THERE’S A ROBOT IN THE OPERATING ROOM

The device uses computer tomography (CT) imaging to guide a robotic drilling arm while it performs some of the tasks for total hip replacement surgery. UAMS Medical Center was selected as a second test site in the country for a clinical trial under the auspices of the Food and Drug Administration.

"The robot doesn’t go on vacation, and it can’t get ill," said Carl L. Nelson, M.D., Professor at the UAMS College of Medicine and Chairman of its Department of Orthopaedic Surgery. "It’s capable of tireless, precise movements without a flaw."

RoboDoc is essentially a highly sophisticated milling machine. It makes precise cuts in the femur (upper leg bone) for insertion of surgical implants. The current method requires an orthopaedic surgeon to manually bore a hole in the bone with a mallet and a hand-held reamer. The result is often a cavity that may not precisely adhere to the implant. A gap of from 1 to 4 millimeters may not be a good enough "fit" between bone and implant for a secure attachment.

The process starts with a radiologic scan of the femur. Once the computer acquires the three-dimensional image in its memory, it enables the surgeon to use a computer mouse to determine an exact placement of the implant. Computer and physician also interact by deciding on what type of implant to use.

The information is then uploaded from the CT computer to one in the operating room connected to the robotic surgical arm. The surgeon helps the robot find the exact location of the patient’s femur by using a Digitizer to pinpoint specific markers on the bone. Once the robot correlates that information with the computer image stored in its memory, it signals the surgeon that it’s ready to cut. The robot uses the predetermined mapping to make a precise incision, while the surgeon controls the process in real time by watching a monitor.

"What we’re trying to do with the robot is reduce the subjective "feel factor" for this surgery and add a more measurable, accurate, and reproducible way to do it," Dr. Nelson said. RoboDoc promises to make delicate cuts the same way every time, in a wide range of surgical procedures, not just hip replacement. Dr. Nelson said he first learned about the FDA trial when he called Integrated Surgical Systems, Inc., the California-based company that is developing the technology, to inquire about a device suited for especially delicate unicondylar knee surgery.

ISS President and CEO Ramesh Trivedi, Ph.D., says his company was attracted to UAMS because it offered the chance to broaden the spectrum of patients in the trial beyond California. Sutter Hospital in Sacramento is the other testing site. Dr. Nelson’s outstanding reputation as a world-class orthopaedic surgeon also played a part. "We realized that the orthopaedics department of the college is ranked in the top 25 in the nation," Dr. Trivedi said. "And we also wanted to go to a university-based teaching hospital. Also, UAMS expressed an interest in developing into one of the foremost robotics surgery centers in the country."

Dr. Trivedi said he is currently negotiating with Stephens Spine and Neurosciences Center Director T. Glenn Pait, M.D., for a similar robotics system. The Stephens Center would perform some brain surgery with the NeuroMate, if an agreement can be reached.

Before robots can take over certain steps of the process, Robodoc must gain FDA approval. Candidates for hip implant surgery between the ages of 21 and 80 can call the Department of Orthopaedics at 501-686-7841 or 501-686-7813 for more information about this clinical trial.

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