Ankle injuries Flashcards
What guides clinical examination of ankle injuries? Why?
Ottawa ankle rules
To minimise unnecessary X-rays
What is stated by the Ottawa ankle rules?
X-rays are only necessary if there is pain in the malleolar zone AND:
1. Inability to weight bear for 4 steps
2. Tenderness over the distal tibia
3. Bone tenderness over the distal fibula
Describe the anatomical landmarks of the lateral malleolar zone
Tip of lateral malleolus to include lower 6cm of posterior border of fibular
Describe the anatomical landmarks of the medial malleolar zone
Tip of medial malleolus to lower 6cm of posterior border of tibia
List 3 classification systems for ankle fractures
Potts
Weber
AO
Describe the Weber classification of ankle injuries
Related to level of fibular fracture
A: Below syndesmosis
B: fractures start at level of tibial plafond + may extend proximally to involve the syndesmosis
C: Above syndesmosis which may itself be damaged
Name a subtype of Weber fracture
Maisooneuve fracture
May occur with spiral fibular fracture that leads to disruption of syndesmosis with widening of ankle joint
(Requires surgery)
How should all ankle fractures be managed?
Promptly reduced to remove pressure on the overlying skin + subsequent necrosis
How should young patients with unstable, high velocity or proximal ankle fracture injuries be managed?
Surgical repair
Often using compression plate
How should elderly patients, even with potentially unstable ankle fracture injuries be managed?
Conservative Mx as their bone does not hold metalwork well
Describe the configuration of the ankle joint
Distal tibia + fibula form a mortise
Superior aspect of the talus acts as a tenon
What binds the distal fibula and tibia together? What is this composed of/
Syndesmosis
Anterior inferior tibiofibular ligament (AITFL)
Posterior infection tibiofibular ligament (PITFL)
Interosseous ligament (IOL)
Interosseous membrane
What secures the distal fibular to the talus?
Anterior + Posterior talofibular ligaments (ATFL + PTFL)
What secures the distal fibular to the calcaneus?
Calcaneofibular ligament
Which ligaments are referred to collectively as the lateral collateral ligaments?
ATFL, PTFL + Calcaneofibular ligament
What secures the distal tibia to the talus?
Deltoid ligament
What is a strain?
Stretching, partial or complete tear of a ligament
How are ankle sprains divided?
High ankle sprains (involving syndesmosis)
Low ankle sprains (lateral collateral ligaments)
Which type of ankle sprain is most common?
Low ankle sprains with injury to ATFL most common
What is the most common mechanism of low ankle sprain?
Inversion injury
How may patients present with low ankle sprains?
Pain, swelling + tenderness over affected ligaments
+/- bruising
Usually able to weight bear unless severe
What are the grades of low ankle sprain?
I (mild): stretch/ micro-tear of ligament, minimal bruising + swelling, no pain on weight bearing
II (mod): partial tear of ligament, mod bruising + swelling, minimal pain on weight bearing
III (sev): complete tear of ligament, severe bruising + swelling, severe pain on weight bearing
What investigations should be performed for suspected ankle sprain?
X-ray according to Ottawa ankle rules (15% a/w fracture)
MRI if persistent pain
Describe management of low ankle sprains
RICE
Occasionally removable orthosis, cast +/or crutches
If Sx persist/ significant joint instability: MRI + surgical intervention (rare)
