Manning's career may be at risk after his latest spinal procedure

The surgery was explained to me by Dr. Ty Thaiyananthan, the co-medical director of the Chapman Neurosurgical and Spine Institute at Chapman Medical Center in Orange, Calif. The procedure removes the damaged spinal disc and replaces it with a plate and a spacer. The spacer is made of a medical plastic or of a cadaverous bone graft. The surgeon goes through a small incision at the front of the neck, removes the disc, puts the plate and spacer in place, and makes sure that the nerves are given plenty of room to release.

"The common healing time is about a year," said Thaiyananthan. "At two to three months, most patients are just getting out of the collar." All patients who have had this type of procedure will lose movement in all planes -- flexion, extension, and rotation. "It's a chain and one of those is now locked in."

Thaiyananthan explained to me that fighter pilots who have this injury would be pulled out of their flight assignments. While players have come back in the NFL -- a recent example is Steve Slaton of the Texans -- there are no known quarterbacks, and among the more notable players who didn't return is Sterling Sharpe, whose career was ended after similar surgery. A study presented to a 2010 meeting of the American Academy of Orthopaedic Surgeons by Dr. Wellington K. Hsu found 40 players had come back from similar surgery to play in the NFL again.

Manning's original microdiscectomy in May did not resolve the problem and after diagnostic tests on Monday and Tuesday, Manning and his doctors made the decision to have the more extensive fusion performed. Two sources say that the decision was not even discussed until Wednesday and that everyone agreed this was the best course of action, in fact, the only reasonable course. "There was no procedure until the fusion," I was told, "and no discussion of it. Anyone saying so wasn't basing it off any information that Manning or the Colts were privy to."

Manning will immediately begin rehab and will be in a cervical collar for an extended period. A key point will be seeing when that brace comes off. To return at the period the Colts stated, he would need to be out of the brace in about four to six weeks.