Pediatric Lower Extremity

Question 1

Describe where the following are located on a femur…

epiphysis

metaphysis

physis

epiphysis

Answer 1

Question 2

What unique fracture patterns are found in pediatric bone?

Why?

When considering treatment options there is more wiggle room regarding deformity…why?

What are the most active physes in the upper and lower extremities?

Answer 2

Fracture patterns
buckle and greenstick

Elasticity leads to incomplete fractures which are rare outside of these scenarios

Deformities are more acceptable when considering pediatric treatment due to remodeling potential

Most active physes in upper extremity
proximal humerus
distal radius

Most active physes in lower extremity
distal femur
proximal tibia

Question 3

Label these zones on the physes starting at the epiphysis to the diaphysis.

Give a broad description in what is happening as you move through these zones.

Answer 3

Epiphysis

Reserve/Resting zone
sore lipids, glycogen, and proteoglycans

Proliferative zone
proliferation and stacking of condrocytes
highest rate of ECM production

Hypertrophic zone

1. Maturation: prep for calcification and chondrocytes growth
2. Degenerative zone: chondrocyte growth
3. Zone of provisional calcification: chondrocyte death with calcium release and calcification of matrix

Metaphysis

1. Primary spongiosa
2. Secondary Spongiosa

Diaphysis

Question 4

Describe the 5 types of physeal fractures using the Salter-Harris classification.

HINT: USE SALTR

Answer 4

1. physeal separation
2. Physeal separation exiting metaphysis
3. Physeal separations exiting epiphysis
4. Fracture transverses metaphysis and epiphysis
5. Crush injury

Question 5

How do femur fractures typically present?

What ages is this most common in?

What pathologic etiologies should be considered given a minor traumatic mechanism of injury?

How common is this in child abuse?

Answer 5

Presentation of femur fractures
pain
shortening
inability to bear weight

Ages
bimodal - very young and older children

Pathologic etiologies
Osteogenesis imperfects (OI - image)
tumor
osteopenia

2nd most common child abuse-associated fracture
(humerus is first)

Question 6

What imaging is required to diagnose a pediatric femur fracture?

What are the treatment options based on the following ages:

<6 months

6 months to 5 years

5y/o to 11 y/o

over 11y/o

Answer 6

Plain X-rays are diagnostic

<6months:
Pavlik harness

6 months to 5 years:
spica cast
or traction followed by spica

5 years to 11 years
ORIF
Flexible nails

11 years or older
flexible nails
antegrade intermedullary nail
external fixation

Question 7

What attaches to the tibial eminence?

How does this fracture present?

What ages is this this fracture the most common?

What mechanism causes this injury in children and what injury does this mechanism typically cause in adults?

What imaging is diagnostic?

Answer 7

ACL attaches to tibial eminence

presentation:
pain
knee effusion
positive anterior drawer (similar to ACL rupture)

most common ages 8-14

Mechanism
twisty turny on planted foot
similar to ACL rupture in adults - but children more likely to just avulse the bone

Xray is diagnostic

Question 8

What are the classifications of tibial eminence fractures and the associated treatments?

What is a common residual complication

Answer 8

I: nondisplaced
immobilization in extension

II: intact posterior hinge
reduce, immobilize in extension

III: completely displaced
ORIF

IV: completely displaced/rotated/comminuted
ORIF

Complications:
ACL laxity in 10%

Question 9

What is a patella sleeve fracture?

What ages is this common in?

What mechanism typically causes this?

How does this present? What physical exam finding is particularly indicative of a patella sleeve fracture?

What imaging should be ordered and what findings would you expect?

What is the treatment?

Answer 9

Patella sleeve fracture
unique to peds
avulsion of distal patella from cartilage “sleeve”

Ages: 8-12

Mechanism: indirect injury

Presentation:
pain and swelling
high patella
**knee extensor lag**

Radiographs: show fragments of bone and high patella

MRI useful to show cartilage separation

Treatment:

nondisplaced: cylinder cast in extension
displaced: ORIF

Question 10

What are two common types of tibial shaft fractures found in pediatric patients?

What are the associated mechanisms?

How long do they take to heal?

What imaging is used to diagnose?

What is the standard treatment?

Answer 10

1. Tibia/fibula fractures
“bumper” injuries - like hit with car bumper
6-8 weeks to heal

2. Non-displaced spiral toddler(<3y/o) fractures
low energy rotational - distal 1/3 of tibia
3-4 weeks to heal

Xrays are diagnostic

Treatment:
long leg casting : 50% apposition, <1cm shortening, 5-10degrees angulation
surgical tx is RARE