HIPA sonographic study of perinatal hip development: from 34 weeks of gestation to 6 weeks of ageStiegler, Helmara; Hafner, Erichb; Schuchter, Katharinab; Engel, Alfreda; Graf, ReinhardcAuthor Information Departments of aOrthopaedic Surgery bObstetrics and Gynecology, Danube Hospital, Vienna cDepartment of Orthopaedic Surgery, General and Orthopaedic Hospital Stolzalpe, Stolzalpe, Austria Correspondence and requests for reprints to Dr Helmar Stiegler, Donauspital, SMZO, Department of Orthopaedic Surgery, Langobardenstrasse 122, A-1220 Vienna, Austria Tel: +43 1 28802 3502; fax: +43 1 28802 3580; e-mail: Helmar.Stiegler@SMZ.magwien.gv.at Journal of Pediatric Orthopaedics B: November 2003 - Volume 12 - Issue 6 - p 365-368 Buy Abstract A sonographic study of perinatal hip development was performed by consecutive measurement of Graf's α and β angles in fetal and newborn hips. The study group consisted of infants with sonographically normal hip findings at birth. Forty fetuses were examined by fetal hip sonography at 34, 36 and 38 weeks of gestation. Postnatally, hip sonography was performed in the first and sixth week of age. Maturation curves of the bony (α-angle) and cartilaginous (β-angle) acetabular roof from 34 weeks of gestation to 6 weeks of age were established. Prenatally, the mean α-angles were above the level that corresponds to a mature hip joint. A significantly higher value of the mean α-angles was found after birth. The mean β-angles of the fetuses did not differ from those of the newborns. Our results revealed that the fetal hip joint is sonographically mature at 34 weeks of gestation. Further progression of hip development occurs around term. © 2003 Lippincott Williams & Wilkins, Inc.