As recently as 2008 back pain was the number one reason patients visited emergency rooms in the United States. That is incredible to consider.
Chronic lumbar back pain is an incredibly difficult condition to treat often. In some because identifying pain generators in the back is difficult.
I had an interesting discussion and lecture today on the innervation of the lumbar vertebral column.
In very basic terms the anterior portion of the vertebral column and the posterior part of the intervertebral disc are innervated by the sinuvertebral nerves which are recurrent coming off the ventral rami at each level. These nerves form extensive anastamoses with the sympathetic trunk.
The posterior aspect of the vertebral column, including the facet joints, is innervated by lateral, inermediate and medial brances of the dorsal rami. These branches as well enjoy connections with the sympathetic trunk.
Lots more details exist obviously. The most interesting detail however may be that, at least in some animal studies, for all the sinuvertebral and lateral, intermediate and medial branches at all the levels they all eventually “return” through the L1 and L2 dorsal ventral rami.
That means that nocioceptors through a broad area are all returning the same. Is this signal coming from L4 or L1? It may help explain the visceral nature of much back pain and the difficulty in localizing the pain generator at times.
Or maybe I just don’t stand the implications of such. That’s always a possibility as well.