AO/OTA classification of acetabular fractures

Last revised by Dr Joachim Feger on 06 Sep 2021

The AO/OTA classification is one of the most frequently used systems for classifying acetabular fractures. Like other fractures, they are divided into three groups subject to the severity and complexity of the respective injury 1.

  • type A: partial articular isolated wall or column fracture
    • A1: posterior wall fracture with or without marginal impaction
      • A1.1 simple fracture
      • A1.2 multifragmentary fracture
    • A2: posterior column fracture
      • A2.1 with ischial bone involvement
      • A2.2 with obturator ring involvement
      • A2.3 with simple or multifragmentary posterior wall fracture and possible marginal impaction
    • A3: anterior wall or column fracture with or without marginal impaction
      • A3.1 anterior wall fracture
      • A3.2 high anterior column fracture through the iliac crest
      • A3.3 low anterior column fracture below the anterior superior iliac spine
  • type B: partial articular transverse type fracture
    • B1: transverse fracture ± posterior wall fracture ± marginal impaction
      • B1.1 infratectal fracture
      • B1.2 juxtatectal fracture
      • B1.3 transtectal fracture
    • B2: T-fracture ± posterior wall fracture ± marginal impaction
      • B2.1 infratectal fracture
      • B2.2 juxtatectal fracture
      • B2.3 transtectal fracture
    • B3: posterior hemitransverse and anterior wall or column fracture
      • B3.1 anterior wall fracture
      • B3.2 high anterior column fracture through the iliac crest
      • B3.3 low anterior column fracture below the anterior superior iliac spine
  • type C: simple or multifragmentary complete articular both column fracture
    • C1: high anterior column fracture
    • C2: low anterior column fracture
    • C3: sacroiliac joint involvement

ADVERTISEMENT: Supporters see fewer/no ads

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.