A meta-analysis of common risk factors associated with the diagnosis of developmental dysplasia of the hip in newborns.

BACKGROUND: Although there is no clear consensus about the process of screening for developmental dysplasia of the hip (DDH), there are six common risk factors associated with DDH in patients less than 6 months of age (breech presentation, sex, family history, first-born, side of hip, and mode of delivery).

METHODS: A meta-analysis of published studies was conducted to identify the relative risk ratio of the six commonly known risk factors. A total of 31 primary studies consisting of 20,196 DDH patients met the following inclusion criteria: (1) contained empirical data on at least one common risk factor, (2) were peer-reviewed from an English language scientific journal, (3) included patients less or equal to 6 months of age, and (4) identified method of diagnosis (e.g., ultrasound, radiographs or clinical examination).

RESULTS: Fixed effect and random effects models with 95% confidence intervals were calculated for each of the six risk factors. Reported relative risk ratio (RR) for each factor in newborns was: breech presentation 3.75 (95% CI: 2.25-6.24), females 2.54 (95% CI: 2.11-3.05), left hip side 1.54 (95% CI: 1.25-1.90), first born 1.44 (95% CI: 1.12-1.86), and family history 1.39 (95% CI: 1.23-1.57). A non-significant RR value of 1.22 (95% CI: 0.46-3.23) was found for mode of delivery.

CONCLUSION: Results suggest that ultrasound and radiology screening methods be used to confirm DDH in newborns that present with one or a combination of the following common risk factors: breech presentation, female, left hip affected, first born and family history of DDH.