Retired Friends Invent Knee Flexion Device

What do you get when you cross an orthopedic surgeon, age 72, with an industrial engineer, age 70, who are looking for something to do? You get a new machine called the X10 that will restore and maintain knee flexibility and strength after a total knee replacement. The machine, invented by the two friends, uses pressure to flex the knee to the point where fluid in the knee is released, thereby avoiding the buildup of scar tissue that causes knees to deteriorate after surgery.

Gary Anglebrandt told the story on Crains Detroit Business website. David Halley, M.D. is a Columbus, Ohio-based surgeon who has performed 8, 000 knee replacements. Paul Ewing is an engineer who sold his cold-forming steel business, NSS Technologies, in 2000. Together the two launched Halley Orthopedic Products LLC in 2009. As Halley explained, “Paul had sold his business. He made a lot of money with it, and he was going nuts. There was nothing for him to do. We started talking about it (knee problems following surgery) and, oh my God, did he get involved. It’s amazing how quickly he caught on.”

The initial idea, as Anglebrandt explained it, was to improve the straightness of patients’ knees, post-surgery. One patient of Halley’s had made a contraption at home using wood, rope and a plunger to keep his knee straight. Ewing couldn’t bear to see that and set to work building something better. In a short time Halley and Ewing discovered that the device they were working on would also treat “flexion, ” or bendability, not just straightness of the leg. A complication with total knee replacement is that while flexion might be perfect immediately after surgery, it can quickly diminish because a built-up of fluid can cause scarring.

It took the two men several years and $1 million to work through eight variations, but they eventually came up with a machine they liked and registered it with the U.S. Food and Drug Administration. A computer screen displays biofeedback information, mainly angle and pressure readings, so patients can monitor their improvement and adjust the settings. The company rents the machine for however many weeks the patient needs it to restore the knee to an acceptable level of motion. The inventors say it saves money for patients by avoiding nursing homes and reducing physical therapy visits.

As Halley explained, “People would come back in six weeks and have a flexion contracture. It wasn’t that many people but, still, you want 100% because right after surgery everyone could straighten it out.”

The critical extension point for the releasing of fluid is reached at the very last point before real pain is felt, he said. The X10 reaches this point slowly and precisely. A doctor initially sets the X10 to extend the leg to just before the patient feels pain. As flexibility improves, the patient can adjust it to move the leg farther.

The two inventors want their patients to achieve a better range of motion than they had prior to surgery. (Many doctors consider it a success when patients achieve 110 degrees of motion instead of the 130 degrees normally seen in healthy knees.) Some patients use their X10 device three or four times a day in the hope they will achieve superior results. The machine, which measures a foot and a half wide and about 2 1/2 feet tall, became available in March 2013. Since then, about 100 patients have used it.