June 24, 2023

The Japan Society of Mechanical Engineers
Hokkaido Branch“Biomechanics Research Meeting”
41st Seminar(Cosponsored by Hokkaido branch, The Japan Society of Mechanical Engineers and The
176th“Biomechanics” technical sessions, Japanese Society for Medical and BiologicalEngineering)

Chairman: Toshiro Ohashi
The Biomechanics Research Meeting will sponsor a presentation by distinguished scientists,Prof. Ashvin Thambyah from University of Auckland, New Zealand and Prof. Peter Lee,
University of Melbourne, Australia. Faculty members, graduate students, and undergraduates
are encouraged to participate in the seminar.
Date&Time: Thursday, July 6, 2023, 10:30-12:00
Place: Room L252, Faculty of Engineering, Hokkaido University【10:30 - 11:15】
Speaker: Prof. Ashvin Thambyah, Department of Chemical and Materials Engineering,
University of Auckland, New Zealand
Title: Mechanical Factors for Pre-Osteoarthritis
Abstract:
The aim of our research has been to understand, from mechanical and structural viewpoints,
the initial degenerative processes in the joint tissues, related to the initiation and progressionof osteoarthritis (OA). To this end we have established an animal model to study early or
pre-OA joint tissue degeneration. Our work is framed around addressing three researchquestions. Does the initiation of OA begin with changes in (1) cartilage or bone, (2)proteoglycans or collagen, (3) cells or tissue? Our studies have shown that in the early
degenerative state of the joint tissues, where macro-scale mechanical properties are yet to beaffected, micro-to-nano scale destructuring of the collagen network had already taken place.
These collagen network changes were found to be strongly associated with bone cement-line
microstructural changes. The changes in the bone-cement line were indicated by the presenceof ‘bone spicules’, which were remarkably similar to ‘cutting cones’ seen in primary boneformation during fracture healing. This similarity provided a mechanical rationale for the bonechanges in the joint system in early tissue degeneration. The collagen network and bone
structural changes were also associated with significant changes in an ensemble of proteins.
These included certain SLRPs, angiogenic proteins and TGF-β. High resolution imaging of thechondrons, in tissues exhibiting early cartilage degeneration, further revealed fibrillar-structurechanges in the territorial matrix and pericellular capsule, showing a morphology likened tothickened baskets of fibrillar encapsulation of the chondrocytes. The significance of the above
descriptions, of the multi-length scale tissue and cell mechanics in the joint, are discussed witha view on how OA is initiated by mechanical factors.
【11:15 - 12:00】
Speaker: Prof. Peter Vee Sin Lee, Department of Biomedical Engineering, University ofMelbourne, Australia
Title: Safer Personalised Medical Implants
Abstract:Advances in computer-aided engineering, patient-specific computer models, and additivemanufacturing transform patients' treatment through personalised solutions. Manufacturers
and hospitals are now trialling 'bespoking' as the new standard of care in orthopaedics andmaxillofacial surgery. However, there are significant challenges to facilitating personalised
medical implant commercialisation and widespread use. Regulatory frameworks for
personalised implants are in their early stages. Current standards for testing off-the-shelfdevices are not directly transferrable to devices designed for individual patients. Instead,future test standards could be based on information from the patient's anatomy and evenlifestyle. There is no well-defined framework or methodology to support the use and increase
personalised implants' success rate. The fabrication of the implant is only the first step.
Successful treatment requires a comprehensive approach to optimise the use of thepersonalised medical device. This presentation will focus on the development of a seamless
framework based on the Measure-Model-Manufacture-Manage (4M) for point-of-caremanufacturing. Comprehensive biomechanical measurements will be used to build
patient-specific biomechanical models to represent the underlying physiology of the humanbody. The models will be used to analyse scenarios that are too expensive or infeasible toperform on patients directly (e.g. loading an implant to failure in the human body). The aim in
the measure-model stage is to optimise implant/device design that considers all
the biomechanical information before manufacturing using 3D printing. Finally, themeasure-model-manufacture becomes a reinforcing loop that improves patient management
and outcome. The presentation will also discuss our experience and benefits, from a
researcher's perspective, working closely with physicians, industry, and government leaders inpushing the frontiers of personalised medical implants.

Contact:Toshiro Ohashi
Division of Mechanical and Aerospace Engineering, Faculty of Engineering, Hokkaido
UniversityTel&Fax: 011-706-6424, Email: ohashi@eng.hokudai.ac.jp