Potential Role for Stem Cell Regenerative Therapy as a Treatment for Degenerative Disc Disease and Low Back Pain: A Systematic Review.

Back pain is the single leading cause of disability worldwide. Despite the prevalence and morbidity of lower back pain, we still lack a gold-standard treatment that restores the physiological function of degenerated intervertebral discs. Recently, stem cells have emerged as a promising strategy for regenerative therapy for degenerative disc disease. In this study, we review the etiology, pathogenesis, and developing treatment strategies for disc degeneration in low back pain with a focus on regenerative stem cell therapies. A systematic search of PubMed/MEDLINE/Embase/Clinical Trials.gov databases was conducted for all human subject abstracts or studies. There was a total of 10 abstracts and 11 clinical studies (1 RCT) that met the inclusion criteria. The molecular mechanism, approach, and progress of the different stem cell strategies in all studies are discussed, including allogenic bone marrow, allogenic discogenic cells, autologous bone marrow, adipose mesenchymal stem cells (MSCs), human umbilical cord MSC, adult juvenile chondrocytes, autologous disc derived chondrocytes, and withdrawn studies. Clinical success with animal model studies is promising; however, the clinical outcomes of stem cell regenerative therapy remain poorly understood. In this systematic review, we found no evidence to support its use in humans. Further studies on efficacy, safety, and optimal patient selection will establish whether this becomes a viable, non-invasive therapeutic option for back pain.

How Is Spinal Cord Function Measured in Degenerative Cervical Myelopathy? A Systematic Review.

Degenerative cervical myelopathy (DCM) is a prevalent condition in which spinal degeneration causes cord compression and neurological dysfunction. The spinal cord is anatomically complex and operates in conjunction with the brain, the musculoskeletal system, and numerous organs to control numerous functions, including simple and coordinated movement, sensation, and autonomic functions. As a result, accurate and comprehensive measurement of spinal cord function in patients with DCM and other spinal pathologies is challenging. This project aimed to summarize the neurological, functional, and quality of life (QoL) outcome measures currently in use to quantify impairment in DCM. A systematic review of the literature was performed to identify prospective studies with at least 100 DCM subjects that utilized one or more quantitative neurological, functional, or QoL outcome measures. A total of 148 studies were identified. The most commonly used instruments were subjective functional scales including the Japanese Orthopedic Association (JOA) (71 studies), modified JOA (mJOA) (66 studies), Neck Disability Index (NDI) (54 studies), and Nurick (39 studies), in addition to the QoL measure Short-Form-36 (SF-36, 52 studies). A total of 92% (320/349) of all outcome measures were questionnaires, whereas objective physical testing of neurological function (strength, gait, balance, dexterity, or sensation) made up 8% (29/349). Studies utilized an average of 2.36 outcomes measures, while 58 studies (39%) utilized only a single outcome measure. No studies were identified that specifically assessed the dorsal column sensory pathway or respiratory, bowel, or sexual function. In the past five years, there were no significant differences in the number of total, functional, or QoL outcome measures used, but physical testing of neurological function has increased (p = 0.005). Prior to 2017, cervical spondylotic myelopathy (CSM) was the most frequently used term to describe the study population, whereas in the last five years, DCM has become the preferred terminology. In conclusion, clinical studies of DCM typically utilize limited data to characterize impairment, often relying on subjective, simplistic, and non-specific measures that do not reflect the complexity of the spinal cord. Although accurate measurement of impairment in DCM is challenging, it is necessary for early diagnosis, monitoring for deterioration, and quantifying recovery after therapeutic interventions. Clinical decision-making and future clinical studies in DCM should employ a combination of subjective and objective assessments to capture the multitude of spinal cord functions to improve clinical management and inform practice guidelines.