670 bone density

Common tumors in 0-20 y/o

Osteo sarcoma, ewing, simple bone cyst, osteoid osteoma

common diseases in peds

rickets (osteomalacia) and osteogenesis imperfecta

common disease/tumors for older pts

osteoporosis, MM, Paget’s, chondrosarcoma,

most common benign bone tumor

osteoma

benign chondroid matrix bony growth extending out from the metaphysis of a long bone

osteochondroma

well-defined intramedullary benign tumor with chondroid matrix

enchondroma

most common site for an enchondroma

hands and feet

dense overgrowth of benign solid osteoid matrix arising from the surface of a bone

osteoma

most common place for osteoma

skull/sinuses

a benign focus of compact bone within cancellous bone

bone island

tumor that extends from the epiphysis into the subchondral bone

giant cell tumor (GCT)

GCT

lytic expansile lesion with no matrix and periosteal new bone in the form of cortex remodeling

Lesion in the metaphysis/diaphysis with dense cortical sclerosis surrounding a nidus

Osteoid Osteoma

pain pattern of osteoid osteoma

pain at night fixed w/ NSAIDS

Pediatric lesion in the metaphysis of a long bone, centrally located, symmetric bone expansion, cortical thinning (periosteal new bone)

simple bone cyst

Tell sign of SBC

“fallen fragment” sign

When are SBC usually detected

after patholgic fx

ballooning of bone, off-center in the metaphysis

ABC (aneurysmal bone cyst)

how to tell an ABC from a SBC

ABC appears separated internally, and SBC seems to be one big sac

tell sing s of malignancy

permeative margins, wispy new bone, codman triangle, cortical destruction, lamellated new bone

most common primary malignant bone tumor in children

osteosarcoma

common appearance of osteosarcoma

osteoid matrix, aggressive periosteal new bone, ill-defined margins,

common placement of osteosarcoma

peds: metaphysis of long bones especially around knee (distal femur proximal tibia)

Mature pt with ill defined lesion producing chondroid matrix, and mild to no new bone production

chondrosarcoma

common sites for chondrosarcoma

any bone

permeative lytic lesion in the diaphysis of a pediatric pt with no matrix and lamellated periosteal new bone

Ewing

common placement for ewing sarcoma

metaphysis of long bones and pelvis/sacrum

if a bone presents with multiple lytic lesions assume

MM or Mets

what is MM

malignancy arising from plasma celss in the bone marrow

Common placement of MM

spine, pelvis, ribs, and proximal appendicular skeleton

radiographic appearance of MM

strictly metaphyseal, no matrix or periosteal reaction, well-defined punched-out lesions with no sclerotic rim

What is metastatic bone disease

cancer that spreads to bone from another primary site

Common distribution of mets

spine, pelvis, ribs, appendicular of spread that far

Radiographic appearance of mets

multiple ill-defined lesions, areas of radiodensity or lucency (can be blastic or lytic), can affect cortex of bone

Osteoporosis problem

The bone is chemically normal, but has a decreased quantity

Pt presents with diffuse osteopenia and fragility fxs

osteoporosis

common sits for fx related to osteoporosis

hips/pelvis, spine, wrist, humerus

risk factors of osteoporosis

inc age, menopause, steroid use, immobilization

osteomalacia problem

faulty bone mineralization

most common cause of osteomalacia

vit D metabolism issue

Two precursers to Vit D production

diet and intake

if diet and intake levels of Vit D are adequate it goes to

liver

After the liver ___ produces the active form of Vit D

kidney

Pt presents with osteopenia pseudofractures /looser zones

osteomalacia

peds pt presents with widened physis and frayed metaphysis

rickets

looser zone

incomplete fx occasionally surrounded by sclerosis and cortical thickening

disorder of excess PTH

hyperparathyroidism

hyperparathyroidism causes

increased osteoclast activity, calcium pulled from bone into the bloodstream

problem in hyperparathyroidism

PTH excess cause bone to break down faster then it can rebuild

Pt presents with subperiosteal resorption in the middle phalanges (appears as cortical erosion)

hyperparathyroidism

Disorder of abnormal bone remodeling in three stages

pagets

stages of pagets bone remodeling

1. excessive osteoclast destruction 2. disorganized osteoblast repair 3. formation of weak, enlarged bone

classic triad of pagets

enlarged bone, coarse trabeculae, thickening cortex

Three phases of pagets

lytic end (blade of grass), mixed, blastic end

OI AKA

Osteogenesis imperfecta

Problem with OI

A genetic disorder of defective collagen formation causes abnormal bone matrix

Age of OI presentation

congenital

Common reason for OI diagnosis

multiple fractures of multiple different ages with bowed bones

DDH

developmetnal dysplasia of the hip

DDH problem

Acetabulum is too shallow and the delayed ossification of displaced femoral head

Effects of DDH

hip subluxation and dislocation, asymmetrical hip positioning

Scoliosis

structural alignment disorder of lateral curvature of the spine with vertebral rotation

most common scoliosis

Adolescent idiopathic

common causes of scoli

idiopathic, congenital, bone dysplasia, infection, asymmetric neuromuscular control

normal spine curvature at T5-T12

27 degrees kyphosis

normal spine curvature at L1-L5

40 lordotic

cobb angle

"gold standard" orthopedic measurement for diagnosing and quantifying scoliosis severity via X-ray, defined by an angle of or more