With multiple teams likely to pursue Peyton Manning's services when he is officially released by the Indianapolis Colts, the primary question that remains is whether the future Hall of Fame quarterback has recovered sufficiently from last September's cervical vertebral fusion to play at the level we are all accustomed to watching.
Ultimately, the answer will have less to do with the health of Manning's surgically-repaired neck than it does the nerves along his right arm.
Manning's most recent operation, the fourth performed on his neck, was performed last September to relieve arm pain and weakness due to the presence of a bulging (herniated) disc in his neck. A herniated disc occurs when the contents of the cartilage that normally separate the vertebrae spill out and start "pinching" on the nerves that exit the spine. The type of radiating pain that often follows is referred to as radicular pain (or radiculopathy) and may be felt in other parts of the body such as the leg or arm. Along with pain, numbness, tingling and muscle weakness can be present in the affected extremities. Although a herniated cervical disc (located in the neck) may originate from trauma or injury to the spine, the symptoms commonly start spontaneously and without warning.
Surgical treatment for a cervical herniated disc can be approached either anteriorly (incision made from the front/side of the neck, such as today's procedure) or posteriorly (incision made from the back of the neck). During an anterior cervical fusion, as was performed last September, the offending disc is removed through the front of the neck and then the vertebrae above and below the empty disc space are usually fused using a combination of bone grafts, plates, screws and/or rods. This cervical fusion process stabilizes the spine, keeping the vertebrae in position and out of the way of the offending nerves.
Most side effects from cervical fusion generally relate to either the integrity of the bone graft itself or to damage to the nerves that arise from the spinal cord near the site of the surgery. Although much of the concern since Manning's latest procedure has been directed at the potential for damage to his fused vertebral column, the most critical window for graft failure is within the first several months following surgery, when the remodeled bone undergoes reshaping and hardening. By all indications, this window has long since closed, and therefore Manning's risk for injury to the vertebral column surrounding his neck going forward is related to the degree of force and torque applied during the course of action. Which is to say, not terribly unlike the risk most quarterbacks in the NFL face every Sunday.
The issue of nerve regeneration, however, is one that will require a great deal of scrutiny from any team considering Manning as its next quarterback. A number of nerves run from the vertebral column in the neck down to the arms. When they are damaged, as in Manning's case, significant weakness and/or pain of the affected limbs may result. These nerves consist of one long strand from the neck down through the arm and to the hand, and this length is one key reason the nerves tend to heal slowly. The nerves heal from the top down, and depending on how much damage is done at the time the nerve becomes impinged, it may take months for the nerve to fully heal, with the hand coming last of all. For a quarterback, whose ability to throw the ball with velocity and accuracy, this nerve strength is of paramount importance.
Reports as recently as six weeks ago seemed to indicate that Manning's healing process was progressing slowly, with some outlets reporting him having trouble putting zip on the ball beyond 15-20 yards and struggling to throw the ball to one side or the other. This would indicate that the muscles in the triceps and hand muscles, which are directly affected by the cervical nerves, had not been rebuilt sufficiently since the last surgery.
But days ago, a video surfaced of Manning running an offense at an impromptu practice session at Duke University, seemingly having recovered much of his arm strength and running an offense as we have grown accustomed to watching Peyton Manning do. The fact that there appears to have been consistent improvement in Manning's nerve and muscle function over the past weeks indicates not only that he is in a phase of rapid improvement, but also that his recovery has not plateaued yet, which can occur prior to individuals reaching their level of function prior to similar surgeries.
Was this 30-second clip proof that Manning will ever regain the same level of nerve and muscle function as prior to his surgery last September? This question remains to be answered. But either way, it highlighted the fact that in the coming days and weeks, the progress of Manning's nerve regeneration, rather than the strength of his bone graft, is the key factor teams must consider when deciding whether he is the man to lead them in 2012.