Bone: Infection & Metabolic bone disease Flashcards
Most common agent of osteomyelitis?
Staph
Most common mechanism for contracting osteomyelitis?
Direct penetration
Hematogenous osteomyelitis is most commonly seen in…
boys (post infection) and IV drug users
What area of the bone does hematogenous osteomyelitis mainly affect?
Metaphysis
Hole formed in the bone during the formation of a draining sinus?
cloaca
Fragment of necrotic bone that is embedded in pus?
Sequestration
Reactive bone formation from the periosteum and the endosteum (which surrounds and contains the infection)?
Brodie infection
Peristeal new bone formation forms a sheath around the necrotic sequestration?
Involucrum
What occurs in veterbral osteomyelitis?
intervertebral disk expands with pus and is destryed
What are two possible complications of osteomyelitis?
amyloidosis, chronic osteomyelitis, and SCC
What # vertebrae does TB effect in Pott disease?
T11
In Pott Disease TB…how are the vertebrae destroyed?
resorption of bony trabeculae (mechanical collapse)
Aside from pott disease, how else can TB manifest int the bone?
- Tubercuous Arthritis… granulomas in synovial/ joint tissue
- Osteomyelitis of the Long Bones
How can syphilis affect the bone?
slowly progressive, chronic, inflammatory disease of bone characterized by granulomas necrosis and reactive bone formation
In congenital syphilis what is the most commonly affected joint?
knee
In acquired syphilis when are bone lesions seen?
Tertiary syphilis…2-5 years after inoculation
In acquired syphilis which bones are commonly affected?
tibia, nose, palate and skull
“saber shin” and “saddle nose” deformities
What are the bone defects seen in langerhans cell histiocytosis?
Punched out lytic defects without reactive bone formation
Name the 3 langerhans cell histiocytosis?
1- eosinophilic granuloma
2- Hand- Schuller- Christian disease
3- Letterer- Siwe Disease
Which is the worst langerhans histiocytosis?
Letterer- Siwe Disease
failure to thrive, cachexia, hepatosplenomegaly, anemia, leukopenia, skin lesions
Name the disease:
“diffuse skeletal lesions marked by decreased skeletal mass and inadequate mechanical support”
osteoporosis
Main causes of osteoporosis?
Menopause and aging
Match the categories:
1: Type 1 Primary Osteoporosis, Type 2 Primary Osteoporosis
2: Menopause, aging
3: decreased osteoblast function, increased osteoclast recruitment
Type 1–> menopause–> increased osteoclast recruitment
Type 2–> aging–> decreased osteoblast function
Name the disorder:
“inadequate mineralization of newly formed bone matrix”
Osteomalacia and ricketes
What is milkman- Looser syndrome:
formation of radiolucent psuedofracutres )often on the concave side of long bones)
What does von Kossa stain do?
colors calcified tissue black
“Buddha-like” posture? “Pigeon breast”? “potbelly”?
seen in children with rickets
What is a common causes of osteomalacia and rickets?
Vit D deficiency–> decreased Ca
What is the difference between vit D dependent rickets type I and type II?
Type I: mutation in 1-alpha hydroxylase (treat with vit D)
Type II: mutation of vit D receptor (treat with Ca)
Name the disease:
mutation of PHEX–> inactivation of FGF23–> phosphate wasting and impaired osteoblast function
X- linked hypophosphatemia
What is fanconi syndrome?
Wasting from the proximal tubule leading to renal tubular acidosis resulting in rickets and osteomalacia
What can cause fanconi syndrome?
Bence -Jones proteinuria, amyloidosis, Iron/ Mercury poinoning, glycogen storage diseases
In what disease is osteitis fibrosa seen (accelerated bone remodeling)
primary hyperthyroidism
What are the stages of osteitis fibrosia?
1- dissecting osteitis
2- osteitis fibrosa
3- osteitis fibrosa cystica
How does osteitis fibrosa cystica present?
“brown tumor”–> bulbous swelling with multiple lytic lesions
Symptoms of renal osteodystrophy?
Decreased GFR
Hypocalcemia
Increased PTH and phsophate
Osteomalacia
Name the disease:
lytic lesions of bone resulting from disordered remodeling
Paget disease of the bone
What are the 3 stages of paget disease?
1- “hot” or osteoclastic resorptive stage
2- mixed stage (osteoblast and osteoclast activity)
3- “cold” or burnt-out stage (decreased cellularity)
What is the pathological cell of pathologic disease?
osteoclast (super-multinucleated osteoclasts)
Most common symptom of paget’s?
Bone pain
Name the disease:
developmental abnormality characterized by a disorganized mixture of fibrous and osseous elements in medullary region of affected bones
fibrous dysplasia
What is McCune- Albright Syndreme?
form of fibrous dysplasia, short stature, pigmented “cafe-au-lit” macules
