AO/OTA classification of malleolar fractures

Last revised by Joachim Feger ◉ on 8 Jan 2022

Citation, DOI, disclosures and article data

Citation:

Feger J, Qureshi P, AO/OTA classification of malleolar fractures. Reference article, Radiopaedia.org (Accessed on 28 May 2023) https://doi.org/10.53347/rID-86633

DOI:

https://doi.org/10.53347/rID-86633

Permalink:

https://radiopaedia.org/articles/86633

rID:

86633

Article created:

7 Feb 2021, Joachim Feger ◉

Disclosures:

At the time the article was created Joachim Feger had no recorded disclosures.

View Joachim Feger's current disclosures

Last revised:

8 Jan 2022, Joachim Feger ◉

Disclosures:

At the time the article was last revised Joachim Feger had no recorded disclosures.

View Joachim Feger's current disclosures

Revisions:

8 times, by 2 contributors - see full revision history and disclosures

Systems:

Musculoskeletal, Trauma

Sections:

Classifications

Tags:

cases

Synonyms:

AO/OTA classification of distal fibular fractures
AO/OTA classification of malleolar segment fractures

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:

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.