osteoarthritis Flashcards
osteoarthritis general info
most common arthropathy primary pathology involves cartilage characteristically non-inflammatory involves active enzymatic factors multi-factorial pathology and findings same regardless of joint
primary osteoarthritis
aging or idiopathic
genetic- nodal O.A.
secondary OA
due to disorders that damage joint surfaces
pathogenesis of OA
- damage to normal articular cartilage by physical forces
- fundamental defective cartilage fails under normal joint loading
damage to normal articular cartilage by physical forces
macro or microtrauma
chondrocytes react -> release degredative enzymes
inadequate repair response
fundamental defective cartilage fails under normal joint loading
type II collagen gene defect (orchronosis) ochronotic cartilage (pigmented and defective)
OA pathologic characteristics
- altered chondrocyte fnx
- loss of cartilage
- subchondral bone thickening- sclerosis
- remodeling of bone
- marginal spurs (osteophytes)
- cystic changes in subchondral bone
- mild reactive synovitis
systemic risk factors for OA
age obesity genetics gender menopause
local risk factors for OA
mm strength joint proprioception repetitive use configuration of joint trauma
common osteoarthritis joints
cervical and lumbar spine 1st CMC PIP DIP hip knee 1st MTP
uncommon OA joints
shoulder thoracic spine elbow wrist MCP ankle subtalar
OA hands
nodal osteoarthrits
heberdens nodes: DIP
bouchards nodes: PIP
1st CMC joint: base of thumb
OA knees
most common location 3 compartments (med/lat/pat-fem)
OA spine
spondylosis- involves disc degeneration and facet involvement
DISH
OA feet
1st MTP
symptoms of OA
insidious onset joint pain associated with movement limited ROM/decreased fnx minimal stiffness after rest referred pain acute flares suggest another Dx systemic symptoms are rare
why is OA painful
cartilage is avascular and aneuritc synovitis joint capsule/lig stretching periosteal irritation from osteophytes trabecular microfractures mm spasm intraosseous HTN
OA PE
boney changes in joint shape crepitus malalignment/instability joint line tenderness cool effusions (not inflammation) spasm or atrophy of adjacent mm
OA labs
ESR, RD neg synovial fluid- class 1
OA images
cartilage loss/ joint space narrowing
subchondral sclerosis
osteophytes at joint margins
subchondral cysts
subsets of OA
generalized nodal spondylosis erosive OA inflammatory diffuse idiopathic skeletal hyperostosis (DISH) chondromalacia patellae
inflammatory OA
inflammed heberdens nodes
erosive OA
may appear normal on x-ray
osteophyte
bone spur
