Front cover image for Rôle biomécanique de la cage thoracique dans le traitement de la scoliose par orthèse

Rôle biomécanique de la cage thoracique dans le traitement de la scoliose par orthèse

This Ph. D. thesis addresses the overall hypothesis that biomechanical relationships and coupling mechanisms exist between scoliotic trunk anatomical structures which may explain incomplete and unexpected results obtained by orthotic and surgical treatments. A biomechanical finite element model of the scoliotic spine and rib cage was developed in order to investigate this hypothesis. The input geometry to the model was obtained from a personalized geometric model built using an hybrid method which combines multi-view radiographic 3-D reconstructions of the spine and rib cage of given scoliotic patients with serial CT-scan 3-D reconstructions of typical human vertebrae. The biomechanical model was then used to simulate orthotic and surgical loads in order to address the hypothesis of this thesis. In parallel, a clinical retrospective study was conducted on a cohort of 36 adolescent idiopathic subjects treated by Boston brace in order to confirm biomechanical studies and verify the existence of relationships and coupled corrections between the spine and rib cage initiated by brace wear. The retrospective clinical study done on a cohort of 36 adolescent scoliotic subjects showed that the Boston brace treatment produces complex trunk motions. Rib cage offsets were statistically correlated to corresponding apical spine offsets (r = 0.88 in frontal plane and r = 0.65 in sagittal plane). However, rib hump rotation and axial rotation at apical thoracic level were not correlated. Substantial forward displacements of the thorax were observed and were found to be coupled with lateral exteriorly oriented displacements of the spine (r = $-$0.41)
Thesis, Dissertation, French, [1996]
National Library of Canada = Bibliothèque nationale du Canada, Ottawa, [1996]
École polytechnique de Montréal