CHICAGO (AP) -- Nearly 1 in 20 Americans older than 50 have artificial knees, or more than 4 million people, according to the first national estimate showing how common these replacement joints have become in an aging population....
By LINDSEY TANNER, Associated Press
Fri, 02/10/2012 - 4:16am
CHICAGO (AP) -- Nearly 1 in 20 Americans older than 50 have artificial knees, or more than 4 million people, according to the first national estimate showing how common these replacement joints have become in an aging population....