Advantages and disadvantages of various access routes in sonographic diagnosis of dysplasia and luxation in the infant hip.

The purpose of the study is to clarify the access route that is most suitable in sonography of the infant hip for diagnosis of luxation and dysplasia. The process of luxation gives rise to deformation of the hyaline cartilaginous preformed part as well as the osseous acetabulum. These deformations are located in the superoposterior part of the acetabulum. With a posterior exposure only the luxated head of the femur can be imaged sonographically, but the dysplastic acetabulum cannot be diagnosed. In anterior exposures the pathological changes in the superior part of the acetabulum are detected poorly or not at all. The lateral exposure can image all deformations of the acetabulum. The strictly standardized lateral sonographic exposure is hence recommended using a standardized plane of measurement.