Three patients at the Texas Back Institute in the Dallas suburb of Plano have died during what prosecutors later called an illegal clinical trial of a bone cement promoted by Synthes Inc., the medical device maker near West Chester, PA, and its wholly owned subsidiary Norian Inc. between May 2002 and fall 2004. Pharmaceutical executives rarely get jail time for corporate crimes, but federal prosecutors in Philadelphia this week will argue for sentencing guidelines that could mean up to a year in prison for four former Synthes executives in connection with the illegal testing and marketing of Norian bone cement. Synthes and Norian hoped to profit from the spinal surgery market created by millions of older Americans with back pain. Court documents show that former Synthes board member and spine surgeon Ken Lambert referred to the trials in e-mails to company leaders as "human experimentation whose only defense seems to be that it will be a small study."