Chapter 32- fractures of the forearm and wrist

Question 1

What is the typical history of a fracture to both forearm bone?

Answer 1

• Can occur due to direct and indirect forces such as a blow to the forearm resulting in a transverse fracture line, or twisting injury causing a spiral fracture

Question 2

What are the findings on examination of fracture of both forearm bones?

Answer 2

• Swelling and angular deformity

- Exclude compartment syndrome and neural or vascular injury

Question 3

What is the treatment of fractures to both bones in the forearm in children

Answer 3

• Majority of cases: closed reduction under anaesthesia and maintained in a plaster of paris cast for 3 - 4 weeks
• Re-Xrayed in 7- 10 days to check for re-displacement

Question 4

What is the treatment of fractures to both bones in the forearm in adults

Answer 4

• Undisplaced (rare): managed in plaster and re Xrayed at regular intervals to ensure that the position is maintained
• Most cases: Elevate and splint swollen arm until the swelling has settled –> Open reduction and internal fixation (usually with plating) –> Neurovascular observations for 24 hours

Question 5

If a single forearm bone is fractured and significantly displaced, what usually happens to the other bone?

Answer 5

• Dislocation of intact bone at either the distal or proximal radio-ulnar joints

Question 6

What is the Monteggia fracture dislocation pattern?

Answer 6

-Fracture at the proximal end of the ulna, with dislocation of the radial head at the proximal radio-ulna joint

Question 7

In the Montegia fracture dislocation how may the radial head dislocate and which is more common?

Answer 7

-It may dislocate anteriorly (Extension type) or posteriorly (Flexion type); the anterior being more common

Question 8

What ligament holds the proximal radio-ulna joint in place?

Answer 8

Annular ligament

Question 9

What is the typical history in a Monteggia fracture dislocation and a Galeazzi fracture dislocation?

Answer 9

• Fall on an outstretched hand accompanied by twisting

- The direction of displacement of the radial head depends on the direction of the force that fractures the ulna

Question 10

What are the typical findings on examination of a Monteggia fracture?

Answer 10

-Swelling, tenderness and deformity over the proximal ulna and the radio-ulna joint

Question 11

What is the surgical treatment of a Monteggia fracture dislocation?

Answer 11

• Accurate anatomical open reduction of the ulna and plating will usually result in spontaneous reduction of the radial head
• If it does not reduce, it should be explored

Question 12

Why may an open reduction of a Monteggia fracture dislocation fail?

Answer 12

• Annular ligament may have been folded in the joint and obstructing reduction
• Ulna has not had its anatomical shape restored

Question 13

What is the non-surgical management of a Monteggia fracture dislocation?

Answer 13

• Manipulation of the ulna and splinting in above elbow plaster with the forearm fully supinated and the elbow flexed to above 90 degrees for the anterior type or elbow extended for the posterior type
• Xray taken at 1 week and again at two weeks as the position may be lost

Question 14

What is a Galeazzi fracture dislocation?

Answer 14

Fracture of the distal third of the radius, with a dislocation of the ulna at the distal radio-ulna joint, which has a rather tenous capsule

Question 15

What are the examination findings in a Galeazzi fracture dislocation?

Answer 15

• Forearm deformity with tenderness and swelling of the forearm and wrist region
• The distal ulna will be prominent and may be balloted by pressure over the ulnar head

Question 16

What is the treatment of Galeazzi fracture dislocation?

Answer 16

Surgical: Open reduction and plating of the radius is the treatment of choice
If the ulnar head remains unstable it can be temporarily pinned to the distal radius

Question 17

What is a defence fracture of the ulna?

Answer 17

Minimally displaced, isolated fracture of the ulna with no dislocation of the radius

Question 18

What is the typical history in a defence fracture of the ulna?

Answer 18

Direct blow over the subcutaneous border of the distal ulna, usually in an effort to avert a blow to the head or the face

Question 19

What are the examination findings in a defence fracture of the ulna?

Answer 19

-Local tenderness, swelling or bruising over the subcutaneous border of the distal ulna

Question 20

What is the treatment in a defence fracture of the ulna

Answer 20

-Below elbow plaster cast for the relief of pain is usually sufficient unless the fracture is proximal to the midpoint of the ulna or severely displaced- in this case an above elbow plaster or an open reduction should be considered

Question 21

What are the parameters of the distal radius?

Answer 21

• tilted volarly by 15 degrees
• ulnar inclination of 20 degrees in its AP projection
• radius is generally 5 mm longer than the ulna at the wrist

Question 22

Where do extra- articular fractures of the distal radius occur?

Answer 22

Distal 2.5 cm or metaphysics of the distal radius and do not extend into the wrist joint or involve the radio-ulnar joint

Question 23

Which two types of extra- articular fractures are there?

Answer 23

• Colles: dorsal angular deformity at the fracture line

- Smiths: volar angular deformity at the fracture line

Question 24

Name and describe the types of intra-articular fractures of the distal radius

Answer 24

a) Shearing fractures of the joint surface: oblique fractures of the metaphysis which extend into the joint, with either dorsal or volar shift but no angular deformity
b) Compression fractures of the joint surface: impaction r depression on the distal radial articular surface primarily
c) Avulsion of the radial or ulnar styloid
d) Combined fractures and fracture-dislocations due to high-velocity injuries

Question 25

Typical history of fractures of the distal radius?

Answer 25

Common with falls on the outstretched hand and vehicular injuries, particularly motorcycle injuries

Question 26

Findings on examination of a distal radius fracture

Answer 26

• Swelling and angular deformity over the distal forearm and wrist
• Painful limitation of all wrist movements, including pronation and supination

Question 27

What is the treatment of a Colles fracture?

Answer 27

• Manipulation under anaesthesia and below elbow POP for 6-8 weeks in the elderly
• Manipulation under anaesthesia and above elbow POP for 6-8 weeks in young patients –> ORIF if unstable or imperfectly reduced
• Needs to be disimpacted by traction and reduced by bringing the hand and the wrist into palmar flexion and ulnar deviation

Question 28

What are the signs of malunion of a Colles fracture?

Answer 28

-Shortened radius with prominent ulnar head

Question 29

Treatment of Smiths fracture

Answer 29

• Manipulation under anesthesia and above elbow POP (with the wrist supinated and either flexed or extended) for 6-8 weeks, if unstable, ORIF
• If position cannot be maintained in a cast, open reduction and internal fixation should be performed through a volar approach

Question 30

Treatment of shearing fractures of the joint surface of the distal radius?

Answer 30

ORIF with plate or inter-fragmentary screws

Question 31

Treatment of compression fractures of the joint surface of the distal radius?

Answer 31

-Open reduction with bone grafting if necessary to achieve restoration of the joint surface. Once this has been obtained the fracture may be stablised with either a small plate or external fixator

Question 32

What complication may a patient develop if a step of 1mm or more is left in the articular surface of a compression fracture of the distal radius?

Answer 32

Post-traumatic arthritis

Question 33

Treatment of avulsion fractures of the distal radius

Answer 33

• Undisplaced (less than 1mm): Below elbow POP for 4 weeks

- Displaced: Percutaneous or open reduction and fixation with screws

Question 34

What investigation is important in combined fractures and fracture-dislocations due to high velocity injuries

Answer 34

CT scan - to help delineate the bony involvement of the radio-ulnar joint

Question 35

What is usually the treatment of choice for combined fractures and fracture-dislocations due to high velocity injuries

Answer 35

Limited open reduction so as not to jeopardize the soft tissue status any further, and immobilization with external fixator

Question 36

The MCPs are prone to stiffness, therefore what should be done after applying a cast to the forearm?

Answer 36

They should be actively mobilized from 0 - 90 degrees (pain permitting)

Question 37

In children, how can fractures to the distal radius be divided?

Answer 37

• Growth plate injuries (Salter-Harris)

- Fractures proximal to the growth plate

Question 38

which is the most common injury to the distal radius in children? And in which children does this mostly occur?

Answer 38

• Salter-harris injury of the distal radial growth plate, which is commonly a salter-harris 2/ 1 injury.
• Tend to be in pre-pubertal children, age +- 10 years old

Question 39

What is the common displacement of the salter-harris injury to the distal radial growth plate

Answer 39

Radial and dorsal shift and tilt of the distal radial epiphysis and the ulnar growth plate is also occasionally involved

Question 40

What is the displacement of fractures proximal to growth plate?

Answer 40

-Similar to that in a physeal injury but can be more extreme with the whole hand being carried with the distal radial fracture fragment to lie dorsal to the radial shaft

Question 41

What is the treatment of growth plate injuries of the distal radius?

Answer 41

MUA with image intensifier or check X-ray

BE POP moulded in wrist flexion and ulnar deviation

Question 42

What is the treatment of fractures proximal to the growth plate in the distal radius?

Answer 42

MUA with image intensifier or check Xray
AE POP moulded in wrist flexion and ulnar deviation.
If irreducible or unstable – ORIF

Question 43

What is the typical history and examination findings for a fracture the carpal scaphoid

Answer 43

• Fall on outstretched hand
• Pain on radial side of wrist
• Tenderness and swelling of the anatomical snuffbox

Question 44

Initial Xrays may fail to show a fracture of the carpal scaphoid, what is done to overcome this?

Answer 44

Special views are done in 4 planes

Question 45

What is the management of a suspected carpal scaphoid fracture, if the Xray is negative and there is tenderness in the snuffbox

Answer 45

-Scaphoid plaster is applied for three weeks and Xrays then taken out of plaster. At this stage, a fracture line is often evident

Question 46

What is the treatment of a scaphoid fracture?

Answer 46

• Apply scaphoid plaster: hand held in a position as if holding a glass. Similar to BE POP but it extends to the DIP joint of thumb
• Maintain for 8 weeks
• Leave free if no pain and Xray looks satisfactory (united)
• If not, replace POP for another 4 weeks
• If widely displaced, an open reduction and internal fixation is indicated initially

Question 47

Complications of a fracture of the carpal scaphoid

Answer 47

-Delayed union: due to impairment of blood supply, bone graft may be done in some cases
-Non- union
-Avascular necrosis
Risk increasing the more proximal the fracture

Question 48

What type of injury causes dislocation of the lunate?

Answer 48

• Hyperextension injury of the wrist

Question 49

What is the main early complication of dislocation of the lunate ?

Answer 49

Carpal tunnel syndrome

Question 50

What is the appearance on Xray of a dislocated lunate?

Answer 50

• on AP views, the normally 4-sided lunate is ‘triangular’ in shape
• On lateral, the lunate lies anteriorly to the rest of the carpal bones

Question 51

what is a peri-lunar dislocation of the lunate?

Answer 51

Lunate remains in place and the carpus is displaced dorsally. Often associated with scaphoid fracture

Question 52

Treatment of dislocation of the lunate?

Answer 52

• Urgent closed reduction- wrist is hyperextended, dislocated lunate is pushed back into position and placed in a padded POP with wrist moderately flexed
• If this fails open reduction is indicated

Question 53

What is a late complication of dislocation of the lunate?

Answer 53

Avascular necrosis