= SPONDYLOARTHROPATHY
= group of chronic inflammatory rheumatic diseases not associated with rheumatoid factor / rheumatoid nodules
Prevalence: 0.51.9%
Subgroups:
Stage of Spondyloarthropathy by MR characteristics
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Location: predominantly axial skeleton (sacroiliac joints frequently first involved)
Site: vertebra, intervertebral disk, synovial joints of spine, tendon, ligamentous attachment (enthesis)
Extraaxial involvement:
Prognosis: syndesmophytes + ankylosing spondylitis with longstanding disease
Rx: NSAID, TNF (tumor necrosis factor)α inhibitors, intensive physical therapy
DDx: rheumatoid arthritis, degenerative disk disease, diffuse idiopathic skeletal hyperostosis, pyogenic spondylodiskitis, vertebral fracture, Paget disease
= ROMANUS LESION (ENTHESITIS)
= inflammation of attachment of annulus fibrosus to vertebral endplate (rim of endplate)
Site: edge of endplates
MR:
= ANDERSON LESION = RHEUMATIC SPONDYLODISKITIS
= noninfectious inflammation of intervertebral disk by spondyloarthritis
Prevalence: 8% of radiographs in ankylosing spondylitis
Site: diskovertebral unit (= intervertebral disk and adjacent halves of superior and inferior vertebrae)
MR:
Dialysis-associated Spondyloarthropathy
= spondyloarthropathy in patients on long-term hemodialysis of >3 years duration
Frequency: 20% of patients on long-term hemodialysis
Cause: amyloid (β2-microglobulin) deposition in synovium and intervertebral disks
Location: lower cervical spine >craniocervical junction >thoracolumbar spine
Associated with: amyloid arthropathy of hands + wrists
Site: usually multiple levels of involvement
MR:
DDx: