Objective: To evaluate the knowledge on developmental dysplasia of the hip (DDH) by professionals involved in its diagnosis.Methods: This is a cross-sectional study using questionnaires to assess the knowledge about DDH. Orthopedic surgeons and pediatricians, residents and medical students from a tertiary teaching hospital were included in the study.Results: We evaluated 142 medical students, eight orthopedic residents, ten pediatric residents, seven pediatricians, and nine orthopedic surgeons; 50% declared not having examined any DDH case in the last year and only three had diagnosed more than 10 cases during their career. Regarding self-assessed knowledge (0-10), the average score was 4.25 [n=186; SD=2.43]. Nineteen percent of the participants ignored semiological tests and 26.1% of pediatricians (specialists and residents), were unaware of how to perform them. The most acknowledged and neglected risk factor was pelvic presentation (68%) and CMT (9.3%), respectively. None of the participants were able to identify all the risk factors. The average number of risk factors identified was two (n=186; SD=1.58). Forty seven point three percent of the participants failed to recognize the time of birth as the ideal moment for diagnosis; 17% reported it was after the first month. Regarding neglected severe DDH, 45.3% failed to recognize its natural history.Conclusion: Knowledge on DDH among health professionals who are involved in screening is flawed. Level of Evidence IV, Developing a Decision Model.

Considering appropriateness for age, correctness of installation (in the back seat in the correct orientation), and frequency of use, only 50.85% (149/293) of the children were reported as always protected with a CRS. Children between 1 and 4 years were more likely to always use a CRS in this Brazilian survey. We were also able to identify an important gap in the knowledge about airbags among parents. Further efforts are needed to correct those distortions.