Speaker
Hanna Isaksson
(Lund University)
Description
The musculoskeletal system enables locomotion of the human body, by force transfer through bone, cartilage, tendons and ligaments. Each tissue has a unique composition and hierarchical structure that result in an optimized mechanical function. Bone provides mechanical stability and support, while softer tissues such as tendons have a more damping function. With an aging population, the number of patients with musculoskeletal diseases, including fragile bones (osteoporosis), degenerated cartilage in the joints (osteoarthritis), and tendon pain (tendinopathy) is increasing.
We use scattering methods as one tool to understand how the quality of musculoskeletal tissues are affected by age and disease. In combination with other high-resolution imaging methods, we unravel how composition, structure and orientation in these tissues are affected on the macro-, micro- and nano-scales. By studying the tissues in-situ, under concurrent mechanical loading, we can link the alteration in nanostructure to mechanical competence of the tissues, and thereby the anatomical function.
As an example, we have combined experimental tensile testing inside SAXS and WAXS setups together with cameras on the surface and tomographic imaging, to study deformation simultaneous at multiple length scales in compact bone (Figure 1). We found that the orientation of the microstructure relative to the tensile loading influenced the strain magnitude on all length scales. Strains in the collagen fibers (measured by SAXS) were 2-3 times higher than the strains in the mineral crystals (measured by WAXS) for samples with microstructure oriented parallel to the loading. This will be extended to answer how the mineral crystal size and collagen fibre orientation and their response to load is altered in patients that are highly prone to bone fractures, e.g. osteoporosis.
Alterations in tissue quality can be addressed by combining the knowledge from advanced structural, compositional and mechanical analyses. A better understanding of tissue quality help predicting the functional integrity of the tissue and supports the development of better diagnostics methods and treatment options.
![enter image description here][1]
[1]: https://indico.esss.lu.se/event/874/picture/3.png
Figure 1. Setup of experimental study to unravel the nanoscale behaviour in bone in different microstructural directions in situ during mechanical loading (Gustafsson et al., 2018).
Primary author
Hanna Isaksson
(Lund University)
