Regenerative Strategies and Intervertebral Disc Degeneration

Background

The likelihood of back pain increases with age, affecting approximately 80% of people at some point during their lives, and causes disability with estimated healthcare costs of up to $100 billion/year in the United States. ^, Although back pain is multifactorial, a large-scale twin study revealed that intervertebral disc degeneration is one independent risk factor. Furthermore, disc degeneration not only presents as back pain but is also associated with other clinical diagnoses (disc herniation, spinal stenosis, spondylolisthesis) which may lead to radicular pain, numbness, muscle weakness, and ultimately—in the worst-case scenario—paralysis. Although most patients have successful outcomes after conservative treatments such as medications and physical therapy for disc diseases, nonresponders unfortunately do require surgery. Intervertebral disc herniation, an injury produced by degenerative wear and tear that occurs even in adolescence, limits participation in daily activities and sports, and 10% of patients require surgery when nonsurgical treatments yield unsatisfactory improvement. Lumbar spinal stenosis, a narrowing of the spinal canal and/or intervertebral foramina, is the most frequent indication for spinal surgery in elderly patients. Surgical interventions predominantly include the excision of pathologically affected discs and/or spinal fusion, resulting in a loss of function and additional complications because of alterations in biomechanics. However, none of these surgical interventions are directed toward the underlying pathomechanism of disc degeneration itself.