OA Flashcards
T/F OA is a “wear and tear” arthritis
F
T/F OA is a “whole joint disease”
T
What are the components of the joint affected in OA
Cartilage
Synovial Membrane
Ligaments
Bone
Is the synovial membrane as affected in OA as it is in RA
no more affected in RA
What is OA characterized by
cell stress and extracellular matrix degradation
What initiates OA
micro and macro injury that activates maladaptive repair responses including pro-inflammatory pathways of innate immunity
Release of inflammatory enzymes + abnormal biomechanical forces -> damage of cartilage -> cartilage loss
What occurs to bone in OA
Increase in bone turnover and localized density - osteophytes
OA risk factors?
- Age
- Sex
- Genetic
- Obesity
- Physical inactivity
- Injury
- Joint stress
Knee OA prevalence
- African american > Caucasians
- Medial compartment: Caucasian>chinese (men
- lateral compartment: Chinese>Caucasian (men)
Hip OA prevalence
Caucasian > Chinese
Hand OA prevalence
Asymptomatic: Caucasian>Mexican americans>african americans
- Caucasian>Chinese
What occurs to bone turnover and localized density in OA vs normal aging
Increases in OA
Decreases in normal aging
What occurs to water content in cartilage in OA vs. normal aging
Increased in OA
Decrease in NA
What occurs to fibrillation in OA vs. normal aging
In OA: focal + progressive (will see it crossing joint line
In NA: at WB sites & not progressive
What occurs to metabolism and inflammatory enzymes in OA vs. normal aging
In OA: Increased
In NA: normal metabolism and no inflammation
What occurs to lean muscle mass in OA vs. normal aging
OA: Decrease (type I fibres)
NA: Decrease Type II fibres (fast)
What is the clinical pattern of OA in the knee
mostly bilateral; tibio-femoral?patella-femoral
What is the clinical pattern of OA in the hip
UNilateral> bilateral
What is the clinical pattern of OA in the spine
Facet joint OA
What is the clinical pattern of OA in the hand
PIP, DIP, CMC joints
This is unlike RA - which normally occurs in the MCP and rarely occurs in the CMC joint
What is OA in the PIP called
Bouchard’s Node
What is OA in the DIP called
heberden’s Node
How does OA get diagnosed?
- Radiographic OA
- Symptomatic OA
- MRI- Defined OA
What grading system is used for diagnosis of OA via radiography
Kellgren-Lawrence Grading System
What are the main features you would see in Xray of someone with OA
- Loss of joint space
- Osteophytes
- Subchondral scelerosis
- Subchondral cyst formation
What are subchondral sclerosis caused by
Increased periarticular bone density
What is the first characteristic of OA you would see on an xray (what is the first clincal sign to occur)
- Osteophytes
What causes subchondral cyst formation
Typically cyst formation
Using the Kellgren-Lawrence Grading system, what are the grades? At what grade do you begin to see changes on xray
0 - No radiographic features
1 - Doubtful: minute osteophyte, doubtful significance
2 - Minimal: Definite osteophyte, unimpaired joint space
3 - Moderate: Moderate decrease in joint space (pain)
4 - Severe; Joint space greatly impaired, sclerosis of subchondral bone (pain and all other Loss syndromes)
Clinical Feature of OA
- Pain after using the joint
- Relieved by rest
- Morning stiff less than 30mins
- Stiffness after a period of inactivity
- Only 40% of patients with joint damage experience pain
Why may there be no pain in OA
Cartilage likes pressure and compression - unless soft tissue structures are being put on strain there is often limited pain, other causes of pain can be bone being exposed (very painful!!) or inflammation
what needs to occur for symptomatic diagnosis of OA
Yes to all 4 questions: Constant or intermittent discomfort or pain…
- at any time on most days of the month?
- In the past year?
- Worse with activity?
- Relieved with rest?
One or more of 3 signs:
- Effusion. Flexion contracture. Gait abnormality
___% of people with knee pain had MRI-detected OA that was not evident on xray
55%
MRI is very useful to catch OA early, how does it do this?
- Picks up on bone marrow edema (bone bruise) which are found in acute traumatic injuries
Is there an association between weather and OA
- The climate is not the cause or the cure but warmth does relieve symptoms
- changes in barometric pressure and ambient temperature may affect OA
What is the first line of treatment for oa
- Exercise
- Weight loss
- Acetaminophen
70% of knee joint loading is in the _____ compartment when walking - bringing the leg into the ___ position
medial
varus
relationship between quad strength and hip/knee OA
in women only - lower risk with greater quad strength
Is obesity related to risk of OA in WB or non-WB joints
Both - because fat tissues can increase the levels of inflammatory enzymes in the body
Is BMI or waste circumference used to determine risk of OA
BMI
If you lose 1 lb of weight you lose _____lb of knee joint load per step
4 lb
Best to start diet or exercise program first?
both at same time
Which diet is best : atkins, ornish, weight watchers, zone diets
all reduce weight but with poor adherence - need to choose one which person will stick to!
