Clayton Adam’s background was in Mechanical Engineering, and he was interested in the application of computational and experimental mechanics approaches to the study of structure and function in biological tissues. Biological materials are intricately hierarchically structured from the nano-scale to the whole organ level, and his work involved image-based modelling and experimental characterization of structural biological materials from the macro (whole organ) scale to the micro (extracellular matrix and cellular) scale. He extensively employed nonlinear computational mechanics-based approaches to study disorders and treatment of musculoskeletal tissues, however he also had a strong interest in experimental imaging and sensing modalities for the generation of patient-specific model geometry, and in the close integration of experiments with models. Accordingly the research group he led usually performed their own biomechanical experiments which were closely integrated with the computational modelling work being performed.
Clayton’s central research theme in his last decade was studying the human spine, with a focus on paediatric spinal deformities such as scoliosis. Mechanics plays a key role in the progression of spinal deformities, as well as in the response of the vertebrae and intervertebral discs of the spine to surgically placed implants. Spine biomechanics is therefore a topic of significant interest in a field where post-operative complication rates are currently around 20%. In the early 2000s Clayton initiated the development of a patient-specific computational model of the thoracolumbar spine and ribcage which continues to be further developed by his colleagues today to investigate the biomechanical response of the scoliotic spine. He also supervised Masters and Doctoral projects on the biomechanics of ‘fusionless’ (motion sparing) surgical implants for scoliosis correction in the growing spine, the development of a large animal (ovine) model for spine tissue engineering using synthetic scaffolds, and sequential high resolution magnetic resonance (MR) imaging of scoliotic anatomy and curve progression in a cohort of adolescent scoliosis patients and healthy participants at the collaborating Spine Deformity Clinic in Brisbane, Australia. The Sequential MRI study remains to be the only of its kind to document and analyse scoliosis growth and progression worldwide.
In the area of bone mechanics, Clayton performed studies of vertebral cancellous bone mechanics and microarchitecture in both elderly osteoporosis patients (to study how changes in cancellous bone microarchitecture with osteoporosis adversely affect overall vertebral fracture resistance) and adolescent idiopathic scoliosis patients (to investigate whether bone tissue is under-mineralised in adolescent scoliosis patients). These studies combined the techniques of nanoindentation, atomic force microscopy, and finite element modelling to develop elasto-plastic constitutive models for modelling and simulation of trabecular bone tissue at the nanoscale in both health and disease.
Professor Clayton Adam’s most recent major project prior to his passing was a multi-scale investigation of the mechanics of the intervertebral disc (IVD), funded by a prestigious Marie Curie FP7 Fellowship for experienced researchers (DiscSim 274964) and was undertaken in Paris, France at Arts et Metiers ParisTech between 2012-15. The IVD is the largest avascular structure in the human body, and in this project Clayton developed novel (serial milling and polarised light microscopy) imaging techniques to study IVD microstructure across entire discs, then used image-based computational modelling to elucidate how disc microstructure (in particular the collagen and elastin networks of the annulus fibrosus) confers spinal joint function. On completion of the EU funding for this project in 2014, project funding was extended by the Institut de Biomecanique Humaine Georges Charpak in Paris, France, and the development of the multiscale IVD models continued until his death in March 2018. The 3D polarised light imaging techniques which Clayton developed during this project have significant potential for imaging large regions of mixed soft (unmineralised) and hard (mineralised) biological tissue at a resolution of several microns, and therefore the imaging system fills a gap between micro-computed tomography (which is excellent for mineralised tissues but provides poor contrast in soft tissues) and magnetic resonance imaging (which is limited to ~100 microns voxel resolution). Furthermore, the polarised light imaging modality provides quantitative information on collagen alignment. Three dimensional maps of the tissue microarchitecture of the IVD thus obtained can be used in the development of specimen specific finite element models of the disc, and in his latest published works he used these models to evaluate the influence of the interlamellar interface on overall disc compression mechanics.
Clayton Adam led the research activities of the QUT Paediatric Spine Research Group in Brisbane, Australia between 2002 and 2017, and therefore had extensive experience in research management and in particular, liaison between researchers and clinicians to achieve clinically relevant research outputs. These skills are reflected in his extensive publication record which includes both basic biomechanics as well as applied clinical publications in the area of adolescent spine deformity and in particular, scoliosis.
Student Supervision – Ten students (Masters by Research) and ten students (PhD)
Vale Clayton James Adam, a first class colleague, friend and mentor to many, who will be forever missed by his family and all who knew him. Please consider donating to the Clayton Adam Florence Wilson Award for Spinal Research at QUT, created to honour Clayton’s stellar contribution to scientific innovation in spine research, scoliosis and bone microdamage, as well as his impact on the academic community in general. Our vision is to ensure Clayton’s work continues, by growing the fund to a level where it can support excellent students through higher degree scholarships and travel bursaries.
Make a single or regular tax-deductible donation towards this award fund – donate to ‘Clayton Adam Florence Wilson Award’
With your support we can reduce suffering and create a better future for children, adolescents and adults with spine disorders and at the same time create a fitting tribute for an outstanding Australian, Clayton James Adam (20.5.72 – 6.3.18).