CloakNNNdagger
Hall of Fame
Per NFL Network, Tony Romo has a broken bone in his back.
Romo has a lumbar compression fracture. What happens in most of these is the force abnormally compacts/impacts the bone, the crushed bone remains stable. With a period of immobilization and concentrated rehab, as long as this is indeed his only injury, he should be able to avoid surgery and realistically return to play at ~10 weeks.

If this fracture was a type that was or became unstable (such as one of the segments sliding forward or adjacent discs be ruptured), then surgery would become indicated.

As long as he is careful not to torque his torso, you may see him begin to throw lightly in the next 2-3 weeks.