The Hip: Preservation, Replacement and Revision

Pathoanatomy of Cervical Spondylosis



- Pathoanatomy:
    - osteophytosis occurs as result of breakdown in the out annular fibers of annulus fibrosis;
            - disk material stretching & displacing these fibers, causing stress at ligamentous attachments leading to formation of osteophytes;
            - osteophytes collects initially extend horizontally;
            - later on osteophytes extend vertically from edges of vertebra, sometimes bridging disk space;
    - involves the disc, two facet joints & two false uncovertebral joints (Lushka);
    - cervical cord becomes impinged when diameter of canal (normally about 17 mm) is reduced to less than 13 mm;
    - hyperextension:
           - cord increases in diameter and it & roots are pinched between discs and adjacent spondylitic bars anteriorly, and hypertrophic 
                  facets and infolded ligamentum flavum posteriorly;
    - hyperflexion:
           - cord narrows and the neural structures are  tethered anteriorly across discs or spondylitic bars;
    - radiculopathy:
           - spondylotic changes in the foramina primarily from chondro-osseous spurs of the joints of Luschka may restrict motion and may 
                  lead to nerve root compression;
    - soft disc herniation:
           - is usually posterolateral, between posterior edge of uncinate process & lateral edge of posterior longitudinal ligament, resulting in 
                  acute radiculopathy;
    - myelopathy:
           - central herniation;
           - spondylotic bars with a congenitally narrow canal;

- Apophyseal Joints:
    - show early irregularity and blurring of the joint surfaces;
    - joint space narrowing and eventual spurring and sclerosis;
    - lateral view & oblique view:
           - allows evaluation of facet joints;
           - determine if osteophytes of apophyseal joints project medially into foramina canal;
    - specifically, osteophytes arising from the ventral portion of superior articular process may cause symptomatic foraminal narrowing;
    - rarely osteophytes may also project anteriorly and impinge upon vertebral artery, resulting in arterial insufficiency;
    - loss of disk height leads to reduced neuroforaminal volume, rendering root more susceptible to compression;

- Joints of Luschka:
    - joints give rise to bony spurs or ridges -osteophytes- as can main fascet joints & edges of vertebral bodies adjacent to intervertebral disc;
           - this is symphysis type of articulation between vertebral bodies;
           - exiting nerve root on each side travels between these joints, & can be compressed by osteophytes extending into intervertebral 
                 foramen from any or all three of sources mentioned



 



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Wednesday, December 21, 2011 3:06 pm