Cervical Spondylosis - Spine

Introduction
Cervical spondylosis represents the natural degenerative process of the cervical motion segment (intervertebral disc and facets) often leads to the clinical conditions of cervical radiculopathy cervical myelopathy discogenic neck pain Epidemiology incidence typically begins at age 40-50 85% of patients >65 years of age demonstrate spondylotic changes regardless of symptomatology demographics more common in men than women location most common levels are C5-6 > C6-7 because they are associated with the most flexion and extension in the subaxial spine Pathophysiology pathoanatomy see below risk factors include excessive driving smoking lifting professional athletes
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 desiccation, loss of disc height, disc bulging, and possible disc herniation joint degeneration uncinate spurring and facet arthrosis ligamentous changes ligamentum flavum thickening and infolding secondary 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
Mechanism of Neurologic Compression
Nerve root compression leads to the clinical condition of radiculopathy foraminal spondylotic changes secondary to chondrosseous spurs of facet and uncovertebral joints posterolateral disc herniation or disc-osteophyte complex between posterior edge of uncinate and lateral edge of posterior longitudinal ligament (PLL) affects the exiting nerve root (C6/7 disease will affect the C7 nerve root) foraminal soft disc herniation affects the exiting nerve root (C6/7 disease will affect the C7 nerve root)s Central cord compression (central stenosis) leads to the clinical condition of myelopathy occurs with canal diameter is < 13mm (normal is 17mm) worse during neck extension where the central cord is pinched between degenerative disc (anterior) hypertrophic facets and infolded ligamentum (posterior)
Imaging
Radiographs common radiographic findings include degenerative changes of uncovertebral and facet joints osteophyte formation disc space narrowing endplate sclerosis decreased sagittal diameter (cord compression occurs with canal diameter is < 13mm) incidence radiographic findings often do not correlate with symptoms lateral important to look for sagittal 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 is given via C1-C2 puncture and allowed to diffuse caudally or given via a lumbar puncture and allowed to diffuse proximally by putting the patient in Trendelenburg position. particularly useful in patients that can not have an MRI (pacemaker) or has artifact from hardware Discography controversial and rarely indicated in cervical spondylosis approach is similar to that used with ACDF risks include esophageal puncture and disc infection
Clinical Presentation
Axial neck pain Cervical Radiculopathy Cervical Myelopathy