Ankylosing Spondylitis

by David A. Hayes


Spondyloarthropathies are a group of disorders which are considered to be variants of Rheumatoid Arthritis (RA). Ankylosing Spondylitis (AS) is one of the spondyloarthopathies which affects various joints of the axial skeleton.1


AS can occur in individuals in various places of the body. The major places of incidence with AS include: sacroiliac joints, apophyseal joints, costoveterbral joints, and the intervertebral disc articulations.1 In as many as 33% of cases of AS, individuals have been known to have unilateral symptoms of peripheral joints.


Figure above shows areas affected by Ankylosing Spondylitis1


Ankylosing Spondylitis (AS) affects approximately 0.1 -0.2 percent of the general population of the United States. AS is more common in Caucasians and Native Americans than other ethnic groups. AS has been found to be more prevalent in males than females. Typically, AS is found to affect individuals between the ages of 15 and 30 years of age; however, it can be found in individuals after age 40, but these cases are rare.1

Potential Etiologies

The literature states there is no known cause for AS or any of the other spondyloarthropathies; however, there is evidence in support of genetic factors. 90% - 95% of individuals who are diagnosed with AS are positive for HLA-B27 and also individuals who are positive for HLA-B27 are at an increased risk of developing AS.2 The chances of an individual developing AS becomes substantially higher if an immediate family member is positive for HLA-B27. Other causes of the development of AS (also other spondyloarthropathies) researched is the interaction of bacteria and HLA-B27, and the overexpression of TNF-alpha.2 Even though there is a genetic influence on those who are diagnosed with AS, it has been found that that disease is not sex-linked. Although the disease seems to be more prevalent in males, it is hypothesized that women may have milder forms of AS, resulting in the disease being underdiagnosed in women.1

Clinical Presentation

One of the chief complaints of inidviduals diagnosed with AS is low back pain. The pain sensation is due to the inflammation of the sacroiliac joints and possible other areas of the axial spine. Other symptoms of As are spinal stiffness and loss of mobility, both can be caused by the inflammation. Some individuals may have involvement of the hip and shoulder with AS. When the hip is involved during the progression of the disease, it is viewed as a bad sign for prognosis; however, there is no definite measure of the severity of the disease.2

Diagnostic Testing

The ASsessment in AS (ASAS) has suggested that X-rays should be taken of the lateral lumbar spine, lateral cervical spine, and the anteroposterior pelvis to track the presence of progression of AS. Progression of AS seen with X-rays include: new syndesmophytes, verterbral ankylosis, verterbral fractures, sacroiliac sclerosis, erosion and ankylosis, and hip involvement. X-rays are considered to be the standard in diagnosing AS, however there are disadvantages. X-rays can detect changes in the spine over an extended period of time, but are not accurate in detecting minimal changes that may occur when performed frequently.3

Magnetic Resonance Imaging (MRI) is also used in assessing AS. MRI is used to dectect inflammation of the axial skeleton as well as spinal changes better than X-rays. MRI is different than other diagnostic testing tools because it has the ability to view the inflammation that may occur in the thoracic spine. The main disadvantages to the use of the MRI is cost and availability.3

Ultrasound, though it is have poor sensitivity and specificity, can be used as treatment for AS. Pain as a result of Enthesitis, the inflammation of the site of the tendon-bone junction, is alleviated with use of ultrasound.3

Evaluation/Special Orthopedic Tests

Presently, diagnostic testing (X-rays and MRI) are the most effective way to diagnose AS. If a patient is suspected of having AS, there are a few questions a Doctor may ask during the Initial Evaluation. Blood tests may also be performed to determine if an individual is HLA-B27 positive.

Conservative Treatment

ASAS and The European League Against Rheumatism (EULAR) have desgined reccommendations for the management of individuals with AS. The first reccommendation is that both non-pharmocologic and pharmocologic treatments should be used in the management of AS.4 In regards to non-pharmocological treatments, specifically a home exercise program is reccommended. A few examples of exercises used to manage AS are chest expansion, back extensions, and cervical neck rotation and lateral flexion. Medications used to manage pain associated with AS include non-steroidal anti-inflammatory drugs (NSAIDs) and disease-modifying antirheumatic drugs (DMARDs). 5 Anti-tumor necrosis factor alpha drugs are also being used in the management of AS. Adalimumab, entarecept, and infliximab are three anti-TNF alpha drugs used to help reduce the over expression of TNF alpha and reduce the inflammation process. 5 Corticosteroid injections maybe used to treat localized inflammation, but systemic corticosteroids are not reccommended.4

Surgical & Post-Operative Treatment
Surgery for individuals with AS is only performed under specific circumstances:

  • The individual's cervical spine is locked in a full flexed position.
  • The spine is determined unstable.
  • AS has caused neurological deficits.

Types of Surgeries done for AS:

  • Osteotomy
  • Decompression
  • Spinal Fusion

Post-Op Management:

  • Medications for pain relief
  • Presciption of an orthotic (TLSO brace or halo)
  • Physical Therapy to help increase mobility and strengthen


Modalities can be used to treat a variety of problems individuals may have. Modalities can also be used to help patients diagnosed with AS. Modalities are not used to cure or reduce the progression of the disease; modalities can be used in relieving symptoms patients may have from day to day. In the literature today, there are very few studies that assess the implications and efficacy of modalities in the treatment of ankylosing spondylitis; however, the uses of various types of modalities are still used by individuals. Spa therapy, cryotherapy, thermotherapy, and transcutaneous electrical nerve stimulation (TENS) are among the popular modalities used in the treatment of ankylosing spondylitis.

A review of a systematic review titled, Physiotherapy interventions for ankylosing spondylitis, summarized the effects of spa therapy combined with exercise as treatment for individuals with AS. In this study, there was a significant change in pain of the spa therapy group as compared to the control group within the first 4 months; however, there was no significant difference between the two groups after seven or ten months6. There were also significant positive effects to patient’s global assessment of wellbeing with the first 7 months6.

The efficacy of modalities such as cryotherapy, thermotherapy, and TENS have not been studied in the literature as it relates to the treatment of AS, but due to the mechanism by which these modalities act there maybe certain times when the application of these modalities can help individuals with the symptoms. Cryotherapy, such as ice packs, can be used in times of inflammation. Thermotherapy, moist heat packs, can be used to treat stiffness by increasing muscle extensibility. TENS can be used to treat pain that may increase due to AS. TENS manages pain by use of the "Gate Theory". The gate theory uses the A-alpha and A-beta nerve fibers to inhibit the signal of the C-delta nerve fibers.

Additional Resources



1. Goodman CC, Fuller KS. Pathology Implications for the Physical Therapist. 3rd ed. St. Louis, MI: Saunders Elsevier; 2009.

2. Braun J, Sieper J. Ankylosing spondylitis. Lancet. 2007;369:1379-1390. 10.1016/S0140-6736(07)60635-7.

3. Zochling J, Braun J. Assessments in ankylosing spondylitis. Best Pract Res Clin Rheumatol. 2007;21(4):699-712. 10.1016/j.berh.2007.02.010.

4. Zochling J, van der Heijde D, Burgos-Vargas R, et al. ASAS/EULAR recommendations for the management of ankylosing spondylitis. Ann Rheum Dis. 2006;65(4):442-452. 10.1136/ard.2005.041137.

5. McLeod C, Bagust A, Boland A, et al. Adalimumab, etanercept and infliximab for the treatment of ankylosing spondylitis: a systematic review and economic evaluation. Health Technol Assess. 2007;11(28):1-158, iii-iv.

6. Dagfinrud H,Hagen KB, Kvien TK. Physiotherapy interventions for ankylosing spondylitis. Cochrane Database of Systematic
Reviews 2008, Issue 1. Art. No.: CD002822. DOI: 10.1002/14651858.CD002822.pub3.

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