The femoro-sacral posterior angle: an anatomical sagittal pelvic parameter usable with dome-shaped sacrum

Abstract

IntroductionThe interdependence between the pelvis and the sagittal spinal curvatures is obvious. The leading part of the pelvic sagittal anatomy in this orientation was well established by Duval-Beaupe`re thanks to the description of the angle 'Pelvic Incidence' (PI) [14]. It is the angle between the line perpendicular to the superior plate of the first sacral vertebra (S1) at its midpoint and the line connecting this point to the middle axis of the femoral heads. It is own for every individual and independent of the position of pelvis. A strict relation was described between this anatomical parameter and the sagittal tilt of the superior plate of the sacrum, and between this sacral tilt and the amount of lumbar lordosis. So the pelvic morphology modulates the sagittal spinal alignment. During and Itoi [1,7] described also these relations using an angle complementary of the incidence. As well Jackson observed this relation between the pelvic morphology, the sacral inclination and the lumbar curvature. He expressed the pelvic sagittal shape by the 'Pelvic Lordosis' (PR-S1) [8][9][10][11][12]. The measurement of these angles is easy in most of the cases. Their reliability and their reproducibility were established. Each author agrees to use as femoral axis the middle point of the line connecting the centers of the two femoral heads.However, the exact assessment of the upper plate of the sacrum (and consequently the values of the anatomical Jean LegayeThe femoro-sacral posterior angle: an anatomical sagittal pelvic parameter usable with dome-shaped sacrum Abstract The sagittal pelvic morphology modulates the individual alignment of the spine.

What is the Risk of Developing Proximal Junctional Kyphosis During Growth Friendly Treatments for Early-onset Scoliosis?

“…40,41 A recent review 42 showed that pelvic incidence had been concluded as a predictive factor for spondylolisthesis in some of the published literature. 13,15,39 It had also reported that few studies showed no significant difference between PI of normal and subjects with scoliosis.…”

Does Degenerative Lumbar Spine Disease Influence Femoroacetabular Flexion in Patients Undergoing Total Hip Arthroplasty?

“…Third, we did not image the entire spine; however, we found strong correlations using lumbar images alone. Fourth, the accuracy of measuring sacral slope angles is dependent on the radiographic definition of the anterior part of the sacrum [27]. We did not evaluate the accuracy of methods for measuring pelvic, lumbar, and femoral angles.…”

“…We did not evaluate the accuracy of methods for measuring pelvic, lumbar, and femoral angles. The accuracy of the measurements is disputed in the literature, since accuracy is dependent on the ability to identify landmarks in the presence of degenerative diseases of the spine [18,27]. However, excellent intra-and interobserver reliability for measuring sacral slope and lumbar lordosis angles on lateral radiographs has been reported [9].…”

The intrinsic shape of the human lumbar spine in the supine, standing and sitting postures: characterization using an active shape model

“…In the sagittal plane the curvature is dictated by the wedged shape of the vertebral bodies and intervertebral discs (Masharawi et al. 2008), the pelvic incidence (defined as the inclination of the sacral end‐plate with respect to a line joining the midpoint of the end‐plate to the axis of the hip joints) (Legaye, 2007), and the orientation of the pelvis about the hip joints (Day et al. 1984).…”