Peds Flashcards
Peds multisystem organ failure vs adult
Peds: occurs early after admission, affects ALL ORGANS simultaneously***
Adult: occurs 48 hours after injury and begins with lungs**
how many mL of intravascular blood volume per kg in a 5 year old child?
75-80 mL/kg**
Cast burn risk higher in plaster or fiberglass?
fiberglass***
What are 5 zones of physical growth plate? Diseases?
1- Reserve zone*
Cells store lipids, glycogen, PG for later
Dz: Gaucher’s*, diastrophic dysplasia, psuedoachondroplasia
2- Proliferative zone
Proliferation of chondrocytes w/ longitudinal growth and stacking of chondrocytes
Highest rate of extracellular matrix production
Increased O2 tension inhibits calcification
Dz: Achondroplasia, Gigantism, MHE*
3- Hypertrophic zone
Zone of maturation, chondrocyte hypertrophy and calcification
3 zones w/in hypertrophic
1-Maturation: prep for calcification and growth
2-Degenerative zone: further prep and growth in size (5X)
3-Zone of provisional calcification: chondrocyte death to release Ca2+ for calcification
Type X collagen produced** (important for mineralization)
dz: SCFE*
Rickets*
Fx’s most common through zone of provisional calcification**
4- Primary spongiosa
Vascular invasion, osteoblasts algin on cartilage bars, forms woven bone that later remodels
dz: metaphyseal “corner fx” in NAT**, Scruvy
5 - Secondary spongiosa
Internal remodeling, replacing woven bone w/ lamellar bone
dz: renal SCFE
What growth factor regulates chondrocyte maturation?
Indian headgehog gene***
What is Groove of Ranvier and why important?
dz?
During fist year of life, zone spreads over adjacent metaphysic to form a fibrous circumferential ring bridging from epiphysis to diaphysis
- Ring increases mechanical strength of physics and is responsible for APPOSITIONAL bone growth
dz: osteochondroma
Distal humerus physeal separation - what to be worried about? findings on XR?
Tx?
Worried about NAT**
XR: posteromedial displacement of the radial and ulnar shaft relative to distal humerus***, forearm not aligned with humeral shaft
Tx: generally CRPP, combine w/ arthrogram to determine direction of initial displacement and adequate reduction**
complications of distal humeral physeal separtaion?
Can be indicative of NAT**
Posteromedial displacement***
May lead to:
Cubitus VARUS**
AVN of medial condyle**
When to treat humeral shaft fx operatively in peds?
Open
floating elbow
POLYTRAUMA***
Age of fusion of peds elbow?
CTE-ROI for order, internal/medial epicondyle fuses at 16-18**
How to image medial epicondyle fx in peds?
Internal oblique** or DISTAL HUMERAL AXIAL VIEW*
Improves accuracy of measuring displacement
Obtain by angling beam 25 degrees anterior to long axis of humerus
What cord doe ulnar nerve originate from in plexus? where does it run?
Ulnar from MEDIAL cord
splits two heads of FCU in proximal forearm
Runs SUPERFICIAL to transverse ligament at wrist
Runs MEDIAL to associated artery at level of wrist
Through Guyon’s canal
Which direction does fx displace for medial epicondyle fx in peds and what is best imaging to see it?
fx displaces ANTEROMEDIALLY*** (from flexor pronator mass)
Best view: distal humeral axial XR** (other best view is IR)
What happens to LCL with lateral condyle fx for peds?
Remains INTACT and attached to the lateral condyle fragment proximally and the radial neck distally***
Classification of lateral condyle fx?
Best imaging modality?
Tx?
Complications?
Milch classficiation
Type I: fx line is lateral to trochlear groove
Imaging: INTERNAL OBLIQUE view most accurately shows displacement as fx is POSTEROLATERAL***
Tx:
If <2 mm displacement can tx in LAC for 4-6 wks
2-4 mm displacement = CRPP
>4 mm displacement = ORIF***
AVOID POSTERIOR dissection = –> blood supply from posterior***
Complications
Most common: stiffness
NONUNION = higher than other elbow fx*
CUBITUS VALGUS and TARDY ULNAR NERVE PALSY*
Due to physeal arrest or more commonly a nonunion**, 10% of time, tx w/ supracondylar osteotomy after maturity and ulnar n. transposition
LATERAL OVERGROWTH
Up to 50% no matter what - counsel family, disruption of periosteum, lateral periosteum realignment will prevent this**
Tx of radial neck fx?
Nonop
<30 degrees angulation, immobilize for 7 days
CRPP
>30 degrees of residual angulation after closed reduction***
ORIF
>45 degrees with closed or perc methods
Ass’d with greater decrease ROM, increased AVN** (up to 70% with ORIF***)
Who does worse after radial neck fx fixation in peds?
Patients OVER 10 YEARS OLD***
What position does child keep arm in for nursemaid elbow? Tx?
slightly flexed and pronated*
Reduce in supination and flexion***
Most common nerve injury after supracondylar humerus fx in kids? second? Flexion type?
Most common: AIN (ok sign), median nerve
2nd: radial
flexion: Ulnar***
Benefit of crossed pin in SCH fx?
Better torsional stability***
When to remove pins in SCH fx? How to deal with postop stiffness?
3 weeks*** in clinic
stiffness: rare, but will normalize by 6 months***, no PT necessary
What type of SCH fx is more likely to require open reduction?
Flexion type***
Also ulnar nerve deficits
What causes cubits varus after SCH fx?
Reason to fix?
Malreduction of fx***
NOT overgrowth of lateral physics or growth arrest of medial physis***
Reason to fix generally COSMESIS***
Most common fx ass’d with peds elbow dislocation”
Medial epicondyle fx***