B6.007 Prework 2 Osteoarthritis Flashcards
what parts of a joint can osteoarthritis affect?
articular cartilage, bone, synovium, and soft tissue
clinical presentation of OA
gradual onset (years)
morning stiffness < 30 min
geling phenomenon (stiffness from sitting to standing)
crepitus with movement
most common locations of OA involvement
knee
hip
hands (PIPs, DIPS, CMC)
spine (neck, lumbar)
epidemiology of OA
most common joint disorder
leading cause of disability related to pain and reduced function
person level risk factors for OA
age female gender joint biomechanics inflammation adiposity genetics
joint level risk factors for OA
joint injury
repetitive use
malalignment / developmental changes
classifications of OA
primary (no comorbidities driving pathology)
secondary (atypical joints, young age, comorbidities present)
etiologies of secondary OA
trauma (athletes)
genetics - Stickler’s (collagen mutation)
metabolic (hemochromatosis, hyperparathyroidism, acromegaly, amyloidosis)
neuropathic/Charcot’s
hemophilia induced
hypermobility (Ehlers Danlos)
components of articular cartilage
70% water
organic compounds: type 2 collagen, aggrecan
number of other collagens, proteoglycans, and non collagenous proteins
what creates the tensile strength of articular cartilage
collagen networks
what creates compressive resilience in articular cartilage
charged proteoglycans entrap water through their hydrophilic glycosaminoglycan side chains
pathological findings of articular cartilage in OA
surface fibrillation/fissuring chondrocyte proliferation chondrocyte hypertrophy tidemark duplication subchondral bone thickening vascular invasion of subchondral bone
impact of increased mechanical load on joints
mechanical load decreases production of sclerostin
decreased sclerostin leads to increased osteoblast bone formation
increased osteoblast bone formation leads to increased bone mass
what is sclerostin
inhibitor of Wnt pathway
regulates osteoblast mediated differentiation
decreased sclerostin
increased osteoblast production