6. Osteoarthritis Flashcards
when do molecular changes begin prior to onset
20 years before clinical symptoms appear
what are the two forms of osteoarthritis
primary and secondary
what is the difference between primary and secondary OA
Primary OA is the gradual degeneration of a joint without any particular reason, found mainly in the knee joint
secondary OA is often caused by trauma and can occur in any joint
what percentage of the UKs population live with a musculoskeletal condition
28.9%
is there a gender bias in the number of people suffering with musculoskeletal conditions
yes : 10.1 million females to 7.7 million males
what is the cost per minute to the economy of treating OA and RA
19K a minute
genetic factors account for how much of hand and hip OA
60%
people who are overweight or obese are how many times more likely to develop knee OA
2.5-4.6 times
what occupation is likely to exacerbate OA
desk-based jobs
what molecules is cartilage composed of
water
collagen II
proteoglycans (aggrecan)
small proteoglycans
what is the most abundant
proteoglycan
what is the structure of aggregcan
it has a protein core attached to glycosaminoglycans (which can hold the water)
what two properties define cartilage
aneural and avascular
cartilage is aneural and avascular, what does this mean
it has no neurons and no blood supply
cartilage is constantly undergoing a slow remodelling process, why is it so slow?
all processes happen by diffusion - this is why the remodelling process is so slow
what happens to the cartilage in the knee joint when u stand
pushes the water in the cartilage out into the synovial gap
what happens when pressure is no longer applied to the knee joint
cartilage soaks the water back up
what happens when the water is lost
loss of functionality
how is aggrecan and collagen attacked
matrix metalloproteinases and aggrecanase
how else can we run out of functional collagen
there is an imbalance between the degradation and anabolic synthetic processes
(degrading it quicker than we are resynthesising it)
what holds the water in collagen
aggrecan
describe the structure of the cartilage in OA
thinner than normal, the surface is rough and the meniscus is damaged or missing
where is the meniscus located
between the tibial plateau and the femoral condyl
what is the role of the meniscus
involved in load transmission, shock absorption and lubrication
what does meniscal damage correlat ewith
an increased incidence of osteoarthritic disease
name 2 inflammatory cytokines
IL1 and TNF-alpha
name 2 anti-inflammatory cytokines
IL-4 and IL-10
what do inflammatory cytokines do
inhibit anabolic processes and promote catabolic processes
by stimulating the activity of proteases
what do anti-inflammatory cytokines do
promote anabolic processes and inhibit catabolic processes
by increasing protease inhibitor production
name a protease inhibitor
tissue inhibitors of metalloproteinase (TIMP)
what are some symptomatic treatments available for OA
NASIDs - inhibit COX enzymes - e.g. ibuprofen
what is the issue with NASIDs and COX2 inhibitors
produce unwanted outcomes - gastrointestinal issues
what surgical options are there for managing OA
resurfacing joint replacement
how could infliximab therapy be used to treat OA
inhibit the effects of TNF-alpha and up-regulate anti-inflammatory cytokines (IL-10)
what is the problem with prospective treatments for OA, what needs to be further researched
by the time symptoms appear it may be too late
research needs to look for biomarkers of acicular cartilage breakdown as an early sign of OA
