High-tech implant eases limb-saving treatment

Kansas City, Kan. — Young patients at The University of Kansas Hospital are some of the first in the nation to receive a unique bone prosthesis that expands easily as the child grows.

The device, essentially a bionic bone, is implanted in arms or legs, replacing cancerous bones. The standard bone implant, if used in a child, requires follow-up surgery several times a year to lengthen the device as the child matures. 

The new implant, however, can be adjusted externally without surgery. It involves some creative engineering: A tiny but powerful gearbox inside the implant controlled by a whirling magnetic coil, called the drive unit, outside the limb.

The process lengthens the implant a millimeter at a time – up to 4 mm in the span of 15 minutes. The result: A painless expansion and the youngster walks out of the physician's room ready for action.

"It's tremendous technology," said Howard Rosenthal, MD, the only surgeon in the region who has used the new prosthesis. "By not doing these repetitive surgeries to lengthen the implant, it means we save the child from continued pain and we're lowering the risk of infection to essentially zero.

Fewer surgeries also mean less cost, he noted. "And we also don't have to take the child out of school several times a year and interrupt their life."

Each implant must be custom-built for each patient, requiring extensive planning between Rosenthal and the manufacturer, Stanmore Implants in the U.K.

The bionic bone is so unique it has encountered import issues. In December, U.S. Customs in New York held up three of the prostheses created for Rosenthal's patients. The surgeon had to contact U.S. Sen. Pat Roberts' office to help clear the prostheses for shipment into the country.

One of those implants was made specifically for 14-year-old Brett Palmatiero-Meyers, who has Ewing's Sarcoma in his left thigh. The three-hour surgery to replace nearly 8 inches of the Wichita boy's cancer-infected femur was a success.

Eventually Brett will be able to return to his passion, playing for his school's baseball team. He may have to change positions from his previous role of catcher, but Rosenthal anticipates that Brett will be able to play any sport he wants to. And when he heads to Rosenthal's office in several months to have the high-tech implant in his leg lengthened, the surgeon has a special treat for him.

"I'll let him turn on the machine himself."