Pathophysiology of OA Flashcards
What are we treating in patients with OA?
- Inflammation
- Mechanical stress
- Decreased SF viscosity
- Cartilage breakdown
Stages of Joint Dz
- Synovial inflammation/ Deteriorating Jt Fluid - “Synovitis”
* After this is “point of no return” - Cartilage changes/Jt Capsule fibrosis - “Degenerative Jt Dz”
- Bony changes - “OA”
How do we dx OA?
Imaging!
- rads, US, nuclear scintigraphy, CT, MRI
Sx
- Diagnostic, therapeutic
Aims of Tx:
- Dec inflammation systemically
- Dec inflammation IA
- Provide Supportive therapy
Give examples of each
- Dec inflammation systemically
- phenylbutazone
- Legend
- PSGAGs (adequan)
- Chondroitin sulfate/glucosamine - Dec inflammation IA
- HA
- Steroids - Provide Supportive therapy
- Acupuncture/chiropractic/physical therapy
What is the goal of Chondroprotection?
To support jt structure and fxn
- normalize synthesis of matrix components
- dec matrix degradation
Name 4 Chondroprotective Agents
- Corticosteroids (low dose)
- Hyaluronan
- PSGAGs (Adequan)
- Biologic meds (BMDMSCs, IRAP)
- Oral, slow acting agents (Cosequin, Glycoflex)
Are low doses of steroids chondroprotective?
Yes! and they are a good 1st line of defense
What are the benefits of Corticosteroids?
- stabilize lysosomal enzymes
- inhibit IL1 production by synovium
- inhibit collagenase, prostaglandin release
- retard WBC migration, fibrin deposition
What are the benefits of LOW DOSE corticosteroids?
- Cartilage sparing effect
- inhibit inflammation but do not cause proteoglycan degradation
What are some cons of corticosteroids?
- GAG depletion
- Demonstrated in vitro & in vivo
- suppressed collagen synthesis
- suppressed HA synthesis
- laminitis
- steroid arthropathy
What is a steroid flare?
Steroid injection gone wrong!
- acute inflammatory response
- heat, pain, swelling, lameness
- 8 to 24 hours post-injection
- low incidence (2%)
- vehicle related
basically –> infection
How do NSAIDs work? Name a safe NSAID
Inhibit COX
Equiox - safer –> blocks COX 2
What is the principle lubrican of soft tissues in the joint?
Sodium Hyaluronan (HA)
This is responsible for viscoelasticity of fluid
Liposomes - bottom line
The net effect of liposomes is to put the right drg in the right place and to hold it there for a prolonged effect. This promotes maximal effect with minimal toxicity
What are we trying to do in Physical Therapy?
Intent of PT is to strengthen all tissues
- PROM: decrease scar tissue/increase jt environment
- Swimming
- Icing?
