Associated risk factors in children who had late presentation of developmental dysplasia of the hip

J Child Orthop. 2007 Sep;1(3):205-10. doi: 10.1007/s11832-007-0041-5. Epub 2007 Sep 6.

Abstract

Purpose: The purpose of this study was to assess the role of clinical examination, associated risk factors and plain radiograph of the pelvis in children who had late presentation of DDH.

Methods: We report on a 7-year prospective study, in children who had late presentation of developmental dysplasia of the hip (DDH). For this purpose, 740 hips in 370 referred children, age range 3-7 months (mean 3.44 months) were clinically and radiologically assessed, and the associated risk factors recorded.

Results: Female sex, first born, positive family history and breech presentation were confirmed as risk factors for DDH. Significant findings were an increased risk for vaginal delivery over caesarean section for breech presentation (P = 0.002). There was an increased risk for caesarean section in the absence of breech presentation. Multiple births and preterm births had a reduced risk. For breech presentation, the risk of DDH was estimated to be at least 1.6% for girls and 3.4% for boys; a combination of factors increased the risk. Limitation of abduction (43.2%) and asymmetry of the groin skin folds (72.7%) were found to be the two most common clinical findings associated with DDH. Bilateral acetabular dysplasia is more common than unilateral dysplasia. Foot deformities were rarely encountered in children with acetabular dysplasia.

Conclusions: The percentage of first-born babies who had DDH is lower than reported in the literature (34%), but still shows significant risk. We did find that bilateral acetabular dysplasia is more common than unilateral dysplasia. Torticollis and foot deformities are rarely found to be associated with DDH. All these findings needs further evaluation in children who had surgical treatment for DDH, to see if they are different from dysplastic groups. Limitation of abduction is an important clinical finding, but is not always associated with DDH. Asymmetry of the skin folds in the groin were found to be an important clinical finding associated with DDH for all age groups. As clinical examination depends on many factors, and most DDH cases are of the dysplastic type, it is mandatory to depend on further diagnostic tools for confirmation of DDH.