Musculoskeletal-Dr. Walby Flashcards
What does the Musculoskeletal system include?
Bones, Joints, Soft tissue, Muscle
If you dont have vit C what will you get?
scurvy
if you dont have vit D what will you get?
rickets, osteomalacia
What are the 2 abnormalities of bone growth?
achondroplasia (aka ostechodrydysplasia)
Mucopoysacchardioses
What are the three types of osteomyelitis?
pyogenic
chronic
tuberculous
What are the four bone-forming tumors?
- osteomas
- osteoid osteoma
- osteoblastoma
- osteogenic sarcoma
What are some acquired metabolic disorders affecting bone?
osteoporosis
osteopetrosis
Paget’s disease
What is the CT of bone?
35% organic matrix
65% inorganic elements
(blank) percent of calcium is stored in the bone.
(blank) percent of phosphorus is stored in bone.
(blank) percent of sodium (Na+) and magnesium (Mg++)
99%
80%
65%
un-mineralized bone is known as (Blank)
osteoid
What is the inorganic component of bone and what is its function?
calcium hydroxyapatite-gives bone hardness
What do the organic components of bone made up of?
cells of marrow and proteins of matrix
What are osteoprogenitor cels and where do you find them?
pluripotential mesenchymal cells that lienear and on all bony surfaces
What do osteoblasts do?
build
(found on the surface of bones, synthesize, transport and arrange proteins of the matrix, starts process of mineralization)
Tell me about osteoclasts
derived form granulocyte-monocyte precursor
multinucleated
responsible for bone resorption
-reside in howships lacunae
What do osteocytes do?
important role in Ca2+ and phosphorus homeostasis; communicate with sruface and each other via canaliculi
Which has bigger lacunae, osteocytes or osteoclasts?
clasts!!!
Which is closer to the outside, spongy bone or compact bone?
compact bone
What do you find within the medullary cavity?
trabeculae
What is on the outside of ocmpact bone?
Periosteal vessels
Osteoprogenitor cells derived from (blank) cells
mesenchymal cells
Where do osteblasts develop from?
osteoprogenitor cells that line inner periosteum, the endosteum and lining the haversian canal.
Osteoblasts synthesize the (blank) components of bone matrix; some gradually become surrounded by matrix and become osteocytes.
organic components
(blank) lie in a lacuna within the matrix; involved in exchange of nutrients and wast with blood via canaliculi
osteocytes
(blank) are derived from a bone marrow precursor. They secrete enzymes and biochemically concentrate H ions to dissolve bone and calcium salt crystals thereby releasing minerals into blood.
Osteoclasts
(blank) forms 90% of the organic component of bone
Type I collagen
What are the 2 types of collagen deposition?
1) Woven bone
2) lamellar bone
Where do you see woven bone?
- fetal skeleton
- adult pathologic states requiring rapid growth (fractures, infections, tumors)
- pattern is random weave and weaker
Where do you see lamellar bone?
seen in adults, replaces woven bone at growth plates, deposited slowlly, more stable and stronger than woven bone
What are these:
Absence of a phalanx, rib, or clavicle
Extra bones (supernumary ribs, digits)
Fusion of adjacent joints (syndactylism)
Formation of long, spider-like digits (arachnodactylism) as is seen in Marfan’s syndrome
congenital malformations-uncommon
What is the most common disease of the growth plate?
Achondroplasia (aka osteochondrodysplasia)
What is achondroplasia?
impaired maturation of cartilage leading to disorganized chondrocytes caused by mutation in FGFR3
What does achondroplasia result in?
dwarfism
Tell me about heterozygous achondroplasia
more common
- AD
- infants have shortened extremities , normal trunks trunks and enlarged heads
- normal life span
What will happen if you have homozygous achondroplasia?
-compromised respiratory capcity-> often die in infancy
growth hormone doesnt help!!!
What is this:
lysosomal storage disease invoving acid hydrolases-> results in abnormalities of hyaline cartilage, and hence growth plates and articular surfaces, due to abnormalities of chondrocytes, and hence growth plates, and articular cartilage.
Mucopolysaccahridoses
What do mucopolysaccharidoes manifest as?
as chest wall deformities, short stature, and malformed bones
What is this:
abnormal type I collagen formation-> afects joins, eyes (blue sclear), ears (deafness), skin and teeth….results in too little bone and results in multiple fractures.
Osteogenesis imperfecta
brittle bone disease
In osteogenesis imperfecta, there are four major types, what are they?
type 1: postnatal fractures with BLUE SCLERA, Deafness (AD)
type 2: perinatal demise (mostly AR)
type 3: progressively deforming w/ growth retardation (AR)
type 4: Postnatal fractures w/out blue sclerae (AD)
Survivors of osteogenesis imperfecta usually have what?
- hearing deficits
- blue-yellow teeth
- all have fractures
What deficiency is this:
defective mineralization and increase in non-mineralized osteoid, bones are softer
Vit D deficiency
What is this:
decreased bone mass/densitiy-> increased fragility (no abnormality in ratio of minerals to protein matrix)
Osteoporosis
What are the primary types of osteoporosis?
postemenopausal women
senile
Who are most likely to get osteoporosis?
whites/mexican
What are risks for osteoporosis?
alcohol, caffeine, carbonation, smoking, anticonvulsants, benzos, hypogonadism, hypercortical states, hyperparathyroidism, inadequate Calcium and vit D
What is phenytoin (dilatin)
anticonvulsant
What is valium and Xane?
benzos
What is a test that is specific or sensitive to osteoporosis?
there isnt one :(
Using some DEXA bone scans to help
Why dont you use Xrays to diagnose osteoporosis?
cuz it wont show anything until 30-40% of bone mass is depleted
What is a scary complication of osteoporosis?
Pumonary embolism and pneumonia with a very high mortality (more than CA of the breast and endometrium combined)
When do you have peak bone mass and what affects this?
3rd decade
-genetic, vit D receptor, sex, race, activity, diet, hormonal status0
What happen to our osteoblasts and osteoprogenitor cells?
have decreased biosynthetic ability over time
Where do you start losing bone density?
spine and femoral head (increased trabecular bone here)
LOw (Blank) intake during rapid bone grwoth in girls leads to osteoporosis later in life
Calcium
What is postemenopausal osteoporosis?
yearly reducion in mass is 2% of cortical, 9% cancellous
- 35-50% decrease in 30-40 years (80-90 yo)
- 1/2 women-> osteoporotic bone fracture (1/40 men)
If you have a deficiency in (Blank) hormone that you get increase bone resportion
estrogen
What happens if you dont have estrogen?
get increases in IL-1 which increases increases osteoclast activity
How do you treat osteoporosis?
Medications, hormone replacement/ estrogen receptor modulators, calcitonin, vitamin replacement, exercise/activity, decrease in smoking, alcohol, corticosteroid use
Excercise helps with preventing osteoporosis, which is better, endurance training or weight training?
weight training
What is the most potent activator of osteoclasts?
IL-1
What bone is most affected by IL-1 induced osteoclast activity?
affects bones with increased surface area, such as the trabecular bone of vertebral bodies-resulting in progressive microfractures and vertebral collapse
Paget’s disease (osteitis deformns) is caused by (Blank)
osteoclast dysfunction
What are the three phases of Paget’s Disease?
1: osteoclast/osteolytic stage- hypervascularity, and bone loss
2: mixed osteoclastic/osteoblastic stage, which ends with a predominance of osteoblastic activity
3: culminates in a burnt-out quiescent osteosclerotic stage
When do you usually see Paget’s disease?
5th decade, slight male predominance-> usually white
What is the characteristic histologic feature of paget’s disease?
mosaic pattern, making bone appear like a jigsaw puzzle, virtually pathognomonic-> the woven bone is weaker and more prone to fracture
What are the three phases of pagets disease?
Osteolytic phase
mixed phase
steosclerotic phase
The (blank) is solid but woven and called “burned out
osteosclerotic phase
What causes Paget’s disease?
a “slow virus” made up of paramyxovirus like particles, this virus induces production of IL-6 which induced IL-1 which recruits osteoclasts
Many cases of pagets disease are (Blank) and only found incidntally on X-ray
asymptomatic
90% of polyostotic cases of Paget’s involve the (blank) (blank) and (blank)
pelvis, spine, skull
In paget’s disease what is a cardinal symptom?
Leonine faces (bone overgrowth in craniofacial area)
In severe polyostotic disease, the increased blood flow causes a (Blank) resulting in high output cardiac failure
functional arterio-venous shunt
In the skull, the cortex is thickened and irregular. The findings probably corresponds to the “cotton wool spots” seen on plain films in the later stages of (blank)
Paget’s disease
What are the lab findings of paget’s disease?
- elevated serum alkaline phosphatase
- elvated urinary hydroxyproline
- normal serum calcium and phosphate
What is the tx of paget’s disease?
success wih anti-resorptive agents
(act to inactivate osteoclasts)
-bisphosphonates
-calcitonin
What is this:
bones are abnormally brittle and fracture despite excess deposits and increased density
Osteopetrosis (rare)
-can cause osteosclerosis (bone in bone appearance on radiology)
What causes osteopetrosis?
variant with carbonic anhydrase II deficiency
What does carbonic anhydrase do?
enzyme necessary for bones and renal tubular cells to excrete hydrogen ions and acidify their environment (this prevents osteoclasts from resorbing matrix)
What is this:
Decreased calcium, phosphate
elevated alkaline phosphatase, PTH
osteomalacia and rickets
What is this:
only alkaline phosphatase is elevated-> see thick dense bones also known as marble bone
Osteopetrosis
When you have a defect in vit D, you will get defective mineralization and an increase in (blank)
non-mineralized osteoid
How can you have a metabolism problem?
like in osteoporosis, mass is decreased but bone that is present has normal mineral content
Vit D gets converted to (blank) with UV light/
D3
If you get Vit D from plants, the precursor is ergosterol which is converted in body to (blank)
Vit D2
What are the three organs involved in vit D metabolism?
skin/sunlight, kidney, liver
What does Vit D do?
- stimulates intestinal absorption of Ca and P
- works w/ PTH in mobilization of Ca from bone
- stimulates PTH dependent reabsorption of Ca in distal renal tubules
(blank) is required for nomal mineralization of epiphyseal cartilage and osteoid matrix.
Vit D
In vit D deficiency, the overall reaction results in (blank) which results in resorption of bone or lack of proper mineralization
hypocalcemia
WHat is the mechanisms of deformation in rickets?
overgrowth of epiphyseal cartilage
What are the clinical symptoms of rickets?
- excess of osteoid->frontal bossing
- square head
- pidgeon breast
- Harrison’s groove
- Lumbar lordosis and bowing of the legs
What is this:
- derangement of remodeling process that occurs throughout life
- newly formed osteoid matrix is inadequately mineralized, with resultant
- excess of persistent osteoid
- contours of bone not affected
- bone is weak and prone to microfractures, most likely affecting vertebral bodies and femoral necks
Osteomalacia
What are the first bones that break in osteomalacia?
vertebral bodies and femoral necks
(blank) regulates calcium homeostasis
PTH
In hyperparathryoidism, what happens?
increased PTH levels-> stimulate receptors on osteoblasts
- release of mediators
- increase osteoclast activity
Increased osteoclast activity affects (blank) bone more than (blank)
cortical bone
cancellous bone
In hyperparathyroidism microfractures and secondary hemorrhages elicity influx of multinucleated macrophages and reactive fibrous tissue to form an (blank)
apparent mass known as “brown tumor”
THe changes caused by hyperparathyroidism is collectively known as (blank)
osteitis fibrosa cystica
What is this:
Increased osteoclastic bone resorption which mimics osteitis fibrosa cystica
Delayed matrix mineralization (osteomalacia)
Osteosclerosis
Growth retardation
Osteoporosis
renal osteodystrophy
What is the mechanism behind renal osteodystrophy?
renal failure results in phosphate retnetion-> hyperphosphatemia causes hypocalcemia, which causes secondary hyperparathyroidism
WHy will renal failure cause increase osteoclast activity?
renal failure-> lack of vit D and calcium-> upregulate PTH to increase Ca-> increased PTH leads to increase osteoclast activity
Low levels of Vit D and Ca contribute to the (blank)
osteomalacia
(blank) is a bone disease that occurs when your kidneys fail to maintain proper levels of calcium and phosphorus in the blood. It’s common in people with kidney disease and affects most dialysis patients.
Renal osteodystrophy
What is aluminum deposition in bone (iatrogenic) due to?
dialysate solutions and aluminum containing oral meds to bind phosphate (major cause)
Why is aluminum deposition bad?
interferes with deposition of calcium hydroxyapatite
What is a simple fracture?
(closed) if overlying tissue is intact
What is a compound fracture?
if fracture site communicates with skin surface, skin broken-> infection w/ S. aureus
What is a comminuted fracture?
if bone is splintered
What is a displaced fracture?
if ends of bone at fracture site not aligned
What is a stress fracture?
if fracture develops slowly due to increasing repetitive loads which eventually cause break
What happens post fracture?
- bloot clot,
- fibroblasts move in
- osteoclasts and vessels move in, -cartilage forms early
- woven bone forms first
- after months woven bone changes to lamelar bone
- healed bone is stronger than original bone
Whats up with cartilage and fractures?
found as a early part of healing of a fracture, if fracture is not immobilized then it may stay as cartilage
What are other names for avascular necrosis?
bone infarction
osteonecrosis
aseptic necrosis
ischemic bone necrosis
ALL instances of avascular necrosis result from (blank)
ischemia-> most commonly occurs in the hip
What are the most common causes of avascular necrosis?
idiopathic
prior steroid administrations (mechanism unclear)
What can these cause:
CT diseases, sickle cell disease, radiation, alcohol abuse, tumors, trauma (ie joint displacement)
Avascular necrosis
How come sickle cell can cause avascular necrosis?
cuz it can plug the small vessels
What are the 2 types of avascular necrosis?
1) subchondral infarcts
2) medullary infarcts
(blank) are triangular or wedge-shaped, they lay over articular cartilage and remain viable due to contact with synovial fluid for nutrients.
subchondral infarcts
Subchondral infarcts are triangular or wedge-shaped,(blank) shaped overlying articular cartilage remains (blank) due to contact with synovial fluid for nutrients)
wedge shaped/ triangular
viable
(subchondral means under cartilage so just remember the cartilage remains intact and underneath it is messed up and the cartilage remains viable because of the synovial fluid giving nutrients to it)
Medullary infarcts are (Blank) and cortex is (blank) involved due to collateral blood flow
geographic
not usually
What do the symptoms of avascular necrosis depend on?
location and extent of infarction
SUbchondral infarcts cause (blank)
chronic pain->
starts off as pain with movement then becomes persistant
What is this:
cartilage may collapse and predisopose to severe osteoarthritis, with eventual joint replacement necessary (10% of all joint replacements)
Subchondral infarcts
(blank) are clinically silent except for larger ones
medullary infarcts
In (blank) disease, fatty substances-sphingolipids accumulate.
Gauchers disease
Which type of infarct remains stable, medullary infarcts or subchondral infarcts?
medullary infarcts
In pyogenic osteomyelitis, most cases are caused by (Blank) which typically reach bone by (blank)
bacteria hematogenous dissemination (major)
What is the most common organism that causes pyogenic osteomyelitis?
What are some other common ones?
staph aureus
What organism commonly causes pyogenic osteomyelitis in neonates?
E. coli and Group B strep
What organism commonly causes pyogenic osteomyelitis in sickle cell patients?
salmonella
What organisms commonly cause pyogenic osteomyelitis in trauma patients?
mixed baterial infections, including anaerobes
In pyogenic osteomyelitis, up to (blank) percent of cases, a causative organism cannot be islated, due to prior antibiotic therapy, inadequate sampling or suboptimal culture methods
50%
In children with osteomyelitis, what three things are common?
bone abscess
periosteal lift
extension to the joint
Where does pyogenic osteomyelitis commonly occur in children?
Adults?
metaphysis
anywhere
After an acute infection with pyogenic osteomyelitis, what occurs?
chronic osteomyelitis
(blank) is a piece of dead bone that has become separated during the process of necrosis from normal or sound bone.
sequestrum
What do you see in chronic osteomyelitis?
sequestrum surrounded by a rim of reactive new bone-> this is called involucrum
-Brodies abscess
What is this:
well-defined rim of sclerotic bone surrounds a residual abscess
Where do you see this?
Brodies abscess
Chronic osteomyelitis
How can you find chronic osteomyelitis?
radionuclide scans
How should you treat chronic osteomyelitis?
vigorous antibiotic therapy +/- debridement
What are some complications of chronic osteomyelitis?
bacteremia endocarditis Systemic amyloidosis (rare) squamos cell carcinoma along sinus tracts (rare)
What is often seen associated with AIDS, it is spread hematogenously, favors long bones and vertebrae?
TB osteomyelitis
In TB osteomyelitis, bacillus needs oxygen, infection usually starts at (Blank) then spreads into bone.
synovium
In TB osteomyelitis, extension of infection to adjacent soft tissues is common in spinal lesions (Pott’s DIsease) and these are called (blank)
cold abscesses
What are the four kinds of bone forming tumors?
- Osteomas
- Osteoid Osteoma
3. Osteoblastoma - Osteogenic Sarcoma (osteosarcoma)
What are the three kinds of cartilaginous tumors?
Osteochondroma (osteocartilaginous exostoses)
Enchondroma (chondroma)
Chondrosarcoma
What is the most common malignant tumor of bone?
osteogenic sarcoma
Benign tumors are most common in the first (blank) decades of life
3
Malignant tumors are most common in the (blank)
elderly
What are the four bone-forming tumors?
- osteomas
- osteoid osteoma
- osteoblastoma
- osteogenic sarcoma (osteosarcoma)
Bone forming tumors are usually deposited as (Blank) and are variably mineralized.
woven trabeculae
Osteomas are bosselated, round to oval, and project from the (blank) or (bank) surfaces of the cortex
subperiosteal or endosteal
Are osteomas benign or malignant?
benign-> but may impinge on brain, eye, or interfere w/ function of oral cavity
Can osteomas undergo malignant transformation? WHat do they look like histologically?
NO!!!!!
normal
Multiple osteomas (skull) may be associated with (blank) syndrome
Gardner’s syndrome (familial polyposis)
What is the difference between osteoid osteoma and osteoblastoma?
When do they occur?
identical histology, but differ in size, location and symptoms
2nd and 3rd decades of life
Osteoid osteomas by definition are how big?
what about osteoblastomas?
less than 2 cm
greater than 2 cm
If you completely excise osteoid osteomas and osteoblastomas what will happen?
both will recur
What is this:
occur in peripheral skeleton, femur or tibia (~50%)
Painful, usually at night
due to production of excess prostaglandin E2
-characteristically relieved by aspirin
Osteoid osteomas
What is this: involves spine more frequently sometimes painful pain when present-dull ache pain is NOT relieved by aspirin
osteoblastoma
How do you get primary osteogenic sarcoma?
How do you get secondary osteogenic sarcoma arise from?
- De novo
- in conjunction with Paget’s disease, radiation, etc.
In whom does osteogenic sarcoma occur in?
people less than 20 years of age
-secondary form occurs in elderly
Most osteogenic sarcomas occur where?
In metaphysis of long bones (60% about the knee)
What mutation is associated with osteogenic sarcomas?
p53 tumor suppressor gene
If you see primitive bony trabeculae and lung mets what should you be thinking?
osteosarcoma
What are the three cartilaginous tumors?
- osteochondroma (aka osteocartilaginous exostoses)
- enchondroma (chondroma)
- chondrosarcoma
What are the most common benign tumors of the bones?
osteochondroma (aka osteocartilaginous exostoses)
What is an osteochondroma?
benign proliferation composed of mature bone with a cartilaginous cap (cauliflower look)
Where do osteochondromas occur?
at metaphysis near growth plate of long bones, firmly anchored to the cortex (asymptomatic)
(blank) percent of osteochondromas occur as hereditary multiple osteochondromas
15
(blank) are benign lesions formed by mature hyaline cartilage.
enchondroma (chondroma)
Where do you get enchondromas?
short tubular bones of hands and feets-> asymptomatic
What is Ollier’s disease?
Multiple enchondromas
-PREFERENTIALLY on one side of the body
What is Maffucci’s Syndrome?
multiple enchondromas
-asso. w/ hemangiomas of soft tissue
Is it common to get chondrosarcomas from enchodromas?
about 1/3 of patients with multiple tumors can get this
What is the 2nd most common matrix forming tumor of bone?
chondrosarcoma
When do you get chondrosarcomas?
4th decade and older
Where can you find chondrosarcoma?
starts in medullary cavity and spreads in the central skeleton (pelvis, shoulder and ribs)-> clear cell variant arises in epiphyses of long tubular bones
THe clear cell variant of chondrosarcoma occurs where
epiphysis
Who gets giant cell tumor of the bone?
females b/w 20-40 usually
What kind of cells do you find in giant cell tumor?
neoplastic mononuclear cells
-reactive osteoclast-like multinucleated cells
Where do you see giant cell tumors?
epiphysis of long bones
What is the cardinal sign of giant cell tumor?
“soap bubble” appearance on radiology
What is the 2nd most common childhood malignancy of bone?
Ewing’s sarcoma
What is the translocation involved with Ewings sarcoma?
t(11:22)
What does Ewings sarcoma affect?
femur, tibia, pelvis (metaphysis and diaphysis)
What is this:
small blue cell tumor w/ sheet of small cells w/ uniform nuclei containing glycogen
Ewings sarcoma
Is ewings sarcoma dangerous?
YES, has abundant necrosis and young children a less likely to survive
What is this:
- pockets of plasma cells
- abundant cytoplasm, large eccentric nuclei, w. clock-face chromatin
- produces immunoglobulin
Multiple myeloma
What is this:
benign, tumor-like condition w/ possible fractures
-normal trabecular bone is replaced by proliferating fibrous tissue and disorderly islands of deformed bone
Fibrous dysplasia
What is the most common form of fibrous dysplasia and what are its clincal manifestations?
mono-ostotic form (most common 70%)
-> ribs, calvarium, femur, tibia, JAW are common sites
What is the clinical manifestation of polyostotic form of fibrous dysplasia?
craniofacial involvement, with deformity
YOu can get the polyostotic form of fibrous dysplasia with endocrine abnormalities, what is the clinical manifestation of this?
unilateral bone lesions, with cafe au lait spots on same side, precocious puberty, also ass. w/ hyperthyroidism, and cushings disease
What are the diseases of joints?
- osteoarthritis
- rheumatoid arthritis
- infectious arthritis (supperative, lyme disease)
- gout
- pseudogout
What is osteoarthritis?
degenerative joint disease that is the most common disorder of joints
Why is osteoarthritis a stupid name?
because there is no inflammation it is caued by degeneration of articular cartilage
How do you get primary osteoarthritis?
arises w/out predisposing factors
How do you get secondary osteoarthritis?
arises in a joint previously deformed, or in context of a metabolic disease (i.e. hemachromatosis, DM)
What are the most important factors for osteoarthritis development?
aging and wear and tear
Where does osteoarthritis occur most commonly?
in weight bearing joints -> due to abnormal mechanical stress on joints such as obestiy, predispose to degenerative joint disease
In (blank) you get changes in composition and mechanical properties of cartilage.
osteoarthritis
What are the changes in cartilage that occur in osteoarthritis?
-increased water and decreased proteoglycans
-weakening of collagen network (type II)
chondrocytes secrete IL-1, which activates proteolytic enzymes, collegnases etc
What is eburnation and where do you see it?
subchondral bone becomes thickened and gives appearance of ivory-> osteoarthritis
(blank) may from within bone as cracks in cartilage alow synovial fluid into bone in OA
cysts
In RA< osteophytes (bony excresences) called (Blank) are found on distal interphalangeal joints (DIPs). (blank) nodes are found on the PIP
Heberden’s nodes
Bouchard’s nodes
RA is part of a (blank) disease which affects many organ systms (joints, skin, heart, BVs, muscles, lungs)
systemic chronic inflammatory disease
WHo is affected by RA more, mles or females and when?
females in the 4th and 5th decade of life
What are the signs and symptoms of RA?
symmetric, small joints affected, morning stiffness with gets better with heat and movement, joint swelling, redness, and warmth
What will the labs look like in RA?
synovial fluid -> lots of neutrophils, poor mucin, increase ESR, RF
What is this:
proliferation and hypetrophy of synovial lining cells (pannus/mantle)
-villous projections
-infiltration of lymphocytes, macrophages, plasma cells
-lymphoid follicles
-neovascularization
Non-suppurative (chronic) proliferative synovitis
Where do you see this; subcutaneous nodules along extensor surfaces of forearm and other points of pressure. Microscopically: central focus of fibrinoid necrosis -surrounded by palisading macrophages -rimmed by granulation tissue
RA
How can you get infectious arthritis (suppurative)?
ALL infectious agents have been implicated
Most commonly: GC, staph, strep, H. influenza, gram-neg rods
What are predisposing factors for infectious arthritis?
immunodeficiency
joint trauma
IV drug use
Patients with sickle cell who get salmonella have potential to get what?
infectious arthritis
What is lyme disease caused by?
Borrelia burgdorferi (a spirochete)
How does lyme disease get transmitted?
from rodents to humns by deer rickes (i.e ixodes dammini)
What is the major arthropod borne disease in the US and what does it involve?
lyme disease
-multiple organ systems as well as joints (skin, heart, lymph nodes, meningitis, arteritis)
Most affected joints in lyme disease are large and affected in a (blank) fashion
migratory
What does early lyme disease resemble?
lyme disease
In lyme disease you can have extensive erosion of (Blank)
large joint cartilage
What is gout?
when uric acid accumulates in tissue as monosodium urate crystals
What does gout look like?
needle-shaped birefringent
With gout you get recurrent episodes of (blank)
acute arthritis of 1st metatarsal
What are tophi?
large accumulations of crystalline material in soft tissue-> chronic granulomatous reaction that is found in gout
GOut crystals may lead to what?
joint deformity and renal tubular injury or stones
Primary gout (90% of cases) is caused by what?
overproduction of uric acid due to HGPRT enzyme defect or something
How do you get secondary gout ( i.e gout is not the primary disorder)?
- any large increase in urate production (rapid cell lysis during TX for lymphoma or leukemia)
- decreased excretion of uric acid
- Lesch-Nyhan syndrom
HOw could you get a large increase in urate production leading to secondary gout?
rapid cell lysis during TX for lymphoma or leukemia
How can you get decreased excretion of urinc acid leading to secondary gout?
Chronic renal insufficiency
How can Lesch-nyhan syndrome cause secondary gout?
over production and over excretion of uric acid with TOTAL lack of HGPRT
Urate crystals (from gout) in synovium are chemotactic are activate (blank) to cause (blank)
activate complement
-> generates C3a and C5a-> neutrophils and macrophages in joint and synovium-> arthritis
What is this:
deposition of calcium pyrophosphate crystals-> derived from nucleosides in chondrocytes, commonly found in knees after trauma/surgery, may be associatd with other systemic diseases, such as hemochromatosis
Pseudogout
How is pseudogout clinically manifested?
self-limited attacks of acute arthritis lasting 1 day to 4 weeks
Pseudogout involves what body parts and what do they crystals look like?
knees, ankles, wrist, elbows, hips, shoulders
-crystals are coffin shaped and weakly bi-refringent
What are the four skeletal muscle diseases?
- neurogenic atrophy
- myasthenia gravis (MG)
- muscular dystrophies
- skeletal muscle neoplasms
What are the three types of skeletal muscle?
Type 1: slow twitch
type 2: fast twitch
What is this:
Muscle deprived of normal innervation resulting in skeletal muscle fibers undergoing progressive atrophy. Both type I and type II muscle fibers.
Neurogenic atrophy
What are the clinical features of neurogenic atrophy?
muscle weakness is hallmark feature
-infants present as floppy baby syndrome
Where do you see “small group atrophy”?
In neurogenic atrophy
What is the most common type of muscle atrophy?
type II myofiber (fast-twitch) atrophy
What is type II myofiber atrophy due to?
- disuse (bedridden)
- glucocorticoid use (long term)
- Hypercortisol state for any reason
What is this:
acquired autoimmune disorder of neuromuscular transmission at the junction (F>M)
- antibodies to the acetylcholine receptor
myasthenia gravis
What is myasthenia gravis associated with?
thymus hyperplasia
thmomas
Thymus cells from patients with myasthenia when implanted into immunodeficient mice elicit production of (blank)
AChR antibodies
What are the clinical features of myasthenia gravis?
ptosis and diplopia (double vision) due to involvement of extraocular muscles
-respiratory involvement with subsequent respiratory failure
HOw do you treat myasthenia gravis?
- anticholinesterase agent (edrophonium chloride aka tensilon)-> transient improvement
- cholinesterase inhibitors (e.g. mestinon or progstimin)
- thymectomy
What are the 2 muscular dystrophies?
DMD
BMD
What is DMD?
x-linked, 1/3500, calf enlargement, absence of dystrophin
-progressive degeneration of muscle fibers
In DMD, (blank) is increased overall throughout the muscle
CT
What is becker muscular dystrophy (BMD)?
x–linked, mutation in dystrophin (unlike duchenne where it is absent) resulting in abnormal form of the protein
(similiar to duchennes but less severe)
What is this
-a skeletal muscle neoplasm, cardiac form associated with tuberous sclerosis (probably a hamartoma)
Rhabdomyoma
What is the most common soft tissue sarcoma in pediatrics, peak in 1st decade?
rhabdomyosarcoma
What are the three variants of rhabdomyosarcoma?
- embryonal
- alveolar type
- pleomorphic type
What do you call rhabdomyosarcoma in the GU tract?
sarcoma botryoides (gelatinous grape-like structures)
What will you see in embryonal rhabdomyosarcoma morphologically?
primitive small round blue cells with scattered skeletal muscle “strap cells”
Where do you see alveolar type rhabdomyosarcoma?
favors torso and extremities, mets to lungs
If you see white grapes hangout out of vagina what is it?
sarcoma botryoides varient of rhabdomyosarcoma
what are the fatty tumors?
lipoma/angiolipoma
lipsarcoma
What are the fibrous tumors?
- nodular faciitis
- fibromatosis
- fibrosarcoma
- fibriohistocytic tumors
What are the skeletal muscle neoplasms?
rhabdomyosarcoma
What are these the associated with: Radiation therapy Chemical and thermal burns Trauma Exposure to some organic chemicals AIDS/Kaposi’s sarcoma/virus
soft tissue tumors
What is the most common soft tissue tumors?
lipoma
WHen will lipopmas become painful?
if it turns into an angiolipoma on volar surface of forearm
What is this
benign slow growing mass that are usually painless
lipoma
WHen do you typically see liposarcomas?
Where do you see them?
5th and 6th decades of life
- usually arise in deep tissues of proximal extremities, but may arise in retroperitoneum
- lower extremities and abdomen
What is this:
most common in upper extremities and trunk
-history of trauma
-rapid growth
-not a true neoplasm, it is an over-reaction of fibroblasts
-may be confused with sarcoma due to cellularity
Nodular fasciitis
What is this:
a GROUP of fibroblastic proliferations that grow in an infiltrative fashion and RECUR after excision
Fibromatosis
WHat are the two well-known superficial fibromatosis?
- Dupuytrens contracture (palmar fibromatosis)
- Peyronie’s Disease (penile fibromatosis)
What is the difference between deep fibromatoses and what tumor is a deep fibromatoses?
growth is more aggressive than superficial types and includes Desmoid tumor
If you see contracted fingers and thickened bands, what is the disease?
Dupuytrens disease
What is this::
favors deep tissues of thick, knee and trunk
-mets usually to lungs via hematogenous route
-comprised of fibroblasts, and may grow slowly
Fibrosarcoma
Who gets fibrosarcomas and where does it originate?
males aged 30-40 and it originates in fibrous tissues of the bone -> invades long or flat bones
If you have a central fibrosarcoma, where does it arise from?
within intramedullary canal
If you have a peripheral fibrosarcoma, where does it arise from?
from periosteal tissues
If you have a secondary fibrosarcoma where, does it arise from?
pre-existing lesion or s/p radiation (with generally a poorer prognosis)
In infants, fibrosarcoma is usually (Blank) and so present in the first (blank) years of their life
congenital
2
What is this:
osteolytic with “motheaten” appearance. No sclerosis with cortical destruction
Fibrosarcoma
If you see a herringbone pattern on a histo slide what is the issue?
fibrosarcoma
Are fibrohistiocytic tumors, benign or malignant tumors?
they range from benign to aggressive malignant tumors
WHat is the most important fibrohistiocytic tumor?
malignant fibrous histiocytoma (MFH)
What is a pleomorphic sarcoma?
It is a fibriohistocytic tumor found in lower limbs and retroperitoneal areas and it is the most common type of post-irradiation tumor
-> common in 5th to 7th decades of life
(Blank) accounts for about 10% of all soft tissue sarcomas, and does not arise from synovial cells.
synovial sarcoma
Where do synovial sarcomas come from?
mesenchymal cells around joint cavities
Most synovial sarcomas develop in the vicinity of (Blank) of lower extremities, especially the knee
large joints