Degenerative vs Inflammatory Joint Conditions Flashcards
Briefly explain the process of OA.
Chondrocytes have phenotypical alteration. Get old/stressed, and don’t produce good quality proteoglycans and collagen. They end up with ECM degradation which causes local low grade inflammation, which sets up the vicious cycle. Pro-inflammatory cytokines cause more stress to the chondrocytes. Eventually the cartilage is lost and this affects the subchondral bone, leading to osteophyte formation which will irritate the synovium, which leads to even more inflammation.
Briefly explain the process of RA.
RA is an autoimmune disease that creates large inflammatory response within the joints. It also affects the heart, kidney, gut, eyes (basically all body systems). Pro-inflammatory cytokines are not specific to the joint. Inflammation affects synovial membrane, which proliferates and grows to form pannus which degrades ECM of cartilage and bone. Cartilage is damaged and bone is exposed.
What is the prevalence of osteoarthritis in the US?
26.9 million
What is the prevalence of gout in the US?
6.1 million
RA is the most common autoimmune condition. What is the prevalence in the US?
1.3 million (860 per 100,000)
What is the prevalence of psoriasis in the US?
380 per 100,000
What is the prevalence of diabetes in the US?
192 per 100,000
What is the most common form of arthritis, with everybody developing age-related degenerative changes?
Osteoarthritis
What causes osteoarthritis?
Mechanical wear and tear on the joint
How many % of the population are affected by rheumatoid arthritis?
1%
Which joints are affected in OA?
Distal and proximal IP joints Big toe (as it carries more of the weight) Big weight-bearing joints e.g. knee and hip Spine
What is the main difference in the distribution of OA and RA in the body?
OA - bilateral or unilateral
RA - symmetrical
Which joints are affected in RA?
Any synovial joints can be affected
Cervical spine, shoulder, elbow, wrist, hip, knee, ankle, carpals, MCP…
Doesn’t affect distal joints in the hands/feet.
How does the age at which the condition starts differ between RA and OA?
RA – may begin at any time, usually mid 20s to 40s
OA – usually begins later in life
How does the speed of onset differ between RA and OA?
RA - Relatively rapid, over weeks to months
OA - Slow, over years
How do the joint symptoms differ between RA and OA?
RA - joints are painful, swollen (increased synovial fluid production), and stiff
OA – joints ache and may be tender but have little to no swelling
How does the pattern of joints that are affected differ between RA and OA?
RA - often affects small and large joints on both sides of the body (symmetrical), such as both hands, both wrists or elbows, or the balls of bothfeet.
OA - symptoms often begin on one side of the body and may spread to the other side. Symptoms are often limited to one set of joints, such as the DIPs and PIPs or the thumbs, largeweight-bearing joints (hips,knees), orthe spine.
How does the duration of morning stiffness differ between RA and OA?
RA - morning stiffness (synovial fluid gels at rest) lasts longer than 1 hour.
OA - morning stiffness lasts less than 1 hour. Stiffness returns at the end of the day or after periods of activity.
How does the presence of symptoms affecting the whole body (systemic) differ between RA and OA?
RA - frequentfatigueand a general feeling of being ill are present
OA - systemic symptoms are not present
Osteoarthritis is strongly __ related and is rare __ ___.
Age
<45 years
How many % of 65 year olds have OA on X-rays?
80%
When can degenerative changes begin to be seen on x-ray?
As early as 20 years old
Osteoarthritis mainly affects … joints.
Weight bearing
There is pronounced female preponderance for more severe symptoms and changes on radiographic examination, especially of what joints? Why?
Hand and knee
The knee is because women have wider pelvis, so have more severe OA of the knee (due to way the weight is carried).
OA of hips uncommon in…?
Africans and Asians
Polyarticular OA of the hand rare in…?
Africans and Malaysians