Ankylosing Spondylitis: Symptoms and Rehabilitation

Ankylosing spondylitis

Ankylosing spondylitis (AS) is a chronic inflammatory disease that primarily affects the spine and sacroiliac joints. It belongs to the group of seronegative spondyloarthropathies and represents the most common form of spondylitis, with a prevalence of 0.1-1.4% in the general population. It more frequently affects males (ratio 2-3:1) with typical onset between 20 and 35 years of age, making it one of the few rheumatic diseases affecting young adults.

The term “ankylosing” derives from the Greek ankylos (stiff, bent) and describes the disease’s tendency to lead to the progressive fusion of the vertebrae (ankylosis), resulting in stiffness and deformity of the spine. If not adequately treated, AS can evolve into severe dorsal kyphosis with significant disability. However, early diagnosis and a structured program of physiotherapy and exercises can drastically alter the course of the disease.

Table of Contents

• What is Ankylosing Spondylitis
• Causes and Risk Factors
• Symptoms
• Diagnosis
• Treatment
• When Surgery Is Necessary
• Prognosis
• Frequently Asked Questions (FAQ)
• Frequently Asked Questions
• Resources
• Sources and Scientific References

What is Ankylosing Spondylitis

AS is an autoimmune disease in which the immune system attacks the entheses, which are the points where tendons and ligaments attach to bone. Chronic inflammation of the entheses (enthesitis) triggers an abnormal repair process: instead of inflamed tissue, new bone tissue forms, gradually filling the space between the vertebrae, creating bony bridges called syndesmophytes.

Over time, syndesmophytes can completely fuse the vertebrae, creating the characteristic radiographic image of the “bamboo spine”. This process typically begins in the sacroiliac joints and progresses in an ascending direction towards the lumbar, thoracic, and finally cervical spine.

The Role of HLA-B27

The HLA-B27 gene is present in 90-95% of AS patients, compared to 6-8% of the general population. However, only 5-20% of HLA-B27 carriers develop the disease, indicating that other genetic and environmental factors are necessary for onset.

Causes and Risk Factors

Genetic Factors

• HLA-B27: the most important genetic risk factor
• Family history: the risk of developing AS is 10-20 times higher in first-degree relatives of affected patients
• Other genes: ERAP1, IL-23R, and other loci contribute to susceptibility

Environmental Factors

• Intestinal infections: alterations in the gut microbiome have been associated with AS
• Mechanical stress: entheses subjected to greater mechanical load are more vulnerable
• Smoking: a risk factor for progression and for a poorer response to treatment

Who Is Most at Risk

• Young males (20-35 years old)
• HLA-B27 carriers with a positive family history
• Patients with inflammatory bowel diseases (Crohn’s, ulcerative colitis): 5-10% develop AS
• Patients with psoriasis: association with psoriatic arthritis and spondyloarthropathies

Symptoms

Early Symptoms

The cardinal symptom is inflammatory low back pain, which is distinguished from mechanical low back pain by some typical characteristics:

• Insidious onset: pain develops gradually, not after trauma
• Age of onset < 40 years
• Prolonged morning stiffness: lasts more than 30 minutes (often 1-2 hours)
• Improves with movement: unlike mechanical low back pain which worsens with activity
• Worsens with rest: pain is more intense at night and upon waking
• Responds to NSAIDs: anti-inflammatory drugs provide significant relief

The pain is typically localized in the lumbosacral and gluteal region, often bilateral and alternating (sacroiliitis).

Symptoms of the Active Phase

• Widespread pain and stiffness in the spine (lumbar, thoracic, cervical)
• Enthesitis: pain at tendon insertion points — heel (Achilles tendon, plantar fascia), iliac crests, ischial tuberosity, greater trochanter
• Peripheral arthritis: involvement of hips, knees, shoulders (in 30-40% of cases)
• Chest pain: inflammation of the costovertebral joints can limit chest expansion and mimic cardiac pain
• Chronic fatigue: fatigue is an underestimated but very impactful symptom

Extra-Articular Manifestations

• Anterior uveitis (iritis): acute ocular inflammation — affects 25-40% of patients. It manifests with red eye, pain, photophobia, and blurred vision. It is an ophthalmological emergency
• Inflammatory bowel disease: subclinical intestinal inflammation in 50-60% of cases
• Cardiac involvement: aortitis, aortic insufficiency, conduction disturbances (rare, in advanced stages)
• Osteoporosis: paradoxically, despite new bone formation, AS causes vertebral osteoporosis with a risk of fractures

Long-Term Evolution

Without treatment, typical progression includes:

• Loss of lumbar lordosis: the lumbar spine flattens
• Accentuation of dorsal kyphosis: the patient develops a “bent forward” posture
• Cervical stiffness: the cervical spine becomes fixed in flexion
• Characteristic posture: the patient cannot look at the horizon, needing to flex the knees to compensate
• Reduced chest expansion: predominantly diaphragmatic breathing

Diagnosis

Clinical Criteria

The diagnosis of AS requires a combination of:

• Inflammatory low back pain with the characteristics described above
• Limited spinal mobility (flexion, extension, lateral flexion)
• Reduced chest expansion (< 2.5 cm at chest circumference)

Specific Clinical Tests

• Schober’s Test: measures lumbar spine flexion mobility. Mark 10 cm above S1: in flexion, the distance should increase by at least 5 cm. Lower values indicate stiffness
• Occiput-to-wall distance: the patient stands with heels against the wall — the distance between the occiput and the wall indicates the degree of kyphosis
• Chest expansion: measured at the nipple line during maximal inspiration/expiration
• Sacroiliac joint tests: FABER, compression/distraction, Gaenslen’s test

Laboratory Tests

• ESR and CRP: elevated in active phases, but can be normal in 40% of cases
• HLA-B27: positive in 90-95% of patients (but not diagnostic on its own)
• Rheumatoid factor: typically negative (hence “seronegative”)

Imaging

• Pelvic X-ray: bilateral sacroiliitis is the key finding — classified into 5 grades (0-IV). Grade ≥II bilateral or III unilateral is diagnostic
• Magnetic resonance imaging (MRI) of the sacroiliac joints: can show inflammation (bone edema) before changes are visible on X-ray — crucial for early diagnosis
• Spine X-ray: syndesmophytes, squaring of vertebral bodies, “bamboo spine” in advanced stages

Differential Diagnosis

AS must be distinguished from:

• Lumbar disc herniation
• Spinal canal stenosis
• Mechanical low back pain
• Other spondyloarthropathies (psoriatic arthritis, reactive arthritis)
• Fibromyalgia

The average diagnostic delay is still 5-8 years, making greater awareness of the disease crucial.

Treatment

Pharmacological Therapy

Pharmacological management is the responsibility of the rheumatologist and includes:

• NSAIDs (ibuprofen, naproxen, etoricoxib): first-line, often very effective. Continuous use (vs. on-demand) appears to slow radiographic progression
• Biological anti-TNFα drugs (adalimumab, etanercept, infliximab): indicated when NSAIDs are insufficient. They reduce inflammation and slow structural progression
• IL-17 inhibitors (secukinumab, ixekizumab): alternative to anti-TNF biologics
• JAK inhibitors (tofacitinib, upadacitinib): new class of oral medications
• Sulfasalazine: particularly useful in forms with peripheral arthritis
• Corticosteroids: useful in flare-ups, but not as chronic therapy

Physiotherapy and Rehabilitation

Physiotherapy is fundamental and irreplaceable in the management of AS. EULAR/ASAS guidelines recommend it as a central component of treatment alongside pharmacological therapy.

The goals of rehabilitation are:

• Maintain spinal mobility in all planes
• Preserve chest expansion and respiratory function
• Prevent deformities (kyphosis, loss of lumbar lordosis)
• Strengthen extensor and stabilizing musculature
• Manage pain and fatigue
• Maintain functional capacity and autonomy

Exercise Program

Exercises must be performed daily (at least 30 minutes a day) and represent the pillar of long-term management. The program should be personalized by a doctor or physical therapist.

1. Spinal Mobilization

• Seated trunk rotations: sitting astride a chair, rotate the trunk right and left with arms crossed over the chest. 15 repetitions per side.
• Standing lateral flexion: lean the trunk sideways, sliding the hand down the thigh. 10 repetitions per side.
• Cat-cow on all fours: alternate spinal flexion and extension. 15 slow and controlled repetitions.
• Cervical rotation: bring the chin towards the shoulder, alternating sides. 10 repetitions per side.

2. Extension Exercises

• Prone extension: from prone, lift the trunk by resting on forearms (sphinx), then on hands (cobra). Hold for 10 seconds, 10 repetitions.
• Standing extension: hands on the lower back, extend the trunk backward. 10 repetitions.
• Foam roller extension: place the roller transversally under the thoracic spine and extend backward. 2 minutes.

3. Breathing Exercises

• Chest expansion: inhale deeply, expanding the ribs laterally, exhale slowly. 10 repetitions, 2-3 times a day.
• Diaphragmatic breathing: hand on the abdomen, inhale by expanding the abdomen, exhale by emptying it. 5 minutes.
• Breathing with elevated arms: raise arms above the head during inhalation. 10 repetitions.

4. Muscle Strengthening

• Prone spinal extensions: lift the trunk and legs simultaneously. 3 sets of 10.
• Glute bridge: supine with knees bent, lift the pelvis. 3 sets of 15.
• Front plank: hold the position for 20-30 seconds, 3 repetitions.
• Scapular retraction with resistance band: pull the band bringing the shoulder blades together. 3 sets of 15.

5. Stretching

Stretching is fundamental to counteract the tendency towards stiffness:

• Hip flexor stretch (iliopsoas): kneeling lunge, hold for 30 seconds per side
• Pectoral stretch: in a wall corner, 30 seconds
• Hamstring stretch: leg on a raised surface, lean the torso forward. 30 seconds per side
• Quadriceps stretch: standing, bring the heel to the glute. 30 seconds per side

Recommended Sports Activities

• Swimming: the best activity for AS — unloaded work, global mobilization, muscle strengthening
• Pilates: excellent for mobility and postural control
• Yoga: improves flexibility and stress management
• Walking/Nordic walking: low-impact aerobic activity
• Cycling: good aerobic exercise (pay attention to posture — adjust handlebars high)

To avoid: sports with violent impact (rugby, contact sports), especially in advanced stages with a rigid spine (risk of fractures).

When Surgery Is Necessary

Ankylosing Spondylitis is an autoimmune inflammatory disease primarily affecting the spine, characterized by progressive fusion of vertebrae and loss of spinal mobility due to abnormal bone formation. Surgical intervention is reserved for specific situations:

• Hip replacement: coxarthrosis secondary to AS is one of the most common indications
• Corrective spinal osteotomy: in cases of severe and disabling kyphosis, to improve sagittal alignment and allow the patient to look at the horizon
• Stabilization of vertebral fractures: the ankylosed spine is fragile and prone to fractures even from minor trauma

Prognosis

The prognosis of AS is highly variable:

• Mild forms (the majority): with adequate treatment, patients maintain a good quality of life and work capacity
• Severe forms (15-20%): progression towards stiffness and deformity despite treatment
• Life expectancy: slightly reduced in severe forms with cardiac involvement or amyloidosis

Negative prognostic factors include: young age at onset, early hip involvement, persistently elevated CRP, poor response to NSAIDs, presence of syndesmophytes at diagnosis, smoking.

Early diagnosis and consistent physiotherapy are the two factors that most positively influence the disease’s evolution.

Frequently Asked Questions (FAQ)

Frequently Asked Questions

What is the significance of HLA-B27 in Ankylosing Spondylitis?

HLA-B27 is a genetic marker strongly associated with Ankylosing Spondylitis, found in a high percentage of individuals with the condition. While its presence increases susceptibility, it is not a sole determinant, as many people with HLA-B27 never develop AS.

What methods are typically used to diagnose Ankylosing Spondylitis?

Diagnosis of Ankylosing Spondylitis involves a comprehensive approach including clinical assessment, specific physical tests, and laboratory analyses for inflammatory markers and genetic factors like HLA-B27. Imaging studies such as X-rays or MRI of the sacroiliac joints and spine are also crucial for confirming the diagnosis.

What are the primary goals of Ankylosing Spondylitis treatment?

The main goals of Ankylosing Spondylitis treatment are to reduce pain and stiffness, prevent or slow down spinal deformity, and maintain functional mobility. This comprehensive approach aims to improve quality of life and enable individuals to continue daily activities.

What is the role of a physical therapist in managing Ankylosing Spondylitis?

A physical therapist plays a crucial role in developing individualized exercise programs to improve posture, spinal mobility, and muscle strength. They guide patients through therapeutic exercises and provide education on pain management techniques and activity modification to enhance daily function.

Sources and Scientific References

1. Dagfinrud H et al. (2008). Physiotherapy interventions for ankylosing spondylitis. Cochrane Database Syst Rev. 2008:CD002822. DOI | PubMed
2. Sharan D et al. (2017). Physiotherapy for Ankylosing Spondylitis: Systematic Review and a Proposed Rehabilitation Protocol. Curr Rheumatol Rev. 13:121-125. DOI | PubMed
3. Braun J et al. (2007). Ankylosing spondylitis. Lancet. 369:1379-1390. DOI | PubMed
4. Millner JR et al. (2016). Exercise for ankylosing spondylitis: An evidence-based consensus statement. Semin Arthritis Rheum. 45:411-27. DOI | PubMed
5. Dagfinrud H et al. (2001). Physiotherapy interventions for ankylosing spondylitis. Cochrane Database Syst Rev.:CD002822. DOI | PubMed