Deterioration of a primarily normal hip without developmental disorders

Abstract

Ultrasonography of the hip joint in babies has been established as a standard method for examination and classification of dysplasia of the hip as well as for monitoring of the treatment. It has been believed until now that, in a hip once classified as normal, the development of the hip joint will continue to be normal if there is no developmental disorder or other skeletal dysplasia. We report the case of a patient who clearly showed normal sonographic and radiological findings initially but who experienced significant developmental dysplasia of the hip (DDH) within the first two years of life. Even more interesting aspects are the treatment of the contralateral side for severe hip dysplasia: with both hips in optimally centered position the initially affected hip had been operated successfully while the initially normal hip deteriorated. Therefore we consider this as one of the rare examples of “endogenous hip dysplasia” which underlines the occurence of DDH and which does not necessarily mean inadequate primary diagnosis or inadequate reading of ultrasonographic or radiographic images.