Patient education: Ankylosing spondylitis and other spondyloarthritis (Beyond the Basics)
- David T Yu, MD
David T Yu, MD
- Emeritus Professor
- University of California Los Angeles
OVERVIEW OF ANKYLOSING SPONDYLITIS AND SPONDYLOARTHRITIS
Ankylosing spondylitis (AS) is a chronic inflammatory disease that causes pain in the back, neck, and sometimes hips and heels. The back and neck are made up of a column of individual bones known as vertebrae. The prefixes “spondyl” and “spondylo” are derived from the term Greek term for “vertebra.” The ending “itis” means inflammation; thus, “spondylitis” is inflammation of the spinal vertebrae. “Ankylosing” means “fusing together” and refers to the loss of flexibility of the back and the neck that can result from the inflammation. AS is a member of a family of diseases referred to as spondyloarthritis (SpA). The words “spondylitis” and “spondyloarthritis” are synonymous.
This topic discusses the symptoms, diagnostic tests, complications, and treatment of one of the family of SpA diseases, AS. It also discusses some of the other diseases that are classified as subtypes of SpA. Separate topic reviews are available that discuss in more detail some of the medications used to treat AS as well as exercises, such as stretching and strengthening, that are suggested for patients. (See "Patient education: Disease-modifying antirheumatic drugs (DMARDs) (Beyond the Basics)" and "Patient education: Arthritis and exercise (Beyond the Basics)".)
SPONDYLOARTHRITIS FAMILY OF ARTHRITIS
Spondyloarthritis (SpA) is a family of arthritis-associated diseases, of which ankylosing spondylitis (AS) is the most common member. The other diseases in this group are:
●Non-radiographic axial SpA
●Arthritis associated with psoriasis (psoriatic arthritis)
●Arthritis associated with inflammatory bowel diseases (ulcerative colitis or Crohn disease)
SpA has also been subdivided into “axial” and “peripheral” SpA according to whether the involvement is mainly in the spine or outside the spine, such as in the knees and heels. AS belongs to the axial class of SpA. Some of the patients initially diagnosed as having non-radiographic axial SpA or undifferentiated SpA may subsequently develop AS.
Separate topic reviews discuss reactive arthritis, psoriatic arthritis, and inflammatory bowel diseases. (See "Patient education: Reactive arthritis (Beyond the Basics)" and "Patient education: Psoriatic arthritis (Beyond the Basics)" and "Patient education: Ulcerative colitis (Beyond the Basics)" and "Patient education: Crohn disease (Beyond the Basics)".)
ANKYLOSING SPONDYLITIS SIGNS AND SYMPTOMS
The most common symptom of ankylosing spondylitis (AS) is pain in the lower back. Pain, stiffness, and limited mobility outside the spine, such as in the knees and heels, also occur in some patients. More detailed information for clinicians is available separately. (See "Clinical manifestations of ankylosing spondylitis in adults".)
Spinal pain — Spinal pain, almost always in the lower back, is usually the first and most common symptom of AS. Back pain that occurs with AS generally has some of the following characteristics:
●Begins in early adulthood (before 45 years of age)
●Has a gradual onset (rather than sudden onset after an acute injury)
●Lasts longer than three months
●Is worse after rest (for example, in the morning)
●Improves with activity
●Wakes you up in the second half of the night
●Can cause morning stiffness lasting more than 30 minutes
●Can be associated with buttock pain that alternates between the left and right sides
Limited spinal mobility and head-forward posture — Some patients with AS develop limited flexibility of the back and neck. Limitations in flexibility of the back and neck have negative consequences on daily activities, such as putting on shoes and stockings. The most serious consequence is an irreversible head-forward “hunchback” posture. This posture should be avoided by vigilant posture training exercises. (See 'Exercise and posture training' below.)
HOW DO I KNOW IF I HAVE DEVELOPED A HUNCHBACK POSTURE?
You can test for a hunchback posture by standing against a wall, with your back and heels touching the wall. Normally it is possible to touch the wall with the back of the head while keeping the chin parallel to the floor. If you cannot touch the wall with the back of the head, this indicates that you have an abnormal head-forward hunchback posture.
●Fatigue and sleeplessness – Inflammation in ankylosing spondylitis (AS) can affect the entire person, causing fatigue and sleeplessness.
●Anxiety and depression – These may sometimes occur in people with AS.
●Hip pain – Arthritis of the hips is relatively common in AS, and can cause pain in the groin or buttocks or difficulty walking.
●Heel pain – A common area of inflammation is the heel. This can cause pain at the back of the heel (Achilles tendinitis) and in the sole of the foot (plantar fasciitis).
●Shoulder pain – Inflammation of the tendon and bone may cause shoulder pain and limited mobility of the affected shoulder(s).
●Arthritis in other joints – Pain, stiffness, and swelling of other joints may occur. A single joint (monoarthritis) or a few joints (oligoarthritis) may be affected.
●Other organs – Body systems other than the joints can be affected. (See 'Ankylosing spondylitis complications and associated conditions' below.)
HOW DO I KNOW IF I HAVE ANKYLOSING SPONDYLITIS?
The diagnosis of ankylosing spondylitis (AS) depends on the combination of a number of symptoms, signs, laboratory tests, and radiographic (x-ray) or magnetic resonance imaging (MRI) changes. Because the combination varies from patient to patient, the diagnosis of AS must be made by a clinician. It cannot be diagnosed using an itemized checklist. In general, AS should be considered if you have back pain for more than three months that starts before the age of 45. (See 'Ankylosing spondylitis diagnosis' below.)
HOW DO I KNOW HOW ACTIVE MY ANKYLOSING SPONDYLITIS IS?
The level of activity of disease varies greatly from one individual to another. In the same individual, the disease activity can improve or worsen either spontaneously or in response to treatment. In general, high disease activity is associated with more intense pain, fatigue, and sense of stiffness in the morning. Several web-based, self-administered questionnaire tools are available for assessing disease activity. One of them is the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) (calculator 1).
Measurement of disease activity is very useful, because it helps you and your clinicians decide what forms of treatment to use, and whether a particular treatment you have started is effective or not.
HOW DO I COPE WITH ANKYLOSING SPONDYLITIS?
In addition to physical symptoms, some people with ankylosing spondylitis (AS) also have feelings of sadness or frustration, and a sense that they are missing out on a lot of activities or letting people down. Brain imaging studies show that some patients with AS even have changes in structures of the brain associated with mood (happiness, sadness, etc).
There are two types of coping strategies. One is passive coping, in which you rely totally on medications or your clinicians for help. The other is active coping, in which you rebuild your psychological defense systems. Participating in patient-organized groups is one of the active coping strategies. (See 'Support groups' below.)
HOW DO I ASSESS HOW MUCH MY DAILY ACTIVITIES AND PSYCHOLOGICAL WELLBEING ARE AFFECTED BY ANKYLOSING SPONDYLITIS?
Ankylosing spondylitis (AS) can affect daily life in various ways. Dressing, reaching, rising from a chair, getting up from the floor, standing, climbing steps, looking to the side or over the shoulder, exercising, and doing household and other work-related tasks can become more difficult as a result of the limited joint and spinal motion.
Some patients with AS will require assistance from family and friends because of functional limitations. A web-based, self-administered questionnaire tool (the Bath Ankylosing Spondylitis Functional Index [BASFI]) is available for assessing the degree of functional impairment (http://basdai.com/BASFI.php). More in-depth evaluations into the quality of life and psychological wellbeing include the Ankylosing Spondylitis Quality of Life Questionnaire (ASQoL) and the Assessment of SpondyloArthritis international Society (ASAS) Health Index.
ANKYLOSING SPONDYLITIS RISK FACTORS
Ankylosing spondylitis (AS) is three times more common in males than in females. It is usually diagnosed in young adults between the ages of 20 and 30 years.
The disease can be more common in certain families. For example, a person's risk of developing AS increases if a first-degree relative (parent, sibling, or child) has AS. The presence of a gene called human leukocyte antigen (HLA)-B27 may also increase the risk of developing AS.
RISK FOR HAVING MORE SEVERE ANKYLOSING SPONDYLITIS
Smoking is the single most important risk factor for developing more severe disease. If you are a smoker and have been diagnosed with ankylosing spondylitis (AS), you should try to quit as soon as possible. Your healthcare provider can help you make a plan to quit. (See "Patient education: Quitting smoking (Beyond the Basics)".)
ANKYLOSING SPONDYLITIS DIAGNOSIS
Ultimately, the diagnosis of ankylosing spondylitis (AS) is based upon a combination of symptoms, physical examination, blood tests, and imaging tests. Based on these, a clinician can assign a degree of probability to whether AS is the cause of your symptoms. (See "Diagnosis and differential diagnosis of ankylosing spondylitis and non-radiographic axial spondyloarthritis in adults".)
Blood tests — There are no blood tests that, by themselves, are capable of definitively diagnosing or excluding AS. However, testing for the presence of one particular type of the human leukocyte antigen (HLA) gene, HLA-B27, can be helpful in select groups of patients. AS is unlikely in a patient with a negative test for HLA-B27 who is white and of European descent. Tests for proteins called “acute phase reactants” are sometimes helpful but are not diagnostic for AS; these tests, which are markers of inflammation in the body, include C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) tests.
Imaging tests — Patients with AS develop characteristic changes in the sacroiliac joints. These are the joints that connect the base of the spine (sacrum) to the large pelvic bone (ilium) on both sides. These changes can be seen on radiograph (x-ray) images, although radiograph changes take time to develop and may not be apparent until years after the onset of symptoms.
Imaging tests such as magnetic resonance imaging (MRI) are more sensitive than plain radiographs and may be used if AS is suspected but is not clearly seen on radiograph. AS is less likely if radiographs and MRI show no changes to suggest damage to the sacroiliac joint or inflammation in that area.
In people already diagnosed with AS, radiographs of the vertebrae are also useful in assessing the degree of structural damage to the spine.
ANKYLOSING SPONDYLITIS TREATMENT
Ankylosing spondylitis (AS) treatment is tailored for each individual, based on the characteristics and severity of the disease. A detailed discussion for clinicians is presented elsewhere (see "Assessment and treatment of ankylosing spondylitis in adults"). Treatment may include some or all of the following:
Exercise and posture training — Exercise should be part of the treatment program for everyone with AS. It can include home exercises, individual or group exercise with a physical therapist, or physical therapy (PT) treatments. Optimally, you should be evaluated and given instructions by a physical therapist.
The minimum exercise program includes core strengthening, and should also contain isometric strengthening, stretching, and dynamic movements. (See "Patient education: Arthritis and exercise (Beyond the Basics)".)
Because AS can lead to the spine being frozen in an awkward posture, posture training is very important. Modern sedentary life encourages sitting in front of the computer, which causes shortening of the muscles at the back of the thighs, tilting of the hips forward, weakening of the muscles of the upper back, and a tendency to hold the neck and head too far forward. A vigorous posture training program should be aimed at compensating for these issues.
Information about exercises designed for people with AS is available on the following website: www.nass.co.uk/exercise/.
Support groups — Support groups for AS are available in the United States (http://www.spondylitis.org/) and many other countries.
Safety issues — A fused, immobile, inflexible spine is more easily fractured than a normal spine. Because of the increased risk of serious spinal injury from even minor falls or other accidents, people with AS should take care to avoid such mishaps. Safety measures you can take include the following:
●Limit the amount of alcohol you drink. Narcotic pain-relieving drugs (such as codeine) and sedatives (sleeping pills) should be used cautiously, if at all, since these also increase the risk of falling.
●Modify your home to decrease your risk of falling – Shower or tub grab-bars and night lights decrease the chance of a fall. Remove or secure loose rugs, and keep walkways free of clutter, electrical cords, and other things that could be tripped over.
●Take precautions in the car – Seat belts reduce the risk of injury in a car crash and should always be worn while driving or riding in a vehicle. A wraparound rearview mirror can improve visibility while driving if you cannot turn your head and neck.
●To avoid developing deformities of the neck, use a thin, rather than thick, pillow for sleeping.
●If you have an inflexible spine, avoid contact sports and other high-impact activities.
Nonsteroidal antiinflammatory drugs — Nonsteroidal antiinflammatory drugs (NSAIDs) are commonly used to control pain and stiffness. NSAIDs need to be taken on a regular basis for several weeks before their maximum effect can be judged. If one NSAID is not effective, your doctor might try another one. (See "Patient education: Nonsteroidal antiinflammatory drugs (NSAIDs) (Beyond the Basics)".)
Sulfasalazine — Sulfasalazine is a disease-modifying antirheumatic drug (DMARD) that may be given to slow or stop the progression of AS. It may be given along with NSAIDs. This drug provides some relief of arthritis symptoms, but is not as helpful if your AS only affects your spine. (See "Patient education: Disease-modifying antirheumatic drugs (DMARDs) (Beyond the Basics)" and "Patient education: Sulfasalazine and the 5-aminosalicylates (Beyond the Basics)".)
Anti-tumor necrosis factor therapy — A group of medicines known as anti-tumor necrosis factor agents (anti-TNF agents or TNF inhibitors) are often effective in the treatment of AS. Examples of anti-TNF medications include infliximab, etanercept, adalimumab, certolizumab pegol, and golimumab. People who do not respond to one anti-TNF treatment may respond to another. Improvement in symptoms is common and may occur within a few weeks of starting the drugs.
●Who should use anti-TNF therapy? – Not every patient with AS needs anti-TNF therapy. In general, people with active disease in the spine who have not responded fully to NSAIDs may be candidates (see 'How do I know how active my ankylosing spondylitis is?' above). Your clinician may also recommend a glucocorticoid (cortisone-like drug) injection into painful or swollen joints before starting an anti-TNF drug, if these areas continue to bother you despite using NSAIDs (see 'Glucocorticoids (steroids)' below). The decision to use anti-TNF therapy depends upon several factors that should be discussed with your clinician.
Secukinumab — Secukinumab (brand name: Cosentyx) may be an alternative treatment option for some people who do not respond adequately to anti-TNF therapy.
Glucocorticoids (steroids) — Some clinicians may also recommend a glucocorticoid injection into particularly painful or swollen joints, especially if only one or two areas are causing the most pain. In some cases, a glucocorticoid injection into the sacroiliac joint may help provide relief in patients who have sacroiliac pain that has not responded to other therapies.
By contrast, taking glucocorticoids by mouth is rarely necessary in AS treatment.
Surgery — Hip or spine surgery may be beneficial in selected patients with AS. Surgical procedures may include one or more of the following:
Total hip replacement — Insertion of an artificial hip may be recommended in patients with AS who have severe, persistent hip pain or severely limited mobility due to hip joint arthritis. (See "Patient education: Total hip replacement (arthroplasty) (Beyond the Basics)".)
Spinal surgery — Fusion of the bones in the cervical (upper) spine may be recommended for a very small number of patients who develop dislocation of these bones. Such surgery may help prevent spinal cord damage.
Wedge osteotomy — Wedge osteotomy involves the removal of a wedge-shaped piece of bone from a vertebra, followed by realignment of the spine. The spine is then braced and is allowed to heal in a better position. This type of procedure may be recommended for people who have severe deformities of the neck.
ANKYLOSING SPONDYLITIS COMPLICATIONS AND ASSOCIATED CONDITIONS
Complications related to ankylosing spondylitis (AS) and problems outside the spine, joints, and related tissues are uncommon, with the exception of anterior uveitis.
Anterior uveitis — Uveitis, or inflammation of part of the eye, is the most common AS-related problem that does not involve the joints. Anterior uveitis affects the iris (the colored part of the eye). It causes pain in the eye, blurring of vision, and light sensitivity. Uveitis requires immediate medical attention and treatment with eye medications. It is usually responsive to treatment with eye drops and often resolves within several months.
Spinal fractures and spinal cord injuries — Spinal fractures and spinal cord injuries are, respectively, 4 and 11 times more common in patients with AS than in the general population. Most of the acute fractures occur in the neck. Because a spine affected by AS is more easily fractured than a healthy spine, in many cases, injury can result from even a low-impact activity or incident. Patients with spinal cord injuries may have only minor initial neurological symptoms such as neck pain, numbness, or weakness. Any neck or spine injury requires immobilization, consultation with a doctor, and evaluation in an emergency facility. More than half of neck fractures in patients with AS are undetectable by plain radiograph (x-ray). Computed tomography (CT) and magnetic resonance imaging (MRI) are more sensitive imaging techniques.
Neurologic problems — Cauda equina syndrome is a rare complication that occurs in people with longstanding disease who have severe stiffening of the spine. The symptoms result from damage to many nerves in the lower back and include abnormal sensation and weakness of the lower extremities and difficulty with bladder and bowel control. Men may experience erectile dysfunction or impotence.
Cardiovascular disease — The most serious problem that can affect the heart is a leaking aortic valve (aortic regurgitation) which can cause symptoms of heart failure, including leg or ankle swelling (edema) and shortness of breath during exercise or exertion. This requires monitoring and, in some cases, treatment with medications or even surgery. (See "Patient education: Heart failure (Beyond the Basics)".)
Pulmonary disease — Many people with AS are unable to fully expand the chest normally during breathing because of stiffness between the ribs and the spine. In some cases, there are actual changes in the lung tissues. This may or may not cause breathing problems.
Ulcerations in the bowel — Some people with AS will develop ulcerations in the lining of the bowels, although these ulcerations do not usually cause any symptoms.
PREVENTING ANKYLOSING SPONDYLITIS COMPLICATIONS
Because the severity and outcome of ankylosing spondylitis (AS) vary considerably among patients, treatment must be tailored to each particular patient. However, all patients can benefit from the following:
●Stop smoking cigarettes, if you smoke. People who smoke and have AS can have problems with their breathing. AS can limit the movement of the chest and can reduce the amount of air the lungs can hold. (See "Patient education: Quitting smoking (Beyond the Basics)".)
●Maintain correct posture and participate in an exercise program. (See "Patient education: Arthritis and exercise (Beyond the Basics)".)
ANKYLOSING SPONDYLITIS AND DIET
There is no one particular diet or dietary supplement which has been scientifically validated to be useful for ankylosing spondylitis (AS).
Someone who has spondyloarthritis (SpA) but who does not have sufficient features to be diagnosed as having ankylosing spondylitis (AS), reactive arthritis, or arthritis associated with psoriasis, ulcerative colitis, or Crohn disease may be diagnosed as having undifferentiated SpA. The major involvement might be the spine, extremities, or both. The approach by the clinicians to treatment are similar to those of AS that are listed above (see 'Ankylosing spondylitis treatment' above). If the symptoms are mostly in the spine, the clinician may diagnose it as non-radiographic SpA instead of undifferentiated SpA.
If a diagnosis of undifferentiated SpA or non-radiographic SpA is made, additional medical visits are necessary, because with time one of the more specific types of SpA may be diagnosed. However, some patients continue to have undifferentiated SpA or non-radiographic SpA, and some go into remission and can even stop taking medications for pain and stiffness.
NON-RADIOGRAPHIC AXIAL SPONDYLOARTHRITIS
Patients with non-radiographic axial spondyloarthritis (SpA) are very similar to those with ankylosing spondylitis (AS), except that the sacroiliac joints of the pelvis look normal or nearly normal (and not affected enough to definitively diagnose AS) on radiograph (x-ray). Some patients with non-radiographic axial SpA do have changes of the sacroiliac joints that can be seen by magnetic resonance imaging (MRI).
WHERE TO GET MORE INFORMATION
Your healthcare provider is the best source of information for questions and concerns related to your medical problem.
This article will be updated as needed on our web site (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.
Patient level information — UpToDate offers two types of patient education materials.
The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.
Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.
Patient education: Disease-modifying antirheumatic drugs (DMARDs) (Beyond the Basics)
Patient education: Arthritis and exercise (Beyond the Basics)
Patient education: Nonsteroidal antiinflammatory drugs (NSAIDs) (Beyond the Basics)
Patient education: Sulfasalazine and the 5-aminosalicylates (Beyond the Basics)
Patient education: Total hip replacement (arthroplasty) (Beyond the Basics)
Patient education: Quitting smoking (Beyond the Basics)
Patient education: Calcium and vitamin D for bone health (Beyond the Basics)
Patient education: Bone density testing (Beyond the Basics)
Patient education: Osteoporosis prevention and treatment (Beyond the Basics)
Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.
Clinical manifestations of ankylosing spondylitis in adults
Diagnosis and differential diagnosis of ankylosing spondylitis and non-radiographic axial spondyloarthritis in adults
Diseases of the chest wall
General guidelines for use of anti-tumor necrosis factor alpha agents in ankylosing spondylitis and in peripheral and non-radiographic axial spondyloarthritis
Pathogenesis of spondyloarthritis
Assessment and treatment of ankylosing spondylitis in adults
Clinical manifestations and diagnosis of peripheral spondyloarthritis in adults
The following organizations also provide reliable health information.
●National Library of Medicine
●Spondylitis Association of America
●Spondyloarthritis Research and Treatment Network
●National Institute of Arthritis and Musculoskeletal and Skin Diseases
●American College of Rheumatology/Association of Rheumatology
●The Arthritis Foundation
- Dagfinrud H, Kvien TK, Hagen KB. The Cochrane review of physiotherapy interventions for ankylosing spondylitis. J Rheumatol 2005; 32:1899.
- Brophy S, Mackay K, Al-Saidi A, et al. The natural history of ankylosing spondylitis as defined by radiological progression. J Rheumatol 2002; 29:1236.
- Maugars Y, Mathis C, Berthelot JM, et al. Assessment of the efficacy of sacroiliac corticosteroid injections in spondylarthropathies: a double-blind study. Br J Rheumatol 1996; 35:767.
- Braun J, Pham T, Sieper J, et al. International ASAS consensus statement for the use of anti-tumour necrosis factor agents in patients with ankylosing spondylitis. Ann Rheum Dis 2003; 62:817.
- Mau W, Zeidler H, Mau R, et al. Clinical features and prognosis of patients with possible ankylosing spondylitis. Results of a 10-year followup. J Rheumatol 1988; 15:1109.
- Rudwaleit M, van der Heijde D, Landewé R, et al. The development of Assessment of SpondyloArthritis international Society classification criteria for axial spondyloarthritis (part II): validation and final selection. Ann Rheum Dis 2009; 68:777.
- Rudwaleit M, van der Heijde D, Landewé R, et al. The Assessment of SpondyloArthritis International Society classification criteria for peripheral spondyloarthritis and for spondyloarthritis in general. Ann Rheum Dis 2011; 70:25.
- Sampaio-Barros PD, Bortoluzzo AB, Conde RA, et al. Undifferentiated spondyloarthritis: a longterm followup. J Rheumatol 2010; 37:1195.
All topics are updated as new information becomes available. Our peer review process typically takes one to six weeks depending on the issue.
- OVERVIEW OF ANKYLOSING SPONDYLITIS AND SPONDYLOARTHRITIS
- SPONDYLOARTHRITIS FAMILY OF ARTHRITIS
- ANKYLOSING SPONDYLITIS SIGNS AND SYMPTOMS
- HOW DO I KNOW IF I HAVE DEVELOPED A HUNCHBACK POSTURE?
- HOW DO I KNOW IF I HAVE ANKYLOSING SPONDYLITIS?
- HOW DO I KNOW HOW ACTIVE MY ANKYLOSING SPONDYLITIS IS?
- HOW DO I COPE WITH ANKYLOSING SPONDYLITIS?
- HOW DO I ASSESS HOW MUCH MY DAILY ACTIVITIES AND PSYCHOLOGICAL WELLBEING ARE AFFECTED BY ANKYLOSING SPONDYLITIS?
- ANKYLOSING SPONDYLITIS RISK FACTORS
- RISK FOR HAVING MORE SEVERE ANKYLOSING SPONDYLITIS
- ANKYLOSING SPONDYLITIS DIAGNOSIS
- ANKYLOSING SPONDYLITIS TREATMENT
- ANKYLOSING SPONDYLITIS COMPLICATIONS AND ASSOCIATED CONDITIONS
- PREVENTING ANKYLOSING SPONDYLITIS COMPLICATIONS
- ANKYLOSING SPONDYLITIS AND DIET
- UNDIFFERENTIATED SPONDYLOARTHRITIS
- NON-RADIOGRAPHIC AXIAL SPONDYLOARTHRITIS
- WHERE TO GET MORE INFORMATION