Screening in Developmental Dysplasia of the Hip (DDH)

Screening for Developmental Dysplasia of the Hip (DDH) is a controversial subject. Screening may be by universal neonatal clinical examination (Ortolani or Barlow manoeuvres) with the addition of sonographic imaging of the hip (selective ‘at risk’ hips or universal screening in the neonate). In the UK, the NIPE guidelines recommend universal neonatal clinical assessment of the hip joints, a General Practitioner 6–8 week clinical ‘hip check’ and assessment clinically with sonographic imaging at 4–6 weeks for certain ‘at risk’ hips for pathological DDH.The effectiveness and difficulties arising from the UK current screening policy (clinical and sonographic) are highlighted. The purpose of the review was to assess the risk factors and efficacy of diagnostic methods in DDH, based on longitudinal cohort studies of 10 years or more.

Examining the Short-Term Natural History of Developmental Dysplasia of the Hip in Infancy: A Systematic Review

BackgroundThis study was an update on the AAOS clinical practice guideline’s analysis of the natural history of developmental dysplasia of the hip (DDH). The objective was to delineate the natural history of clinical instability or radiologic abnormalities of the hip in infants by identifying the proportion of cases that resolved without treatment compared to cases that progressed and/or required treatment.MethodsWe performed a literature search of PUBMED to identify studies which evaluated the natural history of DDH. We used the same search strategy as that utilized in the previous AAOS guidelines, updated to include articles published between September 2013 and May 2021. We assessed the quality of included articles using the Oxford Centre for Evidence-Based Medicine level of evidence and reported study demographics and outcomes using summary statistics.ResultsTwenty-four articles met our eligibility criteria. Most included studies were retrospective (14/24), investigated either the incidence of DDH (8/24) or assessed screening programs (7/24). The most prevalent study population followed were Graf 2A hips (7/24). Most studies were low quality with level of evidence 3 (13/24) or 4 (7/24). Sample sizes ranged from 9 to 3251. Twenty studies reported the number of cases resolved over the follow-up period with a mean rate of 84.3% (95% confidence interval 76.1, 92.6).ConclusionWe found most mild-to-moderate DDH can resolve without treatment in early infancy, especially in physiologically immature (Graf 2A) hips. More high-quality evidence is needed to properly assess the natural history of DDH as only one included study was a randomized trial.Supplementary InformationThe online version contains supplementary material available at 10.1007/s43465-021-00510-6.     

全髋关节置换治疗髋关节发育不全

目的：研究全髋关节置换治疗髋关节发育不全（ＤＤＨ）的外科技术。方法：４７例（５４髋）因髋关节发育不全引起严重骨性关节炎的患者行全髋关节置换治疗，其中男８例，女３９例。随访１２个月～１４年，平均５３个月。结果：根据ＭｅｒｌｅＤ＇Ａｕｂｉｇｎｅ评分方法，优８例（１７～１８分）、良３０例（１３～１６分）、中８例（９～１２分）、差１例（＜８分）。结论：根据髋关节脱位的程度可将髋关节发育不全分成四度，其中Ⅰ度、Ⅱ度为半脱位型；Ⅲ度、Ⅳ度为全脱位型。ＤＤＨⅠ度，即低位半脱位，髋臼加深为其手术要点；ＤＤＨⅡ度，即高位半脱位，通过上移髋臼假体可以避免植骨；对于ＤＤＨⅢ度、Ⅳ度则使用小型髋臼假体并且植骨。我们提出的分类方法较Ｃｒｏｗｅ方法简便且实用，特别是对髋臼的处理有指导意义。对髋关节发育不全进行全髋关节置换应严格掌握适应证，只有当疼痛和功能障碍非常明显而保守治疗无明确效果时采用     

Developmental Dysplasia of the Hip: An Examination of Care Practices of Orthopaedic Surgeons in India

BackgroundWe evaluated screening, referral and treatment practices for developmental dysplasia of the hip (DDH) in India by surveying Orthopaedic surgeons who treat patients with DDH. The survey assessed the timing of DDH presentation, resource availability, and current state of screening and diagnosis, which would help in the development of a DDH care pathway for India.MethodsAn online survey was distributed to Orthopaedic surgeons practicing in India via email and administered onsite to those attending the annual conference of the Pediatric Orthopaedic Society of India in 2019.Results173 completed surveys were received from surgeons practicing in a predominantly urban setting. 68.8% of respondents had performed initial evaluations on children with DDH aged over 1 year in the past 12 months, and 49.1% had assessed children with DDH aged > 2 years on initial presentation. There was no consistent use of established guidelines, with only 30% of respondents stating that a care pathway was in place at their institution. However, 91.9% would support the implementation of a care pathway developed in India, to decrease the incidence of delayed diagnosis and facilitate earlier intervention. 85% of respondents had ready access to ultrasound scans and 95.4% had access to X-rays.ConclusionsIn India, there is still a large number of late-presenting cases of DDH, which could be improved with effective screening. The development of a care pathway for DDH in India is well-supported by Orthopaedic surgeons and may help decrease the incidence of late presenting cases; potentially improving outcomes, decreasing morbidity, and upskilling local practitioners.Electronic supplementary materialThe online version of this article (10.1007/s43465-020-00233-0) contains supplementary material, which is available to authorized users.     

Developmental Dysplasia of Hip and Post-natal Positioning: Role of Swaddling and Baby-Wearing

IntroductionTraditional swaddling, which implies restrictive immobilisation of the infant’s lower limbs with the hips in forced extension and adduction, has been shown to be a risk factor for Developmental Dysplasia of Hip (DDH).MethodsWe reviewed the literature regarding the correlation between DDH and post-natal positioning by swaddling and baby-wearing, to draw awareness of healthcare professionals towards an important risk factor for DDH that has often been overlooked.ResultsThere is overwhelming evidence in the literature, by both experimental and clinical studies, that proves the close association between improper post-natal positioning of the baby’s hips in extension-adduction and an increased incidence of DDH. On the other hand, “hip safe” swaddling which allows unrestricted flexion-abduction movements of the infants’ hips, and the use of baby-wearing devices which keep the lower limbs in an attitude of hip flexion-abduction and knee flexion, is optimal for hip development. Populations which practice these “hip-safe” techniques of infant immobilisation have a lower incidence of DDH as compared to those which practice restrictive immobilisation. Furthermore, populations which have adopted “hip-safe” positioning have demonstrated a significant decrease in the incidence of DDH. Understanding this association is vital, since this is a modifiable risk factor, rectification of which can decrease the incidence of DDH.ConclusionPolicy makers and governments must design educational campaigns tailored to their respective populations to increase awareness regarding the benefits of “hip-safe” techniques of infant positioning, since this simple intervention has the potential of decreasing the incidence of DDH.     

An Upgrade of the International Hip Dysplasia Institute Classification for Developmental Dysplasia of the Hip

BackgroundThe purpose of the current study was to upgrade the International Hip Dysplasia Institute (IHDI) classification of developmental dysplasia of the hip (DDH).MethodsThe upgrading was suggested by adding the state of the acetabulum (type A for the normal acetabulum and type B for the dysplastic one). The pelvic radiographic films of 110 children suspected to have DDH were used by three observers to sort out the hips into grades according to the original form and the suggested upgraded one subsequently.ResultsThe interobserver reliability between the observers improved from a good level (intraclass correlation coefficient [ICC], 0.885; 95% confidence interval [CI], 0.856–0.909) with the original form to an excellent level (ICC, 0.919; 95% CI, 0.898–0.936) with the upgraded form. When the upgraded form was used, only the grade 1 hips were divided into types A and B, while those classified as grades 2, 3, and 4 were all graded as type B only.ConclusionsThe IHDI classification of DDH can be upgraded into grade 1A, grade 1B, grade 2, grade 3, and grade 4.     

全髋关节置换术治疗成人先天性髋关节发育不良

目的探讨成人先天性髋关节发育不良（developmental dysplasia hip,DDH）髋臼假体的选择和手术方法。方法全髋关节置换术治疗成人先天性髋关节发育不良24例26个髋;年龄41～68岁,平均52岁。按照Perner分型,其中Ⅰ度10髋应用普通髋臼假体置换,Ⅱ度9髋选用螺旋臼假体,Ⅲ度5髋及度Ⅳ2髋选用小号髋臼假体,真臼部位安置髋臼假体,均为生物型固定,无结构性植骨。结果随访0．5～3．5年,假体与骨床结合牢固,患髋关节疼痛消失,关节功能基本正常,Harris评分平均86分。结论全髋关节置换术是治疗成人先天性髋关节发育不良的有效方法,针对髋臼病变程度的不同分别采用不同类型髋臼假体置换,配合术中的正确操作能简化手术,减少并发症,提高疗效。     

Genetic Predisposition to Developmental Dysplasia of the Hip

BackgroundThe etiopathogenesis of developmental dysplasia of the hip (DDH) has not been clarified. This systematic review evaluated current literature concerning all known chromosomes, loci, genes, and their polymorphisms that have been associated or not with the prevalence and severity of DDH.MethodsFollowing the established methodology of Meta-analysis of Observational Studies in Epidemiology guidelines, MEDLINE, EMBASE, and Cochrane Register of Controlled Trials were systematically searched from inception to January 2019.ResultsForty-five studies were finally included. The majority of genetic studies were candidate gene association studies assessing Chinese populations with moderate methodological quality. Among the most frequently studied are the first, third, 12th,17th, and 20th chromosomes. No gene was firmly associated with DDH phenotype. Studies from different populations often report conflicting results on the same single-nucleotide polymorphism (SNP). The SNP rs143384 of GDF5 gene on chromosome 20 demonstrated the most robust relationship with DDH phenotype in association studies. The highest odds of coinheritance in linkage studies have been reported for regions of chromosome 3 and 13. Five SNPs have been associated with the severity of DDH. Animal model studies validating previous human findings provided suggestive evidence of an inducing role of mutations of the GDF5, CX3CR1, and TENM3 genes in DDH etiopathogenesis.ConclusionDDH is a complex disorder with environmental and genetic causes. However, no firm correlation between genotype and DDH phenotype currently exists. Systematic genome evaluation in studies with larger sample size, better methodological quality, and assessment of DDH patients is necessary to clarify the DDH heredity. The role of next-generation sequencing techniques is promising.     

3D Characterization of Acetabular Deficiency in Children with Developmental Dysplasia of the Hip

BackgroundThe purpose of this study is to determine if a quantitative method can be used to identify differences in 3D morphology between normal and developmentally dysplastic hips and to identify specific areas of undercoverage in children with DDH compared to age- and sex-matched controls.MethodsSubjects were included if they were typically developing children with no other underlying conditions affecting their musculoskeletal system and had an available pelvic CT scan (67 hips). Custom software was used to measure standard variables defining acetabular morphology (version, tilt, surface area). Acetabuli were divided into equal octants; coverage angles were measured for each octant of interest. Variables were compared with age- and sex-matched controls (128 hips) using analysis of variance or the Mann–Whitney test.ResultsHips with DDH were more anteverted compared to normal hips (DDH: 22.6˚, Control: 16.4˚, p < 0.001). The surface area was similar between groups. 28% of hips had a global deficiency, 24% were anteriorly deficient, 19% were laterally deficient, 10% were anteverted (under covered anteriorly and over covered posteriorly), 3% were posteriorly deficient, and 15% of hips had borderline undercoverage. None of the hips in this cohort were found to be retroverted.ConclusionsThis is the first study to quantify the 3D acetabular deficiency in children with DDH compared to age- and sex-matched controls. We found wide variability in coverage patterns among dysplastic hips. It is imperative to define the specific acetabular deficiency for each individual patient prior to surgical correction.Level of evidenceIII – Case–control study.     

The Development of Leg Length Difference and Influence on Persistent Dysplasia in Patients with Developmental Dysplasia of the Hip

IntroductionLeg-length difference (LLD) is common in patients with developmental dysplasia of the hip (DDH). LLD of > 1 cm at skeletal maturity is reported in > 40% of patients, with the majority related to ipsilateral overgrowth. A longer DDH leg might lead to excessive mechanical loading at the acetabular margin, resulting in compromised acetabular development. We hypothesised that the LLD would negatively influence acetabular development. If so, it would be advantageous to identify such patients early in the course of follow-up, and address this if necessary.MethodsA retrospective study was conducted on a consecutive series of DDH patients managed surgically at the Royal National Orthopaedic Hospital, Stanmore, United Kingdom. We included patients with adequate long-leg radiographs at the age of 4–8 years (early-FU) and skeletal maturity (final-FU). Bilateral cases and those who underwent surgical procedures for hip dysplasia during the follow-up period were excluded. Measurements including leg length and centre-edge-angle (CE-angle) were obtained at the 2 time points.ResultsTwenty-seven patients were included, mean age at early-FU 5.7 (± 0.9) years, and 13.9 (± 1.0) years at final-FU. Mean LLD at early-FU was 9.5 (± 7.6) mm and 10.9 (± 9.4) mm at final-FU, p = 0.337. Correlation between early- and final-FU LLD was 0.68 (p < 0.001). The mean CE-angle at early follow-up was 14.6° (± 9.8), this improved to 23.2° (± 8.2) at skeletal maturity (p = 0.003, paired samples t-test). Linear regression analysis showed a non-significant trend towards less CE-angle improvement in patients with more initial residual dysplasia and more initial LLD.ConclusionMost leg-length differences can be identified early in the follow-up period, nevertheless, considerable individual changes in LLD are observed on continued follow-up. Furthermore, a trend was observed towards impaired acetabular improvement in patients with more LLD. These findings justify careful clinical and radiological monitoring of LLD from an early stage in the follow-up period.Supplementary InformationThe online version contains supplementary material available at 10.1007/s43465-021-00492-5.     

The Variation of the Pelvis in Unilateral Crowe Type IV Developmental Dysplasia of the Hip

ObjectiveTo investigate variation of the pelvis in unilateral Crowe type IV developmental dysplasia of the hip (DDH) and analyze the reliability of pelvic landmarks.MethodsWe retrospectively received preoperative anteroposterior pelvic radiographs for 89 adult patients with unilateral Crowe type IV DDH at our institution between September 2008 and May 2019. Forty‐eight patients without a false acetabulum was type IVA and 41 with a false acetabulum was type IVB. The heights of the ilium, acetabulum, and ischium areas in affected and unaffected sides were measured. The ratios of the three areas in entire pelvis are calculated. The discrepancies of bilateral iliac crest, inferior sacroiliac articulation, teardrop, and ischial tuberosity on the bisector of the pelvis were also measured.ResultsThe mean heights of the ilium, acetabulum, ischium areas in the affected side were 74.4, 88.6, and 37.0 mm, respectively, in type IVA group and 77.7, 83.5, and 37.8 mm, respectively, in type IVB group. The heights in the unaffected side were 82.1, 84.6, and 43.8 mm, respectively, in type IVA group and 84.6, 82.0, and 44.0 mm, respectively, in type IVB group. The ratios of the ilium, acetabulum, ischium areas in affected side of Crowe type IVA group were 0.37, 0.44, and 0.19, respectively, and the ratios in unaffected side were 0.39, 0.40, and 0.21, respectively. The ratios in affected side of Crowe type IVB group were 0.39, 0.42, and 0.19, respectively, and the ratios in unaffected side were 0.40, 0.39, and 0.21, respectively. The discrepancies of bilateral iliac crest, inferior sacroiliac articulation, teardrop, and ischial tuberosity on the line of the bisector of the pelvis in Crowe type IVA group were 5.6, 5.2, 2.0, and 7.1 mm, respectively. Those in Crowe type IVB group were 8.1, 3.5, 3.5, and 4.9 mm, respectively.ConclusionsPelvic asymmetry was a common occurrence in unilateral Crowe type IV DDH in adults. Furthermore, it should be reliable to use teardrop as pelvic landmark to balance leg length discrepancy in preoperative planning.     

全髋关节表面置换术治疗成人髋关节发育不良25例中期随访

目的探讨全髋关节表面置换术（total hip resurfacing arthroplasty,THRA）治疗成人髋关节发育不良（developmental dysplasia of the hip,DDH）继发骨关节炎的中期疗效。方法2005年3月至2006年6月,采用THRA治疗DDH患者25例,女18例,男7例;30～59岁,平均48岁;双髋1例,共26髋。根据Hartofilakidis分型,半脱位22髋,低位脱位4髋。采用Conserve-plus金属对金属全髋关节表面置换假体,髋臼假体为非骨水泥固定,股骨头假体采用低黏骨水泥固定。临床随访采用Harris评分,测量髋臼外展角、垂直距离、水平距离、股骨柄干角、髋臼假体覆盖率;记录髋臼和股骨假体周围透亮线及骨溶解;以各种原因所致翻修或影像学松动为随访终点。结果所有患者均随访3年以上,平均随访3.5年。截至随访终点无翻修或影像学松动。患者的Harris评分由术前平均46分提高至术后平均92.1分,26髋均为优。术后轻度跛行2例,所有患者均无迟发感染、术后股骨颈骨折、术后残余股骨头坏死、术后假体松动、脱位、术后异位骨化。髋关节活动度：屈曲由97.5°增加至127.5°,外展由19.3°增加至40°,外旋由23.2°增加至42.5°,内旋由4.2°增加至28.5°。X线片显示：关节假体位置正常,髋臼假体平均外展角为41.6°,髋关节旋转中心位置平均下移6.2 mm、内移15 mm,股骨柄干角平均146.4°。宿主骨对臼杯的平均覆盖率为94.4%,1例宿主骨与臼杯界面在2区出现透亮线,宿主骨与股骨假体柄界面无一例出现透亮线。结论THRA治疗成人半脱位型及低位脱位型DDH继发骨关节炎具有良好的中期疗效,熟练的手术技术和正确的适应证选择是降低中远期并发症的关键。     

Three-Dimensional Evaluation of Innominate Bone Rotation in Female Patients with Developmental Dysplasia of the Hip

BackgroundPatients with developmental dysplasia of the hip (DDH) are known to have abnormal pelvic morphologies; however, rotation of innominate bone features remains unclear. Thus, we investigated innominate bone rotation in patients with DDH by measuring the associated angles and distances using three-dimensional (3D) computed tomography.MethodsWe defined four straight lines in pelvic 3D models: from the anterior superior iliac spine to the posterior superior iliac spine, from the anterior inferior iliac spine to the posterior inferior iliac spine, from the pubic tubercle to the ischial spine, and from the pubic tubercle to the ischial tuberosity. Similarly, we measured the angles formed by these lines using the vertical axis of the anterior pelvic plane on the horizontal plane and the horizontal axis on the sagittal plane. Additionally, we measured the distances between the femoral head centers and the acetabular centers in the coronal plane.ResultsThe difference in internal rotation angle between the superior and inferior parts of the iliac bone was significantly lower, by approximately 1.7°, in the DDH group than in the control group (p = 0.007); the difference between the inferior and superior parts of the ischiopubic bone was significantly higher, by approximately 1.5°, in the DDH group (p < 0.001). In the sagittal plane, the sum of the superior aspect of the iliac bone and the inferior aspect of the ischium was significantly lower in the DDH group (p = 0.001) than in the control group. The distances between the femoral heads and the acetabula were significantly greater in the DDH group than in the control group (p = 0.03, p < 0.01, respectively).ConclusionsPatients with DDH had a more internally rotated ilium and ischiopubic bone than normal individuals; however, it should be emphasized that internal rotation was reduced near the acetabulum, and the acetabulum was shifted laterally. Similarly, it was shown that patients with DDH had different rotations of the ilium and ischiopubic bone in the sagittal plane.     

Residual Acetabular Dysplasia in the Reduced Hip

BackgroundResidual acetabular dysplasia occurs in up to a third of patients treated successfully for developmental dysplasia of the hip (DDH) and has been found to be a significant risk factor for early hip osteoarthritis (OA).DiscussionAge at the time of initial reduction and the initial severity of DDH have been linked to residual acetabular dysplasia. An anteroposterior pelvic radiograph is the main diagnostic modality, but MRI also provides valuable information, particularly in equivocal cases. The literature supports intervening when significant residual acetabular dysplasia persists at 4–5 years of age, and common surgical indications include acetabular index (AI) > 25°–30°, lateral center–edge angle (LCEA) < 8°–10°, and a broken Shenton’s line on radiographs; and a cartilaginous acetabular angle (CAI) > 18°, cartilaginous center–edge angle (CCE) < 13°, and/or the presence of high-signal intensity areas on MRI. Surgical options include redirectional pelvic osteotomies and reshaping acetabuloplasties, which provide comparable radiographic and clinical results.ConclusionRAD is common after treatment of DDH and requires regular follow-up for diagnosis and appropriate management to decrease the long-term risk of OA. Long-term outcomes of patients treated with pelvic osteotomies are generally favorable, and the risk of OA can be decreased, although the risk of total hip replacement in the long-term remains.     

Point-of-Care Ultrasound Reduces Visit Time and Cost of Care for Infants with Developmental Dysplasia of the Hip

BackgroundHealthcare institutions and policymakers are searching for system-wide approaches to reduce costs while maintaining quality and improving patient outcomes. In most healthcare systems infants referred for the detecting or treating developmental dysplasia of the hip (DDH) are sent to a radiology department for sonographic evaluation. The total duration of visit and cost of visit are essential variables in any healthcare setting and affect both efficiency and “the bottom line”. By having the treating clinician perform point-of-care ultrasound (POCUS) for the detection and follow-up of patients with DDH, we hypothesize that there would be a significant reduction in the time spent on the visit and the cost incurred without compromising quality or patient satisfaction. To our knowledge, no prior study has examined the effect of incorporating POCUS on the duration and cost of the visit in patients with DDH.PurposeTo determine if there was a difference in the duration of the visit for patients with DDH when POCUS was performed compared to when traditional “formal” sonography was performed. To determine if there was a difference in the cost of the visit for patients with DDH when POCUS was performed compared to when traditional “formal” sonography was performed.MethodsData for visits to a specialized outpatient office were collected over two years at a single-specialty orthopedic hospital, comparing the duration and cost of the visit between patient encounters for infants who had “formal” sonograms performed in the radiology suite to infants who underwent POCUS of the hip. In all, we included 532 patient encounters, 326 patients had POCUS performed, and 206 had a “formal” ultrasonographic evaluation performed. Of these, 140 were new evaluations and 392 were follow-up evaluations for treatment. Of the 140 new patients, 80 were in the POCUS group, and 60 were in the “formal” US group. Of the 392 follow-ups, 246 were in the POCUS group, and 146 were in the “formal” US group.ResultsThe mean duration of the encounter for the POCUS group was 42 min (range 16–75 min), and for the “formal” US group, it was 92 min (range 36–163 min). This difference was statistically significant (p = 0.002). The mean cost of the encounter for the POCUS group was $121.13, and for the “formal” US group, it was $339.38. This difference was statistically significant (p = 0.002).ConclusionUltimately, our study demonstrated a statistically significant reduction in the duration and cost of a patient encounter for infants with DDH when they undergo POCUS rather than “formal” sonographic evaluation.