Joint Flashcards
What is the articular surface of adjoinging bones made up of?
Hyaline cartilage (Type II collagen)
What secretes the lubricating joint fluid?
Synovium lining secretes fluid rich hyaluronic acid to lubricate the joint
What is another name for Degenerative Joint Disease?
Osteoarthritis?
What is osteoarthritis? Most common cause? Risk factors? Typical joints affected? Classic presentation?
Progressive degeneration of articular cartilage (most common arthritis); Wear and tear; >60 yo, obesity, trauma; Hips, lower L spine, knees, distal interphalangeal (DIP) and proximal interphalangeal (PIP) joints of fingers; Joint stiffness in the morning and worsening during the day.
Pathologic features of osteoarthritis
Disruption of cartilage resulting in joint space filled with “joint mice”; Eburnation (polishing) of bone; Osteophyte formation classically in DIP (Heberden nodes) and PIP (Bouchard nodes)
What is rheumatoid arthritis? Population? Marker? Observed pathology?
Chronic systemic autoimmune disease; Arises classically in women of late childbearing age. HLA-DR4; Hallmark is synovitis leading to formation of a pannus (inflamed granulation tissue) and eventual destruction of cartilage and ankylosis (fusion) of the joint
RA clinical features?
Arthritis w/ morning stiffness that improves w/ activity -general symmetric involvement of PIP joints (swan neck deformity), wrists (radial deviation), elbows, ankles, knees; DIP usually spared; Joint space narrowing, loss of cartilage, and osteopenia seen on xray, fever, malaise, weight loss, myalgias,rheumatoid nodules (central zone of necrosis surrounded by epithelioid histiocytes in skin and viscera), vasculitis, Baker cyst, pleural effusion, lymphadenopathy, interstitial lung disease
RA lab findings
IgM autoAb against Fc portion of IgG (AKA rheumatoid factor), marker of tissue damage and disease activity, Neutrophils and high protein in synovial fluid
Complications of RA
Anemia of chronic disease and secondary amyloidosis
What is Seronegative Spondyloarthropathies? Presentation? Complications?
Group of joint disorders without rheumatoid factor, only axial skeleton involvement (sacroiliac joints and spine) and HLA-B27 association; Classically young adult males, with low back pain and eventual vertebral body involvement; Fusion of vertebrae (bamboo spine), uveitis, aortitis;
What is Reiter syndrome? Population?
Triad of arthritis urethritis and conjunctivitis; Young adult males weeks after GI or Chlamydia trachomatis infection
Mnemonic for Reiter syndrome?
Can’t see, can’t pee, can’t climb a tree
What is Psoriatic arthritis? Clinical presentation?
Arthritis involving 10% people with psoriasis; Axial, peripheral joints, DIP joints of hands/feet - “sausage fingers/toes”
What are general agents that cause infectious arthritis and the associated population involved? Typical clinical presentation?
N. gonorrhoeae - young adults; S. aureus - older children and adults; Classically single joint; Warm joint with limited ROM; fever, increased WBC, elevated ESR
What is Gout? Cause?
Deposition of monosodium urate (MSU) crystals in tissues/joints; Hyperuricemia due to increased production/decreased excretion
From where is uric acid derived and how is it eliminated?
Purine metabolism to the kidneys
What is the etiology of primary gout?
Etiology unknown
What is the relationship between leukemia (myeloproliferative disorders) and gout
There is a lot of cellular turnover and therefore a lot of processed purines. Therefore you can relatively easily get gout
What is the relationship between Lesch-Nyhan syndrome and gout?
X linked deficiency of hypoxanthine-guanine phosphoribosyltransferase (HGPRT) leads to hyperuricemia and gout (along with mental retardation and self mutilation). Usually, the HGPRT is used to salvage purines. If you can’t perform that, purines will be metabolized to uric acid.
Relationship between kidney failure and gout
Can’t excrete uric acid and therefore you get hyperuricemia
What is the classic presentation of gout?
Pain in the great toe (podagra)
What are three common causes of acute gout?
High protein diet, Diuretics, and alcohol
Chronic gout leads to:
Tophi - white chalky aggregates of uric acid crystals with fibrosis and giant cell reaction in soft tissue and joints and renal failure - urate crystals deposit in kidney tubules
Gout lab findings
Hyperuricemia, synovial fluid with needle-shaped crystals with negative birefringence under polarized light
What is pseudogout? What is found in the synovial fluid?
Resembles gout but due to deposition of calcium pyrophosphate dihydrate (CPPD); Rhomboid-shaped crystals with weakly positive birefringence under polarized light
Mnemonic for remembering gout crystals under polarized light
Horizontal crystals “lay LOW and are yelLOW”. Under paraLLel light, they are yeLLow;
