Reducing bone fractures

William Weijia Lu researches degenerative bone diseases

Dr. William Weijia Lu (PhD '95, Kinesiology) has spent most of his life working to find the best treatments and solutions and to reduce the risk of bone fractures in older adults. 

“We have one heart, two kidneys –William Weijia Lu but over 200 bones,” says Lu. “I feel I have the responsibility to use my knowledge to help the elderly; in other words, to help my future self.” 

Lu's research interests include biomaterials and biomechanics, 3D bioprinting and the application of biomaterials for musculoskeletal degenerative diseases, like osteoporosis. 

Throughout his career, he has published more than 290 papers in top scientific journals with more than 10,000 citations. Though he is now retired, he continues to supervise graduate students at the University of Hong Kong and remains active at the Shenzhen Institute of Advanced Technology. 

Predicting risk fractures with AI 

This past July, Lu’s team published a paper on the distribution of ‘bone voids’ – holes or “empty spots” that are present in older bones – throughout the thoracic (upper-middle) and lumbar (lower) areas of the spine. The voids are not a complete absence of tissue, but rather a spot where the bone density is low. The bigger the void, the more likely a fracture can occur. The study shows that bone voids positively correlate with age and increase rapidly after 55 years of age. 

“We recently discovered that with the help of Artificial Intelligence (AI) software, we can detect where the highest bone density is,” says Lu. “We can examine the area where a person feels discomfort or pain and detect if there are bone voids." 

From there, Lu says they can then predict the risk factors for that bone – the likelihood of a future fracture. On patients where surgery is required, they can tell which area of the bone has the best chance of holding a plate or screw. 

A lifelong friendship 

Bob NormanIn the early '90s, Lu came to Canada from Hong Kong looking to expand his knowledge in spinal biomechanics and took on a role as a research assistant to (now Distinguished Professor Emeritus) Dr. Robert Norman, who was the Faculty’s dean at the time. 

Norman’s career included more than 35 years developing and teaching courses and conducting research in neuromuscular and occupational biomechanics and physical ergonomics. Assisted by technologists, master’s and PhD students and faculty colleagues, he contributed to the development of some of the early computer analyses of video and recorded muscle electrical activity (electromyography) during performance of work, sport and tasks of daily living.  

The software calculated the sizes of forces in muscles and on body joints and mechanical energy costs of any physical task of interest. When forces get too high, injury occurs. When mechanical cost is inefficient, fatigue sets in too early. The team used the software to assess injury risk and risk reduction interventions on the lower back and other joints during work, tasks of daily living and high-performance sport.  

Their research methods and findings have been shared in many scientific publications, reports and the teaching of several thousand students, production workers and management, high performance coaches and athletes. “William contributed a great deal to the ongoing development of this software,” says Norman. 

Lu’s lucky place 

William Weijia Lu with a groupWanting to help Lu adjust to life in a foreign country, Norman began inviting Lu over to his house for dinner with his wife and children. Eventually, Norman began inviting Lu to visit his cottage in Muskoka with his extended family. 

“Bob is so friendly; I’m very happy to have been surrounded by so many people who treated me kindly,” says Lu. “I also met my wife at Waterloo – Jackie was a grad student in accountancy, and Bob began to invite her as well. I call Waterloo my lucky place.” 

Lu and his family have since moved back to Hong Kong, but the researchers remain in touch. When Norman and his wife took a trip to China about 15 years ago, they visited Lu, Jackie and their two children, one of whom was born in Waterloo Region. Then when Lu brought his now adult children to Ontario, the two families got together again at the Normans’ cottage. 

The concept of prevention 

When Lu enrolled in the PhD program after his research assistant position with Norman, Dr. Patrick Bishop was his supervisor, with Norman on his PhD committee. 

Lu and Bishop worked on concerns of the neck and back, specifically direct impact and injuries associated with football and hockey in the National Hockey League (NHL).  

“We tested how much stress applied to the neck would lead to a fracture, in sports and also in the event of a car crash,” says Lu. “We began to design football helmets that could protect the neck, and it was then that I learned the concept of prevention, and how much more important is it to prevent than to treat.” 

During the years Lu was a PhD student at Waterloo, a 3D bone model with a CT scan took approximately 20 hours to create. Technology has developed to the point that it can now be constructed within a minute’s time. 

“Thirty years ago, we were using limited technology,” says Lu. “There was no 3D simulation, no AI. Now we’re creating 3D bone void maps that could guide clinical practice in osteoporosis screening.”