Bones, JOINTS, Soft Tissues Part 3

Question 1

What are the two classifications of joints?

Answer 1

• Solid/ Nonsynovial/Synarthroses

- Cavitated/Synovial

Question 2

Name a bunch of different kinds of arthritis?

What are 4 big ones?

Answer 2

4 big ones:

• Osteoarthritis (DJD)
• Rheumatoid arthritis
• Gout
• Calcium Pyrophosphate Crystal Deposition Disease (Pseudogout)

Others:
- Juvenile idiopathic, seronegative spondyloarthropathies,
ankylosing spondylitis, reactive, infectious, suppurative, mycobacterial, viral, lyme

Question 3

What are some major RF for osteoarthritis (OA)?

Answer 3

• For primary arthritis, aging is the main RF

- For secondary arthritis: Joint deformities, trauma, diabetes, ochronosis, hemochromatosis, obesity

Question 4

What are some sx of OA?

Answer 4

• Evening stiffness
• Crepitus
• Limited ROM
• Gets worse with use (v impt distinction)

Question 5

What are commonly affected joints in OA?

Answer 5

• Women: Hands & knees; DIP and PIP joints affected

- Men: Hips

Question 6

What are the nodes called in OA in the PIPs and DIPs?

Answer 6

At PIP joints they are called Bouchard’s nodes

At DIP joints they are called Heberden nodes

Question 7

What happens to the matrix and cartilage in OA?

What does this cause the bones to do?

What can form?

Answer 7

Water content of matrix inc while concentration of proteoglycans dec leading to cracks in the matrix
- Cartilage that sloughs off: “Joint mice” or “loose bodies”

Subchondral bone is exposed and rubbed smooth leading to eburnation (bone on bone)

Microfractures develop which allows for synovial fluid into subchondral region and subchondral cysts

Osteophytes (bony outgrowths) form

Question 8

What patient populations and ages do we see RA most commonly in?

Answer 8

Peaks in 2nd-4th decade, women more commonly than men

Question 9

What is rheumatoid arthritis (RA)?

Answer 9

Autoimmune, nonsuppurative proliferative and inflammatory synovitis

Question 10

What genetic markers do we see in RA?

What is a common genetic mutation seen?

Answer 10

Anti-citrullinated peptide bodies (ACPAs) and rheumatoid factor (IgM and IgA antibodies)

HLA-DR4 common allele a/w ACPA-positive RA

Question 11

What can we see systemically in RA?

Answer 11

Extraarticular lesions in the skin, heart, blood vessels, and lungs
- Overlap w over autoimmune disorders including SL and scleroderma

Leukocytoclastic vasculitis: Acute necrotizing vasculitis of small and large arteries of heart or lungs

Ocular changes like uveitis and keratoconjunctivitis

Question 12

What is the articular cartilage destruction like in RA?

Answer 12

• Ankylosis or joint fusion

- Symmetrically distributed in small joints of hands and feet (PIPs and metacarpophalangeal)

Question 13

What are some clinical symptoms of RA? What do we see happening in the joints?

Answer 13

• Morning stiffness; does not improve w rest
• Deformities of joints
• Nodules
• Pannus: Edematous and thickened hyperplastic synovium that grows over and causes erosion of articular cartilage
• Synovial hypertrophy of villi
• Lymphoid aggregates

After cartilage has been destroyed, pannus bridges the apposing bones to form a fibrous ankylosis which eventually ossifies and causes bon fusion

Question 14

What deformities do we see?

• Boutonniere
• Swam-neck
• Ulnar deviation
• Radial deviation

Answer 14

• Boutonniere: Deformity of finger, hyperextension of DIP, flexion of PIP
• Swam-neck: Hyperextention of PIP, flexion of DIP
• Ulnar deviation of fingers, dec joint space, bony erosions
• Radial deviation of the wrist

Question 15

What are rheumatoid nodules?

Answer 15

Extensor surfaces at pressure points

• Occur in subq tissue of forearm, elbows, occiput, lumbosacral area
• Small, firm, nontender, round to oval
• Necrotizing granulomas w a central zone of fibrinoid necrosis

Question 16

What is juvenile idiopathic arthritis?

What serum marker do we see?

Answer 16

Heterogeneous group of disorders of unknown cause, present w arthritis before 16 years old and persist for at least 6 weeks
- ANA seropositivity (no rheumatoid nodules)

Question 17

What are seronegative spondyloarthropathies? What serum markers and genetic mutations do we see?

Answer 17

Group of disorders unified by the following:

• Autoimmune T cell response
• Pathologies in the ligamentous attachments rather than synovium
• Negative rheumatoid factor
• HLA-B27

Ankylosing spondylitis is part of this

Question 18

What is reactive arthritis?

What is the timeline?

What other body system can be affected?

Answer 18

Part of a seronegative spondyloarthropathy

Reactive arthritis follows an infection (HLA-B27 +)

• Triad of sx is arthritis, nongonococcal urethritis or cervicitis, conjunctivitis
• Episodes may wax and wane for 6 months but 50% have recurrent arthritis, tendonitis, and lumbosacral pain (if longer than 6 months it is chronic)
• May have cardiac valvular disease (aortic insufficiency)

Question 19

What is psoriatic arthritis?

Answer 19

Part of a seronegative spondyloarthropathy

Affects hands & feet, axial joints, ligaments and tendons

• HLA-B27
• “Pencil in cup” deformity, DIPs, can be asymmetric
• Nails can turn thick, rough, rigid, discolored

Question 20

What is infectious arthritis?

Answer 20

Microorganism seed joints via hematogenous dissemination, direct inoculation, or contiguous spread of soft tissue abscesses or osteomyelitis
- Rapid joint destruction leading to permanent deformities

Can also have subset of mycobacterial or viral arthritis

Question 21

What is lyme disease and how does it relate to arthritis?

Answer 21

From borrelia burgdorferi (in ticks)

• Usually tx before progressing to arthritis but if untx, migratory arthritis can develop lasting weeks to months
• Tx w abx

Question 22

What is suppurative arthritis?

What are common agents in infants, young kids, and older kids to adults? Sickle cell? IVDU?

Answer 22

Bacteria that spreads hematogenously from distant site

• Neonates: Contiguous spread from epiphyseal osteomyelitis
• < 2 yo: H. flu
• Older kids & adults: S. aureus most common, gonococcus late adolescent or early adult
• Sickle cell diseae pts are prone to salmonella inf at any age

Acutely painful and swollen joint w restricted ROM, fever, leukocytosis, inc sed rate

Axial jont involvement w IVDU

Question 23

What are the composition of crystals that we can see in crystal-induced arthritis?

Answer 23

Crystals: Monosodium urate, calcium pyrophosphate dihydrate, calcium phosphate

Question 24

What is gout? What are some RF?

Answer 24

Transient attacks of acute arthritis initiated by crystallization of monosodium urate within and around joints
- D/t hyperuricemia (plasma level s>6.8mg/dL)

RF: Age, male, genetics, heavy alcohol consumption, obesity, certain drugs, lead toxicity

Question 25

What is acute arthritis that we see in gout?

Answer 25

Dense neurtophilic infiltrate that permeates synovium and synovial fluid; needle-shaped crystals arranged in small clusters - Sudden onset of excruciating joint pain, hyperemia and warmth - Often in big toe - Second attack months to years later

Question 26

What is chronic tophaceous arthritis that we see in gout? What is an important concept to remember?

Answer 26

Repetitive precipitation of urate crystals during acute gout attacks - Can form pannus that destroys underlying cartilage and leads to bone erosions - Develops 10 years after initial attack - Osteoclastic bone resorption and loss of joint space (impt concept)

Question 27

What are tophi in gout?

Answer 27

Tophi are pathognomonic hallmark of gout: Large aggregations of urate crystals surrounded by foreign-body giant cells. May appear in the articular cartilage, ligaments, tendons, bursae

Question 28

What is urate nephropathy in gout?

Answer 28

Renal complications caused by urate crystals or tophi; can include uric acid nephrolithiasis and pyelonephritis

Question 29

What is calcium pyrophosphate crystal deposition (Pseudo-gout)? What do the crystals look like? What genes do we see?

Answer 29

Chondrocalcinosis: Calcification of hyaline or fibrocartilage - Crystals form that are chalky, white, friable deposits - Crystals are rhomboid and positively birefringent (in contrast: Gout crystals are negatively birefringent) Can be sporadic, hereditary, or secondary types - ANKH - Secondary d/t previous joint damage

Question 30

What are some joint tumors or tumor-like conditions?

Answer 30

- Reactive tumor-like lesions, such as ganglion cysts, synovial cysts, and osteochondral loose bodies (usually d/t trauma or degenerative processes) - Primary neoplasms are rare and usually benign

Question 31

What is a ganglion cyst?

Answer 31

Joint capsule or tendon sheath, 1-1.5cm cyst - Often on wrist - Firm, fluctuant pea-sized translucent nodule - Result of cystic or myxoid degeneration, cyst wall lacks cell linings

Question 32

What is a synovial cyst? Baker cyst?

Answer 32

Herniation of synovium through joint capsule or enlargement of bursa - Baker cyst: Popliteal space a/w RA

Question 33

What is a tenocynovial giant cell tumor? Tx?

Answer 33

Benign neoplasm that develops in the synovial lining of joints, tendon sheaths, and bursae - Can be diffuse (pigmented villonodular synovitis) or localized Tx: Surgical excision, possibly M-CSF antagonists (clinical trails show promise)

Question 34

What do we see in a diffuse tenosynovial giant cell tumor?

Answer 34

Diffuse involves large joints, can be painful w bony erosion and reoccurrence - Red-brown to orange-yellow; tangled mat by red-brown folds, finger-like projections, and nodules - Macrophages that may contain hemosiderin or foamy lipids and can be multinucleated Aggressive diffuse tumors can erode into adjacent bone and soft tissues

Question 35

What do we see in a localized tenosynovial giant cell tumor?

Answer 35

Localized usually is discrete nodule attached to tendon sheath commonly in hand, can be slow-growing and painless - Tendon sheaths along wrists and fingers

Question 36

What cytokines cause flares in gout?

Answer 36

- IL-1 beta leads to neutrophil chemotaxis | - LTB4 leads to tissue injury (phagocytosis of crystals by neutrophils release LTB4)