NEONATAL HIP - FROM ANATOMY TO COST-EFFECTIVE SONOGRAPHY

Therapeutic success in treating congenital dysplasia of the hip is ass ociated with early diagnosis. but the specific neonatal anatomy makes screening difficult. The purpose of this study was to determine whethe r this specific neonatal anatomy is taken into account by current ultr asound (US) techniques. Anatomic studies were performed on 22 hips, US examinations on 7750 neonatal hips; 2370 untreated hips were reexamin ed at 1 month by US and at 3 months by X-ray. The transformation of th e neonatal cartilaginous acetabulum into an osseous cavity is dependen t on harmonious metaphyseal growth and a properly seated femoral head. Defects in the acetabular roof, together with displacement of the fem oral head, cause an abnormal anatomical relationship which leads to fu rther deformities. The described sonographic techniques give only part ial information on these specific abnormalities. The sonographic monop lanar methods as used in Graf's technique. which relies largely on ace tabular development, lead to difficulties in assessing posterior cover age of the femoral head and difficulties in assessing alignment of the metaphyseal weight-bearing surface with the femoral head. Combining G raf's morphological analysis with Novick's dynamic technique enables o ne to more accurately define the relationship of the femoral head and the acetabulum and increases the reliability and predictive value of t he examination, while reducing the number of doubtful cases. This make s screening cost effective.