Diagnosis

44-A3 Infrasyndesmotic lateral lesion, with posteromedial fracture

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Type A3 fractures occur with the foot supinated and an adduction deforming force applied to the talus. The first injury occurs below the syndesmotic ligament on the lateral side, which is under tension. Secondly, the talus tilts which causes a shearing compression fracture of the medial malleolus.. In type A3 these are circumferential lesions, with a posterior extension.

There is no special fracture type in the Lauge-Hansen classification of supination-adduction fractures that describes this posterior marginal extension of the medial lesion.

Options
1. 44-A3.1 Rupture of the lateral collateral ligaments
2. 44-A3.2 Avulsion of the tip of the lateral malleolus
3. 44-A3.3 Transverse fracture of the lateral malleolus

1. 44-A3.1 Rupture of the lateral collateral ligaments

44-A3.1

44-A3.1

Lateral malleolus
Rupture of the lateral collateral ligaments (ligamentum calcaneofibulare and ligamentum talofibulare anterius / posterius).

Medial malleolus
Posteromedial fracture, ie, the fracture has a posterior marginal extension.

44-A3.1

44-A3.1

Radiograph taken from Orozco R et al, (1998) Atlas of Internal Fixation. Used with kind permission.

2. 44-A3.2 Avulsion of the tip of the lateral malleolus

44-A3.2

44-A3.2

Lateral malleolus
Avulsion of the tip.

Medial malleolus
Posteromedial fracture, ie, the fracture has a posterior marginal extension.

44-A3.2

44-A3.2

3. 44-A3.3 Transverse fracture of the lateral malleolus

44-A3.3

44-A3.3

Lateral malleolus
Transverse fracture below the level of the syndesmosis.

Medial malleolus
Posteromedial fracture, ie, the fracture has a posterior marginal extension.

44-A3.3

44-A3.3

Radiograph taken from Orozco R et al, (1998) Atlas of Internal Fixation. Used with kind permission.