Early x-ray diagnosis of hip dysplasia in children]

The author proposes a method of differential diagnosis of hip dislocations and hip joint dysplasia in infants aged 3 months. The alpha-angle of hip dislocation with relation to trochanteric space is determined on an anteroposterior radiogram of the hip joints; 64 degrees means hip dysplasia, 65-69 degrees and more mean dislocation. This method was tested in 75 children (150 joints) aged 3 months. A mean diagnostic accuracy was 90.1%.     

The rational strategies for detecting developmental dysplasia of the hip at the age of 4-6 months old infants: a prospective study

Using ultrasound in evaluation of infant's hip development can reduce surgical procedures, hospitalization and late presentation of developmental dysplasia of the hip (DDH). The increasing incidence of DDH after ultrasound examination is observed and published by many authors. In a prospective study, radiograph of every single ultrasonographic positive hip in infants older than three months, was taken and analyzed in order to see whether it affects infants splintage rate in treating DDH. In a period of 30 months, clinical and simple static ultrasonographic examinations according to Graf were performed on 1430 consecutive infant hips in patients aged between 4 and 6 months. Sonographic positive hips were radiographed and acetabular index (AI) values on simple AP radiographs were analyzed. The sonographic DDH incidence was 51.75 per 1000 hips (51.75 per thousand). After X-ray examination of all 74 ultrasonographic positive hips, only 44 remained abnormal and required treatment indicating a true DDH incidence of 30.77 per 1000 hips (30.77 per thousand). The difference in incidence per ultrasonographic and X-ray positive hips is statistically significant p < 0.01 (t = 5,536). The rational approach in detection of DDH in a child more than 3 months old is to do radiographic assessment of every sonographic positive hip.     

Development and growth of immature hips

The authors investigated the development of the bony acetabulum in type IIa+ immature hips using ultrasound follow-up evaluation of the alpha and beta angle. The study comprised 900 hips in one-month old infants. In the initial ultrasound examination the alpha angle measured less than 60 degrees and the beta angle more than 55 degrees. In the second ultrasound examination at the age of two months a discrepancy between the bony and cartilaginous acetabular component was found in 15% of the hips, which means that the type IIa+ hips were transformed into the type IIa-. The infants with type IIa- hips had more than two risk factors for developmental dysplasia of the hip. The statistical relative risk was 17. These hips were treated with the Pavlik harness during two months on average. After treatment all hips had normal values the alpha and beta angles (more than 60 degrees and less than 55 degrees respectively). This study showed that each newborn and infant with a sonographically confirmed hip development disorder has to be included in the follow-up evaluation of acetabular development, which makes it possible to choose the most adequate therapeutic and prophylactic measures.     

The advancement in the early diagnostics of developmental hip dysplasia in infants--the role of ultrasound screening

Developmental hip dysplasia (DDH) is a deformation of the locomotor system that can occur on previously normal bone structures in late fetal development. The study was undertaken to determine the value of continuous ultrasound screening in early diagnosis of DDH. In the area covered by the Labin Primary Health Center, clinical and ultrasound examination of the hips was performed in all children during the fourth month of life from 1989 to 2001. The incidence of DDH was 3.3%. The authors compared the obtained results with results of clinically examined hips in the period from 1968 to 1988 (incidence 1.7%), before the ultrasound diagnostics was introduced. The hip radiograms were performed only in children with clinically positive signs of higher degree of DHD. The ultrasound examination was performed with Hitachi EUB 410 real time linear transducer with a 5 MHz probe. The examiners used methods and criteria suggested by Graf. The most useful feature of the ultrasound method is that it allows the visualization of cartilaginous femoral head and its relationship to the acetabulum in infants. The method is non-invasive, repeatable, without risk of ionizing radiation or need for the contrast material administration. The results of the study revealed an important increase of DHD incidence after the introduction of ultrasound examination. US is highly sensitive in hip imaging and reveals the existence of a number of dislocated and subluxated hips that otherwise would be missed. The anomaly was discovered in the early period of life, which is very important for appropriate therapeutic effects.     

Difficulties in diagnosing and managing congenital dislocation of the hip.

In a 10-year retrospective study of 25 921 consecutive deliveries in a neonatal unit in Newcastle upon Tyne 271 cases of congenital dislocation of the hips were identified. Of these, the outcome was unsatisfactory in 12: four diagnoses were missed at birth and eight children required further surgical treatment. Radiological abnormalities were detected in a further five children at long-term follow-up examination. From the results of this study and other published series it was concluded that lack of attention to detail was the main cause of inadequate diagnosis and management of congenital dislocation of the hips. More detailed instruction of junior staff, confirmation of the diagnosis by senior staff, the use of a non-removable splint early in treatment, and thorough follow-up by senior staff are all important.     

Incidence and Treatment of Developmental Hip Dysplasia in Mongolia: A Prospective Cohort Study

Background

In Mongolia, adequate early diagnosis and treatment of developmental hip dysplasia (DDH) have been unavailable and its incidence was unknown. We determined the incidence of ultrasonographic DDH in newborns and established adequate procedures for diagnosis and treatment of DDH at the largest maternity hospital in Ulaanbaatar, Mongolia.

Methodology/Principal Findings

During one year (Sept 2010 – Aug 2011) we assessed the hips newborns using ultrasound and Graf’s classification of DDH. 8,356 newborns were screened; median age at screening was 1 day. We identified 14,873 Type 1 (89.0%), 1715 Type 2a (10.3%), 36 Type 2c (0.2%), 70 Type D (0.4%), 14 Type 3 (0.08%), and 4 Type 4 hips (0.02%). Children with Type 1 hips (normal) were discharged. Children with Type 2a hips (physiologically immature) received follow-up ultrasounds at monthly intervals. Children with Type 2c to 4 (DDH; deformed or misaligned hip joint) hips were treated with a Tubingen hip flexion splint and also followed up. The hip abnormalities resolved to mature hips in all children who were followed up. There was no evidence for severe treatment related complications.

Conclusion/Significance

This study suggests that the incidence of DDH in Mongolian neonates is comparable to that in neonates in Europe. Early ultrasound-based assessment and splinting treatment of DDH led to mature hips in all children followed up. Procedures are feasible and will be continued.     

Effect of cup inclination on predicted contact stress-induced volumetric wear in total hip replacement

In order to increase the lifetime of the total hip endoprosthesis, it is necessary to understand mechanisms leading to its failure. In this work, we address volumetric wear of the artificial cup, in particular the effect of its inclination with respect to the vertical. Volumetric wear was calculated by using mathematical models for resultant hip force, contact stress and penetration of the prosthesis head into the cup. Relevance of the dependence of volumetric wear on inclination of the cup (its abduction angle ?_A) was assessed by the results of 95 hips with implanted endoprosthesis. Geometrical parameters obtained from standard antero-posterior radiographs were taken as input data. Volumetric wear decreases with increasing cup abduction angle ?_A. The correlation within the population of 95 hips was statistically significant (P = 0.006). Large cup abduction angle minimises predicted volumetric wear but may increase the risk for dislocation of the artificial head from the cup in the one-legged stance. Cup abduction angle and direction of the resultant hip force may compensate each other to achieve optimal position of the cup with respect to wear and dislocation in the one-legged stance for a particular patient.     

基于三维CT的模拟手术在大龄DDH患儿外科治疗中的应用研究

目的:通过对大龄发育性髋关节脱位(developmental dysplasia of the hip,DDH)患儿进行术前模拟手术,实现术中精确截骨及旋转角度,从而达到个体化治疗,改善患儿预后的目的。方法:本研究按照术前规划方式分为两组,一组为传统手术组;另一组为模拟手术组。共20例患儿均采用骨盆三联截骨术+股骨截骨术治疗,传统手术组10例,模拟手术组10例,手术时平均年龄为11.3岁,平均随访时间24.2个月。所有患儿均于术前行骨盆三维重建CT检查,测量CE角、股骨前倾角及髋臼指数,在mimics软件中,模拟手术方案,确定术中股骨截骨需要旋转的角度及骨盆截骨的位置,术中按照模拟手术的结果进行操作。术前评价指标使用Tonnis分级,术后评价指标使用改进的Trevor评分系统。结果:模拟手术组Tonnis分级3级4髋,Tonnis分级4级8髋;传统手术组Tonnis分级3级4髋,Tonnis分级4级9髋,两组患儿术前严重程度无显著性差异。依据Trevor评分,模拟手术组8髋(67%)优秀,3髋(25%)良好,1髋(8%)一般。传统手术组5髋(38%)优秀,5髋(38%)良好,3髋(23%)一般。两组有显著性差异。并发症:术后传统手术组3例患儿有不同程度的股骨头坏死。结论:大龄DDH患儿术前模拟手术,可以达到术中精确截骨及旋转角度,可改善患儿预后,实现该类患者的个体化治疗。     

Brief communication: developmental dysplasia of the hip in medieval London

Developmental dysplasia of the hip (DDH) is a spectrum of disease starting in childhood and in many cases persisting into adulthood. The spectrum ranges from acetabular dysplasia, through hip subluxation to dislocation. The aim of this research was to determine the prevalence and pathoanatomy of acetabular dysplasia and subluxation in excavated human skeletal remains, to complement past research on dislocation in DDH. The material under study was the medieval cemetery of St. Mary Spital in London, in use from c.1100 to 1539 AD. A series of 572 adults with both hips preserved were analyzed. Acetabular dysplasia was indicated by a shallow acetabulum with upward sloping roof. Subluxation was suggested by degenerative change along the margin of the acetabulum suggestive of labral tears, and degenerative change in the outer part of the acetabular roof suggestive of osteoarthritis. The prevalence of DDH (acetabular dysplasia, subluxation, or dislocation) was 1.7%. Because this a congenital musculoskeletal disorder of relatively high frequency, with significant variation in prevalence between populations around the world, it is a topic that warrants targeted research from physical anthropologists studying past populations.     

Screening for congenital dislocation of the hip: an economic appraisal.

The direct costs of screening for congenital dislocation of the hip (CDH) are compared with the treatment costs resulting from no screening in a cost-effectiveness analysis in British Columbia. Under certain conditions the costs associated with screening and subsequent conservative treatment for 6 to 15 positive cases of CDH/1000 liveborn infants were considerably lower than the costs of either open or closed reduction of the hip for 1.5 infants with CDH per 1000 infants not screened. When adjustments were made to the assumptions about screening costs, rates with which cases were missed and hospital treatment costs, only the assumptions thought to be overly unfavourable to screening and overly optimistic for no screening brought the costs of no screening within the likely range of costs of screening. Some specific and general implications of the cost-effectiveness of screening for CDH in British Columbia are discussed.     

Partial and complete trisomy 9: Delineation of a trisomy 9 syndrome

Summary Two infants with trisomy involving chromosome 9 are described. One had complete trisomy 9 and the other karyotype 47,XX,+der(9),t(7;9)(p22;q32)mat. A trisomy 9 syndrome is delineated, consisting of features of the trisomy 9p syndrome and various other malformations. These include abnormalities of the cardiovascular and urogenital systems, cranial suture anomalies, dislocation of the hips and knees and early death. A possible relationship of some of these findings to regions of 9q involved in cases of partial trisomy 9 is suggested.     

Neonatal screening in Vancouver for congenital dislocation of the hip.

After 20 years'' experience throughout the Western world the effectiveness of screening newborns for congenital dislocation of the hip remains controversial. Is the clinical test for hip instability (the Ortolani or "jump" sing) reliable? Are other equally important physical signs frequently missed by inexperienced examiners? Do some dislocations develop after the newborn period when no abnormality was identifiable during the first week of life? In Vancouver, screening for this condition was initiated in 1964. In the 5-year period 1967-1971 an orthopedic surgeon screened all the infants in the newborn nursery of one hospital, while orthopedic residents screened all those at another hospital. Their rates of neonatal and late (after the first month of lfe) diagnosis of congenital hip abnormalities were, respectively, 6 and 0.3/100 lives births for the surgeon and 5 and 0.8/1000 for the residents. In contrast, at 20 hospitals that did not have regular screenign the average rates were 1.2 and 1.4. Systematic screening the early treatment have great potential for reducing the need for immobilization and surgical treatment of infants who congenital dislocation of the hip is missed in the first month of life. it may also prevent the arthritic sequelae that in adult life afflict many patients whose treatment was begun after the newborn period.     

Hip contact stress during normal and staircase walking: the influence of acetabular anteversion angle and lateral coverage of the acetabulum

Hip contact stress is considered to be an important biomechanical factor related to development of coxarthrosis. The effect of the lateral coverage of the acetabulum on the hip contact stress has been demonstrated in several studies of hip dysplasia, whereas the effect of the anterior anteversion remains unclear. Therefore, the joint hip contact stress during normal level walking and staircase walking, in normal and dysplastic hips, for small and large acetabular anteversion angle was computed. For small acetabular anteversion angle, the hip contact stress is slightly increased (less than 15%) in staircase walking when compared with normal walking. In hips with large angle of acetabular anteversion, walking downstairs significantly increases the maximal peak contact stress (70% in normal hips and 115% in dysplastic hips) whereas walking upstairs decreases the peak contact stress (4% in normal hips and 34% in dysplastic hips) in comparison to normal walking. Based on the presented results, we suggest that the acetabular anteversion should be considered in biomechanical evaluation of the hips, especially when the lateral coverage of the acetabulum is small.     

Apparent or true neonatal hip dislocation? Radiologic differential diagnosis.

A case of neonatal separation of the proximal femoral epiphysis secondary to obstetric trauma is presented. The radiologic differential diagnosis, as in other cases of neonatal dislocation of the hip, included congenital and septic dislocation of the hip and epiphyseal separation - so-called apparent dislocation. When clinical and laboratory signs are minimal or equivocal, x-ray films and, in difficult cases, contrast arthrograms are needed for an accurate diagnosis of neonatal dislocation of the hip.     

Larsen syndrome associated with severe congenital hydrocephalus

Larsen syndrome associated with severe congenital hydrocephalus: Larsen syndrome (LS) is characterized by the association of flattened facies with a prominent forehead, a depressed nasal bridge and hypertelorism, dislocation of hips, elbows and knees, equinovarus or valgus deformities of the feet, long and tapering fingers, normal intelligence. Hydrocephalus has rarely been reported in association with LS. In this article, a newborn infant with the classical features of LS and severe congenital hydrocephalus is presented. Our purpose was to emphasize the importance of congenital hydrocephalus in infants with LS and to highlight the management of cases of LS associated with congenital hydrocephalus.     

Prognostic value of refined Wiberg's angle in hip development

There are many angles measured on hip radiographs, but their prognostic value for hip development in patient with DDH is controversial. Our aim was to find out how the development of congenitally luxated hip could be predicted after reduction using Wiberg's CE angle and CE angle refined according to Ogata. 119 hips of 61 patients were retrospectively evaluated after reduction from 3 months of age until at least full osteomaturity. According to results of CE angles measurements good and poor hip development group were formed. Healthy hips of the patients with unilateral DDH were considered to be the control group. Negative linear trend of the curve connecting Wiberg's CE angle values measured within first postreductive years is a poor prognostic sign of hip development as are absolute negative values of refined CE angles. In cases where negative initial refined CE angles are combined with negative linear trend of Wiberg's CE angles prognosis is extremely poor. Both Wiberg's and Ogata's CE angle are of prognostic value regarding hip development and should be measured when evaluating AP radiographs of infant's hip.     

Computer determination of contact stress distribution and size of weight bearing area in the human hip joint

The mathematical models and the corresponding computer program for determination of the hip joint contact force, the contact stress distribution, and the size of the weight bearing area from a standard anteroposterior radiograph are described. The described method can be applied in clinical practice to predict an optimal stress distribution after different operative interventions in the hip joint and to analyze the short and long term outcome of the treatment of various pathological conditions in the hip. A group of dysplastic hips and a group of normal hips were examined, with respect to the peak contact stress normalized by the body weight, and with respect to the functional angle of the weight bearing area. It is shown that both these parameters can be used in the assessment of hip dysplasia.     

Development of acetabulum after closed reduction in developmental hip dysplasia

The radiographic study of acetabulum development after closed reduction of 87 congenitally dislocated hips in 64 patients who were treated between 1980 and 1990 was conducted retrospectively. An average patient's age at the moment of closed hip reduction was 16 months (range between 6 to 24 months). On the average, patients were 16 months old (range between 6 to 24 months) at the moment of closed hip reduction. Development of bony acetabulum was followed for 8 years by measuring the AC angle. According to the age at the moment of closed reduction patients were sorted into three groups, the first group from 6 months to 12 months old (39 hips), the second group from 12 to 24 months old (28 hips) and the third group from 24 to 36 months old (20 hips). At the beginning of the treatment mean values of the AC angle in the first group were 37.2 degrees +/- 3.31 degrees; in the second group 39.7 degrees +/- 3.2 degrees; and in the third group 43.8 degrees +/- 2.7 degrees. The final values of the AC angle in the first group were 14.7 degrees +/- 3.21 degrees, in the second group 21 degrees +/- 3.02 degrees; and in the third group 24 degrees +/- 3.76 degrees. Normally and mildly dysplastic hips were achieved in 80.5% treated hips, while in 19.5% treated hips medium and serious dysplasia retarded. The acetabulum development in dysplastic hip after retained stable concentric reduction was the same as in the normal hip. The operative reconstruction of acetabulum should not be done before the third year of life.     

Computer Determination of Contact Stress Distribution and Size of Weight Bearing Area in the Human Hip Joint

The mathematical models and the corresponding computer program for determination of the hip joint contact force, the contact stress distribution, and the size of the weight bearing area from a standard anteroposterior radiograph are described. The described method can be applied in clinical practice to predict an optimal stress distribution after different operative interventions in the hip joint and to analyze the short and long term outcome of the treatment of various pathological conditions in the hip. A group of dysplastic hips and a group of normal hips were examined, with respect to the peak contact stress normalized by the body weight, and with respect to the functional angle of the weight bearing area. It is shown that both these parameters can be used in the assessment of hip dysplasia.     

Secondary hip dysplasia increases risk for early coxarthritis after Legg-Calve-Perthes disease. A study of 255 hips

Abstract

The biomechanical parameters of the hip joint articular surface were analysed in 141 adult hips after Legg-Calve Perthes Disease, and 114 contralateral unaffected hips (controls), by using HIPSTRESS mathematical models. Geometrical parameters, assessed from anteroposterior and axial radiograms, were used as input to models for resultant hip force and contact hip stress. Results confirm previous indications that head enlargement after the Legg-Calve-Perthes Disease compensates the values of hip stress. Furthermore, it was found that an increased risk for coxarthritis development after the disease is secondary to concomitant hip dysplasia, with considerable and statistically significantly lower centre-edge angle and unfavourable distribution of stress.