Osteoarthritis Flashcards
Define Osteoarthritis (OA)
heterogeneous disorder involving destruction of articular cartilage and proliferation of the contiguous bone. End stage of all types of arthritis.
name symptoms of OA (5)
1) painwith use, improved with rest. 2) Stiffness - 30 min localized to involved joints 3) relative preservation of function 4) rarely significant symptoms before age 40. 5) Lack of systemic symptoms
signs of OA (5)
1) localized joint tenderness 2) bony enlargement 3) Crepitance 4) restricted movement 5) variable swelling and/or instability
specific patterns of deformity in OA (5)
1) Heberden’s and Bouchard’s nodes @ DIP and PIP respectively 2) squaring of the 1st carpometacarpal joint 3) Genu Varus (bow legged) 4) Hallux Valgus (bunion on big toe) 5) cervical and lumbar spine spondylosis (degenerative change)
Synovial fluid analysis in OA
Type I fluid (200-2000 WBCs), 25% PMN, normal viscosity, Neg crystal exam, normal glucose
6 radiographic evaluation findings
1) loss of cartilage space 2) Cony sclerosis and eburnation 2) cystic changes in the interphalangeal joints 3) osteophyte formation 5) altered shape of bone 6) joint effusion - non-inflammatory
5 specific x-ray changes
1) “Gullwing” interphalangeal joints. 2) medial compartment disease of the knee 3) Horizontal osteophyes of the spine 4) Decreased joint space superiourly with relative medial preservation of hip 5) Hallux Valgus without other metatarsal disease
T or F: OA is the most common arthropathy
TRUE
Risk factors for OA
increasing age, weightbearing joints at risk, women >45 years, Trauma, Obesity, Genetics, but no increased risk with sports
What joints are most affected in OA?
weight bearing and heavily used joints
What joints tend to be spared from OA?
ankle, wrist, shoulder, and elbow (unless previous trama or disease)
What is the main focus of pathology in OA?
Cartilage and chondrocytes
What do chondrocytes do?
synthesize constuctive materials such as collagen and proteoglycans as well as products that degrade these materials
What degrades collagen and proteoglycans?
Matrix metalloproteinases (MMPs)
What can injury to chondrocytes cause?
increased production of MMPs and decreased repair of cartilage from failed proteoglycan and collagen production
Loss of proteoglycan content and aggregation causes what in OA?
loss of hydrophilicity, decreased elasticity, disruption of collagen fibers, loss of collagen, and futher damage to cartilage.
What do chondrogytes do to compensate for all this loss?
initially proliferate making hypercellular cartilage with decreaed matrix, then die off as disease progresses
What cytokines and inflammatory agents cause MMP release?
IL-1, TNF alpha, NO (also cause chondrocyte apoptosis), and prostaglandins
What inhibitory cytokines are implimented in decreased damage and anabolic mechanisms?
IL-10, TGF-beta, IGF-I
As a general rule, what can you say about proinflammatory and damages associated cytokines and OA?
They make it worse
T or F: Adipokines have no role in OA
FALSE, they may explain the risk of hand OA in the obese
genetic abnomalities that can lead to familial OA and chondroplasia
abnormal type II collagen and type IX collagen
T or F: OA is primarily a disease of the cartilage, not synovium
TRUE
T or F: joint fluid in OA in generally non-inflammatory
TRUE! WBC counts are 200/2000/uL
