DJD 1 Flashcards
What is the function of the joint?
-Predictable and energy efficient motion
-Transfer of a load
What is Osteoarthritis (OA)?
Progressive and permanent deterioration of the articular cartilage
-Deterioration of articular cartilage
-Changes in subchondral bone
-Changes in soft tissue of joint
What causes morphological breakdown of articular cartilage?
-Abnormal stress on normal cartilage
-Normal stress on abnormal cartliage
Can you repair articular cartliage?
Yes but has limited ability to regenerate or heal
-Makes fibrocartilage instead
What is the etiology of OA?
-Physical force or trauma
-Chondrocyte response to insult
-Extra-cartilaginous factors secondary to cartilage change
What are some changes associated with OA?
-Increased intramedullary pressure
-Periosteal elevation
-Trabecular remodeling
-Capsulitis
-Erosion channels
-Desmits
-enthesophyte
-Osteophyte
What happens to the synovial membrane in OA?
-Synovial lining hyperplasia
-Villous hyperplasia
-inflammatory cell infiltration subintima
-Fibrosis
What are synoviocytes?
Rich source of proteolytic enzymes active against collagen and proteoglycans
What occurs when there is synovial insult or injury?
-Direst release of lysosomal enzymes
-Release PGE
-Release free radicals
-Release cytokines
-Source of Pain (in capsule, increase IO pain)
How do you know if there is articular cartilage damage when looking in the endoscope?
Discoloration, fibrillation, erosions, wear lines and eburnation
What is occurring in the cartilage when there is degradation?
-Decrease PG (lubrication and nutrition)
-Decrease aggregation GAG
-Increase water
-Change in collagen structure
-Reduced compressive and tensile strength
How so the chondrocytes respond to the cartilage degredation?
Imbalance, turnover extracellular matrix of articular cartilage, cytokines, mechanical stimuli
What are the destructive enzymes?
IL-1, TNF, IL-17, MMP and ADAMS
What do mechanical forces effect?
Subchondral bone, synovial membrane and chondrocytes
Why does subchondral bone sclerosis occur on rads?
Adapting to repetitive cyclic loading by becoming thicker
-Microbending
