Cementless Total Hip Arthroplasty in Hip Dysplasia with an Extensively Porous-Coated Cylindrical Stem Modified for Asians: A 12-Year Follow-Up Study.

Long-term outcomes of primary cementless total hip arthroplasty were examined for 198 hips of Asian patients with developmental dysplasia of the hip. AML stems were modified for patients' relatively small physique. Stable fixation was achieved despite various proximal femoral deformities. At follow up (mean 12.1 years), radiographs demonstrated fixation in all hips, with 100% stem survivorship. Radiographic changes revealed that the severity of stress-shielding was mild in 55% of hips, moderate in 26%, and severe in 19%. Longer follow up is needed to determine whether these changes will develop into clinical manifestations. A distal fixation stem can be a useful reconstruction option when application of a proximal fixation stem in primary total hip arthroplasty is difficult for various reasons.

Heritability and sibling recurrent risk of developmental dysplasia of the hip in Chinese population.

BACKGROUND: Previous familial segregation studies supported that developmental dysplasia of the hip (DDH) is a multifactorial genetic disease. However, the exact extent of genetic effects has not been fully evaluated, especially in Asian population. The aim of this study is to estimate the sibling recurrent risk and heritability of DDH in a large Chinese cohort. MATERIALS AND METHODS: Four hundred and twenty-nine DDH probands and 534 matched normal controls were recruited from a screening programme for DDH, including 628 siblings in families of probands and 889 siblings in those of controls, respectively. The detailed information of family history was obtained, and the prevalence of DDH among siblings of probands, as well as controls, was determined. The sibling recurrent risk and heritability was estimated using classical liability threshold model. RESULTS: Eighty-seven siblings (13.85%) in families of proband and 14 siblings (1.57%) in normal control families were diagnosed as DDH. The recurrent risk in siblings of probands was at least tenfolds that in siblings of controls. Compared with the normal controls, the sibling recurrent risk was about 12-fold increase in male sib, and 9-fold increase in female sib. Overall, a high heritability of 83.59 ± 4.90% (h(2) ± SE) was observed. When stratified by genders, it was even higher for female siblings (91.02 ± 7.25%). CONCLUSION: This study for the first time exhibits a high sibling recurrent risk and heritability for DDH in Asian population. It also shows there is a high probability to identify the underlying predisposition genes in future genetic study.

Association of a single nucleotide polymorphism in pregnancy-associated plasma protein-A2 with developmental dysplasia of the hip: a case-control study.

Developmental dysplasia of the hip (DDH), previously known as congenital hip dislocation, is a frequently disabling condition characterized by premature arthritis in later life. Genetic influence on DDH has been long known, but is still poorly understood. Previously, we have performed a genome-wide linkage scan with Affymetrix 10K genechip for a four-generation Chinese family, which included 19 healthy members and five patients with DDH. Parametric and nonparametric multipoint linkage analyses were carried out with Genespring GT v.2.0 software, and the logarithm of odds (LOD) score and nonparametric linkage (NPL) score were calculated. For parametric linkage analysis, an assuming autosomal recessive trait was used with full penetrance, and Affymetrix "Asian" allele frequencies. The NPL score of 2.698 (P=0.0156) and LOD score of 2.119 (θ=0) were obtained on chromosome 1q25.2a for one marker (rs726252). The single nucleotide polymorphism (SNP) rs726252 locates in the region of fifth intron of pregnancy-associated plasma protein-A2 (PAPPA2). Although neither LOD nor NPL scores of rs726252 has exceeded 3.0, several researches have demonstrated that PAPPA2 have important consequences for the development of the fetus and normal postnatal growth. To further evaluate this possible association, in the present study, we examined the genetic association of rs726252 in PAPPA2 gene with sporadic DDH in Han Chinese population using case-control study, including 310 patients with sporadic DDH and 487 control subjects, and found a significant association between PAPPA2 and DDH.

Association analysis between HOXD9 genes and the development of developmental dysplasia of the hip in Chinese female Han population.

BACKGROUND: Developmental dysplasia of the hip (DDH) is a congenital or acquired deformation or misalignment of the hip joint which affects mainly females. We hypothesized that HOXD9 gene could be regulated in acetabular size or shape and related in DDH developing. METHODS: Two hundred and nine Chinese Han female DDH patients and 173 ethnic, age matched healthy female controls were genotyped for HOXD9 two tag SNPs using sequenom method. RESULTS: One of the two tag SNPs, rs711822, was not shown significantly differences in genotypic or allelic distribution between case and control group. Comparing the genotypic distribution of rs711819, there was significant differences between DDH patients group and control group (χ² = 7.54, df =2, P =0.023), and the association to DDH developing reached significance (P =0.045, OR =1.79, 95 % CI: 1.01-3.17 by dominant mode). CONCLUSION: In conclusion, the association between one tag SNP of HOXD9 gene and the development of DDH reach significant in our study population, this result indicate the positive correlation between HOXD9 gene and DDH developing. Further study in larger sample size and different population as well as functional studies will help to understand the pathogenesis of DDH.

Lack of evidence for association between DVWA gene polymorphisms and developmental dysplasia of the hip in Chinese Han population.

Developmental dysplasia of the hip is the most frequent inborn deformity of the locomotor apparatus. Genetic factors play a considerable role in pathogenesis of Developmental dysplasia of the hip. Recently, several DVWA SNPs were found to be consistent and most significantly associated in Japanese and Han Chinese knee OA studies. Its functions may be associated with cartilage. It may be involved in etiology and pathogenesis of Developmental dysplasia of the hip. Our objective is to evaluate whether the DVWA SNPs (rs7639618, rs9864422 and rs11718863) are associated with Developmental dysplasia of the hip in Han Chinese. Three SNPs rs7639618, rs9864422 and rs11718863 (in DVWA) were genotyped using a Taqman 5' allelic discrimination assay on an ABI 7500 real-time polymerase chain reaction (PCR) instrument in 368 children who suffered from Developmental dysplasia of the hip and 508 control subjects, and analyzed their associations. The genotype distribution and allele frequency were compared between Developmental dysplasia of the hip and healthy control. Neither genotype distributions nor allelic frequencies of the assayed single nucleotide polymorphisms were found to be significantly different between patients and controls. There was also no significant difference when the patients were stratified by sex or severity (all P > 0.05). Our results indicate that DVWA does not seem to be a risk factor for Developmental dysplasia of the hip etiology in Chinese Han population.

The Relationship Between Subluxation Percentage of the Femoroacetabular Joint and Acetabular Width in Asian Women with Developmental Dysplasia of the Hip.

BACKGROUND: Implantation of the acetabular cup insert in the "true" location of the acetabulum is a fundamental principle of total hip arthroplasty for the treatment of secondary osteoarthritis due to developmental dysplasia of the hip (DDH). As knowledge of the morphology of the acetabulum is required for accurate placement, we investigated the relationship between acetabular width and the Crowe classification of subluxation percentage of the hip. We also analyzed factors associated with the acetabular width ratio (AWR), defined as the acetabular width of the dysplastic hip divided by that of the unaffected, contralateral hip. METHODS: We completed a retrospective review of the preoperative standard anteroposterior radiographs and computed tomography (CT) scans of 207 female patients who underwent primary total hip arthroplasty for unilateral DDH. The "true" acetabular plane was defined on each CT reconstruction as a plane perpendicular to the anterior pelvic plane, parallel to the teardrop line, and passing through the center of the femoral head on the unaffected, contralateral side. The acetabular width was measured for both the affected hip and the contralateral, reference hip on the true acetabular plane, with the acetabular width defined as the distance between the edges of the anterior and posterior walls of the acetabulum. All hips were classified according to the Crowe groupings on the basis of the subluxation percentage of the dysplastic hip; the subluxation percentage increased from groups I to IV, with group IVb showing joint dislocation. RESULTS: The acetabular width decreased from Crowe groups I to IVb, with a negative correlation found between the AWR and the subluxation percentage (Spearman correlation coefficient, ρ = -0.404; p < 0.001). Multivariate regression analysis identified subluxation percentage and femoral neck-shaft angle as independent factors associated with the AWR. CONCLUSIONS: Characterization of factors associated with the AWR, namely subluxation percentage and femoral neck-shaft angle, will guide surgeons in correctly implanting the acetabular cup insert during total hip arthroplasty in patients with DDH.

Congenital dislocation of hips in Malaysian neonates.

A prospective study was carried out in the Maternity Hospital, Kuala Lumpur over a 2-year period. During this time, 52,379 deliveries took place. 36 neonates (0.7 per 1000 births) were found to have congenital dislocation of the hips (CDH) by both the Ortolani and Barlow's manoeuvre. CDH was most common in the females (female to male ratio was 2.3:1), the first borns (50% of the affected cases) and babies who had breech delivery (10.7 per 1000 births). In 21 (58.3%) of the affected neonates, CDH occurred in both hips. According to the classification of newborn infants' hips by Finlay et al, 88.9% of the neonates had unstable hips while 8.3% had pathological hips. Family history of CDH was present in 5% of the patients. 8 (22.2%) of the neonates had other associated congenital abnormalities.

Racial and geographic differences of Wiberg's angle from 400 ultrasonographic normal hips in Italian and Brazilian infants younger than 3 months old.

The Wiberg center edge angle (CEA) of 400 hip sonographies among 200 infants, 100 Italians and 100 Brazilians, aged from 15 days to 90 days, whose hip joints were considered normal, from the ultrasonographic point of view (1a and 1b) according to Graf's classification were measured. For the CEA measurements in the studied material, the authors used their own methodology developed for this purpose, which is based on basic geometric concepts and applied by one graphic computer program. In the studied material, the statistical analysis of the results obtained in the measurement of the CEA showed a better conformation of the acetabular roof complex in the Brazilian infants compared with the Italian.

"Immunity" of Ethiopian Jews to developmental dysplasia of the hip: a preliminary sonographic study.

Developmental dysplasia of the hip (DDH) is one of the most common problems affecting the pediatric musculoskeletal system. The condition represents a broad spectrum of sonographic (anatomic) pathoanatomical situations, ranging from very mild dysplasia to full dislocation, manifesting clinically as stable or unstable hip joints, particularly in the neonatal period. The cause of DDH is unclear. Various theories suggest genetic, hormonal, mechanical, and geographic factors, along with hemotypology and a great variety of other factors, as causes for this condition. In the present study, sonographic criteria for diagnosing DDH according to Graf were used. Although the overall incidence of DDH was 5.9% in white neonates, it was only 0.44% (two hips, one stable and one unstable) among 450 hips of black Ethiopian newborns. Left untreated, these hips became clinically and sonographically normal. Our results could be considered to indicate a zero incidence of DDH among Ethiopian Jews in this series.

Developmental dysplasia of the hip incidence in Ethiopian Jews revisited: 7-year prospective study.

We describe the sonographic and true incidence of developmental dysplasia of the hip among Ethiopian Jews compared with the general Israeli population. Previous results were based on a small number of Jewish Ethiopian children; this study is based on over 7 years of experience, during which 34,048 newborns, 768 of whom were Ethiopian, were examined clinically and sonographically. The incidence of sonographic developmental hip dysplasia was 5.5% in the general Israeli population, compared with 1.24% for the Ethiopian Jews. True developmental hip dysplasia incidence for Arabs and other Jews was 0.51%, as compared with 0.15% in the Ethiopians. Our data support the theory that either a single unknown gene or a multiple gene system plays a major role in the incidence of the dysplasia.

[Hip dislocation in Indians of Quebec]. / La maladie luxante chez les Indiens du Québec.

The prevalence of congenital dislocation of the hip in the Cree Indian population of Canada is very high. On 3 separate occasions, from 1973 to 1976, the author had the opportunity to conduct 3 missions in Quebec Northern Territories with the objective of training the medical personnel for carrying out examination of the hips in the neonatal period for the early diagnosis of congenital dislocation of the hip and the application of simple and efficient methods of treatment. The author reports his observations on the use of the tihkinakan cradle board, the high incidence of ligamentous hyperlaxity and how it may affect the clinical findings, the result of treatment of the older child and the clinical and radiological findings of the untreated dislocation in the adults. Most dislocations of the hip in the Cree Indians are now diagnosed early and a large number of them treated locally with braces and harnesses.

[History and epidemiology of congenital hip dislocation in Brittany]. / Histoire et épidémiologie de la luxation congénitale de la hanche en Bretagne.

Brittany is a region of France with a high rate of congenital dislocations of the hip (CDH). This was shown by Le Damany, who, in 1912, did a systematic screening of newborns and compared the number of CDH in Paris and Rennes. In Paris, there was 0.8% and in Rennes 3.6% CDH. This frequency is not generalized in Brittany, however; and Setter, who did a large survey in Finistère in 1961 and 1962, showed that the epicenter was the canton of Pont l'Abbé, also called "pays Bigouden". However, this disease did not occur in this region of France in earlier times. In 1795, Cambry, according to the "Convention de la Jeune République", travelled in Finistère from village to village and did not notice any limping women. This was a very serious and precise study, and we may conclude that there was no CDH at that time; the disease occurred later in "pays Bigouden". From these basic facts, certain hypotheses are considered. From the point of view of genetics, a mutation apparently occurred in the 19th century, but there is no reliable genetic study. Autosomic heredity with incomplete penetrance, with variable penetrance according to sex may be considered: it includes a multifactorial origin of the disease involving genetics, environmental, biochemical and ethnic factors, including local customs and traditions.

[Sonographic measures of the hip joint of 1328 newborns of Han and Uygur nationalities-relative factors of congenital dislocation of hip].

The four sonographic methods (Engesaeter, Terjesen, Graf, Morin-Harcke) were used for examining the hip joint of 1328 newborns of Han and Uygur nationalities. The difference between Han and Uygur newborns was not statistical significant, but some literatures reported that in our country, the incidence of different nationalities in different regions varied. Our conclusion is that there is no obvious relationship between the depth of the acetabulum and the percentage of the femoral head covered by the acetabulum. It is caused by other factors, inherent or acquired. The value of the hip joint of the male and female has significant difference (P < 0.0005). The incidence of CDH in girls is much higher than that in boys. This may be related to the different depth of the acetabulum and different percentage of the femoral head covered by the acetabulum. In the period of newborn, girl's depth of the acetabulum is smaller than that of boys.

Medium-term outcome of total hip replacement for dysplastic hips in Singapore.

PURPOSE: To review medium-term outcomes of 46 patients who underwent total hip replacement (THR) for osteoarthritis secondary to dysplastic hips. METHODS: Records of 58 hips in 6 men and 40 women aged 32 to 76 (mean, 62) years who underwent THR for osteoarthritis secondary to dysplastic hips and had been followed up for a mean of 4 (range, 2-8) years were retrospectively reviewed. The hips were classified according to the Crowe's grading, Sharp's acetabular angle, and centre-edge angle. The radiological uncoverage of acetabular cup (RUAC) index was calculated. The outcomes of THR were evaluated in terms of cup inclination, RUAC index, cup migration, lysis or loosening (radiolucency), heterotopic ossification, component incorporation and positioning, thigh pain, and subsidence. RESULTS: 51 of the hips were Crowe's type I, 6 were type II, and one was type IV. The mean acetabular angle was 46.3 degrees and the mean centre-edge angle was 15.4 degrees. The mean cup, head, and stem sizes were 50.4 mm, 28.7 mm, and 10.9 mm, respectively. The mean RUAC index was 16.9% and the mean cup inclination was 40.7 degrees. Radiolucency of 1 mm in the acetabular zone I was observed in 16 cases, but only one failed. For cemented and uncemented stems, the most common positioning was neutral and valgus, respectively. Five patients had complications of greater trochanter fracture, aseptic loosening, split calcar, stem loosening, and/or heterotopic ossification. CONCLUSION: Conventional THR can achieve good medium-term results in low-grade dysplastic hips.

Congenital dislocation of the hip in Western Australia. A comparison of neonatally and postneonatally diagnosed cases.

Speculation that neonatally diagnosed congenital dislocation of the hip (CDH) may have a different etiology from cases diagnosed in the postneonatal period has not been examined in Australia because insufficient data have been available. A population-based study of CDH in children up to the age of two years who were born in Western Australia (WA) in 1981, 1982, or 1983 is the subject of this report. Study material comprised cases of CDH from the WA Congenital Malformations Register and denominator data (all births in WA for 1981-1983) from the Health Department of WA. From this material, rates of CDH were calculated for each of the study variables of interest. The rate of CDH was low for babies born to aboriginal mothers, and it is postulated that this may have a cultural basis, possibly in infant carrying postures. Overall, the prevalence of CDH for 1981-1983 was 6.4 cases per 1000 births, with 4.2/1000 diagnosed in the neonatal period and 2.2/1000 in the postneonatal period. Epidemiologic differences were noted between infants diagnosed in the neonatal period and those diagnosed postneonatally; rates of neonatally diagnosed CDH were higher in first births, breech presentation, and postmature infants than were rates of postneonatally diagnosed cases. Bilateral dislocation was more common (45.3%) in neonatally diagnosed cases than in postneonatally diagnosed cases (23.3%). These findings tended to support the idea that the time of diagnosis may define two distinct entities in CDH.

Etiologic factors in congenital displacement of the hip and myelodysplasia.

The two prime factors in the mechanism of intrauterine displacement of the hip are mesenchymal tissue abnormalities and mechanical stress placed on the fetal hip joint by the leg-folding mechanism. The somatic changes involve general laxity of the articular ligaments, attributable to either the physiologic effects of progesterone or a genetic trait consisting of familial joint laxity. The ligamentous laxity not only interferes with the folding mechanism of the fetal legs but also influences the torsional effect on the hip joints. This facilitates the displacement of the femoral head over the posterior rim of the acetabulum. The mechanical stress caused by the delay in leg folding also appears to play a role in a genetically determined occult form of myelodysplasia. Its prevalence has already been partially revealed by sensory evoked potential tests. Possibly, a more refined motor evoked potential test might help to explain a large percentage of the idiopathic cases. Thus, many of the etiologic factors in congenital hip displacement, previously considered to be caused by pre- and postnatal environmental influences, may well have genetic origins. These origins may be associated with varying degrees of underlying myelodysplasia. The relatively high incidence of firstborn affected, the ratio of female to male patients, the seasonal incidence of birth, and familial and racial prevalence may prove to be genetically predetermined.

Congenital dislocation of the hip and its relation to swaddling used in Turkey.

A screening program was initiated and performed at five hospitals in Konya, Turkey from 1988 to 1990. Four thousand one hundred seventy-three infants aged 3-24 months were examined. With this study, we hoped to determine the incidence of and contributing factors to the etiology of congenital dislocation of the hip (CDH) in the central region of Turkey. The overall CDH incidence was 1.34%. CDH occurred about three times more often among girls than boys (40 girls vs. 16 boys). No infant with CDH had been delivered by Cesarean section or breech presentation. No teratologic CDH was detected. The relationship between CDH and swaddling (bundled in extension and adduction) was statistically significant.

[Congenital dysplasia of the hip in children of immigrants from developing countries]. / Displasia congenita d'anca infantile in figli di immigrati provenienti da Paesi in via di sviluppo.

BACKGROUND: Aim of study was to ascertain the possible presence of congenital dysplasia of the hip in infants (CDH) in the population immigrated from countries where the problem is surely neglected from the local health service and estimate its incidence. Moreover to observe the impact of the CDH problem on the parents of these children, sometimes of scarce culture or rather of scarce comprehension of the language. Finally, to verify the answer of parents to the medical prescriptions and to the not simple therapeutic formality. METHODS: From 1989 to 1996, the hip has been examined by Graf ultrasounds (US) method on a population of 181 infants born from developing countries' immigrants in Italy; 77 of them were Egyptians. RESULTS: Even if the density of the population studied was not very high, the results presented in this paper are innovative and differ from the literature on this matter. Among the 362 hips examined with US, only 5 hips were found to be pathologic (4 Egyptians and 1 Philippine; 2 type uD and 3 type IIC of Graf), and they were treated and recovered with a harm in about 3 months. CONCLUSIONS: This work underlines the necessity that all immigrated infants should be studied with US hip exams and that CDH in these people should not be under-evaluated: the very low occurrence of this pathology in developing countries is probably mainly due to scarsity of studies on this matter. This allows not only to avoid hip dislocation in these subjects, but also to the society to avoid the necessary cost of the subsequent treatment of well more serious diseases such as osteoarthritis of the hip on dysplastic basis, in subjects that likely will stay in our country definitely, becoming Italian citizens to all effects.

Racial and gender variations in adult hip morphology.

Pelvic X-rays of 99 adult patients (198 hips) were analysed in 58 men and 41 women to determine the morphology of the adult hip in Malawians. For each hip the centre edge angle of Wiberg, the acetabular angle of Sharp and the acetabular head index were measured. For each parameter, women were more dysplastic than men, and for the acetabular angle of Sharp there was a significant gender difference ( p<0.05, t test). Our figures were compared to those of Fujii et al. who had measured the same parameters in Japanese and British hips. His results taken with ours showed that within a racial group, women were more dysplastic that men and that Japanese hips were more dysplastic than British hips, which were in turn more dysplastic than Malawian hips.

Untreated acetabular dysplasia of the hip in the Navajo. A 34 year case series followup.

Patients born in the Many Farms District of the Navajo Indian Reservation from 1955 to 1961 were studied. Five hundred forty-eight of the 628 infants born (87%) received clinical examinations and pelvic radiographs at some time during the first 4 years of their lives. Eighteen (3.3%) of the 548 infants examined had acetabular dysplasia. Because of traditional cultural beliefs, none of these children received medical treatment. Followup evaluations and radiographs were obtained in these 18 patients during early adolescence. In 10 of the original 18 patients followup evaluations and radiographs were obtained at an average age of 35 years. None of the dysplastic hips progressed to frank dislocation. The mean center edge angle improved from 7 degrees when the patients were 1 year of age, to 29 degrees when the patients were 12 years of age, to 30 degrees when the patients were 35 years of age. Despite overall improvement of hip measurements with maturity, eight hips in five of the 10 patients who were in their fourth decade of life and who were available for examination, had radiographic evidence of residual abnormalities. The hips in patients with subluxation during infancy were less likely to be normal as adults. The results of this 34-year followup study of untreated developmental hip dysplasia showed marked radiographic improvement in all patients during childhood; however, subtle abnormalities persisted in the radiographs of 40% of the hips.