Bone, Joints, and Soft tissue tumors Flashcards
osteoblasts
on surface of matrix
synthesize, transport, and assemble matrix and regulate mineralization
osteocytes
interconnected by intricate network of dendritic cytoplasmic processes via tunnels (canaliculi)
help control Ca and Phos levels and mechanotransduction
osteoclasts
specialized multinucleated macros derived from circulating monocytes
bone resorption
brachydactyly
HOXD13 TF
short terminal phalanges of first digits
achondroplasia
FGFR3
short stature, rhizomelic shortening of limbs, frontal bossing, midface deficiency
osteogenesis imperfecta
COL1A1 and COL1A2
bone fragility
osteogenesis imperfecta
blue sclera d/t missing collagen can see vv
type 1 most relevant
bc type II not compatible with life and III and IV rare
clinical features of osteogenesis imperfecta
blue sclera fractures normal stature no dentin hearing impariment joint laxity
osteopetrosis
aka marble bone disease, albers-schonberg disease
impaired formation/fnx of osteoclasts
osteopetrosis morphology
bones lack medullary canal and ends of long bones bulbous
neural foramina small and compress exiting nn
buzz words osteopetrosis
erlenmeyer flash shaped long bones
missing epiphyses
severe infantile osteopetrosis
AR evident in utero or soon after birth fractures anemia hydrocephaly postpartum mortality
osteopetrosis if survive into infancy
CN defects
infections d/t leukopenia
extramedullary hematopoiesis -> hepatosplenomegaly
mild AD form of osteopetrosis
may not be detected until adolescence or adulthood
discovered d/t multiple fractures
may have mild CN deficits and anemia
dysplasia
in bone just meets disorganization and tissue in the wrong places, not preCA
osteopenia
decreased bone mass
osteoporosis
osteopenia severe enough to increase risk of fracture
what is the most common cause of iatrogenic osteoporosis
over Tx of hypothyroidism
what CA is known to cause osteoporosis
MM
what endocrine disorders can cause osteoporosis
addisons DMI hyperparathyroid hyper/hypothyroid pituitary tumors neoplasia carcinomatosis
what are the most common forms of osteoporosis
senile
postmenopausal
clinical osteoporosis
depend on involved bones
vertebral fractures that frequently occur in T and L are painful with height loss and lumbar lordosis and kyphoscoliosis
complications of fractures
PE
pneumonia
pagets disease
aka osteitis deformans
disorder of increased, but disordered structurally unsound bone mass
hallmark of pagets
mosaic pattern of lamellar bone, seen in sclerotic phase
prominent cement lines
pagets clinical
extremely variable
most cases discovered incidentally on xray
axial skeleton or proximal femur in 80%
pain dt microfractures
many have elevated AlkPhos, but nomral Ca and Phos
monostotic pagets
15%
the rest polyostotic
leonstiasis ossea
lion face
pagets disease
enlargement of craniofacial skeleton
can get so heavy its hard for person to hold head errect
benign lesions associated with pagets
giant cell tumor
giant cell reparative granuloma
extra-osseous masses of hematopoietic tissue
most dreaded complication of pagets
osteosarcoma
buzz word pagets
saber bone
rickets and osteomalacia
vit D deficiency/abnormal metabolism
rickets-kids
osteomalacia-adults
hyperparathyroidism
increased RANKL expression on osteoblasts
increased resorption of Ca by renal tubules
increased urinary excretion of phosphates
increased synthesis o factive bit D
what is most common cuase of hyperparathyroidism
parathyroid adenoma, usually asymptomatic
brown tumor
d/t hemorrhage into cartilage, not real tumor
can occur hyperparathyroidism
renal osteodystrophy
skeletal changes that occur in chronic renal disease, including those associated with dialysis
simple fracture
the overlying skin is intact
compound fracture
bone communicates with skin surface
comminuted fracture
bone is fragmented
displaced fracutes
ends of bone not aligned
stress fracture
slowly developing fracture d/t repetitive load
greenstick fracture
extending only partially thru bone
young children
what can cause iatrogenic fracutes
corticosteroids
avascular necorsis
causes of osteomyelitis
hematogeneous spread
extension from contiguous site
direct implantation (surgery)
what is most common cause of osteomyelitis
S. aureus
if pt has sickle cell prob salmonella
sequestrium
dead bone d/t osteomyelitis
involucrum
newly deposited bone forms a shell of living tissue around infected bone
brodie abscess
small interosseous abscess that frequently involves Cx and is walled off by reactive bone
osteomyelitis clinical
sometimes manifests as acute systemic illness w/malaise, fever, chills, leukocytes, and marked pain over region
can also be subtle with only unexplained fever or pain
Dx of osteomyelitis
xray of lytic lesions with zone of sclerosis
blood cultures may be + or -
Bx to ID pathogen
Dx bone tumors
Bx
benign greatly outnumber malignant
benign bone tumors
usually in first 3 decades of life, if older more likely malignant
most common bone CA
osteosarcoma
chondrosarcoma
Ewing sarcoma
what tumor arises in epiphysis
giant cell
what tumor arises in diaphysis
Ewing sarcoma
osteoid osteoma vs osteoblastoma
osteoid osteoma- typical presentation in pain in heel with tumor 2cm in vertebral TP
osteosarcoma
malignant
cancerous cells produce osteoid matrix or mineralized bone
75% are in pts <20
smaller peak in older adults
risk factors for osteosarcoma
pagets
bone infarcts
radiation
osteosarcoma stats
M>W usually arise in metaphyseal region of long bones 50% at knee area painful progressively enlarging masses fracture may be 1st symptom
osteosarcoma x-ray
large destructive mixed lytic and blastic mass w/infiltrative margins
frequently breaks thru Cx and lifts periosteum
triangular shadow -> CODMANS TRIANGLE indicative of aggressive tumor
where do osteosarcomas metastasize too
lungs
young person distal lytic lesion near knee should think?
osteosarcoma
older person central pelvic lesion
chrondrosarcoma
osteosarcoma clinical
if there are no mets- Tx with neoadjuvant chemo followed by surgery
if mets poor prognosis
