The AO/OTA classification of malleolar segment fractures is one of the most frequently used systems for classifying malleolar fractures. It takes the Danis-Weber classification into account and can be correlated to the Lauge-Hansen classification.
Malleolar fractures are divided into three groups subject to the severity and complexity of the respective injury 1, 2:
-
type A: infrasyndesmotic fibular injury
-
A1: isolated lateral malleolar injury
corresponds to supination-adduction injury – Lauge-Hansen stage I
A1.1 lateral collateral ligament injury
A1.2 lateral malleolus tip avulsion
A1.3 isolated transverse infrasyndesmotic lateral malleolar fracture
-
A2: infrasyndesmotic fibular injury and medial malleolar fracture
A2.1 lateral collateral ligament injury and medial malleolar fracture
corresponds to supination-adduction injury – Lauge-Hansen stage II
A2.2 lateral malleolus tip avulsion and medial malleolar fracture
A2.3 transverse infrasyndesmotic lateral malleolar fracture
-
A3: infrasyndesmotic fibular injury with a posteromedial fracture
no injury pattern in Lauge-Hansen classification
A3.1 infrasyndesmotic fibular injury and posteromedial fracture
A3.2 lateral malleolus tip avulsion and posteromedial fracture
A3.3 transverse infrasyndesmotic and posteromedial fracture
-
-
type B: transsyndesmotic fibular fracture
-
B1: isolated transsyndesmotic fibular fracture
corresponds to supination-eversion injury – Lauge-Hansen stage I-II
B1.1 simple transsyndesmotic lateral malleolar fracture
B1.2 transsyndesmotic lateral malleolar fracture with anterior syndesmotic rupture
B1.3 wedge or multifragmentary transsyndesmotic lateral malleolar fracture
-
B2: transsyndesmotic fibular fracture with medial injury
corresponds to pronation-abduction injury – Lauge-Hansen stage I-III
B2.1 anterior syndesmotic rupture and deltoid ligament rupture
B2.2 anterior syndesmotic rupture and medial malleolar fracture
B2.3 wedge or multifragmentary transsyndesmotic fracture and medial injury
-
B3: transsyndesmotic fibular fracture with medial injury and posterolateral rim (Volkmann) fracture
B3.1 simple transsyndesmotic fracture with deltoid rupture and Volkmann fracture
B3.2 simple transsyndesmotic and medial malleolar fractures and Volkmann fracture
B3.3 wedge or multifragmentary transsyndesmotic, medial and Volkmann fracture
all but type B1.1 transsyndesmotic fibular fractures can be associated with Tillaux-Chaput tubercle fractures or Wagstaffe-Le Fort avulsions
-
-
type C: suprasyndesmotic injury
-
C1: simple suprasyndesmotic fibular diaphyseal fracture with one of the following:
correspond to pronation-eversion injury – Lauge-Hansen stage I-IV
C1.1 rupture of the deltoid ligament
C1.2 fracture of the medial malleolus
C1.3 medial malleolar and posterior rim (Volkmann) fracture
-
C2: wedge or multifragmentary suprasyndesmotic fibular diaphyseal fracture with the following:
C2.1 rupture of the deltoid ligament
C2.2 fracture of the medial malleolus
C2.3 medial malleolar and posterior malleolar (Volkmann) fracture
C1 and C2 lesions can be additionally subcategorised regarding syndesmotic stability
correspond to pronation-eversion injury – Lauge-Hansen stage I-IV
-
C3: proximal suprasyndesmotic injury with the following:
C3.1 medial injury: deltoid ligament rupture or medial malleolar fracture
C3.2 fibular shortening and medial injury
C3.3 medial injury and posterior malleolar (Volkmann) fracture
C3 fractures can be additionally subdivided concerning proximal fibular injury (fracture/tibiofibular joint dislocation) and medial injury (deltoid ligament rupture/malleolar fracture)
-
If isolated medial malleolar fractures and isolated posterior malleolar or Volkmann fractures are not associated with a lateral malleolar injury or a fibular fracture they are classified and coded as partial articular distal tibial end segment fractures 1.
Unable to process the form. Check for errors and try again.