Jess Lonner, an orthopedic surgeon in Philadelphia, is having great success with knee-replacement surgeries these days. He feels he is operating with more precision than ever, and he thanks his robot for that.

Regarding robotic development, the future is rapidly becoming the present in the medical field, where, despite years of rigorous training, doctors make surgical errors.

And they make them with some degree of regularity in knee- and hip-replacement surgeries, where it is sometimes exceedingly difficult for an implant to be fitted precisely into a patient's bone.

William Bargar, an orthopedic surgeon in Sacramento, says that standard methods for shaping and excavating bone are far from sophisticated. As far as many implants are concerned, "You just slam them right in," he says.

Bargar estimates that 50 percent of all patients receiving hip replacement end up with a device that is not a perfect fit.

Enter the robots. One of them, called the Robotic Arm Interactive Orthopedic ("RIO") System, is programmed to disallow a surgeon from cutting beyond a certain planned point. In one study, it was determined that implant placements on knees were off by an average of 2.7 degrees when RIO was not used; when it was, that number went down to 0.2 degrees.

"When I use a robot and I walk out of the operating room, I know it's right," says Los Angeles surgeon Larry Dorr.

Another robot, called "Robodoc," was approved by the FDA for use in the United States in 2008. Unlike RIO, Robodoc works alone, without a human assist, following a predetermined program of drilling. The orthopedic surgeon is primarily an observer, with his or her core task of inserting an implant following the robot's drilling of a precise cavity.

No one can be as accurate as a robot can, says Raymond Dimas, vice president of the company that manufactures Robodoc.

Related Resource: Los Angeles Times, "For knee and hip surgeries, robots show promise for a better fit" Oct. 17, 2011