Ankle/Fibula Fractures

Question 1

What is the common mechanism of ankle fracture?

Answer 1

• Fall or twisting injury

- Or high energy

Question 2

What are the important factors of the initial clinical assessment?

Answer 2

• N/V (ESPECIALLY DP & PT PULSE)
• OPEN/CLOSED (OPEN INJURIES NEED URGENT TREATMENT)
• OTHER SITES OF INJURY

Question 3

What imaging is appropriate of ankle fractures?

Answer 3

X-RAYS : AP (PREFERABLY MORTICE VIEW WITH 15 DEGREES INTERNAL ROTATION ) & LATERAL
• +/- CT IF COMMINUTED

Question 4

How are ankle fractures managed?

Answer 4

Undisplaced (stable):
No reduction required. Short leg cast (or
occasionally removable support boot)

Displaced (unstable):

Sedation with closed reduction maintained by moulded short leg cast

GA with closed reduction maintained by moulded short leg cast (rare: usually only if unfit for open procedure)

GA Open reduction (OR) Internal fixation (IF)

Question 5

What is the criteria for displaced vs. undisplaced ankle fractures?

Answer 5

• Medial clear-space (4mm or less above &
  medial to medial talus)
• Syndesmosis tibia/fibula overlap
• Widening of the medial clearspace implies
  lateral subluxation of the talus i.e. talar shift

Question 6

What is talar shift?

Answer 6

Lateral subluxation of the talus.

Question 7

Why is early reduction of ankle fractures crucial?

Answer 7

• Reduce gross deformity before X-ray, to minimise risk of N/V or sort tissue damage
• Ankle fractures left without reduction quickly
  develop skin damage which increased the risk
  of post-op infection & may prevent surgery.

Question 8

What is the significance of talar shift and dislocation?

Answer 8

Talar shift or dislocation often imply unstable pattern at risk of loss of reduction in cast

Question 9

Summarise ankle fracture management.

Answer 9

REDUCE & STABILISE
• If displaced, reduce
– Sedation (midazolam), Morphine & entonox, GA
– Knee flexed to relax gastrocnemius
• Maintain reduction (Stabilise)
– Moulded short leg cast
– Consider operative fixation if unstable or not reduced
– Elevate (especially pre-surgery)
• X-ray (mortice & lateral) after reduction
• If still not reduced, surgery required

Question 10

Outline the Weber classification of fibula fractures.

Answer 10

• C: above syndesmosis
– Usually unstable
– Syndesmosis tear often present

• B: at level of syndesmosis
– Stable or unstable
– Syndesmosis tear sometimes

• A: below syndesmosis
– usually stable

Question 11

Outline the stability “rule of thumb” in ankle fractures.

Answer 11

ANKLE FRACTURE ARE GENERALLY UNSTABLE (& NEED ORIF) IF INVOLVING 2 OR MORE OF THE FOLLOWING:

1. MEDIAL MALLEOLUS/DELTOID LIGAMENT RUPTURE
2. LATERAL MALLEOLUS
3. POSTERIOR MALLEOLUS
4. SYNDESMOSIS LIGAMENT (WHICH HAS GREATEST RISK OF INJURY IN HIGHER FIBULA FRACTURES)

Question 12

Outline the management of Weber A ankle fracture.

Answer 12

Isolated Weber A fibula fracture:
– Usually stable: non-operative
treatment

Question 13

Outline the management of Weber B ankle fracture.

Answer 13

Isolated Weber B fibula fracture:
– If always undisplaced (even on weight-bearing x-rays) probably stable: most have non-operative treatment
– If displaced, probably unstable: usually ORIF (+/-syndesmosis screw )

Question 14

Outline the management of Weber C ankle fracture.

Answer 14

“Isolated” Weber C fibula fracture:

– Usually unstable & associated with syndesmosis rupture: ORIF + syndesmosis screw

Question 15

How are isolated medial malleolus fractures managed?

Answer 15

• Isolated medial malleolus fractures

* Usually stable but may need ORIF is risk of non-union from thick periosteum stuck in the fracture gap

Question 16

How are bimalleolar fractures managed?

Answer 16

i.e. medial & lateral malleolar fractures:

• Unstable & require ORIF

Question 17

Describe a Maisonneuve fracture and its management.

Answer 17

• Very high fibular fracture (above ankle
x-ray), tearing syndesmosis ligament:

• Unstable: ORIF

Question 18

Outline the conservative management of ankle fractures.

Answer 18

• Usually 6 week short leg cast
• X-rays at 1,2, 3 & 6 weks
• Most NWB for 6 weeks then wean gradually
onto full weightbearing
• If definite of stable injury, earlier weight-bearing or removable support boot can be considered

Question 19

Outline the complications associated with both conservative and operative management of ankle fractures.

Answer 19

• Non-operatively/operatively:

– Neurovascular/tendon injury
– Delayed/mal/non-union (metalwork failure)
– Stiffness/OA
– Compartment syndrome

• With surgery:

– Infection
– DVT/PE
– Anaesthetic/cardioresp. complications

Question 20

Describe a pilon fracture of the ankle.

Answer 20

• Comminuted distal tibia articular surface

* Usually high energy e.g. RTA, fall from height

Question 21

When is an external fixator required in ankle fractures?

Answer 21

• External fixators if:

1. Plafond fracture
2. Severe soft tissue damage
   – Open fracture
   – Ankle with severe blistering as left un-reduced!

• Often temporary until other definitive treatment

Question 22

When is an Ilizarov frame required in ankle fractures?

Answer 22

Circular fine-wire external fixator used in complex
ankle/tibial fractures, especially if soft tissue injury
or periarticular damage.