Trauma Skeletal Radiology

Hand & Wrist

L J Brimicombe

Suspected trauma

Indicate the following

on the request form: Side involved and body part

Mechanism of injury

Exact site of focal tenderness related

to a specific bone or joint

(IRMER requirement)

Incomplete/Inadequate requests

without all the above information

may not be processed.

If clinical findings remain unexplained

recheck that imaging for the area of clinical

concern has been requested with the

relevant and appropriate clinical

Information

Appropriate further management

? Need for delayed imaging/fracture clinic

referral

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Systematic Film Evaluation

Alignment

Bones

Cartilage

Soft Tissue

Evaluate the ABC’S!

Alignment

Bowing

Normal position of bones

Spaces between bones

Symmetry

Angulations

Bones

Periosteal Reaction

Anomalies in the cortex, breaks, overlaps &

steps.

Changes in trabecular pattern

Changes in densities

Cartilage

Look for avulsion fractures

Misalignment

Effusions

Soft Tissue

1. Defect on normal contours

2. Obvious swelling

3. Foreign body (e.g. glass) in soft tissues

4. A fluid/solid interface (lipohaemoarthrosis)

5. A gas/fluid interface (perferation)

Finger Nail Bed Injury

Avulsions of the Medial and/or Lateral Co-lateral Ligaments

Avulsion From the Insertion of the Volar Plate

Avulsion of the Extensor Tendon

Swan Neck Deformity

Swan neck deformity is a

condition in which the

distal joint (behind the

nail) of the finger goes into

flexion and the proximal

joint goes into extension.

Boutonniere Deformity

Initially, the

finger is painful

and swollen

around the PIP

joint.

The PIP joint

may not

straighten out

completely

under its own

power.

Mallet Finger

Intra-articular avulsion

fracture at the insertion of

extensor Tendon

Ligament Rupture without avulsed

fragment

Dislocation

Fracture Dislocation Coaches Finger

• Named after baseball coaches

• Most common hand injury in

athletes, especially among those

who play ball-handling sports

• Most cases, the dislocation happens

because the fingers are bent

backward when an athlete tries to

catch a ball or block a shot.

• Proximal interphalangeal joint

dislocations can happen when an

athlete’s fingers are twisted or bent

by an opponent.

Boxers Fracture

Blow from a “roundhouse" motion, fractures 4th or 5th or both

Fighter’s Fractures

• Instead of using a

"roundhouse" motion,

the blow comes straight

from the body

• This is typical of a skilled

fighter

• The 2nd Metacarpal is

fractured.

Dislocation Carpometacarpal joint

Most common are 4th and 5th metacarpals

Associated with fractures at the base of

affected metacarpal or an adjacent one

When a fracture of hamate is seen it is likely to

have an associated dislocation of the 5th

metacarpal joint.

Hand Less Obvious Fractures

If a base of 5th is suspected an AP rather than PA view and a

reverse oblique can be useful

Trapezio-Trapezoidal Junction

Oblique View

Carpel Arcs

I. Smooth curve outlining

the proximal convexities

of the scaphoid, lunate

and triquetrum.

II. Traces the distal

concave surfaces of the

same bones

III. Follows the main

proximal curvatures of

the capitate and hamate.

Disruption of arc I

There is disruption

of arc I at the lunate

triquetral joint

Suggestive of a

triquetral fracture

A posterior

fragment maybe

seen on the lateral

Disruption of Arc II

There is a step in the

scapho-lunate joint

and the luno-triquetral

joint is seen on the

left.

Terry Thomas Sign

Disruption Arch III

There is an

abnormal step off

at the capito-

hamate joint.

Hamate Fracture

AP rather than PA

view advised

Hand – Fracture Dislocations

Hand – Associated Fractures

Fracture of Hamate With an associated fracture through

the base of the 4th metacarpal

Thumb Attachments

Thumb – Bennetts Fracture Dislocation

Unstable

An oblique intra-articular fracture at the base of

the 1st metacarpal,

The abductor pollicis longus muscle pulls the

main body away.

Thumb – Rolando’s Highly Unstable

Similar to the Bennett’s fracture-dislocation,

but this intra articular fracture is comminuted.

Extra-articular fractures are stable!

Thumb Ulnar Collateral Ligament

A strain or tear to the thumb's ulnar

collateral ligament of the metacarpo-

phalangeal joint of the thumb and often

with an associated avulsion fracture . . .

Skier’s

Gamekeeper’s

Break Dancer’s

Gamekeeper’s Thumb

• Injury occurs breaking rabbits necks

between the ground and the

gamekeeper's thumb and index

fingers.

• A valgus force was placed onto the

abducted MCP joint, leading to the

injury

• Resulting in instability, accompanied

by pain and weakness of the pinch

grasp.

Skier’s Thumb

• Usually results from a fall on an

outstretched hand that continues

to hold the ski pole.

• A valgus force is placed onto the

abducted MCP joint, leading to

injury

• Resulting in instability,

accompanied by pain and

weakness of the pinch grasp.

• May comprise up to 50% of

injuries to hand in skiers

Break Dancer’s Thumb

A valgus force is placed

onto the abducted MCP

joint, leading to injury

A valgus force was placed

onto the abducted MCP

joint, leading to the injury

Resulting in instability,

accompanied by pain and

weakness of the pinch

grasp.

Dislocated 1st Carpometacarpal

Eaton Littler Views

Stress views of thumbs

Osteoarthritis to bases

of 1st metacarpal-carpal

joint

Often shows

subluxation of the joint

Wrist Anatomy

Wrist Anatomy

Normal Wrist Angulation

Normal palmer tilt of the radial

articular surface

If the tilt is not present suspect

an impacted fracture

Normal Wrist Allignment

ANT.

Wrist

A fall on the out-stretched hand (FOOSH) tends to result in specific

injuries depending on the general age of the patient:

4-10years – Torus fracture of the distal radial metaphysis

11-16years – Salter-Harris II fracture involving the physeal plate

17-40years – Scaphoid fracture

Over 40years – Colles-type fracture

Radial Styloid Process Fractures

Fractures are common

due to blunt trauma

directly to the radial

styloid process

Fractures are oblique,

intra-articular and are

usually minimally

displaced

Chauffeur Fracture

A vertical fracture of the radial

styloid process

Typically a blow to the back of

the wrist

Name comes from trying to

start an old-fashioned car with

a hand crank resulted in it

rapidly spinning backwards

out of the driver's grasp and

striking the back of the wrist

Displacement is uncommon

Barton’s Fracture – Dorsal Type

A comminuted intra-articular

fracture of the distal radius,

(shearing fracture) extending

through the dorsal aspect to

the articular surface, and not

to the volar aspect.

Dorsal rim and carpus are

displaced dorsally and

proximally

There can be associated

carpal subluxation /

dislocation.

Reverse Barton’s – Volar Type

A comminuted intra-

articular distal radial

fracture with volar

displacement

Volar rim maintains

relationship with the

carpus, both displace

proximally (blue)

Fracture of radial styloid

process with loss of

radial definition (yellow)

Die Punch

Blue arrow indicates the

depressed fragment of the

lunate fossa.

Note: an articular step-off.

Yellow arrow indicates a

subtle fracture of the radial

styloid process.

There is no disruption of

carpal arc.

EASILY OVERLOOKED!

Wrist – Smith’s

Occur in younger patients

Resulting from high energy

trauma on the volar flexed wrist.

Fracture through the distal 5cm of

radius

An associated fracture through

the ulna styloid process

Anterior displacement of the distal

fragment

Colles’

A fracture of the distal metaphysis of the

radius with dorsal angulation and

displacement leading to a ‘dinner fork

deformity'.

An associated fracture of the ulna styloid

process

Frequently with advancing age and in

women with osteoporosis.

In many cases extra-articular,

uncomplicated and stable fracture

It can be intra-articular.

Look for signs of instability:

– Intra-articular radiocarpal or distal radial

ulna junction extension of the fracture

– Radial shortening

– Loss of radial inclination

Colles an insufficient description ?

Extension into the radiocarpal

joint and the distal radioulnar

joint

Displacement of the articular

fragments (blue arrow)

Radial shortening and loss of

radial inclination resulting in

distal ulna abutting the lunate

(yellow arrow)

Fracture of ulnar styloid

Scaphoid Appearance

Importance of Ulna Deviation

The shape of the

scaphoid changes

with movement of

the wrist.

In ulnar deviation

the scaphoid

elongates to fill the

space between the

radial styloid and

the trapezium

Without With

Scaphoid – most common carpus fracture the majority are waist type

Waist Scaphoid # Often non-displaced

Difficult to see initially

At 10-14 days demonstrates sclerosis

or re-absorption at the fracture line

Important to pick up! As the blood supply enters at the waist and can be disrupted resulting

in delayed union or avascular necrosis of the waist and proximal pole.

Scaphoid Blood Supply

Scaphoid – Distal Pole

•Fractures at the distal

pole are usually avulsion

injuries.

•The distal pole has its

own blood supply, so

healing is quick.

A child’s scaphoid injury

Scaphoid Importance of the 10/14 day rule

1st Presentation 14 days later

Scaphoid Ruptured Scapho-Lunate Ligament

Terry Thomas Sign

Clench Fist View

Demonstrates this well

Scaphoid - Children

7yrs & Below Scaphoid NOT ossified

Younger than 12yrs Dedicated scaphoid views not

necessary. Injuries NOT adult

type and can be

clearly seen on a ulna deviated PA

Wrist.

Triquetral- 2nd most common fracture in carpus

Posterior fragment

seen on the Lateral view

Hamate Fractures

Associated with fracture-dislocations

at the base of the 4th and 5th metacarpals.

(as mentioned before)

Important to spot but often subtle.

Check the cortex of the hamate,

particularly on an oblique view.

Ensure there is a 2mm joint space with

the adjacent metacarpals on the PA view

Pisiform Fractures

A reverse oblique

shows the pisiform

Pisiform Fractures are

occasionally seen due

to direct trauma

Carpus Fractures

Isolated fractures to the other carpus are rare:

Lunate

Capitate

Trapezium

Trapezoid

Obvious seen, subtle overlooked

A Scaphoid and Capitate fracture

Plus a Peri-lunate dislocation.

Differentiation between Lunate and Peri-Lunate Dislocations

The key is what is centred

over the radius.

– If the capitate is centred over the

radius and the lunate is

displaced anteriorly, it is a lunate

dislocation.

– If lunate is centred over the

radius and the capitate is

displaced posteriorly, it is a peri-

lunate dislocation

Lunate Dislocation

• Lunate loses its

articulation with both the

capitate and the radius

• Lunate displaces

anteriorly with up to

90 degrees rotation

• The capitate remains

aligned with the radius

but sinks proximally

Triangular

Appearance

Peri-lunate Dislocation

The lunate maintains its normal

articulation with the radius

But the capitate articular surface

is dislocated from the lunate,

normally posteriorly

Midcarpal Dislocation

The lunate tilts anteriorly

but is not dislocated from

the radius

The capitate is dislocated

from the lunate but not as

posterially as seen in a

perilunate dislocation

Forearm – Galeazzi Fracture Dislocation

•Fracture of the Radius

•Dislocation of the distal

Radio-ulna joint

Normal Abnormal

Zone of Vulnerability

If one abnormality if

detected with the

zone there is

possibly another

within the zone, be it

fracture, dislocation

or both.