Pathophys - Osteoarthritis Flashcards
true or false
carpal tunnel is osteoarthritis
false - it’s not arthritis
true or false
unlike rheumatoid arthritis, osteoarthritis is not chronic
FALSE
it is
osteoarthritis causes the breakdown of what?
joint cartilage and underlying bone
true or false
osteoarthritis is “ware and tare” arthritis
TRUE
true or false
osteoarthritis is commonly seen unilaterally
TRUE
can still be bilateral, but characteristically unilateral
is it possible to have bilateral osteoarthritis
yes - just more frequently unilateral
name some sites that are likely to be affected by osteoarthritis rather than rheumatoid
large joints like hips, shoulders, knees, elbows
baseball pitchers developing arthritis is what kind of arthritis?
osteoarthritis - “wear and tear”
osteoarthritis is more so considered the disease of older or younger people?
older people
can affect younger, but consistent with repetitive ware and tear - and thus more frequently seen in older
true or false
rheumatoid arthritis is the most common form of arthritis
FALSE
osteoarthritis is
osteoarthritis is a ____ diseases that causes the breakdown of what 2 things
joint disease
causes the breakdown of joint cartilage and underlying bone
name 3 causes of osteoarthritis
joint injury/mechanical stress
limb development abnormalities in utero
inherited factors - genetics can play a role
true or false
genetics do not play a role in osteoarthritis
FALSE - it’s possible they do
besides joint abnormalities in utero, joint injury/mechanical stress, and genetic factors, name 3 OTHER RISKS in developing osteoarthritis
being overweight
performing repetitive tasks
legs of different length
explain how joint injury/mechanical stress can be a cause of osteoarthritis
it generates a low grade inflammatory process
true or false
in osteoarthritis, there are NO visual signs of inflammation
true - no redness or heat
there is in rheumatoid
what is Ehlers-Danlos syndrome?
caused by genetic mutation (multiple). a rare connective tissue disorder
causes loose joints and pain, stretchy skin, and abnormal scar formation
a secondary factor in developing osteoarthritis
symptoms of this disease are having loose joints, joint pain, stretchy skin, and abnormal scar formation
ehlers-danos syndrome
secondary factor in developing osteoarthritis
_____ DOUBLES the risk of developing osteoarthritis
diabetes
is ehler-danlos syndrome autosomal dominant or recessive?
may be either
what is alkaptonuria?
a secondary factor in developing osteoarthritis
a genetic metabolic disorder where the body can’t process phenylalanine and tyrosine, resulting in an accumulation of homogenistic acid in the body WHICH CAN DAMAGE JOINTS
there is a mutation in the gene that encodes for the enzyme that breaks down phenylalanine and tyrosine (homogentistate 1,2,3-deoxygenase)
what is the pattern of inheritance of alkaptonuria?
autosomal recessive
what is marfans syndrome and what is the pattern of inheritance?
a genetic disorder of connective tissue - secondary factor in developing osteoarthritis.
autosomal dominant
the result is tall, thin people with long arms, legs, fingers, toes and hyperflexible joints. may involve heart valves. can cause aortic aneurysm and eye ligament weakness
caused by a mutation in FBN1 gene — supposed to produce fibrillin 1 (glycoprotein) which is essential for the proper formation of ECM – especially elastic fibers – leads to issues in making healthy connective tissue and makes joints that dont work properly – begin to wear
as mentioned, Marfans syndrome can affect heart valves
explain further
can cause mitral valve prolapse and aortic aneurysm
name 2 secondary factors that can cause osteoarthritis through the accumulation of certain elements
hemochromotosis - buildup of iron
wilsons disease - buildup of copper
both are rare genetic disorders
true or false
a chronic inflammatory disease can lead to the development of osteoarthritis
true
as mentioned, a chronic inflammatory disease can lead to the development of osteoarthritis
name 2 of them
lyme disease
gout
true or false
acute joint infections cannot lead to the development of osteoarthritis
FALSE - they can
this is bc joint infections can lead to permanent damage of the joint due to the inflammatory process and cause it to not work properly, resulting in the developing of osteoarthritis
explain the pathophysiology of osteoarthritis
balance between compressive forces on joint vs hydrostatic pressure of the water contained in cartilage
compressive forces squeeze cartilage down, hydrostatic keeps cartilage in proper form
exert too much compressive force - proteoglycans lost and water forced out. proteoglycans responsible for maintenance of hydrostatic pressure and hydration which keeps water in and cartilage open and in proper place
increased compressive forces from continual stress – causes decrease in proteoglycan content –> water content decreases –> force keeping cartilage in proper structure is decreased.
this reduced osmotic pressure causes additional stress on collagen fibers in the cartilage, causing them to breakdown.
in summary, when the balance is lost and hydrostatic pressure decreases, compressive forces breakdown collagen
as mentioned, when the balance between hydrostatic pressure and compressive pressure is lost, collagen fibers within the cartilage between the 2 bones starts to breakdown.
what is the result of this?
the breakdown of collagen results in an inflammatory process which FURTHER INJURES the cartilage, thru the release of proteolytic enzymes (like metalloproteases)
as mentioned, the breakdown of collagen results in the induction of inflammatory processes through the release of proteolytic enzymes like metalloproteases.
what is the result of this inflammatory process?
breakdown of further elements in joint.
ligaments
joint capsule may become fibrotic and thicken
meniscus (cartilage covering of bone) can be torn away
in which cells are metalloproteases found?
synoviocytes, macrophages, and neutrophils – all associated with inflammation
what is the result of the wearing away of cartilage in osteoarthritis?
name 2 things
makes movement difficult
puts pressure directly on the head of the bone – can spur bone growth (form a growth) and head of bone becomes misshapen as result of pressure
further interferes with articulation of the 2 bones
the spur (bony growth) that forms from the pressure of bone on bone can do what?
forms a joint mouse - loose piece of cartilage or bone and cartilage
can cause crepitus (popping or cracking sound)
the joint may disarticulate and nearly completely lose function
what maintains the hydrostatic/osmotic pressure within cartilage between bones?
proteoglycans
what is crepitus?
grating sensation or sound when moving a joint - due to bone rubbing against each other
what is ankylosis?
condition in which 2 bones rub against each other
what do ligaments connect?
connect bones and joints
