Subject-specific bone mechanical properties: is there an alternative to X-rays modalities?

David Mitton (1) , Charlène Delimoge (1) , Jean-Gabriel Minonzio (2) , Maryline Talmant (2) , Pascal Laugier (2) , Karine Bruyère-Garnier (1)

1 LBMC UMR T9406 - Laboratoire de Biomécanique et Mécanique des Chocs
2 LIP - Laboratoire d'Imagerie Paramétrique

To build subject-specific models, non-invasive techniques applicable in vivo should be developed. To give an example this study focuses on the thorax. Thoracic injuries are one of the major causes for fatalities and injuries in car crashes. In order to improve users' safety a better knowledge of the ribcage biomechanics is requested. This knowledge allows numerical models of the thorax to be built. Up to now such models represent standard individuals. However there is a need for improving the protection of the entire population of car users. Thus specific thorax models should be developed (e.g. for children at various ages and for adult taking into account the ageing effect). For health applications such as scoliosis correction using brace, patient-specific models are requested to improve treatment outcome. In both cases (safety of car users and in silico medicine for scoliosis), the geometry of the ribcage can be obtained from medical imaging and in particular using a low dose imaging technique. One scientific bottleneck is related to the mechanical properties of the bone. How the apparent mechanical properties of the ribs can be measured non-invasively? Today quantitative computed-tomography is the only clinical modality that allows rib cage density measurement to derive rib apparent elasticity. This approach is based on the hypothesis that the relationships between density assessed using quantitative computed tomography and elasticity (as previously obtained on vertebral cancellous bone6 or femoral cortical bone7) can be also found on the ribs. However the main drawback is the radiation dose of this imaging modality. To overcome this limit, ultrasound techniques could be an interesting alternative. Ultrasound axial transmission was developed to assess in vivo health status of long bones (radius, tibia) at peripheral skeletal sites8 and could be applied to the ribs that look like a long bone and are close to the skin. Before considering in vivo application on the ribs, the goal of this study was to assess in vitro relationships between ultrasonic measurements and apparent elastic properties of ribs.

Domaines: Bio-informatique [q-bio.QM]; Bio-Informatique, Biologie Systémique [q-bio.QM]

David Mitton, Charlène Delimoge, Jean-Gabriel Minonzio, Maryline Talmant, Pascal Laugier, et al.. Subject-specific bone mechanical properties: is there an alternative to X-rays modalities?. Virtual Physiological Human 2012, Sep 2012, London, United Kingdom. ⟨hal-00841073⟩