Walter Reed Patients Test Next-generation Prosthesis

By Christen N. McCluney
Special to American Forces Press Service

Dec. 10, 2009 - Wounded warriors at the Military Advanced Training Center at Walter Reed Army Medical Center here are testing a new microprocessor-controlled prosthetic knee. The X2 microprocessor knee by Otto Bock HealthCare is the result of a medical research project funded in support of the Military Amputee Research Program. This project, administered by the Telemedicine and Advanced Technology Research Center, had the goal of developing "an electronically controlled prosthetic knee joint that meets the specific demands of military staff in real world activity," said Troy Turner, Advanced Technology Research Program manager at TATRC.

He added that in 2005, officials recognized that even the cutting-edge prosthetic devices weren't good enough.

"Otto Bock had the C-Leg," he said. "It was the best that was available, but not the best needed." Soldiers needed a prosthetic knee with a longer battery life that would enable them to walk and run backward and forward and go up stairs foot over foot.

Otto Bock developed a proposal that later was funded and has developed a new knee that has more durability and functionality, extended battery life, remote-control functions and can handle higher weight loads.

Adele Levine, a physical therapist at the center, said many patients were dealing with knee and joint pain with the C-leg, and saw relief almost immediately once they began wearing the new X2.

"Once I got the confidence to trust the leg that it would do what it was supposed to do, I almost got immediate relief," said Marine Corps Gunnery Sgt. Marcus Wilson, one of the three patients at Walter Reed testing out the microprocessor knee. "No knee pain [or] hip pain. Everything evened out."

The leg enables him to stand in any position and rest on the amputated side, relieving pressure on his intact leg, he said. He also can run again without having to switch to another leg.

"With the old C-Leg, you can't run," he said. "Now, it's as simple as getting a remote and putting it in running mode and going. As fast as you can go, the leg will keep up with you."

Army Staff Sgt. Alfredo De los Santos has been using the new X2 microprocessor for a little more than two weeks. "Ever since I got this leg, it's been heaven," he said. "I went to Busch Gardens. I walked all day long. I only take it off when I go to sleep at night."

De los Santos, who works out two or three times a day and recently participated in the Army Ten-Miler and the Marine Corps Marathon using a hand-crank chair, said that before using the X2 he occasionally would use canes to alleviate some of the back pain he was having because he enjoys being active. "Now, I can jump and mostly do everything," he said.

Levine said that with the X2 De los Santos has alleviated a lot of his previous concerns about the pressure he was putting on his intact side and his concerns with quality of living.

"He is so much happier. He tells us this at least 20 times a day," she said. "He's always concerned about the future and his condition in 20 years; this gives him a lot of hope."

The knees are currently being fitted on 30 wounded warriors at Walter Reed and at Brooke Army Medical Center in San Antonio, and are expected to be widely available in 2011.

"It's what you make out of it," De los Santos said when asked about his hope with the X2. "If you can do this, you can do anything. You can accomplish anything, and you have to make the decision to make it work."

(Christen N. McCluney works in the Defense Media Activity's emerging media directorate.)