Basic Science Flashcards
What is the only cell type found in cartilage?
Chondrocytes
What is the most abundant component of articulate cartilage?
Water (60-80% of wet weight)
Collagen is composed of three alpha chains encoded by what gene?
COL2A1
What prevents pathologic degradation of collagen fibrils by collagenases such as MMP-1?
Aggrecan
How do the following change in osteoarthritis? Proteoglycan content | Keratan Sulfate | Chondroitin 4- sulfate?
Proteoglycan decreases
Keratan sulfate decreases
Chondroitin 4-sulfate increases
How do the following change with increasing age? Keratan Sulfate | Chondroitin 4- sulfate | Chondroitin 6-sulfate
Keratan sulfate increases
Chondroitin 4-sulfate decreases
Chondroitin 6 -sulfate remains the same
How does the density of collage, chondrocytes and water change with increasing depths of the articular cartilage zones?
They all decrease
***Proteoglycan content is strange where it is lowest in the superficial zone and highest in the deep zone
The cement line separates calcified cartilage from what?
Subchondral bone
What does BMP-2 do? How about BMP-7?
BMP 2 stimulates ECM synthesis | BMP-7 potentiates chondrogenic differentiation and decreases catabolic activity of IL-1 and MMP-1
How does water content change with aging and osteoarthritis in cartilage?
Water content decreases with age and increases with ostearthritis
Chondrocyte size increases and number decreases with what?
Increasing age, there is NO change with osteoarthritis
What is the normal coefficient of friction for a joint?
0.002-0.04
During routine knee arthroscopic procedures, what percentage of patients have evidence of articular cartilage injury?
60-65%
What size is considered a small cartilage defect that you can try with microfracture, OC autograft, or ACI?
< 2-4 cm 2
What cells produce hyaluronan and lubricin components in synovial fluid?
Type B Synovial cells (Fibroblast-like synoviocytes)