John Cena's surgery was successful and Dr. Joseph Maroon, renowned neurosurgeon, Professor of Neurosurgery at the University of Pittsburgh Medical Center, and team neurosurgeon for the Pittsburgh Steelers, was very positive regarding Cena's condition.
As far as what could’ve gone wrong during surgery, infection and not removing all the disk material were the main concerns.
In Cena’s case, "everything went well," Dr. Armann added. "Dr. Maroon and I expect a full recovery. In a couple of weeks, he’ll be able to start with leg cardio, and then resistance training in four to six weeks. The bone graft that was put into his neck needs to heal before he can see action.”
“You can either do one of two things: be upset or know what you can do to get better,” said the former WWE Champion Cena prior to the surgery. “The ultimate goal is to be as strong as I can and get back into the ring as soon as possible.”