Spinal pain

The spinal pain, and expecially the low back pain (LBP), represents the second cause for a medical consultation in primary care setting and a leading cause of disability worldwide [1]. LBP is more often idiopathic. It has as most frequent cause the internal disc disruption (IDD) and is referred to as discogenic pain. IDD refers to annular fissures, disc collapse and mechanical failure, with no significant modification of external disc shape, with or without endplates changes. IDD is described as a separate clinical entity in respect to disc herniation, segmental instability and degenerative disc desease (DDD). The radicular pain has as most frequent causes a disc herniation and a canal stenosis. Both discogenic and radicular pain also have either a mechanical and an inflammatory genesis. For to be richly innervated, facet joints can be a direct source of pain, while for their degenerative changes cause compression of nerve roots in lateral recesses and in the neural foramina. Degenerative instability is a common and often misdiagnosed cause of axial and radicular pain, being also a frequent indication for surgery. Acute pain tends to extinguish along with its cause, but the setting of complex processes of peripheral and central sensitization may influence its evolution in chronic pain, much more difficult to treat. The clinical assessment of pain source can be a challenge because of the complex anatomy and function of the spine; the advanced imaging methods are often not sufficient for a definitive diagnosis because similar findings could be present in either asymptomatic and symptomatic subjects: a clinical correlation is always mandatory and the therapy cannot rely uniquely upon any imaging abnormalities. Purpose of this review is to address the current concepts on the pathophysiology of discogenic, radicular, facet and dysfunctional pain, focusing on the role of the imaging in the diagnostic setting, to potentially address a correct approach also to minimally invasive interventional techniques. Special attention will be done to the discogenic pain, actually considered as the most frequent cause of chronic low back pain.