Seronegative Spondyloarthropathy
SpineOverview
Seronegative spondyloarthropathy (SpA) is a group of chronic inflammatory conditions affecting the spine and peripheral joints, characterized by absence of rheumatoid factor and the presence of HLA-B27 antigen. These conditions include ankylosing spondylitis, psoriatic arthritis, reactive arthritis, and enteropathic arthritis, presenting with axial and peripheral joint inflammation, enthesitis, and progressive spinal fusion.
Pathophysiology
The pathophysiology involves HLA-B27 genetic predisposition triggering aberrant immune responses to environmental triggers (infections, gut dysbiosis). This leads to TNF-alpha mediated inflammation affecting the entheses (tendon-bone junctions), synovial joints, and spinal facet joints. Progressive inflammation causes ossification of spinal ligaments and disc margins, resulting in syndesmophyte formation and eventual vertebral fusion, restricting spinal mobility and increasing fracture risk.
Patient Education
Early recognition and consistent management with disease-modifying antirheumatic drugs (DMARDs) and TNF inhibitors are crucial to slow spinal fusion and maintain long-term mobility and function.
Typical Presentation
Site
Sacroiliac joints, lumbar spine, thoracic spine, cervical spine, peripheral joints (knees, ankles, shoulders), heels, and entheses
Quality
Deep, inflammatory pain; morning stiffness; intermittent sharp pain at entheseal sites (plantar fasciitis, Achilles tendinopathy)
Intensity
Moderate to severe; typically worse in morning (>30 minutes stiffness), improving with activity; may alternate between rest and activity aggravation
Aggravating
Prolonged rest, inactivity, morning hours, forward spinal flexion (if advanced), certain infections, stress
Relieving
Continued movement and activity, warm showers/baths, NSAIDs, TNF inhibitor therapy, heat application
Associated
Fatigue, systemic inflammation markers, ocular involvement (uveitis in 25-30%), skin manifestations (psoriasis), GI symptoms (inflammatory bowel disease), heel pain, chest wall stiffness, reduced chest expansion, anterior uveitis
Orthopaedic Tests
Test descriptions are written with AI assistance from standard clinical texts. Where a test lists Sources, its description has been checked against them; those sources are independent and do not endorse OsteoKit. Accuracy figures and grades (A–D) appear only when checked against the published study; tests without one are marked “No accuracy study”.
Further reading: full test procedures are described in standard clinical examination texts, e.g. Magee & Manske, Orthopedic Physical Assessment (7th ed.), and Cook & Hegedus, Orthopedic Physical Examination Tests: An Evidence-Based Approach (2nd ed.).
Modified Schober Test (Lumbar Flexion)
Procedure
Patient standing. Mark the skin at the level of the dimples of Venus (PSIS), then 10 cm above and 5 cm below. Ask the patient to bend forward as far as possible with knees straight and remeasure the distance between the upper and lower marks.
Positive Finding
A small increase in the distance, meaning reduced lumbar flexion.
Interpretation
Measures lumbar flexion for monitoring. Suspect axial spondyloarthritis in a young adult with back pain lasting months that started gradually, is worse in the morning and in the second half of the night, and eases with exercise but not rest; refer to the GP or a rheumatologist. Also ask about psoriasis, inflammatory bowel disease, previous uveitis, heel pain (enthesitis) and swollen 'sausage' fingers or toes (dactylitis). Spinal and chest mobility measures show how stiff the spine and ribcage are. They are used to monitor axial spondyloarthritis (several are part of the BASMI index), not to diagnose it. Stiffness usually appears late, so normal mobility does not rule out early disease; inflammatory back pain features, blood tests and MRI matter more. The studies cited for the figure previously stored measured mobility in people already diagnosed, or set normal ranges in healthy people; they did not test diagnosis, so no figure is shown.
Sources
- Educational sitePhysiopedia. Schober Test (Modified Schober section).
Occiput-to-Wall Distance Test
Procedure
Patient stands with heels and back against a wall, knees straight and chin level. Measure the distance from the back of the head to the wall.
Positive Finding
The back of the head cannot touch the wall.
Interpretation
Shows fixed forward posture of the neck and upper back. A late sign used for monitoring; normal in early disease. In established ankylosing spondylitis the fused spine fractures easily: avoid high-velocity thrust to stiff segments, and new spinal pain after even a minor fall needs imaging. A painful red eye with blurred vision suggests uveitis and needs same-day eye review.
Sources
- RelatedSee current literature; widely used clinical screening measure for spinal deformity in axial spondyloarthropathy
Lateral Spinal Flexion
Procedure
Patient stands with heels and back against a wall, arms by the sides. Mark the fingertip on the thigh, ask them to bend sideways without leaning forward or lifting the heels, and measure how far the finger slides down. Repeat on the other side and average.
Positive Finding
Reduced side-bending compared with before or with what is expected.
Interpretation
A part of the BASMI mobility index, useful for tracking change. It does not diagnose spondyloarthritis.
Sources
- Original paperJenkinson TR, Mallorie PA, Whitelock HC, et al. Defining spinal mobility in ankylosing spondylitis (AS). The Bath AS Metrology Index. J Rheumatol. 1994;21(9):1694-1698.
- RelatedSee current literature; functional spinal mobility assessment
Chest Expansion Measurement
Procedure
Patient standing with hands on head. Place a tape around the chest at the fourth intercostal space (nipple line in men, just below the breasts in women). Measure after full breath out and after full breath in; record the difference.
Positive Finding
Reduced expansion compared with what is expected for age and sex.
Interpretation
Suggests stiffness of the rib joints, usually in established disease. Also reduced with age, lung disease and poor effort. Spinal and chest mobility measures show how stiff the spine and ribcage are. They are used to monitor axial spondyloarthritis (several are part of the BASMI index), not to diagnose it. Stiffness usually appears late, so normal mobility does not rule out early disease; inflammatory back pain features, blood tests and MRI matter more. The studies cited for the figure previously stored measured mobility in people already diagnosed, or set normal ranges in healthy people; they did not test diagnosis, so no figure is shown.
FABER (Patrick's) Test
Procedure
Patient lying on their back. Place the heel of the test leg on the opposite knee so the hip is flexed, abducted and externally rotated. Steady the opposite pelvis and gently press the test knee towards the couch.
Positive Finding
Pain in the buttock or sacroiliac region on the test side. Pain in the groin points more to the hip joint.
Interpretation
A sacroiliac pain provocation test. It cannot tell inflammatory sacroiliitis from mechanical sacroiliac pain; inflammatory back pain features, CRP, HLA-B27 and MRI of the sacroiliac joints are needed for that. (The name 'Fabri test' previously shown is not a recognised test.)
Sources
- Educational sitePhysiopedia. FABER Test.
- Reference bookRaj MA, Ampat G, Varacallo MA. Sacroiliac Joint Pain. StatPearls [Internet]. StatPearls Publishing; updated 14 Aug 2023.
- RelatedSee current literature; sacroiliac joint stress test variation commonly used in SpA assessment
Finger-to-Floor Distance Test
Procedure
Patient stands with feet together and knees straight and bends forward as far as possible. Measure from the tip of the middle finger to the floor.
Positive Finding
A larger distance than before or than expected.
Interpretation
Reflects hip and hamstring flexibility as well as the spine, so it cannot show where the stiffness is. Useful to track change. Spinal and chest mobility measures show how stiff the spine and ribcage are. They are used to monitor axial spondyloarthritis (several are part of the BASMI index), not to diagnose it. Stiffness usually appears late, so normal mobility does not rule out early disease; inflammatory back pain features, blood tests and MRI matter more. The studies cited for the figure previously stored measured mobility in people already diagnosed, or set normal ranges in healthy people; they did not test diagnosis, so no figure is shown. Finger-to-floor distance also depends on hip and hamstring flexibility.
⚠ Red Flags
- •Acute anterior uveitis with eye pain and photophobia requiring urgent ophthalmology referral
- •Severe spinal rigidity with loss of extension in cervical spine (high fracture risk)
- •Neurological deficit or myelopathy symptoms suggesting spinal cord compression
- •Acute cauda equina syndrome presentation
- •Uncontrolled systemic inflammation despite appropriate DMARD therapy
- •Evidence of cardiac involvement (pericarditis, aortic regurgitation)
- •Severe anemia or thrombocytopenia suggesting disease complications
⚡ Yellow Flags
- •High health anxiety or catastrophization about progressive spinal fusion
- •Poor adherence to DMARD and anti-TNF therapy due to cost, side effects, or health beliefs
- •Severe functional impairment disproportionate to imaging findings suggesting central sensitization
- •Depression or anxiety comorbidity affecting pain perception and rehabilitation engagement
- •Occupational demands incompatible with spinal rigidity requiring vocational counseling
- •Social isolation or lack of support for managing chronic inflammatory condition
- •Substance use affecting immune function or medication compliance
Osteopathic Techniques
Refer first
Spondyloarthritis needs a medical diagnosis and drug treatment, so refer first. Anti-inflammatories are the first-line drug treatment, with exercise, physical therapy and education as the foundation alongside.
- Reference bookVempala et al. · StatPearls 2026
Rehabilitation Exercises
Spinal Extension Mobilization (prone or standing)
Thoracic Spine Extension Over Foam Roller
Hamstring and Calf Stretching (bilateral)
Chest and Pectoral Stretching (doorway or corner stretch)
Core Stabilization (transverse abdominis engagement with breathing)
Glute Strengthening (bridges, clams, side-lying hip abduction)
Back Extensor Strengthening (prone hip extension, swimming movements)
Postural Awareness and Spinal Alignment Training
Standing Balance and Proprioceptive Training (single leg stance progression)
Low-Impact Aerobic Activity (swimming, cycling, walking)
Cervical Spine Rotation and Lateral Flexion Mobility
Hip Flexor Stretching (lunges, kneeling hip flexor stretch)
Referral Criteria
- •Suspected diagnosis of seronegative spondyloarthropathy (urgent referral to rheumatology for HLA-B27 testing, imaging, inflammatory markers, and DMARD/TNF inhibitor initiation)
- •Acute anterior uveitis or ocular symptoms (urgent referral to ophthalmology)
- •Neurological deficit, myelopathy, or spinal cord compression signs (urgent imaging and neurosurgery consultation)
- •Evidence of cardiac involvement or pericarditis (referral to cardiology)
- •Severe functional impairment or progressive spinal deformity despite optimal medical management
- •Failure to respond to NSAIDs and initial DMARD therapy requiring escalation to TNF inhibitors
- •Complex peripheral joint involvement requiring specialist joint management
- •Suspected inflammatory bowel disease with associated SpA (referral to gastroenterology)
- •Psychological distress, depression, or anxiety significantly impacting rehabilitation (referral to mental health services)
- •Occupational or vocational limitations requiring occupational health assessment