Sammy Full Rad 2B

Open vs closed fx

Open is when the fx penetrates the skin

Closed is when fx doesnt penetrate skin

Open fx is more susceptible to infection T/F

True

Comminuted fx def

Fx with multiple intersecting fc lines resulting in bony fragments

What fragment do we see in comminuted fxs on xray

Butterfly fragment: triangular cortical fragment

Non-comminuted fx def

Single fx resulting in two fragments

Avulsion fx def

Tearing away of bone by forceful muscular or ligamentous pulling

Where do avulsion fx commonly happen

Tuberosities of long bones and cervical spinous processes

What is cervical spinous process avulsion fx called and how does it happen

Clay-shoveler fx

-happens from hyper flexion injury

Which pop do we see avulsion fxs most commonly in and WHY

Children because their growth plates are weaker than their muscles —> avulsions common

When you fall, you ___ your wrist and ___ deviate

Extend, radially

Extension of wrist and radial deviation causes what kind of avulsion fracture

Ulnar styloid (slide 11)

Impaction fracture def

When portion of bone is driven into its adjacent segment

Fracture line is usually ___ at region of impaction

Opaque

Since the radius is a strong bone, if we see a distal radius fracture, what question do we ask?

Is the patient osteoporotic?

3 xray findings for acute compression fractures in the spine

1. Decreased body height

2. Zone of impaction

3. Step defect

Step defect def

Anterior corner of vertebral body fractures off

Zone of impaction def

Increased density

Out of the 3 xray findings for acute compression fxs in spine, which one will never go away

Decreased vertebral body height

Why does zone of impaction and step defect go away over time?

Osteoblast and osteoclast activity remodels

Compression/impaction fractures of femoral neck are more common in which pop and why

Elderly females (osteoporosis due to menopause)

2 types of impaction fractures

Depressed fx and compression fx

Depressed fx def and example

Inward collapse of outer bone surface

Ex: ping pong fx (baby dropped on its head)

Compression fx def

Decreased volume of bone due to trabecular collapse/telescoping

MC mechanism for spinal compression fxs?

Flexion

Bumper fender fx def

Valgus force to femoral condyle while foot is planted —> forces lateral femoral condyles into lateral tibial plateau —> depression fx

Which area in spine is compression fx mc seen

L1 (TL junction) or transitional zones

Complete fx def and which demographic

Completely traverse bones (cortex to cortex)

-mc form of fx in adults (because bones are rigid)

Incomplete fx def and demographic

Broken only on one side from bone bending/buckling on opp side

-mc in children since bone is more bendy

Green stick fx is a type of ___ fx

Incomplete

Green stick fx mechanism

Tension on convex side causes transverse fx, concave side remains intact

Torus (buckling fx) is a type of ___ fx

incomplete

Torus fx def

Compression forces cortex to bulge outward

Where does torus fx usually occur

Metaphysis, 4cm prox to distal end

Can you see the break of bowing fx on xray?

No, can only see bowing deformity, need MRI to see micro fractures

Infraction fx def

A form of impaction, described minor localized break in cortex leaving minimal deformity (incomplete fragmented fx without displacement

Infraction occurs as a result of ___

Infarction (AVN)

Most common infraction is ___ ___

Freiberg infraction (AVN at metatarsals 2 + 3)

Freiberg infraction has two predisposing groups, what are they

1. Young females wearing heels

2. Mortons toe

What is Morton's toe and why does it cause freiberg infraction

Second toe longer than first —> increase stress on 2nd toe —> ischemia —> necrosis

Pathologic fx def

Fx through a bone weakened by localized or systemic disease

Pathologic fx has a ___ fx orientation

Transverse (healthy bone too strong to do this, usually oblique)

Chip fx def and which bones mc affected

Form of avulsion where small chip of bone is broken from parent

- phalanx or short tubular bones mc affected

Which bone did she give an example of chip fx and which name sign does it have

Triquetral fx from hyperextension injury, pooping duck sign present on lateral xray of carpals

Two types of stress fx

Fatigue and insufficiency fxs

Fatigue fx comes from

Repetitive microtrauma to bone —> microfractures —> interruption in bone (more osteoblasts than osteoclast activity —> new bone on weak base —> fatigue fx)

What is gold standard to see fatigue fx

MRI

What do you see on MRI to diagnose stress fx

Marrow or ST edema (bright/opacity = fluid on MRI)

Insufficiency fx def

Stress fx through diseased bone

How does MRI work

1. Magnetic field used to align hydrogen protons in body

2. Radio frequency waves are absorbed by protons then emitted as a signal (protons absorb energy and spin —> take magnetic field away —> protons go back to normal spin —> take pic)

CSF is ___ in T1 MRI and ___ in T2 MRI

Dark, white

Fat is ___ than CSF on T1 MRI

Brighter

How to ddx MRI from CT

Look at cortical bone

MRI cortical bone is black or white

Black

CT Scan cortical bone is black or white

White

Why is cortical bone black in MRI

No protons in cortical bone

Occult fx

No clinical signs or xray findings of fracture

Most common occult fx is at ___, followed by ___

Scaphoid, ribs

Bone bruise is only discovered with what imaging

MRI

What can we see on MRI that we cant on xray for bone bruises

Hemorrhage and bone marrow edema at trabecular microfractures

Pseudofx aka (4)

Looser's line

Milkman's syndrome

Increment fx

Umbau zone

Pseudofx are discreet regions of ____ osteoid

Unmineralized

Pseudofx seen in ____ ____ conditions like pagets, rickets, osteomalacia, fibrous dysplasia

Bone softening

MC conditions with Pseudofx (2)

Rickets and osteomalacia

Rickets and osteomalacia mechanism

Not enough vitamin D —> decrease calcium —> unmineralized fibrous tissue waiting to be ossified but never is (bone not strong enough to support normal forces)

Radiographically, pseudofracture are linear lucencies at ___ degree angle to cortex

90

Three fracture orientations

Oblique

Spiral

Transverse

Oblique mc at ___ of long bone and is ___ degrees of long axis of bone

Shaft, 45

Spiral fractures happen from...

High energy trauma

Spiral fractures components (3)

Torsion + axial compression + angulation

Transverse fractures occur at ___ degree to long axis of bone and is very uncommon through ___ bone

90, healthy

Fracture spatial relationships (3)

Alignment

Apposition

Rotation

Alignment def

Position of distal fragment in relation to proximal fragment for extremities

Position of proximal fragment to distal fragment for spine

Alignment aka

Angulation

Apposition is the

Describes the closeness of bony contact at fx site (Amount of displacement)

Partial apposition =

Partial bony contact

Rotation def

Twisting forces on long axis induce rotational deformity, describes rational malposition of fragments

What is it called on xray when distal portion of extremity goes superior

Telescoping

Questions we ask when looking at apposition (2)

Is it maintaining bony contact?

Which direction is the bone misplaced?

We mainly see rotation in...

High energy trauma

Three traumatic articular lesions

Subluxation

Dislocation (luxation)

Diastasis

Sublux def

Partial loss of contact between articular components of joints

Dislocation def

Complete loss of contact between articular components of joint

If fx is present in dislocation, what is it called

Fracture dislocation

At extremity, describe position of __ in relation to ___

Distal, proximal

At spine, describe position of ___ segment upon ___ segments

Upper, lower

Diastasis def

Displacement or frank separation of a syndesmosis joints

What syndesmosis joints go through Diastasis (4)

Public symphysis, SI joint, skull, distal tibiofibular syndesmophytes

Syndesmosis joints are ____ moveable

Barely

How does public symphysis diastasis happen (2)

A —> P motor vehicle accident and pregnancy

Salter and Harris 1963 proposed a classification system to describe ___ ___ injuries

Growth plate

The ___ of bone ____ in fracture determines classification type

Components, involved

Most common locations for Salter Harris fx (3)

Distal radius

Distal tibia

Proximal femur

SALTR acronym

Slip

Above into metaphysis

Below into epiphysis

Through all of them

Rammed

Most common Salter Harris fx classification

Type 2 (75%)

Which Salter Harris fx classification can happen without trauma

Type 1

Salter Harris type 1 def

Partial or complete separation of epiphysis from shaft of bone from shearing/avulsive force

What about how the growth plate grows does it predispose it to SCFE

It starts as horizontal and as it grows, it goes more vertically oblique —> shearing force increases

SCFE stands for

slipped capital femoral epiphysis

SCFE is a type ___ Salter Harris fx

1

SCFE has a higher incidence in children who are ___ and in children who are growing ___

Obese, rapidly