Howard J. Sweeney, MD (center) tests out the simulator as James A. Hill, MD, (left) and Michael F. Schafer, MD, (right) observe.


Published 10/1/2009
Peter Pollack

Knee arthroscopy simulator meets the real world

Project begins validation study at teaching hospitals across the United States

“I didn’t think it was going to replicate the feel,” says James A. Hill, MD. But after he tested the Virtual Reality Arthroscopic Knee Surgery Simulator, his skepticism faded. “I was pleasantly surprised to find that it really feels like you’re touching meniscus, articular cartilage, and ligaments.”

On August 18, the knee simulator, designed by Touch of Life Technologies, Inc. (Aurora, Colo.), in consultation with AAOS, the Arthroscopy Association of North America, and the American Board of Orthopaedic Surgery, was introduced at the Feinberg School of Medicine at Northwestern University—the second stop on a tour of at least nine medical institutions taking part in a validation study for the project. When the study is complete, the developers hope to have a strong idea of the simulator’s effect on the training of orthopaedic residents in diagnostic arthroscopy.

Beyond the traditional approach
“I think this is going to be the wave of the future,” says Dr. Hill, who is serving as the medical school’s study leader. “This is something orthopaedics definitely needs to develop as a training mechanism for the residents, something beyond the age-old ‘see one, do one, teach one’ approach.”

Dr. Hill points out that, in traditional teaching methodology, if a resident is having difficulty with a procedure, the attending surgeon steps in, and the resident steps back into the role of observer. Using a simulator provides the student with an opportunity to work through the problem and receive instant guidance on a potentially better approach, with no risk to patients.

“Historically, a resident never has the chance to say, ‘I made a mistake. How can I improve next time?’” says Dr. Hill. “In real-life operating room situations, people can’t tolerate mistakes.”

The simulator consists of a computer and monitor, a surrogate model of a human leg, and a pair of surgical “tools”—an arthroscope and probe. Tiny motors (or haptic devices) in the tools are synchronized to the simulated knee to provide an instant tactile response to the learner: maneuver the probe to a ligament on the display, and the probe will respond as though it is touching a real ligament.

A separate “mentor” program runs alongside the simulation software and monitors the student’s actions. When the student completes a task, the mentor grades his or her technique based on preset levels. If a student deviates from the proper technique, the mentor explains what the student needs to do to improve. Students aren’t allowed to progress to another task until they can meet standards set for the current technique.

An excellent teaching tool
Under the validation study, residents are divided into two groups. The first group of residents will use the study site’s traditional educational techniques, such as dry models, wet models, cadaveric specimens, apprenticeship participation in surgery, and other non–computer-based training devices. Residents in the second group use only the knee simulator. Within 14 days of the conclusion of the training period, the study participants will complete one diagnostic examination on an actual patient and will be evaluated on their progress.

Each institution will have the simulator for 3 to 4 months. The simulator’s first stop was the University of California at San Francisco. In addition to Northwestern, all remaining study sites have filed Institutional Review Board requests to take part in the study, which is scheduled to be completed early in 2011. The developer is building a second simulator to help speed the process.

“My real hope is that the simulator does validate, that it improves the resident’s abilities to do the preliminary steps in a diagnostic arthroscopy, and that it teaches them a good fundamental approach to using the arthroscope,” says Michael F. Schafer, MD, chair of the Department of Orthopaedic Surgery at Northwestern. “I think it gives a pretty realistic approach to diagnostic arthroscopy. As more procedures are pushed into outpatient settings, it becomes harder for the residents to get exposure to operative arthroscopy. The simulator helps provide that experience.”

Dr. Hill shares those hopes. Although he doesn’t expect traditional teaching methods to be replaced by simulation, he believes the device will augment students’ education.

“It’s an excellent tool for teaching concepts and principles that you can bring to the real life situation,” he says. “And the residents seem to enjoy working with it.”

Peter Pollack is a staff writer for AAOS Now. He can be reached at

Additional links about the use of simulators in orthopaedics:

Will computers replace cadavers?

Knee simulator project moves from back room to main hall

How have wear testing and joint simulator studies helped to discriminate among materials and designs?

Changing trends in CME present opportunities for AAOS

Simulation in Orthopaedic Education: An Overview of Theory and Practice

Surgical Experience Correlates With Performance on a Virtual Reality Simulator for Shoulder Arthroscopy