August 1998 Bulletin

Future is here does it work?

". . .will these tools improve patient outcomes in a cost-effective manner?"

Panel studies benefits of computer-aided surgery, robots and other technologies

By Sandra Lee Breisch

In another dimension of time and space, the possibilities of 3-D medical imaging and robotic devices used in surgical procedures would be viewed as an impossibility, quackery-something like a trip to the Twilight Zone.

But today, innovative orthopaedic applications such as surgical simulators, image-guided procedures and surgical navigation, and preoperative and pretreatment planning and analysis are being used in research, education and patient care.

Yet, despite such technological advances, skepticism exists among organized medicine, scientists and governmental agencies such as the Food and Drug Administration (FDA) as fears about inconsistencies, accuracy and optimum performance come to mind.

For example, will these innovative orthopaedic applications really solve clinical problems? More importantly, will these tools improve patient outcomes in a cost-effective manner?

These questions and more posed a challenge to a panel of multidisciplinary pioneers in this field at their first joint workshop sponsored by the Academy and the National Institutes of Health (NIH) entitled "New Engineering Technology Transfer in Orthopaedics" on April 30-May 3, 1998.

The goal of this workshop was to assess the potential value of this technology in orthopaedic surgery and rehabilitative medicine and receive feedback from some 80 participants who had a strong interest or expertise in such technologies. They included young investigators, orthopaedic surgeons, researchers, engineers, scientists and an FDA representative.

"There must be a candid review of the problems, needs and possibilities of these new tools in different sub-specialties of our field, stressed Edmund Y.S. Chao, PhD, co-chairman of the workshop. "Such an exercise could also stimulate future research and job opportunities." Chao is the Lee H. Riley, Jr. professor of orthopaedic surgery and vice chairman for research, department of orthopaedic surgery, Johns Hopkins Medicine.

According to Chao, other challenges remain: directing this exciting technology's proper and effective use, as well as justifying utilization in patient care, training health care professionals and guiding biomedical research.

"Dynamic simulation using digital imaging graphic models with the capability to perform biomechanical analyses and to visualize results through animation appears to be a powerful tool for our critical needs," noted Chao. "On the other hand, the field of medicine, especially surgery, possesses the intangible elements combined with psychosocial and emotional aspects which cannot be quantified in scientific terms."

"For example," Chao noted, "unexpected complications and intraoperative variations demand that surgeons react promptly and meticulously. These subtle elements in surgery will be difficult to incorporate into computer algorithms and decision-making logic for robot control. Hence, if medical robots, virtual reality models, telemedicine/telesurgery, computer-assisted surgery and preoperative planning can play a role in the future of orthopaedic medicine, their proper scope and relevant areas of application must be carefully defined and scrutinized."

Chao spoke about the rudimentary stages of the use of virtual reality simulation techniques in orthopaedic research. Whole cadaver or specific anatomic parts with no previous history of orthopaedic trauma were given MRI scans. "The advantage of such a technique lies in its ability to provide realistic models for anatomical structures to predict the treatment outcome of joint replacement, skeletal fracture fixation, soft tissue injury and repair under simulated loading conditions," said Chao. "After incorporating the physical and material properties, the models can be used to conduct experimental tests on a computer workstation with unlimited parametric variations to study the musculoskeletal joint system involved in orthopaedic surgery and biomechanical research. Since these models are quantitative and interactive, they can predict and animate the performance of treatment alternatives as a means of pre-operative planning…."

For years, the entertainment world has been using such advanced technology as virtual reality, however, the medical applications are just emerging as a new area of research and development, noted Anthony M. DiGioia III, MD, workshop chairman. He also is director, Center for Orthopaedic Research, University of Pittsburgh Medical Center (UPMC) Shadyside and co-director, Center for Medical Robotics and Computer Assisted Surgery, Carnegie Mellon University, Pittsburgh. "Much of the early work of computer-assisted surgery (CAS) focused on tumor relocation in neurosurgery, based on principles of stereotaxis," said Dr. DiGioia. "However, this field has expanded to include many surgical subspecialties including orthopaedics."

According to Dr. DiGioia, the use of ROBODOC system, the first active robot to assist surgeons in performing part of a total hip replacement in 1992, "represents only one end of the spectrum of new technology being developed. Today, there are advanced measurement devices and sensors which blend the field of medicine, computer science, robotics, and engineering to solve real clinical problems."

Workshop co-chairman William L. Bargar, MD, who led the first surgical team to use the ROBODOC system at Sutter Orthopaedic Institute, Sutter General Hospital, discussed the problems of surgeon/patient acceptance of such advanced technology. "Most people are skeptical of new technology and rightfully so," said Dr. Bargar, assistant clinical professor, Department of Orthopaedics, University of California, Davis School of Medicine, and attending orthopaedic surgeon, Sutter Hospitals, Sacramento, Calif. "There have been a lot of things touted to us over the years-supposedly big advances such as new polyethylenes, which were really one step forward and two steps back. But I believe that surgeons will ultimately embrace new technologies if they produce superior results and less morbidity. A good example is arthroscopy….there was a lot of resistance to that technology. Yet, it quickly proved to be a tool to improve patient outcome and performance of a task. We need to promote the concept that computer-aided surgery and medical robotics can serve as tools for consistent, optimum performance."

Such imaged-guided technology can be used to minimize the invasiveness of orthopaedic procedures, extend the capability of current surgical applications, and serve as a clinical research tool by incorporating medical imaging modalities and computers during actual surgery. There are many potential orthopaedic applications such as during treatment of pelvic fractures, fracture care, total joint replacement and spinal surgery.

"In essence, any orthopaedic procedure can potentially benefit from the application of these enabling technologies," explained Dr. DiGioia. "One of the most important enabling features of this technology is the ability to permit surgeons to tightly couple and integrate preoperative planning and medical imaging with surgical execution. It also includes tools in measurement devices that provide timely information to surgeons during the actual surgery."

Dr. DiGioia said he expects there will be a natural progression and adoption of this technology by physicians, patients, insurers and regulatory agencies. But the most important goal, he said, is to improve patient outcomes with these CAS tools. "The goal of computer-assisted technology is to assist-not to replace surgeons," Dr. DiGioia said.

Dr. DiGioia acknowledged certain challenges for clinicians and developers of these systems, "to not only understand what these new technologies and tools can accomplish, but also to understand their limitations and choose the proper clinical applications which will allow us to achieve improved patient outcomes in a cost-effective manner."

Concluded Dr. DiGioia, "As this workshop details, many clinical applications exist for these enabling technologies within orthopaedic surgery, as well as many other areas of medicine. Within orthopaedics alone, the applications range from total joint replacement and osteotomies to arthroscopy and ACL reconstruction. The only limitations we currently have in the application and adoption of these technologies is our imagination and understanding of what we can accomplish in the future."

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