WWE.com was the first to break the news, saying that Dr. Andrews, who has successfully performed surgeries on the likes of Triple H, Shawn Michaels, Edge, John Cena, Randy Orton, Tom Brady and Brett Favre, performed a scope on Punk's left knee. The procedure was to remove a piece of torn meniscus in his knee.
Historically, athletes who have this procedure are able to return to practice after 1-to-2 weeks. The average person takes six weeks to recover.
WWE also confirmed on its website that CM Punk will not compete at the TLC pay-per-view, which is just under two weeks away. Instead, Ryback will team with Team Hell No to face The Shield (Roman Reigns, Dean Ambrose, Seth Rollins).
As of today, CM Punk has held the WWE championship for 381 days, surpassing John Cena's 380-day title reign as the longest of the modern era (considered the past 25 years. Not since 1988 has a longer title reign been seen).
Neither CM Punk nor Paul Heyman have commented on the surgery on Twitter.
As of this writing, CM Punk is still champion and hasn't been stripped of the title.