Reduced effectiveness of the selective hip dysplasia screening programme over time

INTRODUCTION: Selective ultrasound screening for developmental dysplasia of the hip (DDH) was implemented in the North Denmark Region, Denmark in 2010 but has yet to be evaluated. This study aimed to evaluate selective hip screening in the North Denmark Region from 2010 to 2021, focusing on referral rates, the incidence of DDH and referral causes. METHODS: We retrospectively identified 3,812 infants (2,091 females) who were referred during a 12-year period for hip ultrasound at Aalborg University Hospital in Denmark. DDH was defined as an ultrasound classification of Graf type IIb or worse. Referral rates and the incidence of DDH and their development over the study period were examined. RESULTS: During the study period, there was a steadily increasing referral rate, with the annual referral rate doubling from 200 (3.3%) in 2010 to 402 (6.8%) in 2021, whereas the incidence rate increased only minimally from 0.15% to 0.22%. The most common referral causes were breech position (41.4%) and positive clinical exam (27.8%). CONCLUSIONS: During the study period, the annual referral rate nearly doubled without a corresponding increase in DDH incidence, suggesting that the screening programme has become less efficient over time. This might explain the relatively low incidence of DDH in the North Denmark Region compared with national and international studies. FUNDING: The authors received no financial support for the research, authorship and/or publication of this article. TRIAL REGISTRATION: This study was registered in the North Denmark Regional internal Project Register as IDF2022-187.