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19 Cards in this Set
- Front
- Back
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What does pannus consist of?
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Hypertrophied synovium – fibrocellular mass of synovium consisting of inflammatory cells, granulation tissue and fibroblasts
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Where does pannus first develop?
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In areas where there is a double reflection of synovium
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What are pocket erosions?
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Erosions that occur at the cartilage margins and juxta-articular margins in the subchondral bone.
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What is the pathogenesis of RA? (overview)
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Trigger unknown. APC activates T Cells (2nd signal required) leading to; 1) B-cell activation → immune complex formation, 2) activation of monocytes, macrophage & synovial fibroblasts → IL-1, IL-6, TNF-α release and angiogenesis, 3) ↑ osteoclast activity. Synovium becomes inflamed, inflammation continues, synovium forms pannus on cartilage → cartilage and bone erosion → loss of joint integrity → surrounding muscles, lig and tendons become weak → bone subluxation.
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What is the main inflammatory mediator?
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TNF-α
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What does IL-1 do when activated?
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Recruitment of neutrophils, leads to release of protease and elastase → degradation of peptidoglycan of cartilage
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What action does TNF-α have when activated?
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Promotes inflammation++, also directly causes ↑ release of IL-1 and activates more macrophages
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What action does IL-6 have when activated?
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Proliferation of synovial fibroblasts → 1) pannus formation and invasion of cartilage, and 2) release of matrix metalloproteinases
- Both lead to cartilage and bone destruction |
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Why is osteopenia seen with RA?
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Activated T Cell activates osteoclast formation via RANKL expression. ↑ Bone resorption occurs, with ↑ in MMP released.
Bone destruction |
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What is the significance of angiogenesis in RA?
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Leads to accumulation of B and T Cells in synovium → release of inflammatory mediators
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What happens with B Cell activation?
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Leads to autoantibody (IgG) production including RF. Activation of complement cascade → accumulation of PMNs; inflammatory symptoms
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Are osteophytes seen with RA?
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Usually NO
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What are the radiographic hallmarks of RA?
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1) Joint effusions
2) Juxta-articular osteopenia 3) Erosion and narrowing of the joint space with loss of articular cartilage 4) Subchondral cysts 5) Large synovial cysts (↑ intra-articular pressure → outpouching of synovium) |
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What are some pathologic changes of joint and complications of chronic synovitis in RA?
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1) Joint deformities (swan neck, boutonnierre, ulnar deviation of MCP, radial deviation of wrist, hammer toes, mallet toe, claw toes, flexion contracture)
2) Atlanto-axial subluxation → neuro impingement 3) ↓ shd mobility and ROM, dislocation, tears of rotator cuff → chronic spasm 4) Carpal tunnel 5) Ruptured bakers cyst 6) Anemia of chronic disease 7) ↓ Functional capacity and early mortality |
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What are the most commonly affected joints in RA?
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PIP, MCP, wrist (but not 1st CMC), elbow, shd, knee, ankle, MTP, C-spine
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T cells in RA have a defect in _______
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Apoptosis
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What is a boutonniere deformity?
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Hyperextension of the DIP joint and flexion in the PIP joint.
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What is a swan-neck deformity?
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Hyperextension of the PIP joint and flexion of the DIP joint
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What is the Terry Thomas Sign?
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Widened space between the carpal lunate and scaphoid bone
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