Degenerative deterioration of the vertebrae, intervertebral disks, the facet, and other joints of the spine can result in cervical spondylotic myelopathy.^1,2 Hypertrophy and ossification of the posterior longitudinal ligament and the ligamentum flavum can lead to spinal cord compression, injury, and subsequent myelopathy.³

This article focuses on the progressive and degenerative musculoskeletal changes that lead to pathologic changes in the spinal cord. Many other conditions can lead to myelopathy (Table 1⁴ ) and should be considered in appropriate clinical scenarios.

A combination of static and dynamic factors plays a role in the development of symptomatic degenerative cervical myelopathy.^5–7 Patients with the condition typically present in their late 50s to early 60s with signs and symptoms ranging from vague cervical spine pain to frank myelopathy from significant spinal cord compression. Patients with degenerative cervical myelopathy usually deteriorate over time; however, the rate of deterioration is unpredictable and highly variable.^8,9

Patients with degenerative cervical myelopathy often first present to their primary care physicians with a wide range of symptoms. Although conservative treatment is an acceptable initial approach for patients with mild to moderate symptoms, 20% to 60% of these patients deteriorate over three to six years and may eventually require surgical intervention.^7,10,11 Studies have shown that a delay in diagnosis and referral by primary care physicians can lead to poorer outcomes.¹² Therefore, it is important to promptly recognize, evaluate, and appropriately refer patients with signs and symptoms of degenerative cervical myelopathy. Primary care physicians play a vital role not only in diagnosis but in treatment coordination and comorbidity management.

Incidence and Prevalence

Degenerative cervical myelopathy is the most common degenerative, nontraumatic, and progressive form of spinal cord compression worldwide.^3,10,13,14 It is also recognized as the leading cause of spinal cord impairment and indication for cervical spine surgery worldwide.^15,16 Because of differences in terminology, it is difficult to determine the exact incidence and prevalence of degenerative cervical myelopathy. In North America, the published annual incidence is 41 per 1 million and prevalence is 605 per 1 million.^3,14 In the United States alone, 15,000 to 20,000 people are hospitalized every year for treatment of degenerative cervical myelopathy at a cost of several hundred million dollars.¹⁷ The average age at presentation is 64 years, it is more common in men (3:1 male-to-female ratio), and C5–C6 is the most common level of cord compression followed by C6–C7 and C4–C5.^1,18,19

The high prevalence of asymptomatic individuals with radiographic evidence of cervical degeneration presents a challenge in determining the burden of this condition and supports the importance of a thorough clinical history and physical examination to avoid overdiagnosis. Multiple studies have shown that in patients older than 40 years, 50% to 60% have evidence of disk degeneration, 20% have foraminal stenosis, and upwards of 10% have clinically significant root or cord compression.^1,8,9,19 These numbers increase with age, and 95% of men and 70% of women older than 70 years have evidence of cervical spondylosis.^15,18