AO CSH Mainstream Study on Cervical Spine Degeneration

Degeneration of the cervical spine is common and encompasses a wide range of pathologies including spondylosis, central canal and neuroforaminal stenosis, facet arthropathy, and ligamentous hypertrophy. Prevalence of MRI cervical degenerative increases with age. Degenerative changes of cervical intervertebral disc from C2 to C7, including loss of signal intensity, posterior and anterior disc protrusion, narrowing of the disc space, and foraminal stenosis, in 497 asymptomatic subjects using MRI; rates of degenerative changes were 17% in males and 12% in females in their 20s and 86% and 89% in males and females in their 60s, respectively. Ten years later, 223 of the 497 subjects were assessed again (FU rate: 44.9%), and the authors reported an overall rate of degenerative changes of 81%, and 34% of subjects developed clinical symptoms. In a 20-year FU of 193 of the 497 subjects (FU rate: 38.8%), the authors found that degenerative changes have progressed in 95% of the subjects, and gross structural failures like anterior compression of the dura/spinal cord and posterior disc protrusion started in half of the subjects in their 30s, gradually worsened with age, and were detected in > 80% of subjects ≥ 40 years of age.

Degeneration of the cervical spine develops over the time due to structural load, repetitive microtrauma, and age-related changes to the spinal axis. The process typically starts with the intervertebral disc physiology resulting in a loss of the supportive nature of the discs and osteophyte formation, which give rise to spinal canal stenosis and chronic compression of the spinal cord. The structural changes may also lead to hypermobility or spondylolisthesis, which, if unstable, will cause dynamic injuries and repetitive microtrauma to the neural elements. C5-C6 is the most affected level owing to its high mobility and increased weight load.

Patients with cervical degeneration may present with a spectrum of symptoms ranging from generalized neck pain, mechanical or axial neck pain, to debilitating neurologic symptoms such as radiculopathy and myelopathy. Degenerative cervical myelopathy is most worrisome presentation and is the most common nontraumatic spinal cord injury with a wide range of symptoms such as hand numbness and paresthesia, gait impairment, motor weakness of the upper and lower extremities, and bladder and bowel dysfunction. Annual incidence of cervical radiculopathy and myelopathy has been estimated as approximately 83 cases per 100,000 persons and 4 per 100,000 persons.

State of the art of the research field Various treatment algorithms have been proposed to manage cervical degeneration Nonsurgical care including analgesics, chronic pain management physical therapy, supervised exercise and manual therapy, acupuncture, and epidural glucocorticoid injections can provide sufficient relief of chronic neck pain and/or radiculopathy. Surgical treatments are indicated especially in the cases of progressive or significant neurologic symptoms and myelopathy. In the past decades, there is an increase of surgical treatments for cervical degenerative radiculopathy or myelopathy as a result of increased availability of MRI diagnostics, an ageing population, advances in surgical techniques, and easier access to specialist healthcare services.

Surgical approaches for treating cervical degenerative radiculopathy or myelopathy include anterior, posterior, and anteroposterior techniques. The goals of the surgery are to adequately decompress the nerve root or spinal cord and stabilize the spinal column while restoring or maintaining relatively normal spinal alignment. ACDF is a recognized and effective surgical treatment for cervical degenerative disease. In a randomized controlled trial of patients with single-level cervical radiculopathy, ACDF plus physiotherapy showed significant improvement in neck disability, demonstrated by a mean reduction of Neck Disability Index score of 21% (95% confidence interval [CI]: 14 - 28%) after 5 to 8 years, compared with 11% (95% CI: 4 - 18%) in the physiotherapy alone group (p = 0.03). Research is ongoing to identify factors predictive of a good or bad outcome of ACDF and techniques to improve the surgical outcomes.