It’s on WWE.com. Apparently he had something called an incarcerated hernia. No word on how long he’s out for.
The following was reported by Mike Johnson from PWInsider.com:
WWE announced they would officially explain what the status of the WWE World Heavyweight championship is during this Monday’s Raw, which will be taped in London, Great Britain.”
The WWE web site reported that the surgery to C.M. Punk was arthroscopic
in nature, and Dr. James Andrews trimmed a cartilage tear that had
caused his knee to lock up.
Given the nature of the surgery, he is only expected out of action a few weeks.
No word on if the title will be vacated or if the PPV will be changed.