Cervical Spondylosis – General

Cervical Spondylosis – General

– degenerative changes are nearly universal in the spine; most patients are older than 40 on presentation
– neurologic picture may be from myelopathy (cord compression), radiculopathy (root compression) or both

– patients younger than 55 are more likely to have radiculopathy from soft disc herniation; those over 55 tend to get canal and foraminal stenosis from “hard disc” formation – osteophytes along facets and uncovertebral joints

– most common degeneration at C5-6; then at C6-7

Pathophysiology

– 5 articulations: disc, 2 facets, 2 uncovertebral joints
– the process starts with disc degeneration – dessication, loses water, then loses height. As the uncovertebral joints are brought into proximity, the collapse at the back is halted, and the collapse at the front leads to loss of lordosis
– eventually, facets and uncovertebral joints are degenerative causing osteophyte formation, ligamentum flavum hypertrophy, and annular disruption.

Soft Disc Herniation – 3 Types
1. Intraforaminal – most lateral – most common in young patients. The disc basically goes right out the uncovertebral joint; a C4-5 intraforaminal disc protrusion will get the C5 nerve root which passes above the C5 body
2. Posterolateral – between the posterior edge of the uncinate process and the lateral edge of PLL
3. Central – right through the PLL – seen in older patients when uncovertebral joint spurs act as barriers to posterolateral and intraforaminal herniation.
Hard Disc – more common in patients > 55 years old
– uncovertebral osteophytes or posterolateral facet osteophytes pinch then nerve as it exits through the foramen
– osteophytes from the posterior vertebral margin can also cause cord compression

Vascular Insufficiency
– disc bulges and anterior spurs may compress the anterior spinal artery and its feeders – causing a vascular myelopathy

Dynamic Compression
– extension decreases the canal diameter
– flexion typically increases the canal diameter, but neural structures may be tethered across osteophytes