The most commonly used modern terms are “developmental dysplasia of the hip” or DDH and “congenital hip dislocation,” CDH.
There were certain difficulties in searching the literature on this topic because of the many variant names for DDH. Exclusion criteria were those manuscripts discussing surgery, therapy, rehabilitation and any foreign language articles without an English abstract.
The goal of these manuscripts is to update the current knowledge of the epidemiology and demographics of pediatric hip disease which may lead to significant morbidity in later life.Ī systematic review was performed for articles on DDH in infants focusing on etiology, epidemiology, and diagnosis. The last major review of the epidemiology of hip diseases was in 1977. Neonatal hip instability, now even more apparent with hip ultrasonography, must also be addressed the clinical challenge is to separate the neonatal hip instability which resolves spontaneously from that which is significant.
The epidemiologic literature regarding DDH is vast and confusing due to different definitions of hip dysplasia, different methods of diagnosis (e.g., physical exam, plain radiographs, ultrasound), different ages of the population studied (e.g., new born, 1 month old, 3 months old, etc.), clinical experience of the examiner, different ethnicities/races in the examined population, and different geographic locations within similar ethnic populations. DDH encompasses a wide spectrum of pathology ranging from a complete fixed dislocation at birth to asymptomatic acetabular dysplasia in the adult. Demographic and epidemiologic studies can determine risk factors for a disease/condition of interest, shed light on its etiology, and guide potential prevention programs.ĭevelopmental dysplasia of the hip (DDH) is an epidemiologic conundrum. Incidence is the proportion of new cases in the population at risk during a specified time interval prevalence is defined as the proportion of individuals with the disease in the study population of interest. Epidemiology is the study of the incidence, distribution, and determinants of disease frequency in groups of individuals who happen to have characteristics in common (e.g., gender, ethnicity, exposure, genetics). Archeological studies demonstrate that the epidemiology of DDH may be changing.ĭemography is the study of human populations with reference to size, diversity, growth, age, and other characterizing statistics.
The role of acetabular dysplasia and adult hip osteoarthritis is complex. The opposite hip is frequently abnormal when using rigorous radiographic assessments. Associated conditions are congenital muscular torticollis and congenital foot deformities. Amniocentesis, premature labor, and massive radiation exposure may increase the risk of DDH. Swaddling is strongly associated with DDH. Many studies demonstrate an increase of DDH in the winter, both in the northern and southern hemispheres. Ligamentous laxity and abnormalities in collagen metabolism, estrogen metabolism, and pregnancy-associated pelvic instability are well-described associations with DDH. Chromosome 17q21 is strongly associated with DDH.
Certain HLA A, B, and D types demonstrate an increase in DDH. Children born premature, with low birth weights, or to multifetal pregnancies are somewhat protected from DDH. Predictors of DDH are breech presentation, positive family history, and gender (female). The incidence of clinical neonatal hip instability at birth ranges from 0.4 in Africans to 61.7 in Polish Caucasians. There is significant variability in incidence within each racial group by geographic location. The incidence per 1000 live births ranges from 0.06 in Africans in Africa to 76.1 in Native Americans. There is a predominance of left-sided (64.0%) and unilateral disease (63.4%). A systematic medical literature review regarding DDH was performed. There are many insights, however, from epidemiologic/demographic information. The etiology of developmental dysplasia of the hip (DDH) is unknown.