Musculoskeletal and Soft Tissue disorders Flashcards
osteogenesis imperfecta (brittle bone)
AD
defect in type I collagen synthesis
blue sclera, deafness
treat with bisphosphonate
osteopetrosis (marble bone disease)
AR (severe), AD (less severe)
deficiency in osteoclasts, osteoblasts work fine–> too much bone
pancytopenia, anemia, pathologic fx and compression of CN
osteomyelitis in sickle cell
due to salmonella paratyphi
pseudomonoas aeroginosa
can cause osteomyelitis from puncture of foot through rubber footwear
sequestra
devitalized bone
involucrum
reactive bone formation in periosteum
draining sinus tracts to the skin surface from osteomyelitis often occur
danger of SCC developing at orifice of sinus tract
treat osteomyelitis with
S. aureus= vanco+ceftazidime
S. paratyphi(sickle cell)= ciprofloxacin
primary osteoporosis
ideopathis type in children and young adults
postmenopausal women
senile type in men and women
secondary osteoporosis
increased cortisol
heparin
hypogonadism (hypopituitarism)
malnutrition
space travel
role of estrogen in osteoporosis
it inhibits osteoclasts and increases activity of osteoblasts
clinical manifestations of osteoporosis
compression fractures of vertebral bodies (most common)
Colle’s fx of distal radius
Dowager’s hump
Dx and Rx of osteoporosis
dual photon absorptiometry
first line agent is bisphosphonate which inhibits bone resorption, then calcitonin
senile osteoporosis
decreased ability of osteoblasts to divide and produce osteoid
aseptic necrosis
femoral head is most common site (subcapital fx)
corticosteroids most common cause
scaphoid most common wrist bone fx
MRI most sensitive test for early detection of aseptic necrosis
Osteochondrosis
aseptic necrosis of ossification centers in children
Legg-Calve-Perthes disease= aseptic necrosis of femoral head ossification center in children 3-10
osteochondritis dissecans is a variant of osteochondrosis limited to articular epiphysis with the distal femur being the most common site
osgood-schlatter disease
painful swelling of tibial tuberosity in active boys
presents as permanent knobby-appearing knees
fibrous dysplasia
defect is osteoblasts maturation and differentiation
medullary bone is replaced by fibrous tissue with cyst formation
ribs most common site
Albright’s syndrome= polyostotic bone involvement, cafe au lait spots, precocious puberty
bone tumors
mets is most common (specifically from breast CA)
multiple myeloma–> osteogenic sarcoma–> chondrosarcoma–> Ewing’s sarcoma
most common benign tumor is osteochondroma
MSU crystals and CPP
MSU crystals have negative birefringence–> yellow when parallel to slow ray
CPP have positive birefringence–> blue when parallel to slow ray
mucin clot test of synovial fluid
to evaluate joint viscosity
acid added to synovial fluid clots hyalouronic acid
poor clot formation reflects decreased quantaity of HUA-> sign of inflammation
morning stiffness of joints, think…
RA, SLE, polymyalgia rheumatica
alkaptonuria
AR
deficiency in homogentisic acid oxidase–> accumulation of HGA in intervertebral discs–> OA and other systemic findings
urine turns black when oxidized
Heberden’s nodes
DIP joint enlargement with pain
Bouchard’s nodes
PIP joint enlargement with pain
RA pathogenesis
HLA-DR4, trigger is EBV, parvovirus, HHV6,mycoplasma
synovial cells express antigen that triggers B cell–> RF which is IgM Ab aganst Fc receptor of IgG–> formation immunocomplexes–> activation of complement–> pannus formation–> release of cytokines that destroy articular cartilage–> ankylosing of joints
systemic manifestation of RA
Lung= interstitial fibrosis, effusions
blood= anemia of chronic disease, autoimmune hemolytic anemia, Felty’s syndrome=autoimmune neutropenia, splenomegaly)
cervical spine=subluxation of atlantoaxial joint–> cord compression along with vertebral artery occlusion
Caplan syndrome= rheumatoid nodules in lung+ pneumoconiosis
CV= pericarditis, aortitis, vasculitis
Baker’s cyst= outpouching of posterior joint space in knee
Labs= +serum RF, ANA
sjorgen syndrome
destruction of minor salivary and lacrimal glands
xerophalmia (sand in my eyes), xerostomia (can’t chew a cracker) and dental carries, arthritis
Labs: +serum ANA, serum RF, anti-SS-A Ab (Ro), anti-SS-B Ab (La)
confirm with lip biopsy and must show lymphoid destruction of minor salivary glands
Rx=artificial tears, pilocarpine eye drops
gout associations
urate nephropathy, renal stones, HTN, artery disease and Pb poisoning
Acute gout
must confirm with joint aspiration. Hyperuricemia does not define gout
tophus
MSU deposits in soft tissue around joint
it destroys subadjacent joints causing erosive arthritis
Rx for gout
prevent with low purine diet and low EToH intake
treat acute with NSAID or colchicine
treat chronic with uricosuric agents for underexcretors like probenecid
Allopurinol for over-producers
CPP dihydrate induced gout
increased with hemochromatosis, hemosiderosis (due to increased pyrophosphate inhibitor in these 2 disorders) and primary HPTH (due to increased Ca)
CPPD OA variant presents with knee involvement–> chondrocalcinosis which presents as linear deposits of CPP in articular cartilage
RF seronegative spondyloarthropathies
-RF, +HLA-B27, male, sacroiliitis, spondylitis
Ankylosing spondylitis
bamboo spine over time, aortitis, uveitis with potential for blindness
Reiter’s syndrome
C. trachomatis, urethritis, conjunctivitis, arthritis
Achillis tendon periostitis is diagnostic
psoriatic arthritis
sausage-shaped DIP joint in finger or toe
pencil-in-cup deformity and extensive nail pitting
Late lyme disease
disabling arthritis, bilateral Bell’s palsy, myocarditis and pericarditis
babesiosis
tick-transmitted hemolytic anemia
due to babesia microti
treat with atovaquone and azithromycin
septic arthritis due to cat or dog bite
by pasteurella multocida
most common infection secondary to animal bite
see cellulitis, septic arthritis/tendinitis, osteomyelitis, endocarditis, meningitis
treat with amoxicillin-calvulanate
type I and II muscle fibers
type I= slow-twitching, red, rich in mitochondria, myoglobin and oxidative enzymes, weak ATPase enzymes (long muscles in back)
type II= fast-twitching, white, poor in mitochondria, myoglobin and oxidative enzymes, rich in ATPase enzymes (extra-ocular muscles and fine muscles of hands)
myotonic dystrophy
AD, most common adult muscular dystrophy
CTG trinucleotide repeat
inability to relax muscles
see sagging face, frontal balding, cataracts, testicular atrophy, cardiac involvement
