Finite element analysis of the pelvis including gait muscle forces: an investigation into the effect of rami fractures on load transmission

Pierre-Louis Ricci,Torsten Gerich,Stefan Maas,Jens Kelm

doi:10.1186/s40634-018-0151-7

Abstract

BackgroundThe objective of the study is to investigate the load transmission within the pelvic ring under physiological loading during gait and to correlate these results with clinical findings. In a second approach, we analysed how load distribution is altered by fractures of the anterior pelvic ring.MethodsMuscle forces and joint reaction forces are calculated by inverse dynamics and implemented in a finite element pelvis model including the joints.ResultsWith the intact configuration and according to the moment of the gait, left and right superior and inferior rami show the highest stresses of the model, corresponding to the typical location of an anterior pelvic ring fracture. A superior ramus fracture induces larger stresses to the lower ramus and a slight increase of stresses on the posterior structures. A total disruption of anterior rami redirects the loads to the back of the pelvis and introduces significantly higher stresses on the posterior structures.ConclusionsThis investigation enhances the understanding of the biomechanics of the pelvis and highlights the important role of the rami in load carrying and in maintaining integrity of the pelvic ring.

Highlights

The objective of the study is to investigate the load transmission within the pelvic ring under physiological loading during gait and to correlate these results with clinical findings
The left and right ilium and the sacrum are linked at the level of the pubic symphysis anteriorly and by two sacroiliac joints posteriorly (Netter 2007)
12 0,42 forces applied to the pelvic ring originating from muscles, hip joints and the lumbosacral joint were calculated according to the gait of a healthy person (62 kg, 173 cm)

Summary

Introduction

The objective of the study is to investigate the load transmission within the pelvic ring under physiological loading during gait and to correlate these results with clinical findings. The left and right ilium and the sacrum are linked at the level of the pubic symphysis anteriorly and by two sacroiliac joints posteriorly (Netter 2007). This pelvic ring, reinforced by muscles and ligaments (Schatzker & Tile 2005), enables load transfer from the lumbar spine to the lower extremities. These loads are higher in the dorsal aspect of the pelvis compared to the anterior part. The anterior structures are more filigrane and prone to fracture. We are mainly confronted with osteoporotic insufficiency fractures of the anterior or/and posterior

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