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Table 1.  

Skeletal Axial arthritis, eg, sacroiliitis and spondylitis
Arthritis of 'girdle joints' (hips and shoulders)
Peripheral arthritis uncommon
Others: enthesitis, osteoporosis, vertebral fractures, spondylodiscitis, pseudoarthrosis
Extraskeletal Acute anterior uveitis
Cardiovascular involvement
Pulmonary involvement
Cauda equina syndrome
Enteric mucosal lesions
Miscellaneous, such as amyloidosis

Clinical Features of As

Republished from: Khan MA. Ankylosing spondylitis: clinical features. In: Hochberg M, Silman A, Smolen J, Weinblatt M, Weisman M, eds. Rheumatology. 3rd ed. Edinburgh: Mosby; 2003:1161-1181. Copyright 2003, with permission from Elsevier

Table 2.  

A. Clinical Components:
1. Limitation of motion of the lumbar spine in all 3 planes (anterior flexion, lateral flexion, and extension).
2. A history of pain or the presence of pain at the dorsolumbar junction or in the lumbar spine.
3. Limitation of chest expansion to 1 inch (2.5 cm) or less, measured at the level of the 4th intercostal space.
B. Radiologic Component:
Sacroiliitis (grading on a 0 to 4 scale described in the text below).

The New York (1966) Classification (Not Diagnostic) Criteria for Ankylosing Spondylitis

Definite ankylosing spondylitis if: (1) bilateral grade 3-4 sacroiliitis in the presence of at least 1 clinical component; or (2) unilateral grade 3-4 or bilateral grade 2 sacroiliitis with clinical component 1 or with both clinical components 2 and 3. Probable ankylosing spondylitis: if bilateral grade 3-4 sacroiliitis is present without any clinical component.
Adapted from Khan MA. Ankylosing spondylitis: clinical features. In: Hochberg M, Silman A, Smolen J, Weinblatt M, Weisman M, eds. Rheumatology, 3rd ed. London, UK: Mosby: A Division of Harcourt Health Sciences Ltd; 2003: 1161-1181.

Ankylosing Spondylitis

Authors: Muhammad Asim Khan, MD, MACP, FRCPFaculty and Disclosures



Ankylosing spondylitis (AS) is a chronic systemic inflammatory rheumatic disorder that primarily affects the axial skeleton and leads to limitation of spinal mobility. The etiology is not fully known, but there is a strong genetic predisposition associated with human leukocyte antigen (HLA)-B27.The disease manifestations are very wide and heterogeneous, and so a diverse group of healthcare professionals, ranging from primary care physicians to medical and surgical specialists, do consult these patients. Unfortunately, most of these patients are either never diagnosed or are inadequately treated, and they experience progressive functional impairment over time. Furthermore, multiple referrals of these patients to various specialists for their varied complaints often do not result in a correct diagnosis, often for many years. A correct diagnosis can unfortunately be delayed, on average, by 5 or more years, and over this period many unnecessary and invasive investigations are performed.

Ankylosing spondylitis and related forms of spondyloarthritis (SpA) are almost as common as rheumatoid arthritis (RA), and they represent the second most common form of chronic inflammatory arthritis after RA. AS results in a high cost burden to society because the disease course leads to progressive functional impairment over time, reduced quality of life, and work disability. Functional impairment is the most important predictor of total healthcare cost (both the direct medical expenses and the indirect costs due to lost wages and productivity). Patients with AS report similar pain and functional disability as those with RA, and they leave the labor force at a 3-fold higher rate than the general population. Patients with physically demanding jobs are more likely to change their type of work, decrease their work hours, or experience temporary or permanent work disability in contrast to patients who have jobs that are physically less demanding. Thus, AS has tremendous impact on the society at large in terms of direct medical expenses and indirect costs associated with physical impairment and loss of employment.

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