Spine in Ankylosing Spondylitis

- See: Cervical Spine in Ankylosing Spondylitis

- Clinical Findings:
    - loss of lumbar lordosis;
    - back motion is limited;
           - note that ability to lean forward has more to do with hip flexion than lumbar spine flexion;
           - w/ forward flexion there should be a reversal of the normal lumbar lordosis;
    - hip flexion contractures or cervicothoracic kyphosis is common;
           - these conditions require correction;
    - may have fixed cervical, thoracic, or lumbar hyperkyphosis;
    - may cause marked functional limitations, primarily due to inability of affected patients to face forward;
    - pts may have diminished chest expansion;

- Spine Frx in AS:
      - progressive neural deterioration;
      - loss of reduction
      - epidural hematoma;
            - neurologic deficit occuring at higher level than at frx site may indicate expanding hematoma which is more common in AS;
      - non union;
      - occult frx;
      - progressive kyphosis;
      - death in > 50% of cases;

- Radiographic Changes:


    - symmetric, bilateral subchondral erosions of the sacroiliac joints;
          - subchondral sclerosis then follows, first on the iliac side and then on both sides of the joints.
    - disease first affects lumbar spine and then ascends to thoracic spine;
    - vertebrae appear squared off on the lateral radiographs.
    - longitudinal ligaments & annulus ossify, creating marginal syndesmophytes;
          - spine takes on bamboo appearance from the sacrum to the occiput;
          - SI joint obliteration & marginal syndesmophytes allow radiographic differentiation from DHIS;
          - in Reiter's syndrome and Psoriatic Arthritis, beaklike nonmarginal syndesmophytes may be seen;
    - fascet joint are simultaneously obliterated;

- Treatment:
    - C-spine may be corrected by C7-T1 osteotomy & fusion w/ local anesth;
    - complications of osteotomies include nonunion, loss of correction, & neurologic and aortic injury;
    - extension osteotomy and fusion of the lumbar spine with compression instrumentation can successfully balance the head over the sacrum

Thoracolumbar fractures in ankylosing spondylitis. High-risk injuries.

The pathogenesis of extensive discovertebral destruction in ankylosing spondylitis.

Secure fixation of lumbar osteotomy. Surgical experience with 50 patients.

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

Last updated by Data Trace Staff on Tuesday, August 21, 2012 4:11 pm