Per Reiss he sufferred an infection following the first.
Brady had 2d surgery - The Boston Globe
"This can happen to anyone having a surgery, but it's a relatively rare occurrence after knee procedures," DiNubile said. "The earlier you recognize and treat it - that's surgery and antibiotics - the less likely you're going to have problems down the line. The best-case scenario is that they got it early, and if everything goes right, he would be back at the same time as was expected."
Brady had 2d surgery - The Boston Globe