Late diagnosis of developmental dysplasia of the hip: an analysis of risk factors.

A neonatal clinical screening program for developmental dysplasia of the hip (DDH) operates in South Australia to diagnose DDH as early as possible. However, some cases of DDH are diagnosed late (>3 months of age). The aims of this study were to identify the specific risk factors for late diagnosis by comparing early diagnosed DDH, late diagnosed DDH, and normal controls in the South Australian population. There were 1945 children with DDH born between 1988 and 2003, of which 67 cases were late diagnosis (3.4%). Maternal characteristics, pregnancy, and delivery details were analyzed, and compared with controls (early diagnosed DDH and the general population). There was a trimodal pattern of age at presentation with a gradual increase in the incidence of late diagnosed DDH over the time period in this study. Birthweight (<2500 g), birth in a rural setting, and early hospital discharge following delivery (<4 days) were significant risk factors for late diagnosed DDH. Breech presentation and delivery by caesarean section were protective for late diagnosed DDH. Risk factors for late diagnosed DDH relate to factors that influence the screening program. A rigorous population-based hip surveillance program is important for early diagnosis of DDH.