Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux

Type de document

CHAPITRE D'OUVRAGE (CO)

Langue

anglais

Auteur

SKALLI ; MITTON ; ROUCH ; DUBOUSSET

Résumé / Abstract

Among the essential biomechanical functions of the spine are those of maintaining a stable posture and of allowing movements during walking, activities of daily living or when practicing a sport. This chapter addresses geometric and biomechanical modelling for both basic knowledge and clinical issues related to spine disorders, their prevention and management. Geometric modelling of the skeleton from biplanar X-rays allows quantitative 3D analysis in the erect position. This load bearing posture is characterized by maintaining head above the pelvis. Compensation strategies take place to maintain that constraint, such as pelvic retroversion or cervical lordosis. Progressive understanding of these mechanisms should have clinical impact. Large-scale analysis also progressively provides new biomarkers, such as a severity index for early detection of a progressive scoliosis. Biomechanical modelling takes into account not only the geometry but also the mechanical characteristics of each material in each region of the model. Dedicated software then allows to simulate different types of forces exerted on this structure and to compute the mechanical response, in terms of displacements, local strain and global deformation, and mechanical stresses which, if they are excessive, cause the damage to this system. Such models can drastically reduce the design time of an implant, by sensitivity studies that allow understanding the impact of implants design parameters. Subject-specific modelling opens up promising prospects for helping to plan treatments that consider the specificities of each individual.The spine is an essential component of the musculoskeletal system. A gradual evolution has emerged over the last 30 years, from a very local view of the area of direct interest (functional unit or extended vertebral segment) to the global vision considering the longitudinal skeleton as a whole submitted to gravity loads and muscular forces. Advances in barycentremetry analysis, in personalized muscle modelling and in muscular control modelling, should lead to a better understanding of the interaction between postural and/or muscular troubles and spine disorders.Thus, modelling provides valuable insights for a better, earlier and more accurate diagnosis, and for a quantitative assessment of the effect of treatments. The better understanding of the mechanisms of degradation with individual specificities should be a source of major progress and breakthrough innovations in prevention and therapeutic management.

Editeur

Springer International Publishing