Arthritis Dahnert 8th Ed

Approach to Arthritis

  • Mnemonic: ABCDE'S

    • Alignment

    • Bone mineralization

    • Cartilage loss

    • Distribution

    • Erosion

    • Soft tissues

Signs of Arthritis

  • Prevalence: 15% of the population in the USA

  • Conventional X-ray:

    • Narrowing of radiologic joint space:

    • Uniform = inflammatory arthritis

    • Nonuniform = degenerative arthritis

    • Evidence of disease on both sides of joint:

    • Osteopenia

    • Subchondral sclerosis

    • Erosion

    • Subchondral cyst formation

    • Malalignment

    • Joint effusion

    • Joint bodies

  • Nuclear Scintigraphy (NUC):

    • Increased regional blood flow indicates active disease

    • Distribution of disease

  • Magnetic Resonance Imaging (MRI):

    • Bone marrow edema as a predictor of erosions

    • Gd-DTPA enhancement of synovium indicates active disease

    • Radiographically occult extraarticular inflammation (tenosynovitis + enthesitis)

    • Irregularity and narrowing of articular cartilage

Classifications of Arthritides

A. Septic Arthritis

  1. Tuberculous

  2. Pyogenic

  3. Lyme arthritis

  4. Fungal arthritis:

    • Candida

    • Coccidioides immitis

    • Blastomyces dermatitidis

    • Histoplasma capsulatum

    • Sporothrix schenckii

    • Cryptococcus neoformans

    • Aspergillus fumigatus

  • Note: Tuberculous + fungal arthritis exhibit the Phemister triad:

    1. Prominent osteoporosis

    2. Slower rate of destruction

    3. Less joint narrowing compared to pyogenic infection

B. Collagen / Collagen-Like Diseases

  1. Rheumatoid arthritis

  2. Ankylosing spondylitis

  3. Psoriatic arthritis

  4. Rheumatic fever

  5. Sarcoidosis

C. Biochemical Arthritis

  1. Gout

  2. Chondrocalcinosis

  3. Ochronosis

  4. Hemophilic arthritis

D. Degenerative Joint Disease

  • Osteoarthritis

E. Traumatic Disorders

  1. Secondary osteoarthritis

  2. Neurotrophic arthritis

  3. Pigmented villonodular synovitis

F. Enteropathic Arthropathy

(a) Inflammatory Bowel Disease

  1. Ulcerative colitis (10–20%)

  2. Crohn disease (5%): Peripheral arthritis increases with colonic disease

  3. Whipple disease (60–90%): Transient intermittent polyarthritis, sacroiliitis, spondylitis

    • Resection of diseased bowel may regressive arthritic symptomatology!

(b) Infectious Bowel Disease

  • Infectious agents: Salmonella, Shigella, Yersinia

  • Occurs after intestinal bypass surgery

Spondyloarthritis with Positive HLA-B 27

  1. Ankylosing spondylitis (95%)

  2. Reiter disease (80%)

  3. Arthropathy of inflammatory bowel disease (75%)

  4. Psoriatic spondylitis (70%)

  5. Normal population (10%)

Monoarthritis - Destructive Monoarthritis

  • Any destructive monoarthritis should be regarded as infection until proved otherwise!

A. Septic Arthritis
B. Monoarticular Presentation of Systemic Arthritis

  1. Rheumatoid arthritis

  2. Gout

  3. Amyloidosis

  4. Seronegative arthritis

C. Joint Tumor

  1. PVNS (Pigmented Villonodular Synovitis)

  2. Synovial chondromatosis

  3. Articular hemangioma

Nonseptic Monoarthritis

  • Common causes include:

  1. Gout

  2. Milwaukee shoulder

  3. Rapidly destructive articular disease

  4. Amyloid arthropathy

  5. Hemophilic arthropathy

  6. Primary synovial osteochondromatosis

  7. Pigmented villonodular synovitis

  8. Neuropathic arthropathy

  9. Foreign-body synovitis

Arthritis without Demineralization

Mnemonic: PONGS

  1. Psoriatic arthritis

  2. Osteoarthritis

  3. Neuropathic joint

  4. Gout

  5. Sarcoidosis

Arthritis with Demineralization

Mnemonic: HORSE

  1. Hemophilia

  2. Osteomyelitis

  3. Rheumatoid arthritis

  4. Reiter disease

  5. Scleroderma

  6. Erythematosus, systemic lupus

Nonerosive Deforming Arthropathy

  1. Collagen-vascular disease (especially SLE)

  2. Rheumatoid arthritis (rarely)

  3. Rheumatic fever (Jaccoud arthritis - rare)

Arthritis with Periostitis

  1. Juvenile rheumatoid arthritis

  2. Psoriatic arthritis

  3. Reiter syndrome

  4. Infectious arthritis

Premature Osteoarthritis

Mnemonic: COME CHAT

  1. Calcium pyrophosphate dihydrate arthropathy

  2. Ochronosis

  3. Marfan syndrome

  4. Epiphyseal dysplasia

Charcot Joint = Neuroarthropathy

  • Hemophilic arthropathy

  • Acromegaly

  • Trauma

Synovial Disease with Decreased Signal Intensity

  • Blooming artifact of low SI on gradient-echo pulse sequences:

    1. Pigmented villonodular synovitis

    2. Rheumatoid arthritis

    3. Hemophiliac arthropathy

    4. Synovial hemangioma

Chondrocalcinosis

Mnemonic: WHIP A DOG

  1. Wilson disease

  2. Hemochromatosis

  3. Hemophilia

  4. Hypothyroidism

  5. 1st Degree Hyperparathyroidism (15%)

  6. Hypophosphatasia

  7. Familial Hypomagnesemia

  8. Idiopathic (aging)

  9. Pseudogout (CPPD)

  10. Arthritis (rheumatoid, postinfectious, traumatic, degenerative)

  11. Amyloidosis

  12. Acromegaly

  13. Diabetes mellitus

Gout

Mnemonic: 3 C’s

  1. Crystals: CPPD, sodium urate (gout)

  2. Cations: Calcium (any cause of hypercalcemia), copper, iron

  3. Cartilage degeneration: Osteoarthritis, acromegaly, ochronosis

Subchondral Cyst

  • Also known as:

    • Synovial cyst

    • Subarticular pseudocyst

    • Necrotic pseudocyst

    • Geodes

  • Etiology: Bone necrosis allows pressure-induced intrusion of synovial fluid into subchondral bone; associated with synovial inflammation.