current form is not reliable.

Suggestion for new 4.4 mm pubo-femoral distance cut-off value for hip instability in lateral position during DDH screening

Background and purpose - Current selective screening algorithms for developmental dysplasia of the hip (DDH) are insufficient. Universal screening programs have been proposed but so far have been deemed too expensive and time consuming. The pubo-femoral distance may solve this problem as a quick, low-cost, highly sensitive, and specific sonographic measurement for DDH, but this has only been validated in the supine position. Therefore we validated pubo-femoral distance (PFD) in the lateral position as an indicator for instability of the hip. Methods - All participants had undergone ultrasonographic diagnostics using the modified Graf technique. In addition, PFD measurements in lateral position were performed. Results were compared between 25 infants who had been treated for DDH because of dysplastic appearance on ultrasound combined with clinical instability and a control group consisting of 100 untreated infants screened for DDH. Sensitivity, specificity, and cut-off points were determined using Receiver operating characteristics (ROC) analysis. Results - We found a mean PFD of 6.8 mm (6.2-7.4) in the treated group with a control group PFD of 3.4 mm (3.3-3.6) (p < 0.005). A PFD value above a threshold of 4.4 mm yielded a sensitivity of 100% and a specificity of 93% for detecting unstable DDH. Interpretation - PFD measured in lateral position was statistically significantly increased in hips of children treated for DDH with Denis Browne hip brace compared with healthy children with unaffected stable hips. Furthermore, the PFD measurement had a high level of sensitivity and specificity at a cut-off value of 4.4 mm. A cut-off value of 6.00 mm has previously been reported as the gold standard in supine position. We suggest that 4.4 mm is used in lateral position.

Universal or selective ultrasound screening for developmental dysplasia of the hip? A discussion of the key issues

PURPOSE

To summarize recent developments and provide recommendations as to whether universal or selective programmes are advisable.

METHODS

A literature review was performed and preference given to studies with higher levels of evidence. All programmes reviewed included clinical screening.

RESULTS

Recent studies underline the need for high quality screening programmes to promote the early detection of developmental dysplasia of the hip (DDH). A small number of cases may be missed clinically but with universal ultrasound screening programmes the late presentation rates appear to be virtually zero. Contemporary studies show treatment rates with universal screening programmes which are now lower than those with selective ultrasound. There is little agreement over the criteria used for selective programmes. Alternative outcome measures, such as the first operation rate or the percentage undergoing major (open) surgery are both lowest with universal ultrasound screening programmes. Furthermore, a significant reduction in the rate of surgery for DDH later in life was seen after the introduction of universal ultrasound screening, whereas the defined criteria for selective screening may not detect the majority of patients who require late surgery. Abduction bracing with modern orthoses is associated with a zero rate of avascular necrosis (AVN), whereas closed reduction techniques have an overall risk of 10%.

CONCLUSION

On clinical grounds, if future studies confirm that hip abduction in flexible orthoses is not associated with AVN, it may be time for a paradigm shift of screening for DDH towards a universal ultrasound protocol. The costs associated both with each type of screening programme and with the management of late presenting cases are also important but may be secondary to clinical benefit.

Investigating the need for routine ultrasound screening to detect developmental dysplasia of the hip in infants born with breech presentation

Objectives

Breech presentation is a recognized risk factor for developmental dysplasia of the hip (DDH). Within North America, there is a lack of consensus on screening guidelines for DDH in infants with a negative physical examination of the hips. This study evaluates the need for ultrasound screening in all breech born infants to detect DDH and whether this is influenced by gender, gestational age and mode of delivery.

Methods

A retrospective chart review was conducted to identify breech born infants who underwent routine hip ultrasound to detect DDH between 2010 and 2015. Patients were grouped by physical exam and ultrasound findings and compared based on gender, gestational age and mode of delivery.

Results

Three hundred and eighteen patients were identified (191 female, 127 male; 26 preterm, 57 late preterm, 235 term; 263 caesarean section delivery, 55 vaginal delivery). Three hundred and eight patients had a negative physical exam of which 27 were diagnosed with DDH based on screening ultrasound with females predominant (P<0.05). 12.50% of females with a negative physical exam had DDH compared to 3.23% of males (P<0.05). There was no difference in the rate of DDH detected by screening ultrasound based on gestational age (P=0.94) or mode of delivery (P=0.59).

Conclusions

The diagnosis of DDH in breech born infants by screening ultrasound in those with a negative physical exam of the hips is more predominant in females, with no apparent association with gestational age or mode of delivery. Future analyses with larger sample sizes are needed before conclusions can be made on screening protocols.

The positive predictive value of asymmetrical skin creases in the diagnosis of pathological developmental dysplasia of the hip

Aims

The aim of this study was to identify the association between asymmetrical skin creases of the thigh, buttock or inguinal region and pathological developmental dysplasia of the hip (DDH).

Patients and Methods

Between 1 January 1996 and 31 December 2016, all patients referred to our unit from primary or secondary care with risk factors for DDH were assessed in a "one stop" clinic. All had clinical and sonographic assessment by the senior author (RWP) with the results being recorded prospectively. The inclusion criteria for this study were babies and children referred with asymmetrical skin creases. Those with a neurological cause of DDH were excluded. The positive predictive value (PPV) for pathological DDH was calculated.

Results

A total of 105 patients met the inclusion criteria. There were 71 girls and 34 boys. Only two were found to have pathological DDH. Both also had unilateral limited abduction of the hip in flexion and a positive Galeazzi sign with apparent leg-length discrepancy. Thus, if the specialist examination of a patient with asymmetrical skin creases was normal, the PPV for DDH was 0%.

Conclusion

Isolated asymmetrical skin creases are an unreliable clinical sign in the diagnosis of pathological DDH. Greater emphasis should be placed on the presence of additional clinical signs to guide radiological screening in babies and children. Cite this article: Bone Joint J 2018;100-B:675-9.

How to use… Hip examination and ultrasound in newborns

Developmental dysplasia of the hip (DDH) ranges from a clinically detectable dislocation of the hip to radiologically diagnosed hip abnormalities. It is caused by both antenatal and postnatal factors. The Neonatal and Infant Physical Examination Screening Programme recommends that newborns should undergo a hip ultrasound (USS) when risk factor or clinical features suggestive of DDH are present. The aim of hip ultrasonography is to detect DDH early and prevent late complications through early treatment. Here, we discuss how to use hip examination and USS in newborns.

Clicky hip alone is not a true risk factor for developmental dysplasia of the hip

AIMS

A clicky hip is a common referral for clinical and sonographic screening for developmental dysplasia of the hip (DDH). There is controversy regarding whether it represents a true risk factor for pathological DDH. Therefore a 20-year prospective, longitudinal, observational study was undertaken to assess the relationship between the presence of a neonatal clicky hip and pathological DDH.

PATIENTS AND METHODS

A total of 362 infants from 1997 to 2016 were referred with clicky hips to our 'one-stop' paediatric hip screening clinic. Hips were assessed clinically for instability and by ultrasound imaging using a simplified Graf/Harcke classification. Dislocated or dislocatable hips were classified as Graf Type IV hips.

RESULTS

The mean age at presentation was 13.8 weeks (12.8 to 14.7). In all 351 out of 362 children (97.0%) had Graf Type I hips (normal) that required no treatment. Nine children (2.5%) had Graf Type II hips but all resolved to Graf Type I hips on follow-up scans. One child (0.3%) had Graf Type III hip dysplasia and one child (0.3%) had an irreducible hip dislocation. The two pathological hips were associated with unilateral limited hip abduction. Mean referrals increased from 12.9 to 23.3 each year (p = 0.002) from the first decade of the study to the second, driven by increasing primary care referrals (5.5 versus 16.7 per year, p < 0.001).

CONCLUSION

Most clicky hips required no treatment other than reassurance to parents. Clicky hips with a normal hip examination should be considered a variant of normal childhood and not a risk factor for DDH. However, an abnormal hip examination including unilateral limited hip abduction should prompt urgent further investigations. Cite this article: Bone Joint J 2017;99-B:1533-6.

Late presentation of developmental dysplasia of the hip

Aims

Despite the presence of screening programmes, infants continue to present with late developmental dysplasia of the hip (DDH), the impact of which is significant. The aim of this study was to assess infants with late presenting dislocation of the hip despite universal clinical neonatal and selective ultrasound screening.

Patients and Methods

Between 01 January 1997 to 31 December 2011, a prospective, longitudinal study was undertaken of a cohort of 64 670 live births. Late presenting dislocation was defined as presentation after three months of age. Diagnosis was confirmed by ultrasound and plain radiography. Patient demographics, referral type, reason for referral, risk factors (breech presentation/strong family history) and clinical and radiological findings were recorded.

Results

There were 31 infants with an irreducible dislocation of the hip, an incidence of 0.48 (95% confidence interval (CI) 0.34 to 0.68) per 1000 live births. Of these, 18 (0.28 (95% CI 0.17 to 0.44) per 1000 live births; 58%) presented late. All infants had a documented normal newborn clinical examination and no abnormality reported in the six to eight week check. Of the 18 late presenting cases 72% (n = 13) had no risk factors: 16 were referred by GPs and two were late due to administrative issues (missed appointments). The mean time to diagnosis was 62.4 weeks (19 to 84).

Conclusion

Despite universal clinical neonatal and selective ultrasound screening, late cases of irreducible hip dislocation still occur. We recommend an update of the national screening programme for DDH, a review of training and education of healthcare professionals involved in the physical examination of neonates and infants, and the addition of a further assessment after the six to eight week check. Cite this article: Bone Joint J 2017;99-B:1250–5.

Diagnosing developmental dysplasia of the hip using the Graf ultrasound method: risk and protective factor analysis in 11,820 universally screened newborns

The essential role of ultrasound examinations in diagnosis and treatment of developmental dysplasia of the hip (DDH) is widely accepted while the weighting and correlation of protective factors and perinatal risk for DDH still give rise to debate. Our aim was to investigate the impact of single and twofold combined risk and protective factors on the newborns' hip maturity, assessed with the Graf ultrasound method. Therefore, data sets of 11,820 universally screened newborns were analyzed. Univariate and logistic regression analyses were performed to correlate risk and protective factors with mature or immature but appropriate for age and pathologic hip types. Thereby, female gender (OR 4.07 (95% CI 3.01-5.51), p < 0.001), breech presentation (4.98 (3.71-6.71), p < 0.001), and positive family anamnesis (5.05 (3.49-7.31), p < 0.001) as well as the combination of female gender with high birth weight (3.51 (2.45-5.03), p < 0.001) could be identified as independent predictive risk factors. Only low birth weight (0.27 (0.11-0.66), p = 0.004) could be identified as a single protective factor, while no combination of protective factors was significant.

CONCLUSION

The significance and the informative value of risk and protective factor combinations, e.g., for selective ultrasound surveys, are limited. Early universal ultrasound screening using the Graf method is advised to timely detect hip immaturity and pathologies and to provide the optimal approach for mature or immature but appropriate for age and pathologic hips. What is Known: • Ultrasound screening is essential for diagnosis and treatment of DDH in time while the weighting and correlation of protective factors and perinatal risk and their role for the ultrasound screening protocol still give rise to debate. What is New: • The effects of single risk and protective factors for DDH do not cumulate or counteract, resulting in a limited value of a selective screening protocol based on risk and protective factors. • A universal screening protocol using the Graf ultrasound method is recommended.

Early dynamic ultrasound for neonatal hip instability: implications for rural Australia

BACKGROUND

Neonatal instability of the hip (NIH), where the femoral head can move away from the acetabulum, in the first weeks of life, is an important risk factor for developmental dysplasia of the hip (DDH). In rural areas in Australia, there is a recent trend to increased late diagnosis of DDH. Clinical screening of infant hips, a common practice in Australia, is experience dependent. Best practice early screening techniques are still debated with different techniques and timing used internationally. This systematic review examines early dynamic ultrasound (eDUS) screening for hip instability in the first 6 weeks after birth, and the early interventions informed by these findings and considers the findings for the context of rural Australia.

METHODS

The Cochrane Library, Medline, CINAHL and PEDro were searched for original research or systematic reviews, and clinical studies 1998 to 2015 involving dynamic ultrasound. Critical Appraisal Skills Programme tools were used to appraise the studies.

RESULT

Nineteen studies were included. Early Dynamic Ultrasound (DUS) is consistently described as a reliable assessment of NIH. Early DUS is recommended for risk factors including geographical areas of high prevalence. Approaches to early intervention of hips with excessive movement are somewhat discipline-related and include: primary prevention (advice), secondary prevention (abduction supports), and conservative management (removable splints).

CONCLUSIONS

In the context of increased prevalence of DDH in rural Australia, contemporary evidence suggests that introduction of early DUS could provide rural infants with more effective screening than clinical examination alone. Targeted early advice about posturing and simple removable supports to abduct infant hips could prevent some cases of DDH in rural Australia.

Ultrasound Examination for Infants Born Breech by Elective Cesarean Section With a Normal Hip Exam for Instability

INTRODUCTION

Because of the risk of developmental dysplasia of the hip in infants born breech-despite a normal physical exam-the American Academy of Pediatrics (AAP) guidelines recommend ultrasound (US) hip imaging at 6 weeks of age for breech females and optional imaging for breech males. The purpose of this study is to report US results and follow-up of infants born breech with a normal physical exam.

METHODS

The electronic medical record for children born at 1 hospital from 2008 to 2011 was reviewed. Data were analyzed for sex, birth weight, breech position, birth order, ethnicity, US and x-ray results, follow-up, and cost.

RESULTS

A total of 237 infants were born breech with a normal physical examination, all delivered by cesarean section. Of the infants, 55% were male and 45% female. About 151 breech infants (64%) with a normal Barlow and Ortolani exam had a precautionary hip US as recommended by the AAP performed at an average of 7 weeks of age. Eighty-six breech infants (35%) did not have an US and were followed clinically. Of the 151 infants that had an US, 140 (93%) were read as normal. None had a dislocated hip. Two patients had a normal physical exam but laxity on US. These 2 patients were the only infants treated in a Pavlik harness. A pediatric orthopaedic surgeon followed those with subtle US findings and no laxity until normal.

CONCLUSIONS

The decision by the AAP to recommend US screening at 6 weeks of age for infants with a normal physical exam but breech position was based on an extensive literature review and expert opinion. Not all pediatricians are following the AAP guidelines. The decision to perform an US should be done on a case-by-case basis by the examining physician. A more practical, cost-effective strategy would be to skip the US if the physical exam is normal and simply obtain an AP pelvis x-ray at 4 months.

LEVEL OF EVIDENCE

Level III-this is a case-control study investigating the outcomes of infants on data drawn from the electronic medical record.

Evaluation and Referral for Developmental Dysplasia of the Hip in Infants

Developmental dysplasia of the hip (DDH) encompasses a wide spectrum of clinical severity, from mild developmental abnormalities to frank dislocation. Clinical hip instability occurs in 1% to 2% of full-term infants, and up to 15% have hip instability or hip immaturity detectable by imaging studies. Hip dysplasia is the most common cause of hip arthritis in women younger than 40 years and accounts for 5% to 10% of all total hip replacements in the United States. Newborn and periodic screening have been practiced for decades, because DDH is clinically silent during the first year of life, can be treated more effectively if detected early, and can have severe consequences if left untreated. However, screening programs and techniques are not uniform, and there is little evidence-based literature to support current practice, leading to controversy. Recent literature shows that many mild forms of DDH resolve without treatment, and there is a lack of agreement on ultrasonographic diagnostic criteria for DDH as a disease versus developmental variations. The American Academy of Pediatrics has not published any policy statements on DDH since its 2000 clinical practice guideline and accompanying technical report. Developments since then include a controversial US Preventive Services Task Force "inconclusive" determination regarding usefulness of DDH screening, several prospective studies supporting observation over treatment of minor ultrasonographic hip variations, and a recent evidence-based clinical practice guideline from the American Academy of Orthopaedic Surgeons on the detection and management of DDH in infants 0 to 6 months of age. The purpose of this clinical report was to provide literature-based updated direction for the clinician in screening and referral for DDH, with the primary goal of preventing and/or detecting a dislocated hip by 6 to 12 months of age in an otherwise healthy child, understanding that no screening program has eliminated late development or presentation of a dislocated hip and that the diagnosis and treatment of milder forms of hip dysplasia remain controversial.

Developmental dysplasia of the hip: What has changed in the last 20 years?

Developmental dysplasia of the hip (DDH) describes the spectrum of structural abnormalities that involve the growing hip. Early diagnosis and treatment is critical to provide the best possible functional outcome. Persistence of hip dysplasia into adolescence and adulthood may result in abnormal gait, decreased strength and increased rate of degenerative hip and knee joint disease. Despite efforts to recognize and treat all cases of DDH soon after birth, diagnosis is delayed in some children, and outcomes deteriorate with increasing delay of presentation. Different screening programs for DDH were implicated. The suspicion is raised based on a physical examination soon after birth. Radiography and ultrasonography are used to confirm the diagnosis. The role of other imaging modalities, such as magnetic resonance imaging, is still undetermined; however, extensive research is underway on this subject. Treatment depends on the age of the patient and the reducibility of the hip joint. At an early age and up to 6 mo, the main treatment is an abduction brace like the Pavlik harness. If this fails, closed reduction and spica casting is usually done. After the age of 18 mo, treatment usually consists of open reduction and hip reconstruction surgery. Various treatment protocols have been proposed. We summarize the current practice for detection and treatment of DDH, emphasizing updates in screening and treatment during the last two decades.

Effect of increase in birth weight in a newborn on hip ultrasonography

Exposure to the pressure experienced by higher birth weight babies during the intrauterine period might cause hip dysplasia. The aim of this study is to determine the effect of birth weight in newborns on hip ultrasonography when the paternal and maternal risk factors are excluded. A total of 701 babies born at 38-42 gestational weeks were included in the study. Hip ultrasonography was performed within 7 days following birth using the Graf technique in the babies without risk factors for developmental dysplasia of the hip. Images obtained were controlled with respect to conformity to the Graf method and angular measurements were performed. According to the α and β angle values obtained, type 1A and 1B hips were categorized as mature; type 2A hips were categorized as immature; and type 2C, D, 3A, 3B, and 4 hips were categorized as pathological hips. The results obtained were analyzed for the effect of birth weight on the angular values and hip typing. The birth weight of the babies was 338,488 ± 48,241 g (2030-6124 g). It was determined that the birth weight had no effect on the values of α and β angles in the male babies (P=0.21, 0.76). It was determined that increasing birth weight decreased the α angle value (P=0.001) and caused no difference in the β angle value (P=0.057) in the female babies. It was found that birth weight had no effect on hip typing in both female and male babies (P=0.060, 0.22). Increases in birth weights caused decreases in ultrasonographic α angles only in female babies.

Neonatal clinical screening of the hip in the diagnosis of developmental dysplasia of the hip

Over a 15-year prospective period, 201 infants with a clinically unstable hip at neonatal screening were subsequently reviewed in a ‘one stop’ clinic where they were assessed clinically and sonographically. Their mean age was 1.62 weeks (95% confidence interval (CI) 1.35 to 1.89). Clinical neonatal hip screening revealed a sensitivity of 62% (mean, 62.6 95%CI 50.9 to 74.3), specificity of 99.8% (mean, 99.8, 95% CI 99.7 to 99.8) and positive predictive value (PPV) of 24% (mean, 26.2, 95% CI 19.3 to 33.0). Static and dynamic sonography for Graf type IV dysplastic hips had a 15-year sensitivity of 77% (mean, 75.8 95% CI 66.9 to 84.6), specificity of 99.8% (mean, 99.8, 95% CI 99.8 to 99.8) and a PPV of 49% (mean, 55.1, 95% CI 41.6 to 68.5). There were 36 infants with an irreducible dislocation of the hip (0.57 per 1000 live births), including six that failed to resolve with neonatal splintage.

Most clinically unstable hips referred to a specialist clinic are female and stabilise spontaneously. Most irreducible dislocations are not identified from this neonatal instability group. There may be a small subgroup of females with instability of the hip which may be at risk of progression to irreducibility despite early treatment in a Pavlik harness.

A controlled study is required to assess the value of neonatal clinical screening programmes.

Cite this article: Bone Joint J 2015;97-B:265-9.

Is congenital talipes equinovarus a risk factor for pathological dysplasia of the hip? : a 21-year prospective, longitudinal observational study

There is controversy whether congenital foot abnormalities are true risk factors for pathological dysplasia of the hip. Previous United Kingdom screening guidelines considered congenital talipes equinovarus (CTEV) to be a risk factor for hip dysplasia, but present guidelines do not. We assessed the potential relationship between pathological dysplasia of the hip and fixed idiopathic CTEV. We present a single-centre 21-year prospective longitudinal observational study. All fixed idiopathic CTEV cases were classified (Harrold and Walker Types 1 to 3) and the hips clinically and sonographically assessed. Sonographic Graf Type III, IV and radiological irreducible hip dislocation were considered to be pathological hip dysplasia. Over 21 years there were 139 children with 199 cases of fixed idiopathic CTEV feet. Sonographically, there were 259 normal hips, 18 Graf Type II hips, 1 Graf Type III hip and 0 Graf Type IV hip. There were no cases of radiological or sonographic irreducible hip dislocation. Fixed idiopathic CTEV should not be considered as a significant risk factor for pathological hip dysplasia. This conclusion is in keeping with the current newborn and infant physical examination guidelines in which the only risk factors routinely screened are family history and breech presentation. Our findings suggest CTEV should not be considered a significant risk factor in pathological dysplasia of the hip.

Is limitation of hip abduction a useful clinical sign in the diagnosis of developmental dysplasia of the hip?

AIM

The relationship between the presence and severity of sonographically diagnosed developmental dysplasia of the hip (DDH) and the clinical abnormality of limitation of hip abduction (LHA) was investigated.

METHODS

A prospective, longitudinal, selective 'at risk' and neonatal instability hip ultrasound programme between 1 January 1996 and 31 December 2005. 2876 neonates/infants were initially screened for DDH by clinical examination and by hip ultrasound imaging. Pathological sonographically evaluated DDH was considered to be Graf Type III, IV and irreducible hip dislocation. Inclusion criteria were cases of unilateral or bilateral limitation of hip abduction hip.

EXCLUSION CRITERIA

syndromal, neuromuscular and skeletal dysplasia cases.

RESULTS

492 children presented with LHA (55 unilateral LHA). The mean age of neonates/infants with either unilateral or bilateral LHA was significantly higher than those without (p<0.001). In the sonographic diagnosis of Graf Type III and IV dysplasias, unilateral LHA had a PPV of 40% compared with only 0.3% for bilateral LHA. The sensitivity of unilateral LHA increased to 78.3% and a PPV 54.7% after the age of 8 weeks for Graf Types III, IV and irreducible hip dislocation.

CONCLUSIONS

This study identifies a time-dependent association with unilateral LHA in the diagnosis of 'pathological' DDH after the age of 8 weeks. The presence of bilateral LHA in the young infant may be a normal variant and is an inaccurate clinical sign in the diagnosis of pathological DDH. LHA should be actively sought after 8 weeks of age and if present should be followed by a formal ultrasound or radiographic examination to confirm whether or not the hip is developing in a satisfactory manner.

Prevalence of developmental dysplasia of the hip in preterm infants with maternal risk factors

PURPOSE

The aim of this study was to determine the prevalence of developmental dysplasia of the hip (DDH) in preterm infants with maternal risk factors.

METHODS

A prospective review of the medical records and ultrasound (US) scans of all preterm infants at one tertiary-care children's hospital was completed to identify all premature infants without any infantile risk factors at a particular time frame. We consecutively evaluated 421 babies (842 hips) who satisfied the criteria for inclusion. Hip US images were classified according to Graf.

RESULTS

Overall, one hip was diagnosed as DDH (Graf type 2c). Female infants had significantly lower alpha angles (70.2 ± 6.6 and 71.4 ± 4.4 for females and males, respectively) (P = 0.033). There was no correlation between oligohydramnios and alpha and beta angles and hip sides (P = 0.345 and P = 0.789 for left and right hips, respectively). US examination of the infants revealed no differences between the alpha and beta angles of the hips and birth weight and age at gestation. Although it was statistically not significant, US evaluation of left hips among singletons demonstrated one immature hip (P = 0.864) and that of right hips demonstrated one immature hip for both singletons and twins (P = 0.904).

CONCLUSIONS

Prematurity with or without maternal risk factors does not have an effect on DDH.

Screening of selected risk factors in developmental dysplasia of the hip: an observational study

BACKGROUND

Developmental dysplasia of the hip (DDH) is the most common neonatal musculoskeletal condition. In 2008, the NHS Newborn and Infant Physical Examination committee added selective 'at risk' screening to the existing universal neonatal and general practitioner clinical hip screening guidelines.

OBJECTIVE

Assessment of breech and family history risk factors in DDH.

DESIGN

A 15 year prospective, observational, longitudinal cohort study.

METHOD

Breech presentation and evidence of a strong family history for DDH were the 'risk factors' studied. All infants referred were clinically and sonographically screened by one consultant paediatric orthopaedic surgeon.

RESULTS

From a cohort of 64 670 live births, 2984 neonates/infants, 46.1 (95% CI 44.6 to 47.8) per 1000 live births, were referred and sonographically screened with these risk factors alone. 1360 were male, of which four were identified as having 'pathological' DDH (an incidence of 0.003 (95% CI 0.001 to 0.008)). 1624 were female, of which 45 were identified as having 'pathological' DDH (an incidence of 0.028 (95% CI 0.021 to 0.037)). This difference in incidence of 0.025 (95% CI 0.016 to 0.033) was statistically significant (p<0.001). From those who were clinically stable and screened with either or both of the two risk factors, four individuals were diagnosed with irreducible hip dislocation (0.06 (95% CI 0.024 to 0.159) per 1000 live births). All were females.

CONCLUSIONS

This study questions the current UK screening policy for DDH in clinically stable males referred with risk factors, and may influence future DDH screening programme policy.

Breech preterm infants are at risk of developmental dysplasia of the hip

AIM

There is uncertainty about the risk of developmental dysplasia of the hip (DDH) in breech preterm infants and therefore uncertainty about the benefits of using ultrasound screening in this population. The aim of this study was to determine if preterm infants born in the breech position are at risk of DDH.

METHODS

A retrospective audit of preterm and term infants born in the breech position was performed to determine the incidence of DDH. Group 1 included breech preterm infants (<37 weeks gestational age) born between 2004 and 2008. Group 2 included breech term infants (≥37 weeks gestational age) born between 2005 and 2007. Infants were screened with clinical examination and ultrasound of the hip and were classified into two outcome groups: positive or negative for DDH.

RESULTS

Three out of 129 (2.3%) preterm infants screened had DDH. For term infants, 3 out of 163 (1.8%) infants screened had DDH. The odds ratio for DDH in breech preterm infants compared with breech term infants was 1.27 (95% confidence interval 0.25 to 6.40).

CONCLUSION

Preterm infants born in the breech position appear to have a similar incidence of DDH to term infants and thus require similar screening guidelines.

Current screening recommendations for developmental dysplasia of the hip may lead to an increase in open reduction

Most centres in the United Kingdom adopt a selective screening programme for developmental dysplasia of the hip (DDH) based on repeated clinical examination and selective ultrasound examination. The Newborn Infant Physical Examination protocol implemented in 2008 recommends a first examination at birth and then a second and final examination at six to ten weeks of age. Due to concerns over an increase in late presentations we performed a retrospective review of our 15-year results to establish if late presentation increases treatment requirements. Of children presenting before six weeks of age, 84% were treated successfully with abduction bracing, whereas 86% of children presenting after ten months eventually required open reduction surgery. This equates to a 12-fold increase in relative risk of requiring open reduction following late presentation. Increasing age at presentation was associated with an increase in the number of surgical procedures, which are inevitably more extensive and complex, with a consequent increased in cost per patient. The implementation of an opportunistic examination at three to five months could help to reduce the unintended consequences of the Newborn Infant Physical Examination programme.

The effect of gestational age on sonographic screening of the hip in term infants

Several authors have suggested that the final five weeks of gestation are a critical period for the development of the hip. In order to test the hypothesis that gestational age at birth may influence the development of the hip joint, we analysed the sonographic findings in 1992 hips (in 996 term newborns) with no risk factor for developmental dysplasia of the hip. The 996 infants were born at a mean gestational age of 39 weeks (37 to 41).

The mean bony roof angle (α), cartilage roof angle (β) and the distribution of the type of hip were compared between the 37th, 38th, 39th, 40th and 41st birth week groups. There was a significant difference in the distribution of type of hip between the different birth week groups (p < 0.001), but no significant difference between the α angles of all groups (p = 0.32). There was no correlation between birth week and roof angle (p = 0.407 and p = 0.291, respectively) and no significant correlation between birth weight and roof angle (p = 0.735 and p = 0.132, respectively).

The maturity of the infant hip, as assessed sonographically, does not appear to be affected by gestational age, and the fetal development of the acetabular roof appears to plateau from 37 weeks.

Cite this article: Bone Joint J 2013;95-B:266–70.

Pubo-femoral distance: an easy sonographic screening test to avoid late diagnosis of developmental dysplasia of the hip

OBJECTIVES

To propose an easy and reproducible sonographic screening test able to avoid late presentation of developmental dysplasia of the hip (DDH).

METHODS

The pubo-femoral distance (PFD) cut-off point was determined on 980 infants who underwent ultrasonography of the hips in comparison with the final diagnosis, based on clinical, ultrasound data and follow-up. PFD reproducibility was tested on 52 hips by both an experienced and an inexperienced radiologist. After teaching this screening method to general radiologists, its impact was evaluated by analysing the rate of late diagnosis in an entire administrative area.

RESULTS

An abnormal PFD threshold above 6 mm gave a sensitivity of 97.4 % for the diagnosis of DDH (271 hips) and a specificity of 84 %. Sensitivity increased to 100 % when taking into consideration children of 1 month or older. The PFD measurement stayed reproducible even in inexperienced hands (k = 0.795). For 3 years, following the extension of screening to all female infants, there was no late diagnosis of DDH in girls in amongst a catchment area of 1 million inhabitants.

CONCLUSIONS

PFD measurement with a threshold for abnormality of 6 mm at the age of 1 month, without asymmetry above 1.5 mm, could eradicate DDH late diagnosis.

Risk factors for developmental dysplasia of the hip: a meta-analysis

Early detection and subsequent treatment of developmental dysplasia of the hip (DDH) is thought to improve its prognosis. Frequently reported risk factors for DDH are a positive family history of DDH, female sex and breech presentation, but there is not a lot of systematic knowledge about DDH risk factors. We performed a systematic review and meta-analysis of the available evidence on DDH risk factors. We searched Medline, EMBASE and The Cochrane Library from conception up until October 2011 for primary articles on the subject. All studies reporting on potential risk factors for DDH that allowed construction of a two-by-two table were selected. Language restrictions were not applied. Two reviewers independently selected studies, extracted data and assessed study quality. The association between risk factors and DDH was expressed as a common odds ratio (OR) with a 95% confidence interval (CI). We identified 30 relevant studies reporting on 1,494,387 children; 26 studies were cohort studies and four studies used a case-control design. The risk of DDH was strongly increased in case of breech delivery (OR 5.7, 95% CI 4.4-7.4), female sex (OR 3.8, 95% CI 3.0-4.6) a positive family history of DDH (OR 4.8, 95% CI 2.8-8.2) and clicking hips at clinical examination (OR 8.6, 95% CI 4.5-16.6). This meta-analysis shows that infants born in breech presentation, female infants, infants with a positive family history and clicking hips at clinical examination have an increased risk for DDH. This knowledge can be helpful in the development of screening programs for DDH.

Hip joint development in children with type IIb developmental dysplasia

PURPOSE

The aim of this study was to analyse the results of treatment of sonographically diagnosed type IIb developmental hip dysplasia and to identify residual hip dysplasia using clinical and radiological assessment.

METHODS

We retrospectively reviewed the data of 49 children (59 type IIb and 39 type I hips, according to Graf's monographic classification) treated in abduction braces. The mean age was 9.1 years (range 4-15) at latest follow-up.

RESULTS

According to the clinical classification of Mckay in Barrett's modification, all the type I and type IIb hips had very good results. No statistical differences were found between type I and IIb hips when comparing both measured radiological parameters and radiological results according to the Severin classification at latest follow-up. Using our criteria (two or more radiological parameters were outside of their normal range), 12 out of 49 type IIb hips demonstrated persistent dysplasia. Of the 12 hips, eight sonograms were normal at the end of treatment and four patients failed to normalise. No type I hips demonstrated two or more abnormal radiographic parameters at latest follow-up.

CONCLUSIONS

Despite obtaining normal sonograms at the end of treatment, some children with type IIb dysplasia may demonstrate radiographic evidence of persistent hip dysplasia over a longer follow-up period. Our results suggest that these children should be monitored until skeletal maturity.

Developmental dysplasia in male infants: risk factors, instability and ultrasound screening

OBJECTIVE

To evaluate the relationship between risk factors and presence of developmental dysplasia of the hip (DDH) in male infants, and to compare the efficiency of different ultrasound (US) screening protocols.

MATERIALS AND METHODS

1321 male infants were included in the study. Ultrasound examinations were performed by combining Graf's static method and Harcke's dynamic method. The relationship between the risk factors and DDH and the effect of risk factors on sonographic worsening in type 2a hips were assessed by the chi-square test and Fisher`s exact test.

RESULTS

The incidence of DDH was 1.4%. 13% of the cases had type 2a morphology, among whom in 3.1% sonographic deterioration occurred. The treatment rate was 1.8%. The rate of follow-up US was 17.5%. No risk factor was found to have a statistically significant influence on DDH (= type 2b morphology). Among the 32 cases with DDH, 23(72%) had a risk factor or positive clinical finding while 9(28%) did not (p:0.006).

CONCLUSION

Risk factors do not have a statistically significant relationship with DDH in male cases. In our study 28% of the cases with DDH would be missed by a selective US screening protocol. We recommend assessment of all male infants with hip US.

A meta-analysis of common risk factors associated with the diagnosis of developmental dysplasia of the hip in newborns

BACKGROUND

Although there is no clear consensus about the process of screening for developmental dysplasia of the hip (DDH), there are six common risk factors associated with DDH in patients less than 6 months of age (breech presentation, sex, family history, first-born, side of hip, and mode of delivery).

METHODS

A meta-analysis of published studies was conducted to identify the relative risk ratio of the six commonly known risk factors. A total of 31 primary studies consisting of 20,196 DDH patients met the following inclusion criteria: (1) contained empirical data on at least one common risk factor, (2) were peer-reviewed from an English language scientific journal, (3) included patients less or equal to 6 months of age, and (4) identified method of diagnosis (e.g., ultrasound, radiographs or clinical examination).

RESULTS

Fixed effect and random effects models with 95% confidence intervals were calculated for each of the six risk factors. Reported relative risk ratio (RR) for each factor in newborns was: breech presentation 3.75 (95% CI: 2.25-6.24), females 2.54 (95% CI: 2.11-3.05), left hip side 1.54 (95% CI: 1.25-1.90), first born 1.44 (95% CI: 1.12-1.86), and family history 1.39 (95% CI: 1.23-1.57). A non-significant RR value of 1.22 (95% CI: 0.46-3.23) was found for mode of delivery.

CONCLUSION

Results suggest that ultrasound and radiology screening methods be used to confirm DDH in newborns that present with one or a combination of the following common risk factors: breech presentation, female, left hip affected, first born and family history of DDH.

[Developmental dysplasia of the hip]

At one month, the acetabular depth from a standard lateral coronal section is 4.6 ± 1.0mm. The correlation between experienced and junior radiologists is high (kappa 0.795). A treshhold of 6mm with a Δ (difference between right and left) less than 1.5mm provides a sensitivity of 100% for the detection of DDH at one month. Universal US screening at one month of all high-risk infants in 2009 resulted in a reduction of delayed diagnosis of DDH (zero girls, two boys) in Ille-et-Vilaine due to continuous medical education of general radiologists.

The use of X-ray at 5 months in a selective screening programme for developmental dysplasia of the hip

BACKGROUND

The methods used for any screening programme for developmental dysplasia of the hip (DDH) can be controversial. This was an opportunistic audit of our selective ultrasound screening programme using an X-ray at 5 months to prevent inappropriate discharge due to the learning curve of ultrasound.

METHODS

Between 1990 and 2004 in Nottingham, UK, out of a total population of 108,500 births, approximately 11,500 neonates were screened using ultrasound. Any child with an ultrasound scan showing Graf α-angles greater than 60° (Graf Type I) with the hip in joint were discharged from the clinic. All of those discharged were subsequently X-rayed at 5 months in order to cover the learning curve of ultrasound. The X-rays were reviewed by a consultant radiologist and referred back to orthopaedics if there was lateralisation of the femoral head or an acetabular index above 30°.

RESULTS

Of approximately 11,000 X-rays performed, only 53 patients were referred back to orthopaedics, of which 47 had a complete data set. Of these 47 children, only 8 (17%) required intervention. On review of the original ultrasounds, Graf's α-angle did not seem to correlate well with the need for intervention, as all were Type I hips. The femoral head cover (FHC) appeared to be more predictive of the need for treatment. There have been no late presentations to our unit of DDH following a normal 5-month X-ray.

CONCLUSIONS

We now check the Graf α-angle, FHC and dynamic stability in the ultrasound assessment and only perform X-ray at 5 months if there was a low α-angle or low FHC. Since this change, there have been no late presentations of DDH from the population screened by ultrasound.