Judet and Letournel Classification (Acetabular Fracture)

Elementary (simple) patterns

The elementary (or elemental) patterns fracture the innominate bone through the acetabulum into two major fragments. There are five types:

Anterior wall fracture

• segmental fracture of the middle third of the anterior column, detaching a trapezoidal fragment that contains the anterior acetabular wall from the rest of the innominate bone superiorly, the fracture line begins below the anterior inferior iliac spine medially, the fracture line involves the anterior quadrilateral plate, so this pattern excludes isolated fractures of the anterior acetabular rim inferiorly, fracture line exits at the superior pubic ramus, distinguishing this pattern from anterior column fracture.

Anterior column fracture

• segmental fracture of the anterior column that crosses the obturator foramen, detaching a fragment that contains the anterior acetabular wall and most of the pubis from the rest of the innominate bone
• superiorly, the fracture line begins variably in the anterior ilium?:
  • high: iliac crest
  • intermediate: between anterior iliac spines (anterior interspinous notch)
  • low: below the anterior inferior iliac spine (psoas gutter)
  • very low: anterior horn of the acetabular articular surface to the junction of ilium and pubis (iliopectineal eminence)
  • medially, the fracture line involves the quadrilateral plate in a coronal orientation
  • inferiorly, fracture line exits at the ischiopubic ramus, distinguishing this pattern from anterior wall fracture

Transverse fracture

• fracture across both columns of the acetabulum, separating the inferior (ischiopubic) and superior (iliac) portions of the innominate bone superiorly, superior portions of both columns remain connected to the sciatic buttress (fracture line does not extend superiorly to anterior or posterior iliac surfaces), unlike column fractures inferiorly, the obturator ring remains intact, unlike T-shaped or column fractures
• subclassified by level relative to the acetabular roof :
  • transrectal: traverses weight-bearing dome
  • juxtatectal: traverses the junction of the acetabular (cotyloid) fossa and articular surface of the acetabular roof
  • intrarectal: traverses the acetabular fossa and anterior and posterior horns of the acetabular articular surface

Posterior column fracture

• segmental fracture of the posterior column that crosses the obturator foramen, detaching a fragment that contains the posterior acetabular wall and most of the ischium from the rest of the innominate bone superiorly, fracture line enters at the greater sciatic notch, sparing iliac wing medially, fracture line passes through the acetabular roof and involves the quadrilateral plate in a coronal orientation inferiorly, fracture line exits through ischiopubic ramus or, uncommonly, splits the ischial tuberosity without disturbing the obturator foramen.

posterior wall fracture

• fracture detaching fragment(s) consisting of the posterior articular surface and/or the weight-bearing dome from most of the posterior column, but sparing the quadrilateral plate only pattern in the Judet-Letournel classification that spares the quadrilateral plate N.B. this is an asymmetric definition compared to anterior wall fractures, which do involve the medial acetabular surface includes pure superior rim fractures

Associated (complex) patterns

The five complex patterns break the acetabulum into three major fragments and may be described as combinations of elementary fracture components:

both-column fracture

• fractures detaching most of the anterior column and, separately, most of the posterior column, from the posterior iliac wing entire weight-bearing portion of the acetabulum, is disconnected from the sciatic buttress acetabular roof mostly remains with the anterior column fragment(s) superiorly, two fracture lines enter in perpendicular fashion, one posteriorly (usually at the greater sciatic notch) and one anteriorly or superiorly (anterior ilium or iliac crest) above the acetabulum, descending fracture lines merge in coronal orientation inferiorly, fracture line exits at the ischiopubic ramus.

anterior column/wall and posterior hemitransverse fracture

• fractures detaching a segment of the anterior column and, separately, the inferior part of the posterior column, from the posterior iliac wing part of the acetabular dome remains connected to the sciatic buttress, unlike in both-column fracture superiorly, two fracture lines enter in perpendicular fashion, one posteriorly and one anteriorly or superiorly ^​anteriorly, the fracture line rises variably superiorly to the anterior inferior iliac spine up to the iliac crest, unlike in T-shaped fracture where the fracture line is a straight continuation of the posterior transverse component posteriorly, fracture line follows an oblique sagittal orientation and variably extends to the level of the ischial spine up to the greater sciatic notch, unlike in T-shaped fracture in the quadrilateral plate, fracture lines meet at a right angle inferiorly, fracture line exits superior pubic ramus (anterior wall fracture) or ischiopubic ramus (anterior column fracture)

T-shaped fracture

• fractures detaching two inferior (ischiopubic) fragments, one anterior and one posterior, from the rest of the innominate bone superiorly, the transverse fracture line is similar to the elemental transverse fracture, although the anterior and posterior components may not have a common orientation inferiorly, the vertical stem of the fracture line crosses the acetabular fossa and then either across the obturator foramen or, uncommonly, through the ischium alone includes associated posterior column with anterior hemitransverse fractures includes associated transverse with anterior wall fractures.

Transverse and posterior wall fractures

• fractures detaching the inferior (ischiopubic) portion of the innominate bone and, separately, one or multiple fragments of the posterior acetabular wall morphologically equivalent to elemental transverse fracture (with transrectal, juxtatectal or intrarectal course) that begins in a notch created by the separation of one or multiple posterior wall fragment(s) includes associated T-shaped and posterior wall fractures

Posterior column and posterior wall fractures

• fractures detaching most of the ischium from the rest of the innominate bone and, separately, one or multiple fragments of the posterior acetabular wall (posterior articular surface and acetabular rim) morphologically equivalent to the combination of elemental posterior wall fracture and elemental posterior column fracture, except the posterior column fracture is often partial, with the fracture line extending to the roof of the obturator foramen (ischiopubic notch) but sparing the ischiopubic ramus.

Grouping

Various authors have proposed groupings of the classification of Judet and Letournel that simplify the approach to facilitate radiological diagnosis for nonexpert observers.

Groups of Letournel et al.

Letourneau et al. presented a grouping in later work:

1. fractures involving posterior column only
   1. posterior column
   2. posterior wall
   3. posterior wall and posterior column
2. fractures involving both columns
   1. transverse
   2. transverse and posterior wall
   3. both-column
   4. T-shaped; posterior column and anterior hemitransverse
   5. anterior column and posterior hemitransverse; anterior wall and posterior hemitransverse
3. fractures involving anterior column only
   1. anterior column
   2. anterior wall; anterior wall and anterior column

Groups of Brandser and Marsh

Note some fracture types fall under more than one group:

1. wall fractures
   1. posterior wall
   2. a posterior column with posterior wall
   3. transverse with posterior wall
   4. anterior wall
2. column fractures
   1. posterior column
   2. anterior column
   3. both-column
   4. a posterior column with posterior wall
   5. anterior column with posterior hemitransverse
3. transverse fractures
   1. T-shaped
   2. transverse with posterior wall
   3. transverse
   4. anterior column with posterior hemitransverse

Algorithm of Scheinfeld et al.

This grouping is derived from a three-level diagnostic algorithm based on fracture morphology:

1. fracture line only through posterior acetabular rim (posterior wall fracture)
   • posterior wall
2. fracture line through superior acetabulum and quadrilateral plate (column fractures and anterior wall fracture)
   1. entire acetabulum detached from the sciatic buttress
      • both column
   2. anterior column detached from the sciatic buttress
      • anterior column
      • anterior wall
      • anterior column/wall with posterior hemitransverse
   3. posterior column detached from the sciatic buttress
      • posterior column
      • a posterior column with posterior wall
3. fracture splitting acetabulum into superior and inferior parts (transverse fractures)
   • transverse
   • T-shaped
   • transverse with posterior wall

References