| Introduction |
- Cervical spondylosis is defined as chronic disc degeneration and associated facet arthropathy that can lead to the following clinical conditions
- cervical radiculopathy
- cervical myelopathy
- discogenic neck pain
- Epidemiology
- cervical spondylosis typically begins at age 40-50
- most common levels are C5-6 > C6-7 because they are associated with the most flexion and extension in the subaxial spine
- more common in men than women
- Risk factors include
- excessive driving
- smoking
- lifting
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| Pathoanatomy |
- Spondylosis is a natural aging process of the spine
- characterized by degeneration of the disc and the four joints of the cervical motion segment which include
- two facet joints
- two uncovertebral joints of Luschka)
- Degenerative cycle includes
- disc degeneration
- disc dessication, loss of disc height, disc bulging, and possible disc hernaition
- joint degeneration
- uncinate spurring and facet arthrosis
- ligamentous changes
- ligamentum flavum thickening and infolding secodary to loss of disc height
- deformity
- kyphosis secondary to loss of disc height with resulting transfer of load to the facet and uncovertebral joints, leading to further uncinate spurring and facet arthrosis
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| Mechanism of Neurologic Compression |
- Nerve root compression (radiculopathy) caused by
- foraminal spondylotic changes
- secondary to chondrosseous spurs of facet and uncovertebral joints
- posterolateral disc herniation
- between posterior edge of uncinate and lateral edge of PL
- usually affects the nerve root below (C6/7 disease will affect the C7 nerve root)
- Central cord compression (myelopathy)
- occurs with canal diameter is < 13mm (normal is 17mm)
- worse during neck extension whe central cord is pinched between
- degenerative disc (anterior)
- hypertrophic facets and infolded ligamentum (posterior)
- in asians can be caused by ossification of the posterior longitudinal ligament
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| Evaluation |
- Radiographs
- common radiographic findings include
- degenerative changes of uncovertebral and facet joints
- osteophyte formation
- disc space narrowing
- endplate sclerosis
- decreased sagital diameter (cord compression occurs with canal diameter is < 13mm)
- changes often do not correlate with symptoms
- 70% of patients by 70 yrs of age will have degenerative changes seen on plain xrays
- lateral
- important to look for sagital alignment and size of spinal canal
- oblique
- important to look for foraminal stenosis which often caused by uncovertebral joint arthrosis
- flexion and extension views
- important to look for angular or translational instability
- look for compensatory subluxation above or below the spondylotic/stiff segment
- MRI
- axial imaging is the modality of choice and gives needed information on the status of the soft tissues. It may show
- disc degeneration
- spinal cord changes (myelomalacia)
- preoperative planning
- has high rate of false positive (28% greater than 40 will have findings of HNP or foraminal stenosis)
- CT myelography
- can give useful information on bony anatomy
- most useful when combined with intrathecal injection of contrast (myelography) to see status of neural elements
- contrast given via C1-C2 puncture and allowed to diffuse caudally or given via a lumbar puncture and allowed to diffuse proximally by putting patient in trendelenburg position.
- paricularly useful in patients that can not have an MRI (pacemaker) or has artifact (local hardware)
- Discography
- controversial and rarely indicated in cervical spondylosis
- approach is similar to that used with ACDF
- risks include esophageal puncture and disc infection
- Nerve conduction studies
- high false negative rate
- may be useful to distinguish peripheral from central process (ALS)
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| Presentation and Treatment |
- Cervical radiculopathy
- Cervical myelopathy
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