The News Service
VA Funds Leading-Edge Limb-Loss Research in Providence
The Department of Veteran’s Affairs has awarded $7.2 million to the Providence VA Medical Center to establish a broad-based research program to restore natural function to amputees. The chief goal is to create “biohybrid” limbs that meld human tissue with a prosthesis controlled by an amputee’s own muscles and brain signals. The Providence VA Medical Center is working with Brown University and the Massachusetts Institute of Technology to improve the lives of amputees, particularly Iraq war veterans. (See also fact sheet on individual research projects.)
PROVIDENCE, R.I. — With $7.2 million in funding from the Department of Veterans Affairs (VA), the Providence VA Medical Center, Brown University and the Massachusetts Institute of Technology have begun a five-year, multidisciplinary research project to restore arm and leg function to amputees.
At the end of the project, scientists hope to have created “biohybrid” limbs that will use regenerated tissue, lengthened bone, titanium prosthetics and implantable sensors that allow an amputee to use nerves and brain signals to move the arm or leg. The aim is to give amputees – particularly war veterans – better mobility and control of their limbs and reduce the discomfort and infections common with current prosthetics.
According to a U.S. Senate report, body armor and improvements in combat casualty care have contributed to the lowest “died of wounds” rate in recorded military history. However, the report states, more surviving soldiers from the Iraq war have lost arms or legs. Historically, 3 percent of soldiers wounded in action required some amputation, but that rate has jumped to 6 percent in Iraq, according to the report. Since the invasion of Iraq, Walter Reed Army Medical Center in Washington, D.C. has treated more than 200 soldiers who have lost one or more limbs.
Secretary of Veterans Affairs Anthony J. Principi has strongly and repeatedly emphasized the importance of advancing VA’s research and development efforts on veterans’ special health care needs, including rehabilitation after amputations. “VA must work with the research and medical community to restore the capability of veterans with disabilities to the greatest extent possible,” said Principi.
Jonathan B. Perlin, acting under secretary for health, added, “Refocusing of VA’s research program on the needs of the veteran, including rehabilitation after amputation, is crucial to VHA’s priorities.” Stephan Fihn, M.D., acting VA chief research and development officer, and Mindy Aisen, M.D., the VA’s director of rehabilitation research and development, agreed that twenty-first century warfare has created a need for improved amputee care from new surgical techniques to development of innovative prostheses, and that this research project will work toward meeting this challenge.
Roy Aaron, M.D., professor of orthopaedics at Brown Medical School and attending physician at Rhode Island Hospital and The Miriam Hospital, will lead the project. Aaron, a surgeon and researcher, will serve as the director of the Providence VA’s new Center for Restorative and Regenerative Medicine.
Aaron will oversee nine investigators at Brown and one at MIT. All have research appointments at the Providence VA. Together, the team has expertise in orthopaedic surgery, physical rehabilitation, community health, tissue engineering, neuroscience, artificial intelligence, robotics and materials science.
Research and clinical care will take place at the Providence VA Medical Center, Brown, MIT and Rhode Island Hospital.
Aaron said biohybrid limbs will maximize amputees’ existing tissue and bone. Surgery that lengthens bone will be coupled with tissue engineering techniques to speed healing. The goal is to make bones longer to improve the fit of prosthetics and make bones stronger to reduce fractures.
Researchers will use tissue engineering to further restore limbs. For example, one group will encapsulate time-release growth factors to inject into damaged joints along with precursor cartilage cells and supporting material such as collagen. The aim: Regenerate this shock-absorbing tissue and save elbows and knees.
But Aaron said research also will focus on joining biological tissue with high-tech prosthetics.
A pair of researchers will try to improve a process known as osseointegration, in which a titanium bolt is attached to an amputee’s existing limb, allowing the attachment of prosthetics. These scientists will try to grow skin that will fuse with the titanium, forming a natural seal around the bolts to reduce the rate of infection.
Some patients will be fitted with knees and ankles controlled by the BIONTM, a wireless microchip that will be injected into existing arms or legs. These chips will pick up signals from nerves and send movement instructions to the robotic knees and ankles, improving balance, reducing fatigue and making the gait more natural. Another team will use a mind-to-movement system that will use brain signals to control prosthetics. Pioneered at Brown to help quadriplegics, the system will rely on miniaturized implantable sensors that record and decode brain signals, turning them into movement commands.
“Advances in tissue engineering, robotics and neuroscience put many of our goals within reach,” Aaron said. “While many of the tools and techniques we’re using are being tested across the country, this project marks the first time they will be pulled together to improve care for amputees, particularly veterans.”
While the project’s ultimate aim is to build biohybrid limbs, experiments may yield advances that could be used for many clinical applications. For example, cartilage regeneration could prevent the need for total knee and hip replacement surgeries. A skin seal could improve the safety of catheters, stents and other medical devices prone to infection. And robotic knees and ankles could help people immobilized by stroke, cerebral palsy and multiple sclerosis.
Anyone who has lost a limb – due to injuries or diseases such as diabetes and bone cancer – will be eligible to enroll in clinical trials, but the project is intended to address the needs of veterans, particularly soldiers who have fought in Iraq.