Pediatric MSK Flashcards
Name the histological zone closest to the metaphysis within the growth plate/physis
zone of provisional calcification
What cells make up the zone of provisional calcification?
chondrocytes underrgo apoptosis to make matrix for calcification
Describe Salter Harris classification
Physeal fractures; SALTR, SMETC I. physis II. physis, metaphysis III: epiphysis, physis IV: metaphysis, epiphysis V: physis crushed
Example of type 1 SH injury
SCFE, gymnast’ wrist
Example of type 2 SH injury
nondisplaced fracture of the base of the phalynx
Example of type 3 SH injury
juvenile tillaux fracture; distal tibial epiphyseal fracture
Example of type 4 SH injury
triplane fracture
Example of type 5 SH injury
physis crushed
Name ossification centers of elbow and age
CRITOE
Capitellum, radial head, internal/medial epicondyle, trochlear, olecranon, external/lateral epidcondyle
Pitfall with 3 yr old elbows
make sure trochlear and internal/medial epicondyle are not confused for avulsion fracture
pediatric elbow effusion – think?
pathognomic for fracture; rx xr in 7-14 days
Elbow alignment lines and associated abnormality?
anterior humeral line (supracondylar fracture); radiocapitellar line (elbow dislocation)
most common pediatric fx
supracondylar fx, 2nd is lateral condyle fx
most common adult fracture
radial head
what is a toddler’s fx
nondisplaced spiral fx through tibial metadiaphysis; rotational; faint sclerotic line
radial buckle fx
focal cortical irregularity
what is an apophysis?
growth plate that does not contriute to logitudinal growth
name the 5 pelvic apophysis
iliac crest ASIS AIIS ischial tuberosity pubic rami
name muscular attachments to pelvic apophysis
iliac crest: abdominal muscles ASIS: sartorious AIIS: rectus femoris ischial tuberosity: hamstrings pubic ramus: adductors, gracilis
when do apophyses fuse?
arise in puberty, fuse by 3rd decade
what SH injury are apophyseal avulsion injuries?
type 1
name 2 femoral apophyses
greater trochanter, lesser trochanter
name muscular attacments to femoral apophyses
greater trochanter: gluteus medius/minimus
lesser trochnater: iliopsoas (suspicious for pathologic fx in adult)
bone scintigraphy has high sensitivity for what type of fx? low sensitivity for what type of fx?
posterior rib, low sensitivity for skull fx
specific fx for child abuse
metaphyseal corner fx, posterior rib fx, scapula, sternum fx, spinous process fx
suspicious fx for child abuse
polyfracture, fracture out of proportion to history, digital fracture, long bone fx in nonambulatory child, complex skull fx
nonspecific fx concerning for child abuse
long one fx in ambulatory child, linear skull fx
NM study for child abuse
Tc99 MDP, HMDP, DPD
Several 99mTc-labelled radiopharmaceuticals are available
for bone scintigraphy:
Medronate (methylene diphosphonate, MDP)
Oxidronate (hydroxymethylene diphosphonate, HMDP
or HDP)
Diphosphonopropanedicarboxylic acid (DPD)
Define these terms: rhizomelia, mesomelia, acromelia, micromelia, amelia
proximal limb shortening, middle limb shortening, distal limb shortening, entire limb shortening, limb absent
most common cause of dwarfism
achondroplasia
key XR findings in achondroplasia
frontal bossing of skull, narrowing of interpeduncular distance in the lower spine, posterior scalloping of vertebral bodies, tombstone iliac wings, flat acetabula, short femoral neck
Most common lethal skeletal dysplasia
thanotorphoric dysplasia
inheritance of thanotorphoric dysplasia
AD
Key findings in thanotorphoric dysplasia
platyspondyly, flattening of veretebral bodies (H shaped); curved telephone receiver femurs
Cause for osteogenesis imperfecta
abnormal type I collagen
Key indings in OI
multiple rib, vertebral body, long bone fx (accordian ribs), ; bowed long bones, osteopenia, wormian bones in skull
What is Jeune syndrome
asphyxiating thoracic dystrophy; small thorax causing respiratory distress; AR
XR findings of asphyxiating thoracic dystrophy
short ribs (bulbous anteriorly), high riding handlebar clavicle, trident acetabulum
What is cleidocranial dysostosis?
abnormalities with clavicles; short or partial absent; also associated with wormian bones
Wormian bones associated with?
OI, hypothyroidism, healing rickets, cleidocranial dysostosis, Down syndrome
Key XR findings in cleidocranial dysostosis
wormian bones, delayed ossification of skull, widened pubic symphsyis (seen later), clavicular anomalies, supernumary eeth
What skeletal dysplasia and metabolic bone disease cause stippling of epiphyses?
chondrodysplasia punctata, multiple epiphyseal dysplasia, hypothyroidism, complications of maternal warfin use
What is chondrodysplasia puncata?
rhizomelic, short limbed dwarfism
What is multiple epiphyseal dypslasia
Fairbank disease; mildly short limbed AD skeletal dysplasia that manifests in late childhood/adolescense
What is enchondromatoses?
syndromes; multiple intra-osseous benign cartilaginous tumors in an asymmetric distribution
Types of enchondromatoses
Maffuci ; Ollier
Maffuci syndrome
enchondromatosis with venous malformations/hemangioma, lots of phleboliths
Ollier syndrome
mostly enchondromatosis with associated limb shortening
enchondromatoses can have malignant transformation into?
chondrosarcoma; maffucci > ollier
Multiple hereditary exostoses inheritance pattern? distribution?
AD; symmetric, long bone metaphyses
Multiple benign osteochondromas syndrome?
MHE, osteochondromatosis; usually long bones metaphyses
malignant degeneration of osteochondromas?
chondrosarcoma
What are mucoplysaccharidoses?
lysosomal storage disorders – hurlers, morquio, hunters
XR findings of mucopolysaccharidoses
anterior vertebral beaking, thick ribs, undertubulated bones, Madelung deformity of wrists, J shaped sella/thickened calarium, hypoplastic dens
Hurlers XR findings
anterior beaking of vertebral bodies, mostly inferiorly
Morquio XR findings
anterior beaking of middle potion of vertebral body, spinal stenosis, atlantoaxial instability
Ddx for child with a limp
trauma, septic arthritis, fracture, avascular necrosis, lymphoma
Ddx for septic arthritis
aseptic toxic synovitis, hemarthrosis in trauma, hemophilia
Most common cause of septic arthritis?
S aureus
XR findings for hip effusion
displacement of gluteal/psoas fat planes
widening of teardrop distance
What muscles insert on greater trochanter? lesser trochanter?
gluteus medius/minimus; psoas
best modality of choice to evaluate for hip effusion?
ultrasound
What type of SH is SCFE?
Salter Harris 1
What is SCFE?
fracture of the proximal femoral epiphysis in obese preadolescents 10-16yo
XR findings of SCFE
asymmetric widening of proximal femoral growth plate, lack of intersection of Klein’s line
What is the Klein’s line?
line along lateral margin of femoral neck
Bests view to evaluate physeal widening/displacement for SCFE?
frog leg lateral projection
Is SCFE bilateral or asymmetric usually?
asymmetric, but evaluate both sides still
Age of presentation for LCP?
4-8yo
What is LCP?
avascular necrosis of the capital femoral epiphysis ossification center
XR and NM findings of LCP?
XR: subtle sclerosis –> osteonecrosis and distortion of femoral head
NM: Tc99 MDP; decreased uptake and then increased uptake with attempted repair
Most common pediatric bone tumor? most common site?
osteosarcoma, most common intramedullary type and mostly by the knee (distal femur/proximal tibia)
XR of osteosarcoma
destructive lesion invading cortex; extensive osteoid matrix
second most common primary pediatric bone tumor
ewing sarcoma
cell type for ewing
aggressive small round blue cell tumor; neuroectodermal differentiation
Common locations for Ewing
femoral diaphysis, flat bones of pelvis, tibia, humerus, ribs
common met site of Ewing
lung
XR appearance of Ewing
permeative lesion within the medullary; wide zone of transition; aggressive lammelated/onion skin or spiculated periosteal reaction ; may also have soft tissue mass component
What is langerhans cell histiocytosis?
abnormal proliferation of LCH (dendritic cells/histiocytes) that live in the epidermis/lymph nodes; Birbeck bodies on electron microscopy
Presentation for LCH
age 5-15; pain/tenderness/fever; similar to osteomyelitis
most common variant of LCH
eosinophilic granuloma
XR findings of LCH
skull: beveled edge lytic lesion flat bones: hole in a hole lytic lesion long bones: diaphysis commonly, permeative destruction with lysis and faint rim of sclerosis spine: vertebra plana maxilla: floating tooth
Ddx for lytic lesions in undre 30 yos
LCH, infection, eosinophilic granuloma
Common site for osteomyelitis in bones
metaphysis marrow; transphyseal vessels in infants supply the epiphysis; transphyseal infection in older children rare
Common organisms for osteomyelitis
S aureus, Salmonella in sickle cell
XR, NM, MR findings of osteomyelitis
XR: irregular lucencies/periosteal reaction
NM: Tc 99m MDP scan with increased uptake on all 3 phases (angio, bone, blood pool phases)
MR: increased T2 weighted sequences, marrow edema
Disciitis in kids vs adults
infections begins in disk in kids, spread through disk in adults; blood vessels feed intervertebral discs directly in kids
Presentation for disciitis
young child <4 with preceding URI, new onset back pain/refusal to sit
Cmmon location for discitis
lumbar spine (young children), thoracic spine (preteen)
XR , MR findings of discitis
XR: disc space narrowing and vertebral end plate irregularity
MR: narrowing of disc space, bone marrow edema
What is CRMO
chronic recurrent multifocal osteomyelitis; nonpyogenic inflammatory disorder that mimics osteomyelitis
Key imaging findings of CRMO
lytic/sclerotic lesions migratory separateed by time and space; no soft tissue abscess, bony sequestra, fistula
Associations with CRMO
SAPHO: synovitis, acne, pustulosis, hyperostosis, osteoitis
XR finding with luekemia
metaphyseal lucent band; osteopenia, permeative lytic lesions
Causes of metaphyseal lucent band
leukemia, severe illness, scurvy, TORCH infections, lymphoma
XR rickets findngs
fraying/cupping of metaphyses, rachitic rosary, bowing legs, osteopenia, fractures
What is oncogenic rickets
associated with hemangiopericytoma, NOF due to tumor metabolits that derange vitamin D metabolism
Organism for sphilis
spirochete Treponema pallidum; can cross placenta
What is the Wimberger sign
destructive erosion of medial aspect of proximal tibial metaphysis (different from scurvy Wimberger ring sign)
XR findings of syphilis in peds
symmetric periosteal reaction, Wimberger sign
Most common arthropathy in kids
JIA: 6+ weeks in pt under 16; RF negative
XR findings
early: synotitis like; joint effusion, soft tissue swelling, osteopenia
later: periostitis, erosions
chronic: joint ankylosis (wrist, CMC, cervical sign)
XR findings of Klippel Feil syndrome
segmentation anomalies
What is still dx
subtype of JIA affecting kids <5yo; fever, anemia, leukocytosis, hepatosplenomegaly, polyarthritis
DDH first US performed?
4-6w due to normal neonatal ligamentous laxity after birth (perinatal maternal hormones)
How to measure DDH on US
coronal US
alpha angle: bony ileum/acetabular roof; normal >60 degrees and covers 50% of cartilagenous femoral head
DDH XR performed?
6 mo when femoral head ossification centers appear
Describe Hilgrenreiner line and Perkins line
Hilgrereiner: horizontal line through triradiate cartilage
Perkins line: perpendicular through lateral acetabulm perpendicular to Hilgrenreiner line
Kids who get DDH
breech births
Blount disease XR findings
oxteochondrosis of tibial metaphysis; usually males <6 unilateral
XR: tibia varus/bowing, internal rotation –> limb length discrepancy/gait deviations
Madelung deformity
medial sloping of distal radius; dysplasia of medial distal radial diaphysis
Panner disease
osteochondrosis of capitellum
Little league elbow
osteochondrosis of medial epicondyle
Scheurmann kyphosis
AVN of thoracic vertebral bodies; compression fx
LCG
osteochondrosis of capital femoral epiphysis
Kienbock dx
osteochondrosis of carpal lunate
Osgood Sclater
osteochondrosis of tibial tuberosity
Freiberg infarction
osteochondrosis of 2nd metatarsal head
Kohler dx
self limited osteochondrosis of navicular bone
Sever disease
calcaneal apophysitis; heel pain
What is torticollis?
fibromatosis coli/idiopathic SCM enlargmenet; can’t straighten neck
Tarsal coalition
abnormal fusion of tarsus bones – osseous, cartilaginous, fibrous
Talocalcaneal/calcaneonavicular
Carpal coalition
joining of carpal bones; most common lunotriquetral then capitohamate
Types of periosteal rx in peds
physiologic periosteal rx in newborn, prostaglandid therapy, infectious, syphilis, neoplastic, trauma, metabolic (rickets/scurvy, hypervit A), syndromic (Caffey disease)
