Imelda Williams

Image Interpretation of the upper limbs

& Shoulder girdle

Shoulder: Common trauma

▪ Fracture of the clavicle

▪ Fracture of the humeral head

▪ Fracture of the scapula

▪ Anterior dislocation of the humeral head - over 90%

▪ Posterior dislocation of the humeral head – less 5%

▪ Dislocation of the acromio-clavicular joint

Slide 2

Scapula Fractures

Violent force type injury

Associated with avulsion fractures of acromion or ACJ dislocations

Associated rib or clavicle fractures

Exclude damage to lungs

Slide 3

Monash Image

Anterior Humeral dislocations

▪ Antero-inferior dislocation

▪ Most common shoulder

dislocation: 90%

Slide 4

Monash Image

Posterior Humeral Dislocation

▪ Postero-lateral

rotation of humeral

head produces “Light

bulb” appearance

▪ Less common: ± 5%

Slide 5

Monash Image

Acromioclavicular joint

▪ Common sports injuires

▪ Direct fall or FOOSH

▪ Normal ACJ= 3-5mm

▪ Comparison views:

difference between 2

sides should not exceed

2m

ASSESSMENT OF ACJ

Elbow trauma

▪ Mechanism of injury includes:

• FOOSH• Direct blow

▪ Common fractures:

– Radial head / neck fracture

– Dislocation – Adults vs. paediatric

fractures

▪ Image interpretation criteria of the elbow:

▪ Dislocation assess:

– Anterior humeral line position– Radiocapitellar line position

▪ Fat pad elevation

Slide 7

Elevated fat pads: “Sail Sign”

▪ A visible anterior fat pad can be normal.

▪ A posterior fat pad is never normal and

always signifies fluid in the intra-articular

space.

▪ A positive sail sign in trauma setting is a

reliable indication of an intra-articular fracture

Slide 8

Monash Image

Anterior humeral line: AHL

▪ Accurate with true lateral elbow

▪ Line drawn along anterior

humerus must intercept

capitellum at middle third

▪ Indication of dislocation or

supracondylar fracture

Slide 9

Normal

Abnormal AHL

Supracondylar fracture

Monash Image

Radio-capitellar line: RCL

▪ True AP & lateral of elbow

▪ Indication of joint alignment

▪ Line drawn through centre of

proximal radius should pass

through centre of capitellum

Slide 10

Normal

Abnormal

Monash Image

Wrist traumatic pathology

▪ Typical wrist fractures

– Colle’s

– Smith’s

– Scaphoid

▪ Wrist alignment:

– Lunate dislocation

– Perilunate dislocation

Slide 11

Wrist dislocation

▪ Perilunate dislocation

– Capitate dislocated from lunate

▪ Lunate dislocation

– Dislocated volarly

Slide 12

Perilunate dislocation Lunate dislocation

Monash Image

Colle’s fracture

▪ COMMENT:

– Transverse fracture of

distal of radius with

dorsal displacement

of distal fragments.

Slide 13

Monash Image

▪ COMMENT:

– Transverse fracture of

the distal radius with

palmar/anterior

displacement of the

distal fragment.

Slide 14

Smith’s Fracture

Monash Image

Scaphoid fractures

▪ Fractures across scaphoid

waist has risk of Avascular

Necrosis (AVN) of proximal pole

▪ Only blood supply to scaphoid is

via distal pole.

Slide 15

Monash Image

Metacarpals and fingers

▪ Important to distinguish between extra- vs. intra-

articular fractures.

▪Fractures are common in the 1st & 5th metacarpals.

Slide 16

Bennett’s Fracture

• COMMENT:

• Common two piece

intra-articular fracture

of the base of the

thumb

Slide 17

Monash Image

Boxer’s fracture

▪ Commonly known as a punch injury or “brawler’s fracture”.

▪ The most common sight for a boxer’s fracture is either the neck or the shaft of the 4th or 5th

metacarpal.

18 Monash Image

Paediatric fractures

▪ Joint effusion is a useful sign e.g. supracondylar fracture

▪ Assessing alignment:

– Anterior Humeral Line (AHL)

– Radio-Capitellar Line (RCL)

▪ Periosteal reaction indicates healing fracture

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Common fractures

Torus / Buckle fracture

▪ Can be subtle

▪ Greenstick Variation

▪ Step in cortex

▪ Minimally impacted with intact cortex

Greenstick fracture

▪ Incomplete fracture

▪ Involves one side of the cortex

▪ Opposite side bends

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2

1

Greenstick Fracture

Monash Image

Take home principles

▪ Consider mechanism of injury.

▪ Apply a search strategy when interpreting radiographs.

▪ Know the common fractures and dislocations.

Slide 22