Low incidence of early developmental dysplasia of the hip in universal ultrasonographic screening of newborns: analysis and evaluation of risk factors

Abstract

Purpose: Different timing and approaches to screening for developmental dysplasia of the hip (DDH) are used in the orthopaedic community. Thus ultrasonographic screening programs and reports based on clinical examinations produced differing incidence rates of DDH. Furthermore different risk factors and a change of incidence of DDH in the last decades were discussed. The purpose of this study was the evaluation of incidence and risk factors of the very early DDH in a modern cohort based on a universal ultrasound screening program.

Methods: We analysed the results of the screening program performed at our institution: 5,356 consecutive hips of newborns were screened ultrasonographically and clinically according to the system published by R. Graf within the first two postnatal weeks [1]. A set of risk factors was analysed by univariate and multiple linear regression models.

Results: Sonographic signs of developmental dysplasia of the hip were found in 0.24 % of the newborns. A significant negative influence of the risk factors birth weight, family history of DDH and female gender on the α-angle was found. Early or pre-term delivery showed a protective potential for DDH.

Conclusions: Our data show a very low incidence of DDH in the first two postnatal weeks. Despite the significance of the risk factors analysed, it has to be considered that these factors only showed low impact on the risk of early DDH. In conclusion we favour universal ultrasound screening for DDH at the age of six to eight weeks.

Keywords: DDH; Hip sonography; Incidence of DDH in newborns; Pediatric orthopaedics.