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Updated: Aug 30, 2026
High Frequency Ultrasound for the Analysis of Fetal and Placental Development In Vivo
Published on: November 8, 2018
A sonographic study of perinatal hip development: from 34 weeks of gestation to 6 weeks of age
Helmar Stiegler1, Erich Hafner, Katharina Schuchter
1Departments of Orthopaedic Surgery, Danube Hospital, Vienna, Austria. Helmar.Stiegler@SMZ.magwien.gv.at
Insights
Fetal hip joints are sonographically mature by 34 weeks gestation, with further development occurring around birth. This study tracked bony (alpha) and cartilaginous (beta) angles in developing hips.
Area of Science:
- Perinatal medicine
- Orthopedics
- Developmental biology
Background:
- Hip dysplasia is a common concern in newborns.
- Early detection and monitoring of hip development are crucial for timely intervention.
- Sonography provides a non-invasive method to assess hip joint maturation.
Purpose of the Study:
- To establish maturation curves for fetal and newborn hip joints using Graf's alpha and beta angles.
- To determine the sonographic maturity of the fetal hip joint.
- To investigate the progression of hip development from 34 weeks gestation to 6 weeks of age.
Main Methods:
- Consecutive sonographic measurement of Graf's alpha and beta angles in 40 fetuses and infants.
- Fetal hip sonography performed at 34, 36, and 38 weeks gestation.
- Postnatal hip sonography conducted at 1 and 6 weeks of age.
Main Results:
- Prenatal mean alpha-angles exceeded levels for a mature hip joint.
- Postnatal mean alpha-angles were significantly higher than prenatal measurements.
- Mean beta-angles showed no significant difference between fetuses and newborns.
Conclusions:
- The fetal hip joint demonstrates sonographic maturity by 34 weeks gestation.
- Significant progression in hip development, particularly the bony acetabular roof (alpha-angle), occurs around term and in early infancy.
- Sonographic assessment of hip angles provides valuable data on perinatal hip development.
Abstract:
A sonographic study of perinatal hip development was performed by consecutive measurement of Graf's alpha and beta 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 (alpha-angle) and cartilaginous (beta-angle) acetabular roof from 34 weeks of gestation to 6 weeks of age were established. Prenatally, the mean alpha-angles were above the level that corresponds to a mature hip joint. A significantly higher value of the mean alpha-angles was found after birth. The mean beta-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.
