Low back and neck pain are the leading cause of chronic disability world-wide and they are among the most prevalent chronic musculoskeletal conditions in the United States Military and Veteran populations. Physical therapy and rehabilitation are effective at eliminating acute symptoms in most patients, but the number of patients with recurring back and neck pain is also high. Most commonly, back and neck pain are associated with degeneration of the intervertebral disc. The disc is avascular and relies on passive diffusion for uptake of critical nutrients and clearance of harmful byproducts. The disc's ability to repair and regenerate is constrained largely by its limited uptake of these nutrients and clearance of byproducts. More than four decades ago, convection (bulk flow) was explored as a possible strategy to augment diffusion and enhance uptake and clearance of small molecules to/from the disc. Based on these studies, the predominant opinion in the literature for four decades has been that convection does not contribute to the transport of small molecules in the intervertebral disc. Through our award winning research, we have recently disproven the long-standing belief that convection cannot augment diffusion. In fact, using the appropriate protocols, our exciting new results demonstrate that convection can augment diffusion for transport of small molecules to/from the disc. Our results also suggest a novel therapeutic approach to enhance the metabolic activity of the disc and tip the balance away from degeneration toward regeneration. While we have demonstrated enhanced uptake and clearance and enhanced biosynthesis in the disc through our approach, we have not yet optimized the loading parameters to most effectively enhance transport at all stages of degeneration. In the proposed study, we will optimize the loading parameters to most effectively enhance transport at all stages of degeneration in an animal model. We will also determine the effectiveness of our approach to treat discs through the entire spectrum of degeneration from early stage to significantly degenerated. Results from the proposed research will advance our therapeutic strategy toward translation to clinical trials. Ultimately, this research will lead to the development of motion-based weight bearing exercise regimens that arrest or reverse disc degeneration in Veterans.
Low back pain (LBP) is one of the most common causes of disability among military personnel. Military service significantly increases the odds of chronic LBP relative to non-military personnel. Back pain during mili- tary service is a strong predictor of debilitating LBP later in life with the highest risk of disabling LBP being five years after the initial injury. LBP is among the top leading conditions that bring about board reviews and life- time compensation for the Military. Treating chronic LBP remains a challenge among VA clinics with no uniform consensus as to the most effective means to do so. With the aging Veteran population, the incidence of LBP and the burden on the US economy will likely continue to increase. The proposed research is designed to test a promising new rehabilitation strategy which augments the regenerative potential of the native tissues respon- sible for LBP. The proposed work is highly significant because it will advance our therapeutic strategy toward translation to clinical trials. If successful, this will lead to rehabilitation strategies for Veterans with LBP.
