Exam 4 Flashcards
Osteoarthritis
degeneration of articular cartilage with hypertrophy of bone, joint space loss, subchondral cysts, sclerosis and osteophytes
what joints are involved in OA?
DIPs, PIPs, 1st CMC, weight bearing - hips and knees, Spine - cerivical and lumbar, 1st MTP
Heberden’s
DIPs
Bouchard’s
PIPs
Predisposing factors to OA
Age, obesity, occupational risks, trauma, or secondary OA due to inflammatory disorders like RA, spondylo, or metabolic disorders
sports and OA
no increased risk, exercise may be protective
Cartilage components
avascular and no nerves 1) collage II 2) proteoglycans 3) matrix proteins 4) chondrocyes 5) 70% water
Proteoglycans
in cartilage - chondroitin and keratin sulfate linked to hyaluronic acid - hydrophilic
Matrix proteins in cartilage
Metalloproteinases - like collagenases, gelatinases, stromeylsins and Tissue inhibitors of metalloproteinases TIMPS
Chondrocytes
main cell of cartilage that produces the proteins in cartilage
aggrecans
chondroitin and keratin sulfates bound to collagen. Forms a weave that acts like a sponge to hold onto water
changes to cartilage in OA
increase chondrocytes, increase MMPs, decrease TIMP, proteglycans, Increase water. This is due to a mechanical injury, inflammation, metabolic hit of cartilage. Looses the weave and forms a dish rag instead of a sponge.
Does OA have systemic feaures?
NO - lacks them
Synovial fluid in OA
non-inflammaotry, type I fluid with 200-2000 WMC
Pathophysiology of OA
chondrocytes and synovium produce inflammatory mediators for cartilage destruction - IL1, NO, protsaglandins; they also activate complement and adipokines.
IL-1 release in OA
stimulates MMPs, PGE2, NO, IL6 produciton
NO release in OA
increases MMPs, inhibits protoglycan, induces chondrocyte apoptosis.
Prostaglands in OA
increase production and activation of MMPs
what other cytokines are produces in OA?
TNF, IL6, IL17, IL18
Adipokines
are our own fact cells that make IL6 that go into the liver to make acute phase reactants like CRP. - metabolic aspect of OA.
Radiological findings in OA
Joint space loss, sclerosis, subchondral cysts, osteophytes
Patient will tell about OA
localized pain, worse with use. Stiffness for less than 30 minutes.
Rheumatoid Arthritis - basic
systemic, inflammatory, autoimmune disorder that results in peripheral, symmetric, *synovitis with cartilage and bone destrcution.
Joint involvement in RA
Bilateral and symmetric small joints of hands and feet (sparing DIPs), medium and large too.