From Duke press release.

"Duke head football coach David Cutcliffe announced on Thursday that rising junior linebacker Kelby Brown underwent successful surgery to repair a torn anterior cruciate ligament in his right knee.

The revision surgery was performed on Wednesday by Dr. Claude T. Moorman III, Duke’s head team physician and the director of Duke Sports Medicine. Brown originally injured the knee on November 20, 2010 against Georgia Tech, and underwent surgery weeks later. He re-injured the knee earlier this month."

Perhaps some of our DBR surgeons can let us know what "revision surgery" means.