WASHINGTON — A federal agency’s plan to rein in rising prosthetic costs treats purchases of artificial limbs the same as buying cinder blocks or “mass-produced” widgets, a military veteran told US lawmakers.

The Department of Veterans Affairs is shifting responsibility for ordering some prosthetics from medical personnel to contracting staff. It’s also requiring more documentation on the spending.

The changes are designed to reduce prosthetic costs, which have jumped 80 percent in the past four years, according to the VA inspector general.

Companies including Minneapolis-based Medtronic Inc. and Natick, Mass.-based Boston Scientific Corp. may be affected by the changes.

The VA paid Medtronic about $5 million and Boston Scientific about $3 million for prosthetic products or services in fiscal 2010, according to federal procurement data compiled by Bloomberg.