Research

Osteoporosis is a major health problem in many countries. It is defined as a skeletal disorder, characterized by compromised bone strength, predisposing to an increased risk of fracture. The aging population leads to an even higher percentage of osteoporotic patients. Osteoporosis has an enormous impact on the individual, on society and on health care systems. Current assessment of osteoporosis is mainly based on bone mass, although it is known to have limited accuracy. Therefore, it is our aim to improve the assessment of bone strength, with the goals to better identify the people at risk for fracture, and to improve quantification of treatment effects.

The assessment of structural and mechanical properties of bone is a complex task because they are subject to large individual variations. Even more so, they are affected by features on different length scales: from molecules, to cells, to tissue, to organ. Hence, in order to understand bone competence, a detailed understanding of the geometric and material properties at all hierarchical levels is needed, as well as the knowledge on how they can change during aging and disease processes such as osteoporosis.

After bone fracture, or after joint cartilage degeneration, the placement of orthopaedic implants may be needed. The longevity and functionality of implants is determined in part by peri-implant bone quality. In order to study this in more detail, we are focusing on experimental assessment of implant stability, and peri-implant bone adaptation.

key words: bone mechanical properties, bone adaptation, orthopaedic implants, implant fixation, hierarchical imaging, finite element analysis, bone loading, micro-CT, human, rat, mouse.

Non-healing bone fractures constitute a major clinical problem. It is estimated that 5-10% of all bone fractures develop into a delayed or non-union. Large bone defects, e.g. due to trauma, infection or bone tumours present another challenge to the regenerative capacity of our bones, and to the surgeon who has to treat them. In both cases, tissue engineering can be a solution and alternative to more conventional treatments. This highly multidisciplinary and interdisciplinary research field applies engineering and biological principles and methods in order to understand the relation between structure and function in (human) tissues and to develop biological replacements that can repair, maintain or improve tissue function. Tissue engineers try to regenerate tissues by establishing the appropriate patient-derived cells and environmental signals (such as biochemical and mechanical ones).

Mathematical models are an important tool in order to increase our quantitative understanding of biological processes and to come to a more predictive approach towards the development of new treatments. We want to contribute to the quantitative understanding of biological processes relevant to the regeneration and engineering of bone, by means of an integrative approach that combines experimental and computational work. A major focus is the importance of mechanical signals for osteogenesis (bone mechanobiology), either for in vitro or in vivo applications. All bone engineering related projects are embedded within Prometheus, the Leuven R&D division for skeletal tissue engineering.

Computer technology and mechatronic devices are becoming more and more essential elements in contemporary surgery. This research line investigates new computer aided design methodologies to develop personalized implants and surgical tools, often based upon medical image information. Within these design processes, biomechanical optimization of the devices is applied. Also in robot assisted surgery systems, biomechanics is expected to play an added role, e.g. when optimizing intra-operative tissue manipulation, designing surgical strategies or limiting tissue damage risks.

Several applications and devices for rehabilitation, prevention and comfort benefit from intro ducing biomechanics into the design. It support the restoration of functions that were lost due to trauma or diseases, and it optimizes systems for body support such as mattresses or seats. BMGO is actively involved in research projects on bicycle helmet design and head protection biomechanics in general, and on the design of optimized, also person-specific, mattresses and sleeping systems. Also project investigating the biomechanics of the foot-ankle complex and the biomechanics of the cervical spine fit within this research line.