http://www.youtube.com/watch?v=pWdd6_ZxX8cFirst of all, whoever has told you that these surgical procedures only strengthen Peyton's neck is lying to you. Right now, Peyton has a bone graft in between his C6 and C7 vertebra. Do you know what comes along with that? A loss of motion at that level, because you now have something rigid this is occupying that space instead of the soft, cushion that was there that previously acted as a shock absorber of sorts and was elastic, not rigid. Do you know what this loss of motion in turn does? It changes the spinal mechanics at that level, creating more stress on the vertebra above and below the fused area. Do you know what happens with that increased stress? You ultimately get more bulging of the discs at those levels. You also get uncovertebral hypertrophy and bone spur formation, both of which is a chronic, degenerative condition. You know what comes with uncovertebral hypertrophy and bone spur formation? You get neuroforaminal stenosis, which if great enough, impinges on the nerve. You know what happens then? The same thing that Peyton has already been through. It's only a matter of time. He WILL have this surgery again at the level above or below.
That doesn't even address the fact that he may have let the impingement go on too long before he had the fusion to begin with, and because of that, the nerve may never wake up. It is possible to recruit enough strength from the other muscles to offset the loss of function of the area the C7 nerve innervates within the triceps, serratus anterior, latissmus dorsi, and biceps brachialis muscle that he will be able to throw, but he will not be able to throw with any indurance.
Basically, think of Dan Marino in 1999. That is what Miami will get with Peyton Manning coming off this injury.