Assessment of Diagnostic Value of Single View Dynamic Technique in Diagnosis of Developmental Dysplasia of Hip: A Comparison with Static and Dynamic Ultrasond Techniques

   Background: Developmental dysplasia of hip (DDH) is a common childhood disorder, and ultrasonography examination is routinely used for screening purposes. In this study, we aimed to evaluate a modified combined static and dynamic  ultrasound technique for the detection of DDH and to compare with the results of static and dynamic ultrasound techniques.    Methods:In this cross-sectional study, during 2013- 2015, 300 high-risk infants were evaluated by ultrasound for DDH. Both hips were examined with three techniques: static, dynamic and single view static and dynamic technique. Statistical analysis was performed using SPSS version 11.5. Results:Patients aged 9 days to 83 weeks. 75% of the patients were 1 to 3 months old. Among 600 hip joints, about 5% were immature in static sonography and almost all of them were unstable in dynamic techniques. 0.3% of morphologically normal hips were unstable in dynamic sonography and 9% of unstable hips had normal morphology. The mean β angle differences in coronal view before and after stress maneuver was 14.43±5.47° in unstable hips. Single view static and dynamic technique revealed that all cases with acetabular dysplasia, instability and dislocation, except two dislocations, were detected by dynamic transverse view. For two cases, Ortolani maneuver showed femoral head reversibility in dislocated hips. Using single view static and dynamic technique was indicative and applicable for detection of more than 99% of cases. Conclusion:Single view static and dynamic technique not only is a fast and easy technique, but also it is of high diagnostic value in assessment of DDH.