Chronic spinal pain is a common global problem, one of the most leading causes of disability among adults worldwide. It covers chronic neck, thoracic, and low back pain. Chronic spinal pain in the absence of radiculopathy, myelopathy, or clear serious underlying disease is also called mechanical pain. Despite the frequency of this presenting complaint, a clear understanding of its etiologies is often elusive. Any innervated neck structures, such as muscles, synovial joints, intervertebral discs, dura mater, and ligaments, may cause pain theoretically. Among all the causes of chronic spinal pain, discogenic and facetogenic pain related to degeneration of intervertebral discs and facet joints have been thought as the top two common causes. Despite its enduring presence, pain ostensibly emanating from a disc or a facet joint itself has hitherto remained poorly defined, and its diagnosis and treatment have been exceedingly controversial.

For patients with chronic spinal pain alone, in the absence of obvious lesions, the specific anatomic cause of pain and illness can rarely be known with certainty unless precision and fluoroscopically guided diagnostic procedures are performed. Imaging studies, in particular magnetic resonance imaging, may reveal no abnormality or show common degenerative changes that are most frequently observed among people without spinal pain. Under such circumstances, some invasive diagnostic techniques, such as discography and facet joint injection or nerve block, may have to be used. Acceptable low false positive rates can only be maintained using these diagnostic procedures by adhering to stringent operational criteria.

The conservative therapy includes the use of nonsteroidal anti-inflammatory drugs, muscle relaxants, or even a short course of opioid pain medication in conjunction with nonpharmacological strategies such as physical therapy, all of which lead to improvement in a majority of patients. However, if conservative therapy fails in symptomatic relief, some invasive treatments such as epidural steroid injections, facet injections, and radiofrequency ablations are generally considered. Unfortunately, these invasive procedures may not decrease the need for subsequent surgeries in patients with chronic neck or back pain secondary to degenerative cervical or lumbar intervertebral discs if the exact diagnosis is not confirmed. Surgical intervention in the absence of disc herniation, stenosis, or clear obvious underlying disease is controversial. Because the reported results vary considerably in different studies, the debate continues as to whether surgical treatment should be attempted.

This special issue seeks to cover chronic spinal pain related basic and clinical studies. Authors are cordially invited to submit high-quality review or research articles that may improve our understanding on pathophysiology, diagnosis, and treatment of chronic spinal pain. We will give priority to new pathophysiological insights, new diagnostic and differential methods, and treatment of chronic spinal pain. Of course, long term randomized double-blind clinical control studies are especially welcome in the treatment of chronic spinal pain.

Potential topics include but are not limited to the following:

• Novel insights into pathophysiology of chronic spinal pain
• Epidemiology of chronic spinal pain
• Natural history of chronic spinal pain
• Diagnostic and differential methods
• Discography and facet joint block related basic and clinical study
• Treatment of chronic spinal pain including conservative, invasive, surgical, or biologic methods