Diagnosis

44-A1 Infrasyndesmotic lesion, isolated

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Type A fractures occur with the foot supinated and an adduction force applied to the talus, causing the lateral structures to fail in tension. Group A1 are all isolated lesions of the lateral malleolus or of the lateral collateral ligament. This lesion in all type A fractures is below the syndesmotic ligament. 44-A1 fractures correspond to supination-adduction fractures stage I in the Lauge-Hansen classification.

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1. 44-A1.1 Rupture of the lateral collateral ligaments
2. 44-A1.2 Avulsion of the tip of the lateral malleolus
3. 44-A1.3 Transverse fracture of the lateral malleolus

1. 44-A1.1 Rupture of the lateral collateral ligaments

44-A1.1

44-A1.1

In the subgroup A1.1 the lateral lesion is a rupture of the lateral collateral ligaments (ligamentum calcaneofibulare and ligamentum talofibulare anterius / posterius). The medial malleolus is intact.

44-A1.1 AP view

44-A1.1 AP view

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

2. 44-A1.2 Avulsion of the tip of the lateral malleolus

44-A1.2

44-A1.2

In A1.2 fractures, there is avulsion of the tip of the lateral malleolus. The medial malleolus is intact.

44-A1.2 AP view

44-A1.2 AP view

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

3. 44-A1.3 Transverse fracture of the lateral malleolus

44-A1.3

44-A1.3

Transverse fracture of the lateral malleolus below the syndesmotic ligament. The medial malleolus is intact.

44-A1.3 AP view

44-A1.3 AP view

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