Associations between risk factors and developmental dysplasia of the hip and ultrasonographic hip type: A retrospective case control study

Abstract

Purpose We aimed to revisit the correlation between the previously defined risk factors and the occurrence of developmental dysplasia of the hip (DDH) and to assess the influence of these factors on the ultrasonographic type of hip dysplasia according to the Graf’s classification in patients with DDH. Methods Data of healthy infants (mean age 33 days) who had bilateral mature (normal) hips (Graf type I) were compared with the data of infants (mean age 105 days) who were treated by abduction brace due to unilateral or bilateral DDH (Graf type IIa- and worse hips). Results Infants with at least one risk factor had a significantly higher rate of DDH than those with no risk factors (p < 0.001). Likewise, infants with more than one risk factor had a significantly higher rate of DDH than those with only one risk factor (p = 0.008). Family history, breech presentation and swaddling were found to be the three significant risk factors related to the development of DDH. Family history, swaddling and oligohydramnios were found to be the three significant risk factors correlated with a higher rate of unstable/decentred hip(s) (Graf types D/III/IV) in patients with DDH. Conclusion The risk of DDH significantly increases in infants who have more than one risk factor for DDH. Positive family history and postnatal traditional swaddling are the two main factors both in the aetiology of DDH and in development of a more severe hip dysplasia in patients with DDH. Besides, breech presentation increases the risk of development of DDH and oligohydramnios leads to development of a more severe hip dysplasia in patients with DDH. By introducing these four variables as ‘absolute risk factors for DDH’ to the selective newborn hip screening programmes, the sensitivity and specificity of these programmes may be optimized and the risk of delayed diagnosis may be lessened. Level of Evidence Level III prognostic study

Developmental Dysplasia of the Hip: Management of Graf IIa Dysplastic Hip

“…Kosar et al [22] reported that 5.6% of type IIa hips worsen sonographically at follow-up. Central nervous system anomalies, instability, and unilateral type IIa hips were predictors of worsening in their series [4]. This transition was more likely to occur in type IIa(−) patients according to the initial α angle measurements.…”

“…Although, the influence of various causative factors on the occurrence of DDH has widely been accepted, it is still not possible to put precisely one or more of these factors forward as the main cause(s) of DDH due to heterogeneity of the patient data and methodologies in different studies. Besides, to our knowledge, the correlation between the risk factors and the ultrasonographic types of hip pathology in patients [4]. Therefore, identifying the newborn infants with a higher risk of persistence or worsening of dysplasia is an important issue.…”

“…DDH has been associated with multiple risk factors such as breech presentation, female sex, positive family history, Open Journal of Pediatrics first born baby, oligohydramnios and associated postural deformities such as torticollis and club foot [3]. Studies have shown that the risk of developing DDH is two-times higher in infants with at least one risk factor, compared with infants with no risk factors [4]. Genetically inherited abnormal hip development and/or joint laxity has commonly been considered as one of the main causes of DDH.…”

Developmental Dysplasia of the Hip: A Review of Etiopathogenesis, Risk Factors, and Genetic Aspects

“…Table 1. presents these risk factors (genetic, epigenetic, mechanical and other) that include a number of areas that are not statistically significant but may be of clinical importance nevertheless [22]. Table 1.…”

“…There is a significant risk of DDH due to the high strain on lower extremities posed by the breech presentation [27], although breech babies are more likely to experience spontaneous resolution [22,28].…”