Study of femoral torsion during prenatal growth: Interpretations associated with the effects of intrauterine pressure
Version of Record online: 3 MAY 2011
Copyright © 2011 Wiley-Liss, Inc.
American Journal of Physical Anthropology
Volume 145, Issue 3, pages 438–445, July 2011
How to Cite
Bonneau, N., Simonis, C., Seringe, R. and Tardieu, C. (2011), Study of femoral torsion during prenatal growth: Interpretations associated with the effects of intrauterine pressure. Am. J. Phys. Anthropol., 145: 438–445. doi: 10.1002/ajpa.21521
- Issue online: 14 JUN 2011
- Version of Record online: 3 MAY 2011
- Manuscript Accepted: 31 JAN 2011
- Manuscript Received: 28 JUL 2010
- Olivier Gagey (Hôpital Kremlin-Bicêtre) the Société d'Anatomie de Paris
- proximal femur;
- Homo sapiens
The developing fetus is protected from external environmental influences by maternal tissues. However, these structures have a limited elasticity, such that the fetus must grow in a confined space, constraining its size at the end of pregnancy. Can these constraints modify the morphology of the fetal skeleton? The intensity of these constraints increases between 5 months and birth, making it the most appropriate period to address this question. A sample of 89 fetal femora was analyzed, and results provide evidence that during this period, the torsion of the femoral shaft (quantified by means of a new three-dimensional method) increases gradually. Two explanations were considered: this increase could signal effects of constraints induced by the intrauterine cavity, developmental patterning, or some combination of these two. Different arguments tend to support the biomechanical explanation, rather than a programming pattern formation. Indeed, the identification of the femur as a first degree lever, created by the hyperflexion of the fetal lower limbs on the pelvis, could explain the increase in femoral shaft torsion during prenatal life. A comparison with femora of infants is in accordance with this mechanical interpretation, which is possible through bone modeling/remodeling. Although genetic and epigenetic mechanisms may regulate timing of fetal development, our data suggest that at birth, the fetal skeleton also has an intrauterine mechanical history through adaptive bone plasticity. Am J Phys Anthropol, 2011. © 2011Wiley-Liss, Inc.