December 2001 Bulletin

Surgical training gets ‘virtual’

Academy utilizing virtual reality technology to enhance surgical education

By Carolyn Rogers

Thanks to ongoing advancements in virtual reality (VR) technology, the days of orthopaedic surgeons relying solely on cadavers or living patients for surgical training are numbered. Virtual knees, shoulders, legs–even virtual bodies–are on the horizon, and they promise to alter the teaching process, resulting in a drastic reduction in the amount of effort, time and money required to train students and resident surgeons in anatomical structures and relationships.

Recognizing VR’s potential to revolutionize orthopaedic training, the Academy forged a Task Force on Virtual Reality in 1998. The task force and the Electronic Media Education committee continue to make progress with two innovative VR projects–the VR surgical anatomy project and the VR arthroscopic knee simulator.

The ambitious arthroscopic knee simulator project has been in development for two years and progress is expected to accelerate with the receipt of a U.S. Government Small Business Innovation Research (SBIR) grant.

Knee simulator

Why an arthroscopic knee simulator?

"Arthroscopic surgery lends itself to virtual reality simulation more so than most other orthopaedic procedures because of its restricted field of view and the limited physical interaction between the physician and patient," says Jay Mabrey, MD, chair of the Task Force on Virtual Reality. "Unlike procedures such as tendon repair and basic fracture fixation, there is little, if any, crossover in technique from other procedures. And the most realistic training models available now are cadaveric knees, which are both expensive and difficult to use for more than two days of training. There’s also no guaranteed uniformity among these specimens and it’s difficult to reproduce realistic and consistent pathologies in these knees."

Therefore, successful and timely completion of an arthroscopic knee procedure is now almost entirely dependent upon the surgeon’s experience with earlier clinical procedures involving real patients in a real operating room, Dr. Mabrey says.

According to the task force, virtual reality can be superior to current methods of surgical instruction in the following ways:

Originally, the project was to be underwritten by a large for-profit company, but that arrangement fell through. The task force is now working with Touch of Life Technologies (ToLTech), a small for-profit company allied with the University of Colorado. After aligning with ToLTech, the group submitted a request for a $750,00 SBIR grant to the U.S. government. Once grant monies are received, ToLTech will immediately transfer 4 to 5 staff to the project full-time.

"ToLTech–run by Karl Reinig, PhD and Victor Spitzer, PhD–is developing it," Dr. Mabrey says. "The funding goes to pay for engineers and to help pay for the software." Dr. Reining and Dr. Spitzer hold faculty positions with the University of Colorado Health Sciences Center in the Center for Human Simulation.

Meanwhile, in late August, the task force’s content development group (CDG), led by W. Dilworth Cannon, MD, met in Denver with ToLTech. The CDG reviewed knee anatomy development work for the simulator and was very impressed by the quality of the display and the ability to manipulate the positioning of the knee joint, although more work is required.

"The content committee has come up with a series of requirements for the actual device," Dr. Mabrey says. "Previously they were just suggestions–now the committee has determined what the device should be and what procedures it should perform."

The initial simulator will ask the learner to complete an arthroscopic examination of the knee and to document pathologies seen in the display. The learner will complete multiple examination efforts and the simulator will be programmed so that different pathologies will display for each examination attempt.

The CDG has developed the following educational objectives for the simulator program:

  1. Complete an accurate arthroscopic examination of the knee in a timely manner, documenting each learner attempt. Scuffing of articular cartilage, tissue damage, and wayward passes with instruments will be deducted from the overall performance score.
  2. Demonstrate mastery of the techniques, based on a checklist, for completing an arthroscopic knee examination including manipulating /positioning the leg in order to create access to all of the knee compartments.
  3. Identify and document all pathologies displayed during the exam.
  4. Demonstrate to the learner the pathologies and joint compartments that were not identified. With feedback during the examination, document the process and technique required to identify these pathologies.
  5. Provide the learner with a progress report for each examination attempt with a comparison to previous attempts.

Both the Academy and ToLTech have expressed a goal of completing the simulator project by January 2003 and to conduct validation testing during 2003.

"Once we have the final prototype, the Academy’s Task Force on Educational Effectiveness, led by Jim Kasser, MD, will be charged with evaluating the simulator," Dr. Mabrey says. "The simulator will be tested in the Orthopaedic Learning Center and in selected residency programs. A study protocol has been drafted."

Just phase one

This is just "phase one" of the Academy’s efforts in virtual reality simulation, Dr. Mabrey emphasizes.

"It’s an evolutionary process, " he says. "Our long-term plan calls for creating additional software involving arthroscopic surgical technique for the simulator. And once we have the knee down, moving on to the shoulder and the hip will not be that difficult at all."

VR at Annual Meeting

AAOS members will soon be able to experience the Academy’s second innovative VR project for themselves–demonstrations of the "Virtual Reality Surgical Anatomy" program will be offered at the Multimedia Education Center during the 2002 Annual Meeting. The 3-D program is designed to help orthopaedic surgeons better visualize the unique anatomy of the pelvis and acetabulum for improved care of trauma patients.

Complex pelvic fractures will be displayed in multiple dimensions utilizing the "Immersadesk"–a product developed by the University of Illinois at Chicago (UIC). Immersadesk is a unique visualization tool that allows for true three-dimensional stereoscopic visualization of complex environments. It features a 4x5-foot rear-projection screen that can be oriented as either a ‘drafting table’ or a ‘large screen TV’ VR display, depending on the needs of the application.

The system tracks the user’s head position in relation to the computer generated environment and alters the three-dimensional view based on these changes in head position. This feature allows the user to interact more realistically with the objects within the virtual environment, giving the sensation of total immersion in the demonstration.

VR Surgical Anatomy project leader George W. Wood, II, MD, worked with the orthopaedic departments at the UIC Medical Center and at Rush-Presbyterian St. Luke’s Hospital in Chicago to identify a series of CT scans presenting a complex pelvic fracture with a transverse component and a posterior wall fracture. This allows for comparison between the normal anatomy on the uninjured side and abnormal anatomy on the injured side.

"The Academy’s efforts have focused on digitizing and converting this CT scan data into a 3-D virtual reality presentation for viewing on the Immersadesk unit," Dr. Mabrey says.

The end result is "really cool," according to Dr. Mabrey. "As you look around you get the impression that the pelvis is sitting in front of you and you can enlarge it and walk through it. It gives people a better understanding of the anatomy of a pelvis fracture. We’ll be demonstrating the product at the Academy’s Annual Meeting. Eventually we’d like to employ it as a virtual cadaver."

Members who wish to take the VR Surgical Anatomy program for a "test drive" should stop by the Multimedia Education Center during the Annual Meeting.

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