While many of todays baby boomers were in elementary school, they often
sang a song about human anatomy that featured the lyrics the ankle
bone was connected to leg bone, the leg bone is connected to the knee bone.
But in the future, a growing number of those aging knee bones are going
to need replacement by artificial implants implants that may have been
tested and analyzed by orthopedic specialists at the University of Nebraska
Medical Center, which can soon become the nations premier laboratory for
the simulation and testing of knee implant designs.
The long-term vision for UNMCs growth in orthopedic biomedical technology
is the brainchild of James Neff, M.D., director of orthopedic research
and professor of the department of orthopedic surgery and rehabilitation.
Dr. Neff has an international reputation for innovative surgical procedures;
custom implant design and collaboration with implant manufacturers of many
foreign countries. When Dr. Neff coordinated the purchase of two of the
worlds most sophisticated knee implant simulators, and then recruited
a member of the design team of the simulators, Hani Haider, Ph.D., who
joined the department as associate professor of biomedical engineering,
the stage was set or UNMC to go to the head of the class.
Significant advancement in modern medicine has been and remains technology
driven, and the field of orthopedics is no exception, Dr. Haider said.
The growth in the demand for joint replacement from an increasingly aging
population drives the need to make knee implants perform better and last
longer.
Our immediate strategy is to ensure that UNMC becomes a key player
internationally in the testing of modern knee replacement implants. This,
in my view, is achievable within the short-to-medium term and is the focus
of a lot of our current efforts.
Part of the orthopedic teams mission is to initiate pilot research
projects within UNMC on making knee replacement installation procedures
more precise, less invasive and result in shorter hospital stays.
In addition to using UNMCs premier facilities for testing, team members
will actively participate in modern implant design, computer-aided simulation,
preoperative planning and image-guided or robotic surgery.
As a mechanical engineer and member of the faculty at England’s Sheffield
University from 1988 to 1996, Dr. Haiders research encompassed the study
of fluids in motion, the interface between mechanics and electronics, especially
when using miniature devices, robotics and information technology.
In 1997, he joined the faculty of the Centre of Biomedical Engineering
at the University College of London, in Standmore, England. He was
a key member on the team, along with Peter Walker, Ph.D., that produced
the Instron-Stanmore Knee Simulator and the International Standards Test
(IST) method for simulation and testing of knee replacement systems.
Dr. Haider supervised the production of 13 Instron-Standmore simulators,
most of which are now in use at testing laboratories of major international
orthopedic manufacturing companies. He also trained all the operators
of these simulators, including the engineers of the Instron Company.
Dr. Walker is now director of the biomedical engineering program at the
Cooper Union Research Foundation in New York. He also was appointed
to the position of adjunct professor in the UNMC department of orthopedic
surgery where he facilitates collaboration throughout the orthopedic biomechanics
team.
Russell Alberts, Ph.D., and director of the UNMC Orthopedics Biomechanics
Laboratory, supervises the day-to-day operation of the Instron-Standmore
simulators. Along with Dr. Neff, Dr. Alberts helped develop the Orthopedics
Biomechanics Laboratory, located in the building that houses the unroe-Meyer
Institute. Dr. Alberts holds a joint doctorate in biomedical engineering
and engineering mechanics. He taught engineering mechanics at the
University of Nebraska-Lincoln from 1986 to 1994 before joining UNMC.
He also has done post-doctorate research on the mechanical properties of
bone and cartilage at Renssalear Polytechnic Institute in Troy, NY.
Human knees have to carry most of our body weight and have six different
degrees of freedom of motion, making them the most complex and tasked joints
in the human body, Dr. Alberts said. The success of our implant simulators
relies on precisely recreating the varied motions that occur in the patients
knees, regardless of the individual implant design.
Long term wear is to be minimized for any type of implant. In addition
to reducing implant durability and performance, excessive wear particles
create debris that can cause harmful complications to the patient and accelerate
pre-mature failure due to implant loosening.
In order to prevent or minimize wear on the implant, a huge amount of
energy is invested in design and testing. The orthopedic team and
its simulators so accurately reproduce long-term wear on a knee joint implant
that UNMC is an important contributor to the establishment of national
and international standards for evaluating total knee replacement durability.
UNMCs simulators are currently reserved into 2002 for testing contracts
from manufacturers in the U.S. and Europe. The department is already
seeking funding to purchase a third simulator, or possibly even design
a prototype for the next generation of simulators.
Unless osteoarthritis is defeated, many people are going to require
knee replacements in the coming years, Dr. Neff said. Our joints
are wearing out at earlier ages, and combined with longer life expectancies,
joint replacements are going to have to carry people many more years than
previously. Researchers are experimenting with many different materials
and designs, in hopes of finding the most durable, safest, least invasive
and best performing implants.
We feel that we now have the total collaborative team in place to put
UNMC at the forefront of testing, analyzing and implanting the best of
whats coming next.