There is one thing that is perfectly clear, the number of
catastrophic cervical spine injuries that result in paralysis
have declined since 1977. That was the was the first year
after the NCAA
and high school rule change which occured in 1976 (regarding
helmet contact and spearing). Although it varies by year,
in general there has been over an 80% reduction in these injuries
On the Surface
Things become a bit murkier when you ask, why have these numbers
decreased? Well, we all agree that axial loading of the cervical
spine is the primary mechanism for these injuries in football.
Axial loading occurs as a result of head-down contact. So
the simplest explanation is there has been a decrease in the
incidence of head down contact and spearing (the mechanism
of injury). This in turn reduced the number of axial loading
injuries. Although, one research
article I did contradicted this concept (I still find
it hard to believe that no one has replicated this study for
more recent data).
What's the Best Indicator
Axial loading and head down contact are our primary concern.
It's important to keep in mind that the primary result
of an axial loading injury is fracture or dislocation to the
cervical vertebrae. Injury to the spinal cord and paralysis
occur secondary to the injury of the vertebrae. So
paralysis is actually a secondary result of axial loading.
This means that you can have a fracture/ dislocation of the
cervical spine without paralysis. And historically the numbers
represent that this is quite frequent. Generally there have
been 3-4 times more fractures/ dislocations of the cervical
spine that occur without paralysis than with paralysis. So
we can say, just about every axial loading injury results
in fracture/dislocation of the cervical spine, but not every
fracture/ dislocation results in paralysis.
If you're following my train of thought, you will agree that
the most accurate indicator of axial loading injuries in football
is the number of cervical spine fractures/dislocations that
occur ... regardless of paralysis. If we want to determine
how succesful we have been reducing axial loading, this is
the best indicator.
Here's the Rub
on cervical spine fractures/dislocations occuring without
paralysis have not been officially collected and reported
since 1987 (by the National Football Head and Neck Injury
Registry). Primarily because this data is much harder to collect
and track reliably. Simply put, it is not as well documented/reported
by the football community. This is according to Dr. Torg and
Dr. Mueller, who have been responsible for collecting it.
It is much easier and more reliable to collect data on athletes
who have had cervical spine injuries that have resulted in
paralysis. So by default it's this number that has become
our indicator of success or failure.
But let's take a look at the numbers we do have from 1976
through 1987. The reduction in these injuries has varied between
about 20% and 60%. While still substantial, it's not as successful
as the reduction in the athletes that have been paralyzed
during that period. Graphs representing this data can be found
in this article.
Between 1977 and 1987 there was a high of 96 and a low of
32 for fractures/ dislocations.
for 2005 the National
Football Head and Neck Injury Registry has reported 3
injuries that resulted in paralysis. Only one cervical fracture/
dislocation without paralysis is reported. It is also clearly
stated that the non paralysis data are not considered reliable.
No data is included on previous years for the fractures/ dislocations
(but from my memory of previous reports it's been less than
5/ year). From the numbers we have from the 1980's I would
expect to see between 9-12 fractures dislocations in 2005
if there were 3 athletes paralyzed. In 2004 there were 12
athletes paralyzed and I would expect to see between 36 and
48 fractures/ dislocations.
So have the numbers of fractures/ dislocations occurring without
paralysis really decreased this much from the 1980's? Or are
we just not finding out about them? My guess is the latter.
In my mind, these are the pressing questions:
How much of the decrease in paralyzed football players is
accounted for by improvements in their care after an
axial loading injury has already occured? (Improved on the
field management and improved surgical techniques/ strategies)
And how much of the decrease in paralyzed football players
is accounted for by eliminating head down contact from football
and actually preventing cervical fractures/dislocations
from occurring in the first place? Without the primary injury,
the secondary result of paralysis can not occur.
It seems the answer to these questions lies in finding the
accurate number of fracture/ dislocations that occur without
paralysis on an annual basis. And I don't know that we will
ever have an accurate picture of this.
But keep in mind that the possibility exists that head down
contact occurs about as frequently as it did in the 1970's
and we haven't been as successful as we think in preventing
axial loading injuries of the cervical spine in football.
We have been successful in improving the post injury care.
Or perhaps a sliding scale between the two.