Ra ,ankylospolisis txt

Reading File

Finding Sources

Reading File

Searching Images

rheumatoid arthritis joint deformity hands

Searching Images

ankylosing spondylitis bamboo spine X-ray

Reading File

I now have comprehensive content on both conditions. Let me compile the full structured answer.

Rheumatoid Arthritis (RA) vs. Ankylosing Spondylitis (AS)

RHEUMATOID ARTHRITIS (RA)

Overview

RA is a chronic inflammatory systemic disease in which cellular and autoimmune mechanisms destroy tissues, primarily the synovium. Without treatment, polyarticular, RF-positive RA has >70% chance of joint damage within 2 years. — Textbook of Family Medicine 9e

Epidemiology

Feature	Detail
Sex ratio	Women : Men = 3 : 1
Peak incidence	20–50 years
Prevalence	1–2% of adults
Genetics	HLA-DR association (MHC class II)

Pathophysiology

An inciting event (possibly infectious) triggers synovial lining cell proliferation, forming a pannus. Leukocyte invasion follows, with a cascade involving proteases and cytokines. Rheumatoid factor (RF) = autoantibody to IgG Fc fragment — associated with more severe extraarticular disease.

Clinical Features

Onset: Insidious in 70%, acute in 10%, intermediate in 20%
Hallmark: Symmetric synovitis + morning stiffness >1 hour
Joints affected first: Small joints — PIP, MCP (hands/feet); DIP joints are spared
Constitutional symptoms: Fatigue, malaise, weight loss, low-grade fever, anemia
Cervical spine: C1–C2 instability (transverse ligament tenosynovitis) — can cause neurological complications
Classic late deformities:
- Swan neck: PIP hyperextension + DIP flexion
- Boutonnière: PIP flexion + DIP hyperextension
- Ulnar deviation at MCP joints
- Z-thumb deformity

Extraarticular Manifestations

Rheumatoid nodules (subcutaneous, over pressure points)
Rheumatoid vasculitis
Pulmonary (pleural effusion, interstitial fibrosis)
Cardiac (pericarditis)
Ocular (Sjögren's syndrome, scleritis)
Felty's syndrome (RA + splenomegaly + neutropenia)

Diagnosis — ACR 1987 Criteria (≥4 required, criteria 1–4 must be ≥6 weeks)

Morning stiffness ≥1 hour
Arthritis in ≥3 joint areas
Arthritis of hand joints (wrist, MCP, or PIP)
Symmetric arthritis
Rheumatoid nodules
Serum RF positive
Radiographic erosions / periarticular osteoporosis

Investigations

RF (not specific — positive in normals too)
Anti-CCP (more specific)
CBC: normocytic anemia, elevated ESR/CRP
Synovial fluid: >2000 WBCs/mm³, no crystals
X-ray: periarticular osteopenia → joint space narrowing → erosions (appears months–1 year after onset)

Treatment

Step 1 — DMARDs (Disease-Modifying): Start early; slow/halt joint destruction

Methotrexate (MTX) — first-line DMARD; weekly dosing; requires folic acid supplementation; monitor LFTs
Hydroxychloroquine (Plaquenil) — mild disease; monitor for retinal toxicity
Sulfasalazine — moderate disease
Leflunomide — alternative to MTX

Step 2 — Biologics (for MTX-refractory disease):

Anti-TNF-α: Etanercept (SC weekly), Infliximab (IV q4–8 weeks, must be combined with MTX), Adalimumab (SC q2 weeks)
Screen for TB (PPD) before starting biologics; treat latent TB with isoniazid ×9 months

Adjuncts:

NSAIDs: Symptom control only; do not alter disease progression; risk of GI bleed
Glucocorticoids: Bridge therapy while awaiting DMARD onset; intraarticular injections (≤3×/year per joint)

RA Hand X-ray — classic changes:

RA hands X-ray showing ulnar deviation, MCP subluxation, and erosions

Bilateral hand X-ray: ulnar deviation, MCP joint space narrowing, subluxation, and cortical erosions — late-stage RA.

Swan-neck deformity (5th digit left hand), synovial swelling at wrist — characteristic RA hand findings.

ANKYLOSING SPONDYLITIS (AS)

Overview

AS is a chronic multisystem inflammatory spondyloarthropathy primarily affecting the axial skeleton. It belongs to the seronegative spondyloarthropathies (RF negative). Sacroiliitis and enthesitis are its hallmarks. — Grainger & Allison's Diagnostic Radiology; Textbook of Family Medicine 9e

Epidemiology

Feature	Detail
Sex ratio	Men : Women = 5 : 1
Age of onset	20s–30s (young adults)
Genetics	HLA-B27 positive (strong association)
Peripheral joints	Involved in ~30%

Pathophysiology

Inflammation at the annulus fibrosus–vertebral bone margin (enthesis). This is replaced by fibrocartilage, then ossified. Progressive ossification → vertebral fusion = bamboo spine (late finding). Enthesitis also occurs at ligament/tendon attachments in spine and pelvis → ossification.

Clinical Features

Onset: Insidious low back pain, often felt in buttocks or sacroiliac area
Morning stiffness relieved by activity (not rest — opposite to mechanical back pain)
Pain relieved by hot shower or exercise
Can disturb sleep → fatigue, malaise, low-grade fever, weight loss
Key clue: Back stiffness in a man <40 years, relieved by exercise, persistent
Juvenile onset: hip and shoulder symptoms may predominate
Decreased spinal mobility (early = pain/spasm; late = ankylosis)
Chest expansion reduced (costovertebral joint involvement → diaphragmatic breathing)

Extraarticular Manifestations

System	Manifestation
Eyes	Acute anterior uveitis (iritis) — most common
Cardiovascular	Aortitis, aortic regurgitation
Pulmonary	Upper lobe bilateral fibrobullous disease (late)
Neurological	Cervical fractures from minor trauma

Diagnosis

Clinical: History + physical + radiology
Physical exam: Palpation of sacroiliac joints; Schober's test (spinal mobility)
Imaging:
- Plain X-ray: sacroiliitis (bilateral, symmetric) → erosions → sclerosis → ankylosis; vertebral squaring; Romanus lesions (sclerotic 'shiny' corners); bamboo spine (late)
- MRI: Earliest detection — subchondral bone marrow edema at SI joints and vertebral corners (before X-ray changes)
- CT: confirms erosive change and sclerosis
Labs: HLA-B27 positive (not diagnostic alone); ESR/CRP elevated; RF negative

Radiological Progression

Romanus lesions — sclerotic shiny corners of vertebral bodies (enthesitis at Sharpey fibers)
Vertebral squaring — due to erosion + anterior longitudinal ligament ossification
Syndesmophytes — vertical, thin, bilateral, marginal (annulus fibrosus ossification)
Bamboo spine — complete bony fusion of spine (end-stage)
Sacroiliac joints — bilateral symmetric ankylosis

Treatment

NSAIDs — mainstay; 70–80% report substantial relief; continuous use may slow radiographic progression
Biologics: Anti-TNF agents (e.g., etanercept, adalimumab) for NSAID-refractory disease
Physiotherapy: Back extensor strengthening; maintain erect posture; swim for exercise; firm mattress; sleep with spine extended
Corticosteroids: NOT generally helpful for axial disease
Supervised group exercise > home exercise > no exercise
No role for splints or braces

AS — Bamboo spine X-ray:

Lateral lumbosacral X-ray: classic bamboo spine — vertical marginal syndesmophytes, vertebral fusion, loss of lumbar lordosis — end-stage AS.

AS AP and lateral X-ray with sacroiliitis

AP pelvis + lumbar spine: bamboo spine (blue arrows) + bilateral SI joint ankylosis (red arrows).

MRI of SI joints in AS: T1 shows erosions with joint space loss; T2 fat-suppressed shows extensive subchondral edema (disease activity).

KEY COMPARISON TABLE: RA vs. AS

Feature	RA	AS
Type	Systemic autoimmune	Seronegative spondyloarthropathy
Sex	F > M (3:1)	M > F (5:1)
Age	20–50 (any age)	20s–30s
Genetics	HLA-DR	HLA-B27
Joints	Peripheral (small joints) — symmetric	Axial skeleton (SI joints, spine)
DIP joints	Spared	Can be involved (if peripheral)
Morning stiffness	>1 hour, worsens with activity	Improves with activity
RF	Positive (70%)	Negative (seronegative)
Key X-ray finding	Periarticular erosions, ulnar deviation	Bamboo spine, sacroiliitis
Hallmark pathology	Pannus formation, synovitis	Enthesitis, syndesmophytes
Eye involvement	Sjögren's, scleritis	Acute anterior uveitis (iritis)
Treatment	MTX + biologics (anti-TNF)	NSAIDs + anti-TNF; physiotherapy
Corticosteroids	Bridge therapy (systemic/local)	Not helpful for axial disease

Sources: Textbook of Family Medicine 9e, p. 878–884; Grainger & Allison's Diagnostic Radiology, p. 1119–1120

This is a shared conversation. Sign in to Orris to start your own chat.