Distal radial fractures

Question 1

What % if all fractures seen clinically do distal radial fractures represent?

Answer 1

25%

Question 2

Where do distal radial fractures occur?

Answer 2

Through the distal metaphysis of the radius

With or without articular involvement

Question 3

What is the most common cause of a distal radial fracture?

Answer 3

Fall on an outstretched hand (FOOSH)

Question 4

What are the risk factors for distal radius fractures?

HINT: think about risk factors for osteoporosis

Answer 4

Osteoporosis

Increased age (as risk of osteoporosis increases)

Children aged between 5-15 years

Female gender

Early menopause

Smoking/alcohol excess

Prolonged steroid use

Question 5

What % of the axial load does the distal radius take?

Answer 5

80% of the axial load under the scaphoid and lunate fossae

Question 6

What type of movement and subsequent injury of the distal radius does FOOSH cause?

Answer 6

Forced supination or pronation of the carpus

Increases the impaction load of the distal radius

Question 7

What are the different classifications of distal radius fractures?

Answer 7

Colles’ fracture

Smith’s fracture

Barton’s fracture

Question 8

What is Colles’ fracture?

Answer 8

Extra-articular fracture of distal radius

With dorsal angulation and dorsal displacement

Within 2cm of the articular surface

Typically occurs as a fragility fracture in osteoporotic bone

Question 9

What causes a Colles’ fracture?

Answer 9

Falling forward with outstretched arms in from

Transfer of load as the body falls forces the wrist into supination

Question 10

What is a Smith’s fracture?

Answer 10

Volar angulation of the distal fragment of an extra-articular fracture of the distal radius

i.e., the reverse of a Colles’ fracture)

With or without volar displacement

Less common

Question 11

What causes a Smith’s fracture?

Answer 11

Falling backwards and planting the outstretched hand behind the body

Causes a forced pronation

Question 12

What is a Barton’s fracture?

Answer 12

Intra-articular fracture of the distal radius
+
Dislocation of the radio-carpal joint

Can be described as volar (more common) or dorsal (less common) - depends on whether the volar or dorsal rim of the radius is involved

Question 13

What are the clinical features of a distal radius fracture?

Answer 13

Episode of trauma

Immediate pain +/- deformity

Sudden swelling around fracture site

Neuro involvement = paraesthesia or weakness

Question 14

What is important to check in examination of someone with suspected distal radius fracture?

Answer 14

Neurovascular compromise

Check nerve function of median, ulnar and radial nerve?

Question 15

How would you check the nerve function of the median nerve?

Answer 15

Motor - abduction of the thumb

Sensory - radial surface of 2nd digit or top of the palmar surface of 3rd digit

Question 16

Which nerve branches from the median nerve? How would you check its function?

Answer 16

Anterior interosseous nerve

Opposition of the thumb and index finger

Question 17

How would you check the nerve function of the ulnar nerve?

Answer 17

Motor - abduction of the thumb (Froment’s sign)

Sensory - ulnar surface of the distal 5th digit

Question 18

What is the Froment’s sign?

Answer 18

Tests strength of the abductor pollicis muscle

Innervated by the ulnar nerve and weakened in ulnar nerve palsy

Question 19

How would you test for the Froment’s sign?

Answer 19

The patient is asked to make a strong pinch between the thumb and index finger and grip a flat object such as a piece of paper between the thumb and index finger

The examiner then attempts to pull the object out of the subject’s hands.

There is weakness of the adductor pollicus innervated by the ulnar nerve which would keep the IP joint relatively straight

Instead, the FPL muscle which is innervated by the median nerve is substituted for the AP and will cause the IP joint to go into a hyperflexed position

Question 20

How would you check the nerve function of the radial nerve?

Answer 20

Motor - extension of IPJ of thumb

Sensory - dorsal surface of 1st webspace

Question 21

What are the DDx for distal radius fractures?

Answer 21

Forearm fracture e.g., Galeazzi or Monteggia fractures

Carpal bone fractures

Tendonitis or tenosynovitis

Wrist dislocations

Question 22

Which investigation would you do?

Answer 22

Plain radiography

CT/MRI - complex fractures esp. for operative planning

Question 23

What 3 measurements on plain radiography help with Dx of a distal radius fracture?

Answer 23

Radial height < 11mm

Radial inclination < 22 degrees

Radial (volar) tilt > 11 degrees

Question 24

How would you manage?

Answer 24

Resuscitate and stabilise

Closed reduction - traction and manipulation under anaesthetic

Restriction - allow for bone healing

Stable + successfully reduced fractures can be placed in below-elbow backslab cast - repeat radiographs after 1 weeks to check for displacement

Once bone healed, rehabilitate via physiotherapy to ensure full regaining of function

Question 25

When would you require surgical Mx?

Answer 25

Significantly displaced Unstable fractures As they have a risk of displacing further over time if not stabilised Any fracture with an intra-articular step of the radiocarpal joint > 2mm

Question 26

What are the options for surgical Mx?

Answer 26

Open reduction and internal fixation (ORIF) with plating K-wire fixation External fixation rarely used Patient then placed in a cast to ensure ongoing immobility for a few weeks

Question 27

What are the main complications of a distal radius fracture?

Answer 27

Malunion - poor realignment leads to shortened radius compared to ulnar Median nerve compression - more common in patients who heal in a significant degree of malunion Osteoarthritis - especially with intra-articular involvement from the original fracture

Question 28

What can malunion cause apart from radial shortening?

Answer 28

Reduced wrist motion Wrist pain Reduced forearm rotation

Question 29

How can malunion be treated?

Answer 29

Corrective osteotomy - cuts bone to restore normal alignment

Question 30

What is the typical sign of a Colles fracture?

Answer 30

Dinner fork deformity a.k.a. bayonet deformity Malunited distal radial fracture Distal fragment is dorsally angulated, displaced and often impacted

Question 31

What is the typical sign of a Smith's fracture?

Answer 31

Garden spade deformity

Question 32

In someone that presents with a possible Colle's fracture, apart from the hand what else would you want to examine?

Answer 32

The shoulder Due to impact on falling

Question 33

Sources

Answer 33

https://teachmesurgery.com/orthopaedic/wrist-and-hand/distal-radius-fracture/ https://www.physio-pedia.com/Froment%E2%80%99s_Sign https://radiopaedia.org/articles/smith-fracture?lang=gb https://radiopaedia.org/articles/dinner-fork-deformity-wrist?lang=gb