AAOS Comprehensive Orthopaedic Review 4: Print + Ebook (AAOS - American Academy of Orthopaedic Surgeons)

151

15 | Degenerative Conditions of the Cervical Spine

4. Herniated disk materials can incite the produc tion of various inflammatory cytokines, such as interleukin 1 and 6, substance P, bradykinin, tumor necrosis factor alpha, and prostaglandins. B. Evaluation 1. History and physical examination a. Patients frequently have unilateral neck pain that radiates ipsilaterally into the distribution of the affected root ( Table 1 ). • The most common levels of root involve ment are C6 and C7. • Less common levels of root involvement are C2, C3, C4, C8, and T1. b. The absence of radiating symptoms in a der matomal distribution does not rule out the presence of symptomatic nerve root compres sion. In addition, up to 80% of patients may complain of cervicogenic headaches. c. Patients also may report upper trapezial and interscapular pain. • A physical examination should be per formed to identify the nerve root involved, with the caveat that crossover between myotomes and dermatomes may be present. Anomalous distribution of myotomes and dermatomes is common. • Patients with a prefixed brachial plexus will have C4-C8 nerves comprising the brachial

Figure 1 Axial T2-weighted magnetic resonance image demonstrates a left posterolateral soft disk herniation with compression of the exiting root.

b. Hard disk pathology ( Figure 2 )—Chronic disk degeneration with resultant disk height loss can lead to a combination of annular bulging without frank herniation or the formation of degenerative osteophytes that typically arise from the uncinate regions of the posterolateral vertebral body (uncovertebral osteophytes). 2. Loss of disk height resulting in subsequent foram inal root compression 3. Hypertrophy of the facet joints or synovial cysts

2 | Spine

B Figure 2 Images from a patient with an uncovertebral osteophyte. A , Axial T2-weighted magnetic resonance image demonstrates the spur, which is greater on the right than the left. B , Axial postmyelogram CT image confirms that the compressive entity in A is an uncovertebral spur rather than soft disk material. Note that the axial slice cuts obliquely through the disk space, through the foramen on the right versus the pedicle on the left. It can be difficult to differentiate soft versus hard disk pathology on MRI alone. Although myelography was used in this example, it is not needed routinely when high-quality MRI is obtained if the purpose is to delineate hard versus soft disk pathology. A noncontrast CT image can be used under those circumstances to complement informa tion obtained on MRI. Copyright © Wolters Kluwer, Inc. Unauthorized reproduction of the content is prohibited. 2023 A

© 2025 American Academy of Orthopaedic Surgeons

AAOS Comprehensive Orthopaedic Review 4