Orthopaedic Surgery - Seronegative Spondyloarthropathies

Basics

Seronegative spondyloarthropathies, now more commonly termed:

Spondyloarthritis (SpA)

are a group of related inflammatory disorders characterized by varying combinations of:

Axial spinal inflammation

Sacroiliitis

Peripheral arthritis

Enthesitis

and

Extra-articular manifestations.

Seronegative Nature

These conditions were historically called:

Seronegative

because patients generally lack the typical:

Rheumatoid factor

associated with rheumatoid arthritis.

Antinuclear antibodies are also usually not a defining feature.

However, negative RF or ANA testing alone does:

Not establish the diagnosis.

Enthesitis

A characteristic feature is inflammation of the:

Enthesis

which is the site where a:

Tendon

Ligament

or

Joint capsule

attaches to bone.

For this reason, these diseases have historically also been described as:

Enthesopathies.

Major Disorders

The spondyloarthritis family includes:

Ankylosing spondylitis / radiographic axial spondyloarthritis

Reactive arthritis

Psoriatic arthritis

Enteropathic or inflammatory bowel disease-associated arthritis

as well as other forms of:

Axial and peripheral spondyloarthritis.

Prevention

The underlying inflammatory disease usually cannot be:

Prevented.

However, appropriate treatment and long-term follow-up may reduce complications such as:

Joint contractures

Spinal deformity

Functional limitation

and selected:

Cardiac or pulmonary complications.

Epidemiology

Many spondyloarthropathies begin before:

40 years of age.

Symptoms may first appear during:

Adolescence

or

Young adulthood.

Sex

Axial disease, particularly classic ankylosing spondylitis, has historically been recognized more often in:

Men.

Older studies suggested a male-to-female ratio of approximately:

2–3:1.

Women may have less radiographic axial damage and historically were more likely to experience:

Delayed diagnosis.

HLA-B27 Distribution

The prevalence of:

HLA-B27

varies considerably among different ancestral populations.

Historical estimates include approximately:

Up to 10% in some White populations

Around 3% in African Americans

Very low prevalence in many sub-Saharan African populations

and substantially higher frequencies in some:

Indigenous populations.

Risk Factors

Important risk factors include:

HLA-B27 positivity

Family history of spondyloarthritis

Young age at symptom onset

and, for some manifestations,

Male sex.

Associated Disease-Specific Risks

Additional associations include:

Psoriasis

Inflammatory bowel disease

Recent gastrointestinal infection

Recent genitourinary infection.

Genetics

HLA-B27 has a strong association with:

Ankylosing spondylitis

and a weaker association with several other forms of:

Spondyloarthritis.

HLA-B27 and Ankylosing Spondylitis

A large proportion of patients with classic ankylosing spondylitis are:

HLA-B27 positive.

Historical estimates approach:

90%

in some predominantly European-derived populations.

HLA-B27 Is Not Diagnostic

Most people who carry HLA-B27 do:

Not develop ankylosing spondylitis.

Therefore, HLA-B27 should be interpreted together with:

Symptoms

Physical findings

Imaging

and

Family history.

Pathogenesis

Spondyloarthritis reflects an interaction between:

Genetic susceptibility

and

Environmental or immunologic triggers.

Infectious Triggers

Reactive arthritis may follow infection with organisms such as:

Chlamydia trachomatis

Salmonella

Shigella

Yersinia

and

Campylobacter.

Molecular Mimicry

One proposed mechanism is that bacterial antigens may trigger an immune response that cross-reacts with:

Host tissues

in genetically susceptible individuals.

The exact immunopathogenesis is more complex than a single antigenic mechanism.

Associated Conditions

Extra-articular manifestations may include:

Acute anterior uveitis

Aortic root or valvular disease

Inflammatory bowel disease

Pulmonary fibrosis in advanced disease

and other systemic inflammatory manifestations.

Diagnosis

Diagnosis is based on the overall pattern of:

Inflammatory back pain

Sacroiliitis

Peripheral arthritis

Enthesitis

Dactylitis

Skin or nail disease

Bowel disease

Uveitis

and appropriate:

Imaging and laboratory findings.

Ankylosing Spondylitis

Classic ankylosing spondylitis typically presents with:

Inflammatory back or buttock pain

Sacroiliitis

Progressive spinal stiffness

and

Enthesitis.

Inflammatory Back Pain

Characteristic features include:

Insidious onset before age 40–45

Morning stiffness

Improvement with exercise

Limited improvement with rest

and sometimes:

Night pain.

Uveitis

Acute anterior uveitis may occur and typically presents with:

Painful red eye

Photophobia

and

Blurred vision.

This requires prompt:

Ophthalmologic assessment.

Reactive Arthritis

Reactive arthritis usually follows a:

Genitourinary

or

Gastrointestinal infection.

Classic Triad

The historical triad consists of:

Urethritis or cervicitis

Conjunctivitis

and

Arthritis.

However, many patients do:

Not develop the complete triad.

Additional Reactive Arthritis Findings

Other manifestations include:

Heel pain from enthesitis

Dactylitis

Oral ulcers

Circinate balanitis

and

Keratoderma blennorrhagicum.

Psoriatic Arthritis

Psoriatic arthritis occurs in a subset of patients with:

Psoriasis.

It can involve:

Peripheral joints

Entheses

Digits

and the:

Axial skeleton.

Typical Joint Pattern

The small joints of the hands and feet may be involved, particularly the:

Distal interphalangeal joints.

Nail Findings

Associated nail changes include:

Nail pitting

Onycholysis

and other psoriatic nail dystrophy.

Dactylitis

Diffuse swelling of an entire finger or toe produces a:

Sausage digit

and is highly characteristic of:

Psoriatic arthritis.

Enteropathic Arthritis

Enteropathic arthritis occurs in association with:

Crohn disease

or

Ulcerative colitis.

Axial Pattern

Axial disease may resemble:

Ankylosing spondylitis

with:

Sacroiliitis

and

Inflammatory back pain.

Peripheral Pattern

Peripheral disease often affects:

Large weight-bearing joints

such as the:

Hips

and

Knees.

It may be:

Asymmetric.

Gastrointestinal Symptoms

Underlying inflammatory bowel disease may produce:

Abdominal cramping

Abdominal pain

Diarrhea

Rectal bleeding

Weight loss

and

Dehydration.

Laboratory Tests

No single laboratory test confirms all forms of:

Spondyloarthritis.

Rheumatoid Factor

Rheumatoid factor is usually:

Negative.

A positive result does not absolutely exclude SpA, but strong seropositivity may suggest an alternative or overlapping diagnosis.

Antinuclear Antibodies

ANA testing is generally:

Not diagnostic

for spondyloarthritis.

It is more useful when considering diseases such as:

Systemic lupus erythematosus.

HLA-B27

HLA-B27 testing may support the diagnosis when the clinical probability is:

Intermediate or high.

It has limited value as a:

General population screening test.

Inflammatory Markers

ESR and CRP may be:

Elevated

particularly with active disease.

However, normal inflammatory markers do:

Not exclude spondyloarthritis.

Imaging

Plain Radiographs

Initial radiographic evaluation of suspected axial disease may include:

AP pelvis

and appropriate views of the:

Lumbar or thoracolumbar spine.

Symptomatic peripheral joints should also be imaged when indicated.

Sacroiliac Joints

Radiographs may demonstrate:

Erosions

Subchondral sclerosis

Joint-space narrowing

and eventually:

Ankylosis.

MRI

MRI can identify:

Active sacroiliitis

before definite structural abnormalities appear on:

Plain radiographs.

Important MRI findings include:

Bone marrow edema

and

Osteitis

near the sacroiliac joint.

CT

CT demonstrates structural sacroiliac changes well, including:

Erosions

Sclerosis

and

Ankylosis.

However, its radiation exposure limits routine use compared with:

MRI.

Ankylosing Spondylitis Imaging

Radiographic findings may include:

Bilateral sacroiliitis

Vertebral body squaring

Marginal syndesmophytes

and progressive:

Spinal ankylosis.

Bamboo Spine

Advanced bridging syndesmophytes may produce the classic appearance known as:

Bamboo spine.

Hip Disease

Severe hip involvement may lead to:

Joint-space loss

Protrusio

and secondary:

Arthritic destruction.

Reactive Arthritis Imaging

Reactive arthritis may demonstrate:

Sacroiliitis

which can be:

Asymmetric.

Spinal involvement is variable.

Psoriatic Arthritis Imaging

Typical findings include:

DIP joint involvement

Erosions

Bone proliferation

Joint ankylosis

and severe forms of:

Osteolysis.

Pencil-in-Cup Deformity

A characteristic advanced finding is:

Pencil-in-cup deformity

in which one bone end becomes tapered while the adjacent articular surface becomes:

Cup shaped.

Enteropathic Arthritis Imaging

Axial imaging findings may resemble those of:

Ankylosing spondylitis.

Trauma in Ankylosed Spine

Patients with advanced ankylosing spondylitis require special caution after:

Even relatively minor trauma.

The rigid ankylosed spine behaves biomechanically like a:

Long bone

and is particularly vulnerable to unstable fractures.

Occult Fractures

Plain radiographs may miss:

Nondisplaced fractures

in an ankylosed spine.

Therefore, a patient with significant pain after trauma may require:

CT

or

MRI.

Epidural Hematoma

MRI is particularly useful when there is concern for:

Epidural hematoma

or

Neurologic compression.

Pathological Findings

Characteristic inflammatory abnormalities include:

Enthesitis

and

Synovitis.

Enthesopathy

Chronic inflammation at ligament and tendon insertions may lead to:

Erosion

followed by:

Reactive bone formation

and eventual:

Ankylosis.

Extra-Articular Pathology

Depending on the specific disorder, other pathological changes may include:

Colitis

Aortitis

and, in advanced disease,

Pulmonary fibrosis.

Differential Diagnosis

Important alternatives include:

Rheumatoid arthritis

Mechanical low-back pain

Degenerative spine disease

Infectious sacroiliitis

Lyme arthritis

Fibromyalgia

and other inflammatory arthritides.

Treatment

Treatment should be individualized according to whether disease is predominantly:

Axial

Peripheral

or associated with:

Psoriasis

Uveitis

or

Inflammatory bowel disease.

General Measures

Patients should be encouraged to maintain:

Regular physical activity

Good posture

Spinal mobility

and

Joint range of motion.

Exercise

Low-impact exercises are generally preferred, including:

Walking

Swimming

and other aerobic conditioning.

Postural Training

Postural exercises are particularly important in axial disease to reduce progressive:

Flexion deformity

and maintain:

Thoracic expansion.

Sleeping Position

Patients with ankylosing spondylitis have historically been advised to use:

Supportive sleeping surfaces

and avoid prolonged positions that reinforce:

Spinal flexion.

Contact Sports

Patients with advanced spinal ankylosis should avoid activities with a high risk of:

Collision or spinal trauma.

Physical Therapy

Physical therapy may be required to maintain:

Spinal mobility

Peripheral joint motion

Strength

Posture

and

Cardiorespiratory conditioning.

Contracture Prevention

Regular stretching and range-of-motion exercises help prevent:

Hip

Knee

and

Spinal contractures.

Medication

NSAIDs

NSAIDs are commonly used as first-line treatment for:

Pain

Stiffness

and

Inflammatory symptoms.

Conventional Disease-Modifying Drugs

Agents such as:

Sulfasalazine

may be useful for:

Peripheral arthritis.

Methotrexate may be useful in selected patients, particularly with:

Peripheral psoriatic arthritis.

These drugs are generally much less effective for purely:

Axial disease.

Biologic Therapy

Patients with persistent active disease may require biologic or targeted therapy such as:

TNF inhibitors

IL-17 pathway inhibitors

or other agents selected according to:

Disease phenotype

and associated conditions.

Uveitis Treatment

Acute anterior uveitis may require:

Topical corticosteroid eye drops

and other ophthalmologic treatment.

Management should be supervised by an:

Ophthalmologist.

Surgery

Surgery is reserved for:

Severe structural joint or spinal disease.

Total Hip Arthroplasty

Severe hip arthritis may require:

Total hip replacement.

This can substantially improve:

Pain

and

Mobility.

Spinal Deformity Surgery

Severe fixed:

Cervical

Thoracic

or

Lumbar deformity

may occasionally require corrective:

Spinal osteotomy

and stabilization.

Fracture Surgery

Spinal fractures in patients with an ankylosed spine are frequently:

Unstable

and often require:

Long-segment surgical fixation.

Follow-Up

Patients should be monitored by a multidisciplinary team that may include:

Rheumatologists

Physical therapists

Orthopaedic surgeons

Ophthalmologists

and other specialists according to systemic involvement.

Monitoring Frequency

Patients with active disease may be reviewed approximately every:

3–6 months

with the interval individualized according to:

Disease activity

Medication

and

Complications.

Prognosis

Prognosis varies according to:

Specific diagnosis

Disease activity

Axial involvement

Peripheral joint damage

and response to:

Treatment.

Ankylosing Spondylitis Prognosis

In axial disease, long-term outcome depends on:

Rate of structural progression

and degree of:

Spinal and hip involvement.

Modern therapy can substantially improve:

Symptoms

and

Function.

Complications

Cardiac Disease

Possible cardiac complications include:

Aortic root inflammation

and

Aortic insufficiency.

Conduction abnormalities may also occur in advanced disease.

Pulmonary Disease

Severe long-standing ankylosing spondylitis can occasionally cause:

Upper-lobe pulmonary fibrosis

and restriction related to reduced:

Chest-wall mobility.

Gastrointestinal Complications

Patients with inflammatory bowel disease may develop complications including:

Fistula formation

Stricture

Bleeding

or

Perforation.

Vertebral Fracture

Patients with advanced ankylosing spondylitis are at increased risk of:

Cervical and thoracolumbar fractures

even after:

Low-energy trauma.

Neurologic Injury

These fractures may result in:

Spinal cord injury

or

Epidural hematoma

and therefore require urgent assessment.

Contractures

Chronic inflammation and reduced movement may produce:

Hip flexion contracture

Spinal stiffness

and loss of:

Peripheral joint motion.

Patient Monitoring

Long-term follow-up should evaluate:

Pain

Morning stiffness

Spinal mobility

Peripheral joint involvement

Enthesitis

Uveitis

Skin disease

Bowel symptoms

and treatment-related adverse effects.

Key Principle

Seronegative spondyloarthropathies, now commonly grouped under spondyloarthritis, are inflammatory disorders characterized by varying combinations of:

Sacroiliitis, axial inflammation, peripheral arthritis, enthesitis, dactylitis, and extra-articular disease.

The major disorders include:

Ankylosing spondylitis, reactive arthritis, psoriatic arthritis, and inflammatory bowel disease-associated arthritis.

HLA-B27 is an important:

Genetic association, but it is neither necessary nor sufficient for diagnosis.

Treatment emphasizes:

Regular exercise and physical therapy, NSAIDs, appropriate disease-modifying or biologic therapy, and management of extra-articular manifestations, while surgery is reserved for:

Advanced joint destruction, severe spinal deformity, or unstable fractures of an ankylosed spine.