Judet and Letournel classification for acetabular fractures
The Judet and Letournel classification is the most widely used classification system for acetabular fractures. It classifies acetabular fractures into ten major fracture patterns, which consist of five simple patterns and five complex patterns .
Classification
The morphology of fracture patterns is described from the point of view of looking at the acetabulum en face from the lateral side. Structures that are key to the classification are the anterior and posterior walls (rims) of the acetabulum and the anterior (iliopubic) and posterior (ilioischial) columns of the innominate bones, including their confluence at the sciatic buttress and the quadrilateral plate.
Elementary (simple) patterns
The elementary (or elemental) patterns fracture the innominate bone through the acetabulum into two major fragments. There are five types:
- 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, fracture line begins below the anterior inferior iliac spine
- medially, 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
- 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, 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, 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
- 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, obturator ring remains intact, unlike T-shaped or column fractures
- subclassified by level relative to acetabular roof :
- transtectal: traverses weight-bearing dome
- juxtatectal: traverses the junction of the acetabular (cotyloid) fossa and articular surface of the acetabular roof
- infratectal: traverses the acetabular fossa and anterior and posterior horns of the acetabular articular surface
- 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 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
- 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:
- 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
- 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, fracture line rises variably superiorly to the anterior inferior iliac spine up to 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 level of ischial spine up to 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)
- fractures detaching two inferior (ischiopubic) fragments, one anterior and one posterior, from the rest of the innominate bone
- superiorly, transverse fracture line is similar to the elemental transverse fracture, although the anterior and posterior components may not have a common orientation
- inferiorly, 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
- 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 transtectal, juxtatectal or infratectal 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
- 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.
Letournel et al. presented a grouping in later work :
Groups of Brandser and Marsh
Note some fracture types fall under more than one group :
Algorithm of Scheinfeld et al.
This grouping is derived from a three-level diagnostic algorithm based on fracture morphology :
- posterior wall
- both column
- anterior column
- anterior wall
- anterior column/wall with posterior hemitransverse
- posterior column
- posterior column with posterior wall
- transverse
- T-shaped
- transverse with posterior wall
Epidemiology
The most frequent types, accounting for more than 80% of fractures, are posterior wall, both column, and transverse + posterior wall, followed by T-shaped and transverse . Thus, about one-half of acetabular fractures contain a posterior wall component .
Radiographic features
Plain radiograph
The classification was originally based on three radiographic views (anteroposterior view and two Judet views: obturator oblique view and iliac oblique view).
- fractures involving the anterior column (anterior wall, anterior column, transverse, and all associated patterns except posterior column + posterior wall fracture) disrupt the iliopectineal line
- fractures involving the posterior column (posterior column, transverse, and all associated patterns) disrupt the ilioischial line
- column and T-shaped fractures disrupt the obturator ring
- wall fractures disrupt the corresponding acetabular rim
CT
CT with multiplanar reformations or 3D volume rendering may improve accuracy . As the acetabulum is oriented obliquely, such that the face points slightly anterior and inferior to the true lateral side of the patient, a rotatable 3D rendering with the femur virtually removed is needed to recapitulate the classic diagrams and terminology of the Judet-Letournel classification.
On axial CT images (i.e., in the anatomic transverse plane), at the level of the acetabular roof, various families of fractures have different orientations :
- transverse fracture lines appear sagittal
- column fracture lines appear coronal
- wall fractures appear oblique
Treatment and prognosis
Treatment selection depends on joint stability, fragment size and comminution, and age/comorbidities. The most commonly preferred treatment varies by fracture classification :
- anterior wall: nonoperative treatment
- anterior column, both column, anterior column and posterior hemitransverse, T-shaped: open reduction and internal fixation via modified Stoppa or ilioinguinal approach
- posterior wall, posterior column, transverse and posterior wall, posterior column and posterior wall: open reduction and internal fixation via Kocher-Langenbeck approach
- transverse: open reduction and internal fixation with approach depending on whether predominant direction of displacement is anterior (modified Stoppa) or posterior (Kocher-Langenbeck)
Extensive comminution or displacement of both anterior and posterior fragments may require sequential surgeries (anterior and posterior) or, less commonly, an extended iliofemoral approach .
The fracture type with the worst prognosis is the associated transverse and posterior wall fracture, due to the high incidence of sciatic nerve palsy and osteonecrosis of the femoral head .
History and etymology
The classification was first reported in 1964 by Professor Robert Judet (1909-1980), Dr Jean Judet (1905-1995), and Dr Émile Letournel (1927-1994), who were orthopedic surgeons in Paris, France . Robert and Jean were brothers .
