Chronic low back pain caused by intervertebral disc (IVD) degeneration, often referred to as chronic discogenic low back pain (CD-LBP), stands as one of the most prevalent musculoskeletal conditions affecting individuals worldwide. This complex condition is rooted in degenerative processes within the IVD, characterized by inflammation and the breakdown of the extracellular matrix. These processes lead to the release of neurotrophins, which can have profound effects on the nervous system.
As neurotrophin levels rise locally, they stimulate the sprouting and innervation of sensory neurons. Notably, these newly sprouted sensory nerves connect directly to adjacent dorsal root ganglia, which can trigger an increase in microglia activation. This activation contributes to the maintenance and chronification of pain, making CD-LBP a challenging condition to manage effectively.
Current treatment options for CD-LBP often fall short, particularly for long-term relief. Most therapeutic strategies focus on addressing the underlying degeneration of the disc, concentrating on repair and regeneration, while neglecting the crucial aspect of pain management. This gap highlights the need for more comprehensive approaches that not only target disc degeneration but also consider the chronic pain mechanisms at play.
The role of biomolecular therapies in this context is an area that warrants further exploration. The impact of these therapies on the degenerative IVD environment, pain signaling pathways, and the excitability of sensory neurons remains somewhat unclear. Recent reviews have begun to address this underexplored territory, emphasizing the necessity of investigating chronic pain treatment options specifically tailored for CD-LBP.
Interestingly, several approaches aimed at blocking pro-inflammatory mediators or neurotrophin activity have shown promise in reducing neuronal ingrowth into the disc. Moreover, the regenerative and neuroinhibitory properties of extracellular matrix components and transplanted mesenchymal stem cells present intriguing biomolecular strategies. These methods not only aim to halt IVD degeneration but also seek to minimize pain sensitization.
However, it is crucial to note that most biomolecular therapies currently under investigation are based on acute IVD degeneration models. Consequently, these studies may not accurately reflect the chronic pain scenarios experienced by CD-LBP patients. Future research should prioritize examining the effects of therapeutic interventions in chronic degenerated discs that exhibit established sensory nerve ingrowth.
A thorough understanding of how biomolecular therapies influence pain pathways and contribute to pain relief in CD-LBP is essential for bridging the gap between pre-clinical research and clinical application. This knowledge could pave the way for innovative treatments that effectively address both the physical degeneration of the disc and the accompanying chronic pain.
This insightful review on CD-LBP was authored by Imke Rudnik-Jansen, Sanda van Kruining Kodele, Laura Creemers, and Bert Joosten, who bring a wealth of expertise from their respective fields. Their work underscores the pressing need for a shift in focus within pain management strategies, aiming to enhance the quality of life for those suffering from chronic low back pain.
