Ohtori S, et al.
Spine J. 2014 Mar 19. pii: S1529-9430(14)00279-4. doi: 10.1016/j.spinee.2013.07.490. [Epub ahead of print]
Abstract
BACKGROUND CONTEXT: Although they have been explored in humans and animal models, the pathomechanisms of discogenic low back pain (LBP) remain unknown.
PURPOSE: To review the literature about the pathomechanisms of discogenic LBP.
METHODS: Animal models of discogenic pain and specimens from degenerated human intervertebral discs (IVDs) have provided clues about the pathomechanisms of discogenic LBP. Painful discs are characterized by a confluence of innervation, inflammation, and mechanical hypermobility. These three possible mechanisms are discussed in this review.
RESULTS: Animal models and specimens from humans have revealed sensory innervation of lumbar IVDs and sensory nerve ingrowth into the inner layer of IVDs. Cytokines such as tumor necrosis factor-α and interleukins induce this ingrowth. Nerve growth factor has also been recently identified as an inducer of ingrowth. Finally, disc degeneration induces several collagenases; their action results in hypermobility and pain.
CONCLUSIONS: To treat discogenic LBP, it is important to prevent sensitization of sensory nerve fibers innervating the IVD, to suppress pathogenic increases of cytokines, and to decrease disc hypermobility.