HA, PSGAGs, and PG Flashcards
What are the 2 layers of the synovial membrane?
Subintimal and intimal
Which synovial membrane layer contains blood supply and innervation?
Subintimal
What cells are in the intimal layer of the synovial membrane?
Synoviocytes
What function do macrophage Type A cells perform in the synovial membrane?
Phagocytosis
What type of cells are HA, aggrecan, collagen, cytokines, eicosanoids, and proteases?
Type B fibroblasts
What is the shock absorber of the joint b/c it is more deformable than cortical bone?
Subchondral bone
This disease may contribute to OA progression
Sclerosis
Creates the joint surface and is used to define the health of the joint
Articular cartilage
What does the specialized extacellular matrix do?
Distributes compressive loads
What is the articular cartilage composed of?
80% water, PG, HA, collagens
Backbone of he cartilaginous matrix
HA
What binds to HA via protein ink?
Proteoglycans/glycosaminoglycans
Creates a polarized charge to provide shock absorbing effect
HA
What is the charge of HA?
Negatie
Asking for athleticism over time aka microtrauma
Use trauma
How does OA present?
Effusion, decreased viscosity, increased TP
How will cartilage change grossly w/cartilage changes?
Dull, yellow, fibrillated, ulcerated
What does chronic inflammation cause in a joint capsule?
Thickening
What does pain cause to the synovial lining?
Hypertrophy
What does pain do to the subintima?
Fibrosis
What are clinical signs of OA?
Lameness, joint pain, decreased ROM, joint effusion
Can arthritis be present even w/o radiographic changes?
Yes
Can you stop OA progression with treatment?
No
Designed for post-arthroscopic lavage
Polyglycan (PG)
Why are results of studies of chondroprotectives so inconsistent/confusing?
Absence of a control group
Where does HA come from?
Type B synoviocytes, chondrocytes
Long unbranched non-sulfated GAG
HA
Provides viscoelasticity, boundary lubricaiton
HA
Modulates chemotactic response and scavenges free radicals
HA
Increases production of endogenous HA and decreases degradation of aggrecan
HA
When is HA chondroprotective?
Intra-articular administration
How must HA be administered to reduce cartilage fibrillation?
Intra-articular
What amount of HA is required for lameness improvement?
20mg/joint once weekly for 3wk
Imparts viscosity to synovial fluid, lubriates unloaded joints, and exerts a direct anti-inflammatory effect and restores rheologic properties of synovial fluid
HA
Both ___ and ___ doses of HA result in significant improvement in horses
20mg and 40mg
Is IV or IA HA more efficacious?
IA
Which HA administration treats multiple joints less effectively?
IV
HA + _____ are chondroprotective w/potent anti-inflammatory effect
Triamcinolone
Inhibits degradative enzymes
PSGAGs
Counteracts deleterious effects of IL-1
PSGAGs
What mechanism of PSGAGs do you not see with IA HA?
Reduces of synovial effusion
Decreases inflammatory mediators (PGE2) and improves synovial membrane
Adequan
What is the drawback of Adequan?
It immunosuppresses the joints
How do you counteract joint immunosuppression caused by Adequan?
125mg Amikacin
PSGAG levels that are required to reduce PGE2 are only achieved with what administration?
IA (not IM)
What is polyglycan?
HA + chondroitin sulfate + N-acetyl-D-glucosamine
Both of these drugs have disease-modifying OA actions w/good efficacy in cases of synovitis
PSGAGs and HA
Does PSGAGs or HA have a greater effect on articular cartilage fibrillation?
HA
Does PSGAGs or HA have a greater positive effect on synovial membrane health?
PSGAGs
Is PSGAG or HA more effective for mild synovitis/capsulitis?
HA
What corticosteroid has chondroprotective effects?
Triamcinolone acetonide
Which corticosteroids have been shown to have deleterious effects on chondrocytes @ therapeutic levels (use minimum dose possible for tx)?
Methylprednisolone acetate
Which corticosteroid is “middle of the road” with no deleterious effects on articular cartilage?
Betamethasone
High level of IL-1 antagonists to combat inflammatory process in the joint
IRAP
Aseptic blood draw, draw off supinate, inject into joint once per week for 3 weeks
IRAP