Researchers from the University of Utah Department of Orthopedics and
Worcester Polytechnic Institute (WPI) will use a $3 million grant from the U.S.
Defense Department to develop an intelligent prosthetic implant that will allow
for a more comfortable and infection-free prosthesis attachment for the
amputee.
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| J. Peter Beck |
Researchers are designing a titanium implant that would internally
attach itself to the bone and use a skin seal to prevent bacteria from entering
the site. Replacing the socket with titanium will improve the quality of life
for the patient, according to J. Peter Beck, MD, adjunct professor of
orthopedics at the University of Utah. Beck is confident the implant will be
comfortable and secure for the patient.
“Bones like titanium,” Beck explained to O&P Business
News. “Bone will soldily attach to titanium and this makes it useful
for the patient. We would place a titanium device up the canal of the bone and
bring it out through the skin. The metal post coming out the end of the stump
directly in line with the bone would then be attached to the artificial
limb.”
The development of a new prosthetic implant comes at a crucial time for
soldiers returning from war in Iraq and Afghanistan. With advanced body armor
covering a soldier’s torso, fatalities from bomb blasts have decreased.
However, a soldier’s limbs remain exposed to the blasts which have caused
severe limb injuries that often require amputations, according to Beck.
“The majority of the work we are doing involves soldiers who have
lost three or four limbs in Iraq and Afghanistan,” Beck explained.
“They can survive the blast, but they lose their limbs, especially the
upper extremity.”
Bomb blast amputations often leave short residual limbs, making it
nearly impossible for a residual limb to fit cleanly in a socket. As a result
of skin breakdown and sores at the socket site, the patient can only wear their
prosthesis a couple hours each day, according to Beck. The residual limb
inevitably sweats, making it easy for bacteria to grow. Antibiotics can treat
the bacteria, but eventually new bacteria will form, Beck said.
“We have seen soldiers who only have six inches of femur and it is
nearly impossible to put sockets on them,” Beck said. “The socket
slips, grinds on their groin and slides. They end up discarding their
prosthesis and choose to use a wheelchair. We have these technologically
advanced neuromuscular prostheses that are hooked up to these sockets. But
neuromuscular control is not functional because the socket is slipping. It is
not as workable as it would be if it was solidly attached to the bone.”
Researchers at the University of Utah and WPI are working on
anti-infection strategies including developing an interface to prevent bacteria
from penetrating the implant.
“The trick is to get skin to grow into it and make a seal so
bacteria can not get in,” he said. “It is similar to a cuticle or the
base of your fingernails. We need an interface between the bone and
outside.”
According to Beck, researchers plan to have an implant design ready for
clinical trial within 5 years. With more funding, that timetable may be
accelerated.
“We are hoping to receive a second grant this year,” he said.
“If we can do that, I am hoping we can get to clinical trial in 3 or 4
years.” — by Anthony Calabro
