Metacarpophalangeal joint must be included

Always include another finger to aid identification

AP – the fingers must be placed flat upon the cassette

Lateral – non-opaque pad can be used to help extend the finger

Lateral – trauma – try not to let the finger flex too much

Avulsion #s are common – look for soft tissue swelling

Mallet finger – direct blow plus avulsion of extensor tendon

Dislocation – proximal interphalangeal joint – sporting injury

Joint spaces should be uniform – approximately 1 mm in width

Transverse # – result of hyperextension of the finger

AP – condyles must be equidistant from the cassette

Lateral – condyles must be superimposed

?Trauma – consider alternative AP (trauma) projection

Underpenetration of proximal thumb due to thenar pad

Radiograph can appear normal – look for soft tissue swelling

Avulsion #s may be present

Bennett’s # – # dislocation – result of forced abduction

Skier’s (gamekeeper’s) thumb – acute sprain or rupture – ulnar collateral ligament

Use if injury to base of first metacarpal is suspected

Where indicated support the thumb on a non-opaque pad

Must include the carpometacarpal joint

Increase SID to reduce the magnification

Thumb must be parallel to the cassette

Check the first carpometacarpal joint is included

A magnified image unless an increased SID is used

Bennett’s # – unlikely thumb will be parallel to the cassette

Include the whole of the hand, including carpal bones and distal radius/ulna

?Injury confined to distal digit – limit image to that digit

If you identify an injury – proceed to a lateral

PA oblique – better general assessment if fingers parallel

PA oblique – avoid over-rotation – obscure metacarpals

#s metacarpal neck – usually the result of a direct blow

Common site for #s – head of the fifth metacarpal – Boxer’s #

Look for vertical # through the base with dislocation of joint

Secondary ossification centres appear at age 2–3 years

PA poor at showing #s of the articular surface of the metacarpal heads

Lateral – where indicated support the thumb on a non-opaque pad

If not a true lateral – may result in missing a dislocation

An increase in exposure of up to 5kV may be necessary

Catcher’s – obliquity – metacarpal heads must be free from superimposition

Look for bone alignment – displacement and dislocation

Look for # through the articular surface at the base of phalanx

Check the base of the fourth and fifth metacarpals – dislocation is common

Ball catcher’s – look for early rheumatoid arthritis with loss of bony outline and associated demineralisation

AP – elbow and wrist at the same level

Is there ulnar deviation if a scaphoid # is suspected?

Slightly curl fingers so that carpals are in contact with cassette

Dry plaster of Paris cast increase 1 stud kV + 1 stud mAs

Wet plaster of Paris cast increase 2 stud kV + 1 stud mAs

Synthetic cast increase 1 stud mAs

Be careful of abnormally thick plaster casts

Colles’ # – posterior displacement – most common in the elderly – displacement described as ‘dinner fork’ deformity

Smith’s # – anterior displacement – uncommon

Epiphyses – radial appears in the second year and fuses in the 20th year – ulnar appears in the 8th year and fuses in the 20th year

Styloid processes must be superimposed – rotate further 5°

To achieve superimposition try extending the elbow

Wrist and elbow should be at the same level

Acute injury – horizontal beam will be necessary

In children look for a slipped epiphysis

Look for soft tissue swelling due to haemorrhage

Commonest carpal dislocation – lunate dislocation due to forced dorsiflexion

Triquetrum is the second commonest carpal bone to #

In children – commonest # is the greenstick

PA – ulnar deviation essential where injury will allow

Fine focus is essential

Long axis of the scaphoid should be parallel to the cassette

Increase mAs slightly due to precise collimation

Do not X-ray through plaster due to poor definition

PA – the scaphoid and joint spaces should be demonstrated

80% of #s occur at the waist of the scaphoid and jeopardise blood supply to the proximal part

Scaphoid # may not be evident for 5–10 days after injury – must have a follow-up examination

# of the proximal pole of scaphoid – increased chance of avascular necrosis

Look for reabsorption of bone on follow-up radiographs

A slight over-rotation of the wrist will superimpose the styloid processes

Minimise movement of the wrist as much as possible – move the wrist from the elbow and shoulder

A kV increase will be required for the lateral projection

Oblique – hand, where indicated support with non-opaque pads

If intercarpal joints measure more than 2 mm (adult) then suspect ligamentous injury

90% of carpal #s involve the scaphoid

Lateral – most dislocations involve the lunate bone

Oblique – pisiform and posterior triquetral should be visible

Ulnar deviation essential

Slightly raised fingers are due to carpals in contact with cassette

Angle the central ray 45° – check SID is still 100 cm

Too much angle of central ray will distort the scaphoid

Take care not to project the image off the cassette

Separates the scaphoid from the carpal bones

Exaggerates a # if present

May require RNI if pain persists and X-rays show no abnormality

Elongated projection – use as a supplementary projection only

Always include both joints on the radiograph

Lateral 1 – Flexed elbow

Lateral 2 – full extension of the forearm and elbow

Acute injury – horizontal beam will be necessary

AP – slight superimposition of radial head over proximal ulna

Lateral 2 – Good for bone alignment – radius and ulna superimposed

But Lateral 2 – poor projection of the elbow – oblique elbow

Lateral 1 – Good projection of the elbow and wrist joints

Lateral 1 – Radius and ulna superimposed at the wrist, but separated at elbow

AP – epicondyles equidistant from the cassette

AP – hand should be fully supinated

Lateral – raise and immobilise the wrist on non-opaque pad; alternatively ask the patient to support the wrist with their opposite hand placed beneath the wrist of the affected limb

Children – both elbows may be required for ossification centres

Shoulder higher than the elbow is poor technique

Possible supracondylar # – never forcibly extend the elbow

Look for displaced fat pads – indication of trauma

Common site of injury is the radial head

Normally only the anterior distal fat pad is visible

Check the elbow for avulsion #s – usually the result of a fall onto an outstretched hand

Check soft tissue for swelling – a positive sign of trauma

Supracondylar #s account for 60% of childhood #s

1. Use as a general projection in the case of severe trauma

Difficult position to maintain – immobilisation essential

2. Ensure epicondyles are equidistant from the cassette

Adjust the table to just below the shoulder level

A visible fat pad is abnormal – probable #

Radial head will be slightly superimposed on distal humerus

Forearm and humerus should be superimposed

Olecranon and distal humerus should be clearly seen

Ideally, hand is rotated with the thumb pointing upwards

Painful joint – pronate the hand

Take projection after the lateral – minimises movement

Lead protection must be given – consider central ray

Do not forcibly supinate hand

Common injury due to a fall on an outstretched hand

Radial head should be projected clear of the ulna

Impacted head – slight angulation of the cortex of the neck

Is there a positive fat pad sign?

Image will be magnified and elongated

Humerus should be abducted away from the trunk

AP – elbow epicondyles equidistant from the cassette

Lateral – hand, where possible, should be placed on abdomen

Must include shoulder and elbow joints on the radiograph

Acute injury – do not remove the arm from the sling

Beware – breast shadows may obscure the humeral shaft

#s occur at all levels – direct or indirect violence

AP – head and greater tuberosity of humerus seen in profile

Lateral – are the epicondyles superimposed?

Common site in children – solitary bone cyst

Adults – metastatic deposits – breast or bronchus

Lateral – head of humerus not seen well – shoulder projection may be required