Joint Diseases Flashcards
Explain the major parts of a synovial joint?
Each bone has an articular surface that is hyaline cartilage made of type 2 collagen.
There is a joint capsule that surrounds the two articular surfaces that is lined with synovium that secreted H acid to lubricate the joint.
Explain the problem with degenerative joint disease, or osteoarthritis? What is it commonly due to? 5 common sites? What are 3 risk factors? What is classic clinical presentation?
Degeneration of the articular cartilage Wear and tear Age, obesity and trauma Hips, knees, L spine, DIP and PIP Stiffness in the morning with progressive worsening during the day
What are the 3 pathologic features of DJD?
As the cartilage is broken down, little pieces can end up in the joint space called joint mice
Eburnation or polishing of the surface
Reactive bony outgrowths called osteophytes, classically seen in the DIP (H nodes) and PIP (B nodes).
Characterize rheumatoid arthritis, what is the typical patient population and what is the high yield association?
What is the hallmark of this disease?
Chronic, systemic autoimmune disease in early middle aged ladies
HLA DR4
Synovitis Leading to the formation of granulation tissue called pannus.
Now this granulation tissue has myofibroblasts so there is contractile properties working here. This can lead to ankylosis or fusion of the joint, destruction of the cartilage, or deformity of the joint simply because it is being pulled in different directions due to the contractions.
How is the arthritis typically described from the patient perspective?
What 5 joints are commonly involved and what joint is spared that is significant and why?
What are 4 other clinical signs/symptoms?
Stiff in the morning and better throughout the day
PIP, wrists, elbows, knees and ankles. DIP (DJD has this)
Rheumatoid nodules, baker cyst, pleural effusions, vasculitis
What is the hallmark lab finding with RA?
2 complications because of RA?
IgM autoantibodies against Fc portion of IgG called rheumatoid factor.
Anemia of chronic disease and secondary amyloidosis
Explain what seronegative spondyloarthropathies are and what are the three characteristics?
What are the 3 diseases that fall under this category of disease?
Group of joint disorders characterized by…
1. Lack of rheumatoid factor
2. Axial skeleton involvement
3. HLA B27 involvement
AS, Reactive arthritis/Reiter Syndrome, and psoriatic arthritis
What two areas of the body are involved in AS and what patient population are we dealing with here?
3 clinical features of AS?
SI joints and spine
Young adults, usually males
Back pain and eventually fusion of the vertebral bodies
Uveitis
Aortitis that can lead to aortic regurgitation
What is the triad of reiter syndrome/reactive arthritis?
How and who does it arise in?
Arthritis, conjunctivitis, and urethritis
Young males after a GI of chlamydia infection
What is the classical presentation of psoriatic arthritis?
DIP joints of hands and feet are most commonly affected leading to sausage fingers or toes
What are the two most common pathogens causing infectious arthritis and what patient population do we commonly see each one in?
Infectious arthritis classically involves what?
How does it usually present?
N gonorrhea in sexually active young adults (most common)
Staph in kids and adults
Single joint, usually the knee.
Warm, red, tender joint with limited range of motion and systemic symptoms that are commonly seen with infection
What is going on with Gout?
What do they think the two causes are?
Which type of gout is most common and explain both types?
Build up of MSU, which is derived from Uric acid, and deposited into tissues and joints For primary (most common) they think its overproduction or under excretion of uric acid. Secondary can be due to leukemia and MPD, Lesch Nyhan Syndrome, deficiency in HGPRT, so we cant salvage HX or guanine, renal problems so we cant excrete uric acid.
Explain the mechanism of acute gout, where it happens and what 2 things can precipitate the arthritis?
MSU crystals deposit in the joint and it is the crystals that trigger the inflammatory process. Presents in the big toe.
Eating a lot of meat and alcohol can trigger it.
Chronic gout can lead to what 2 things?
- Development of Tophi, which are white chalky aggregates of uric acid crystals surrounded by fibrosis found in tissues and joints.
- Renal failure due to uric acid crystals depositing in the tubules of kidneys .
What is the key lab finding for gout and what does the synovial fluid show upon examination?
High uric acid in the blood
Needle shaped crystals with negative birefringence under polarized light. This means when the crystals lay flat they are yellow. Also, when they are hit with parallel light they are yellow.
