Ankylosing spondylitis (also known as Bechterew's disease and Marie Strümpell disease) is a seronegative spondyloarhropathy which characteristically (as the name suggests) results in fusion (ankylosis) of the spine and sacroiliac joints, although involvement is also seen in large and small joints.
There is male predilection of 3:1 or more. It usually manifests in adults, with the first symptoms becoming evident in the third decade, although up to 18% of cases manifest in the second decade.
Patients are rheumatoid factor (Rh) negative (hence seronegative). Approximately 90% of Caucasian individuals have the HLA-B27 gene 5.
- anterior uveitis
- ulcerative colitis/ Crohns disease
- upper lobe predominant interstitial lung disease with small cystic spaces (occurs in approximately 1% of patients) 4
- aortic valve disease / aortitis
- amyloidosis (rare)
Features predominantly affect the axial skeleton although can involve the peripheral joints in ≈ 20% of cases
- a sacroiliitis is usually the first manifestation 5 and is symmetrical and bilateral
- joints widen before they narrow
- subchondral erosions, sclerosis and proliferation on the iliac side of SI joints
- at endstage, the sacroiliac joint may be a thin line or not visible
- early spondylitis is characterized by small erosions at the corners of vertebral bodies with reactive sclerosis
- squaring of the vertebral body
- diffuse syndesmophyitic ankylosis can give a "bamboo spine" appearance
- interspinous ligament calcification can give a "dagger spine" appearance
- ossification of spinal ligaments, joints and discs.
- pseudoarthroses may form at fracture sites.
- enthesophyte formation from enthesopathy.
- Romanus lesions of the spine - shiny corner sign.
Hip involvement is generally bilateral and symmetric, with uniform joint space narrowing, axial migration of the femoral head, and a collar of osteophytes at the femoral head-neck junction.
Knees demonstrate uniform joint space narrowing with bony proliferation
Hands are generally involved asymmetrically, with smaller, shallower erosions and marginal periostitis.
Radiographs of the lungs may demonstrate progressive fibrosis and bullous changes at the apices. These lesions may resemble TB infection and bullae may become infected.
- CT may be useful in selected patients with normal or equivocal findings on sacroiliac joint radiographs.
- joint erosions, subchondral sclerosis, and bony ankylosis are better visualized on CT.
- some normal variants of the SI joints may mimic features of sacroiliitis
- CT supplements scintigraphy in evaluating areas of increased uptake
- multi-detector CT (MDCT) is superior to radiographs and MRI in demonstrating injuries
- MDCT is imaging modality of choice in patients with advanced ankylosing spondylitis for whom there is suspicion of cervical spine fracture.
- sagittal reformats should be obtained as axial images poorly assess the transverse fracture plane
- may have a role in early diagnosis of sacroiliitis
- synovial enhancement on MR correlates with disease activity measured by inflammatory mediators
- enhancement of the interspinuous ligamants is indicative of an enthesitis
- increased T2 signal correlates with edema or vascularized fibrous tissue
- superior to CT in detection of cartilage, bone erosions, and subchondral bone changes
- useful in following treatment results in patients with active ankylosing spondylitis
- may be helpful in selected patients with normal or equivocal findings on sacroiliac joint radiographs
- qualitative assessment of accumulation of radionuclides in the SI joints may be difficult due to normal uptake in this location. Thus quantitative analysis may be more useful.
- ratios of SI joint to sacral uptake of 1.3:1 or higher is abnormal
Fracture(s) : Diffuse paraspinal ossification and inflammatory osteitis creates a fused, brittle spine, susceptible to fracture, even with minor trauma. Fractures are more common at the thoracolumbar and cervicothoracic junctions. Recognition of minimally displaced fractures is difficult due to osteopenia and deformity, and it is important to specifically search for disk space widening and discontinuity of the ossified paraspinal ligaments
Andersson lesion(s) : an Andersson lesion is an inflammatory spondylodiscitis which occur in association with ankylosing spondylitis and results in a disc pseudoarthrosis
Treatment and prognosis
Treatment includes NSAIDs, physiotherapy and, for more severe cases, anti-TNF-alpha therapy.
- 1. Riley MJ, Ansell BM, Bywaters EG. Radiological manifestations of ankylosing spondylitis according to age at onset. Ann. Rheum. Dis. 1971;30 (2): 138-48. doi:10.1136/ard.30.2.138 - Free text at pubmed - Pubmed citation
- 2. Resnick D, Niwayama G. Entheses and enthesopathy. Anatomical, pathological, and radiological correlation. Radiology. 1983;146 (1): 1-9. Radiology (abstract) - Pubmed citation
- 3. Wilkinson M, Bywaters EG. Clinical features and course of ankylosing spondylitis; as seen in a follow-up of 222 hospital referred cases. Ann. Rheum. Dis. 1958;17 (2): 209-28. Ann. Rheum. Dis. (citation) - Free text at pubmed - Pubmed citation
- 4. Mayberry JP, Primack SL, Müller NL. Thoracic manifestations of systemic autoimmune diseases: radiographic and high-resolution CT findings. Radiographics. 20 (6): 1623-35. Radiographics (full text) - Pubmed citation
- 5. Wang YF, Teng MM, Chang CY et-al. Imaging manifestations of spinal fractures in ankylosing spondylitis. AJNR Am J Neuroradiol. 2005;26 (8): 2067-76. AJNR Am J Neuroradiol (full text) - Pubmed citation
- 6. Jacobson JA, Girish G, Jiang Y et-al. Radiographic evaluation of arthritis: inflammatory conditions. Radiology. 2008;248 (2): 378-89. doi:10.1148/radiol.2482062110 - Pubmed citation
- 7. Baraliakos X, Landewé R, Hermann KG et-al. Inflammation in ankylosing spondylitis: a systematic description of the extent and frequency of acute spinal changes using magnetic resonance imaging. Ann. Rheum. Dis. 2005;64 (5): 730-4. Ann. Rheum. Dis. (full text) - doi:10.1136/ard.2004.029298 - Free text at pubmed - Pubmed citation
- 8. Bennett DL, Ohashi K, El-khoury GY. Spondyloarthropathies: ankylosing spondylitis and psoriatic arthritis. Radiol. Clin. North Am. 2004;42 (1): 121-34. doi:10.1016/S0033-8389(03)00156-8 - Pubmed citation
- 9. Cawley MI, Chalmers TM, Kellgren JH et-al. Destructive lesions of vertebral bodies in ankylosing spondylitis. Ann. Rheum. Dis. 1972;31 (5): 345-58. doi:10.1136/ard.31.5.345 - Free text at pubmed - Pubmed citation
- 10. Dihlmann W. Current radiodiagnostic concept of ankylosing spondylitis. Skeletal Radiol. 1979;4 (4): 179-88. - Pubmed citation
- 11. Fam AG, Rubenstein JD, Chin-sang H et-al. Computed tomography in the diagnosis of early ankylosing spondylitis. Arthritis Rheum. 1985;28 (8): 930-7. - Pubmed citation
- 12. Graham B, Van peteghem PK. Fractures of the spine in ankylosing spondylitis. Diagnosis, treatment, and complications. Spine. 1989;14 (8): 803-7. - Pubmed citation
- 13. Hanson JA, Mirza S. Predisposition for spinal fracture in ankylosing spondylitis. AJR Am J Roentgenol. 2000;174 (1): 150. AJR Am J Roentgenol (full text) - Pubmed citation
Synonyms & Alternative Spellings
|Synonyms or Alternative Spelling||Include in Listings?|
|Marie Strümpell disease||✓|