Intra-articular Medication Flashcards
What does a healthy joint consist of?
1) synovial membrane
2) joint capsule
3) Cartilage
4) subchondral bone
What is they synovial membrane composed of?
Two layers to the synovial membrane
1)Subintimal (blood supply and innervation)
2) intimal (synoviocytes)
- macrophage type A
- fibroblasts type B
What are the three types of synoviocytes?
In what layer of the synovial membrane are they found?
Type A- Phagocyctes (Macrophages)
Type B- Production cells (fibroblasts: HA, Aggrecan, Collagen, Cytokines, Eicosanoids, Proteases)
Type C
What is Aggrecan?
- Type C synoviocyte
- one of the largest proteoglycans in the joint
- can bind up to 50x its weight in water
- part of the intimal synovial layer
What is subchondral bone?
- shock absorber
- more deformable than cortical bone
- sclerosis may contribute to OA progression
What type of cartilage is used to define the health of a joint?
Articular cartilage
What is articular cartilage composed of?
1) 80% water
2) OG, HA, Collagens
What are proteoglycans composed of?
Protein + glycosaminoglycan (GAG) components
What is the relationship between Aggrecan and Hyaluronic Acid?
- forms aggregates with HA
- protects collagens from damage
What is hyaluronic acid?
The Backbone of the cartilaginous matrix
How do proteoglycans/Glycosaminoglycans bind to HA filament?
They bind via a protein link
What is the importance between the relationship between HA and Proteoglycans/Glycosaminoglycans?
Creates a polarized charge —> providing a sponge like shock absorbing effect!
What are the clinical parameters of OA in the joint?
1) effusion
2) decreased viscosity of synovial fluid (watery)
3) Increased TP
4) Gross cartilage changes
What are some gross cartilage changes associated with osteoarthritis?
Diagnostic arthroscopy
- Yellow
- Fibrillated (mild osteoarthritis)
- Dull
- ulcerated / Pitted
What is effusion?
Visible distention of the joint space
What are some changes in Subchondral bone during joint disease?
1) sclerosis (strengthens bone), brittle
2) Osteophyte formation ( bone covered in hyaline/fibrocartilage
3) Enthesiophyte formation (soft tissue attachment)
What causes decreased range of motion / pain in the synovial membrane/ joint capusule during disease?
1) thickening with chronic inflammation
2) hypertrophy of synovial lining
3) Fibrosis of subintima
What are some clinical signs of OA?
1) lameness (Slowly progressive)
2) joint pain
3) decreased range of motion
4) joint effusion
** can be present with/without radiographic changes!
What are the goals of treatment for Osteoarthritis?
You cannot stop osteoarthritis!!!
1) reduce inflammation
2) slow progression of degeneration
3) reduce pain
4) restore synovial fluid to normal
What are the options to manage Osteoarthritis?
1) chondroprotectives
2) corticosteroids
3) NSAIDs
4) blood based products
5) cellbased treatments
List the chondroprotective agents!
1) Hyaluronic Acid (HA)
2) Polysulfated glycosaminoglycans (PSGAGs)
3) Proteoglycans (PG)
4) Pentosan gold plus halo
5) corticosteroids- TRIAMCINOLONE
What are chondroprotectives?
Used to protect articular cartilage and cartilagenous matrix
What is hyaluronic Acid?
Long unbranched non sulfated GAG
Where does HA come from?
Type B synoviocytes, chondrocytes
What does Hyaluronic Acid (HA/ Sodium hyaluronate/ hyaluronan) do?
1) provides viscoelasticity, boundary lubrication
2) modulates chemotactic response
3) scavenges free radicals
4) increase production of endogenous HA
5) decreases degradation of Aggrecans
What are the three main uses for HA?
1) chondroprotectivew (IA)
2) Analgesic (IA)
3) Reduces cartilage fibirillation (IA)
How much and how often should HA be administered to be effective?
- 20mg/joint for improved lameness
- should be administered 1x weekly for 3 weeks
- IA at site most efficacious
Hyaluronate is usually used in combination with what?
corticosteroid (TRIAMCINOLONE)
*chondroprotective effect of both the HA and TA with potent antiinflammatory effect of TA
What is the common name for Polysulfated Glycosaminoglycans?
ADEQUAN
What is PSGAG indicated for?
MOA unknown
1) inhibits degradative enzymes
2) counteracts deleterious effects of IL-1
3) reduction of synovial effusion***
Additionally:
- upregulates GAGs and collagen synthesis
- decrease in inflammatory mediators (PGE2)
- improves synovial membrane
What are the draw backs of Adequan?
1) immuno-compromises the joint (reduce the number of bacteria necessary to cause septic arthritis)
* Must use in combo with Amikacin to eliminate this effect
What should you never combine ADEQUAN with?
Never combine Adequan with a steroid
T/F: Levels required to reduce PGE2 achieved with IA dose only!
TRUE
When should HA be used over PSGAG (adequan)?
1) early stage OA
2) HA greater effect on articular cartilage fibrillation
What Should not be used in the joints and why?
DEPO
-Methylprednisolone acetate
*deleterious effects on articular cartilage at therapeutic levels
