Stealth computers promise surgery with fewer complications

Dr. Michael Dayton plunges the drill into the sedated patient's thigh, wobbles the bit, finds the bone.

Hitting home, he attaches a metal frame that looks much like an oversize jack from the children's game. A camera overhead snaps a picture.

The orthopedic surgeon continues, clicking more pictures, sending more information to a computer.

"This is cartilage," he said, pointing to a diseased yellow patch on the patient's bony kneecap. "It used to be white and shiny like a porcelain sink. Now it's not."

In a minute the computer will combine the images, calculate exactly how badly the knee is damaged and tell Dayton precisely where to place the artificial joint. It's surgical navigation, the future of orthopedic surgery.

The premise is simple: Navigation is like a global positioning system for surgeons.

Through the use of the Stealth computer, a camera, infrared lights and reflective frames placed strategically, surgeons create a three-dimensional image of the patient on a computer. The computer then guides the surgeon to remove a tumor or replace a knee. The result: greater accuracy and less damage.

As orthopedic surgery moves toward smaller incisions and shorter hospital stays, navigation technology will become essential.

"Without the GPS, you could always get where you want to, but you might spend two hours asking your way on the road," said Nadim Yared, general manager of the division of Medtronic that makes Stealth.

"The GPS makes it much more convenient and straightforward for you. Our technology provides the same utility to the surgeon."

Stealth Technologies began in 1991 with engineer Kurt R. Smith tinkering with computers in his Missouri garage. Smith moved the company to Colorado in 1994. In 1995 SofamorDanek bought Stealth; in 1998, Medtronic bought SofamorDanek.

Medtronic, the largest medical-device company in the world, renamed it Medtronic Surgical Navigation Technologies. The computers still use the Stealth brand name.

Medtronic SNT has 200 Louisville-based employees and will add 20 to 30 employees as business grows by a projected 20 percent next year.

Dayton, an assistant professor at the University of Colorado, has used Stealth for 12 surgeries and is collecting data on the outcomes.

"It allows us to potentially make smaller incisions resulting in potentially less blood loss," he said.