Think of human anatomy as an elaborate exercise in structural and mechanical engineering.
Now look more closely at the pelvis, that bowl-shaped collection of bones that connects trunk to legs by way of the hips. We can walk, run, bend and stand upright thanks to the pelvis. It also helps protect reproductive and other organs.
“You can imagine what happens when a patient has pelvic cancer. Because of the complexity of the anatomy, every case is unique. Pelvic sarcoma can be treated surgically but recovery is slow and difficult. We’re trying to help people with pelvic sarcoma by designing better surgical and rehabilitation procedures that will let them recover more walking function in less time,” said B.J. Fregly, professor of mechanical engineering (MECH) and bioengineering, and CPRIT Scholar in Cancer Research.
CPRIT is the Cancer Prevention and Research Institute of Texas, an agency that has funded research since 2009, after Texas voters approved a 2007 constitutional amendment committing $3 billion to fight cancer. Last year, Rice hired Fregly and helped set up his lab with the aid of $5 million in CPRIT funds.
“I mainly study walking impairments, though my lab is expanding into upper extremity movement impairments as well,” said Fregly, who for 18 years was on the Mechanical and Aerospace Engineering faculty at the University of Florida. There his research focused on modeling the human musculoskeletal system, with emphasis on the knee.
With his colleagues, Fregly has been working to develop personalized computer models of individual patients, to simulate various treatment options and identify new ones. His goal is to design clinical interventions to optimize post-treatment function for individual patients. In short, he has been pioneering new methods of personalized medicine.
For the CPRIT project at Rice, Fregly is focusing on creating personalized computational walking models that will be used to improve treatment design for pelvic sarcoma patients. He is seeking to identify pelvic surgery and rehabilitation strategies that will maximize a patient’s ability to regain mobility. Fregly and his research team work closely with Dr. Valerae Lewis, a surgeon in orthopedic oncology at M.D. Anderson Cancer Center in Houston.
“Up to this point, Dr. Lewis has had to make surgical decisions based on her extensive clinical experience, coupled with intuition. However, the muscles and bones of the human body form a complex mechanical system, making it difficult to predict reliably how a surgical decision will impact post-surgery walking ability. My job is to create computational models of specific patients to help Dr. Lewis identify the optimal surgical and rehabilitation procedures for each of them,” Fregly said.
Removing the cancerous portions of the pelvic bones can keep patients off their feet for more than a year. Furthermore, given the unique challenges posed by each case, patients often enter the operating room without a clear idea of how well they will be able to walk after surgery. Three surgical options are possible: no reconstruction of the removed pelvic bones (and sometimes hip), reconstruction of the removed bones with an allograft using bone from a donor cadaver, or a reconstruction using a customized implant.
“Custom pelvic prostheses have the potential to maximize walking ability and minimize recovery time. We treat their design as an engineering problem,” Fregly said.
With the aid of Fregly’s computer models, Fred Higgs, the John and Ann Doerr Professor of MECH and director of the Particle Flow and Tribology Lab, and Ed Akin, professor of MECH, will create customized prostheses with the aid of 3-D printing.
Fregly’s Rice Computational Neuromechanics Lab has six doctoral students and two post-doctoral researchers. Cancer is a leading cause of death for Texans, leading Fregly to say, “We hope to reduce the number of deaths and improve the postsurgical lives of patients with pelvic sarcoma, regardless of which surgical option they receive.”