Executive Editor: Peter Trafton

Authors: Keith Mayo, Michel Oransky, Pol Rommens, Carlos Sancineto

Acetabulum - Anterior column/posterior hemitransverse

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Glossary

1 General considerations top

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Definition

In this group of acetabular fractures, an anterior column fracture is associated with a transverse fracture across the posterior column.
Typically with these fractures, the femoral head is medially subluxed.
Variations within the anterior column/posterior hemitransverse fracture type depend upon where the anterior column fracture exits from the iliac bone - low, intermediate, or high .

The posterior column fracture may cross the greater sciatic notch at a variable level.

The posterior column fracture morphology usually follows an oblique sagittal orientation unlike the posterior column involvement in a T-shape fracture.


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Approach

The fractures are operated via an ilioinguinal approach.

This group of fractures is usually more easily treated using a fracture table which allows lateral traction.

This technique provides the ability to reduce the femoral head to an anatomic position with traction and then reconstruct the major joint fragments around the head.

2 Cleaning of the fracture site top

Preliminary increase the displacement

Fracture sites are prepared by preliminarily increasing the displacement and then removing early callus and granulation tissue.

Manipulation aids which are useful in this regard are a Schanz screw or Farabeuf clamp for the anterior column, and direct displacement with the femoral head for the posterior column.


Loose bodies and marginal impaction

In some cases loose bodies and areas of joint depression can be addressed through either the anterior or posterior column fracture planes.

When this is not possible, it may be necessary to create a small window under fluoroscopic control for the purpose of disimpacting depressed joint segments.

3 Anterior column: reduction strategies top

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When fracture line extends to the crest

Reduction always starts with the anterior column first.

When the anterior column fracture extends to the iliac crest, reduction is most easily achieved by use of a Farabeuf clamp or a Schanz screw which are used to correct the primary coronal and sagittal plane displacements.


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When fracture is incomplete

In some cases the anterior column fracture is incomplete at the crest and must be osteotomized in order to facilitate the reduction.

 


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This Schanz screw has been placed in the anterior inferior iliac spine (AIIS) for manipulation which will be possible after the fracture line has been completed with an osteotomy to the iliac crest.


When fracture exits inferior to the crest

In patterns where the anterior column fracture exits inferior to the crest, reduction strategies are more limited.

In these cases lateral traction through the proximal femur is even more important. The effect of indirect reduction via the capsule and labrum is critical in these cases.


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Reduction tools

If the anterior column fragment is large enough, it may be possible to use a percutaneous Schanz screw, a picador, or reduction clamp through the first window of the ilioinguinal approach which spans to the external aspect of the intact ilium.

When the fracture obliquity permits, a tong clamp can be used which spans from the internal iliac fossa to the external ilium utilizing a limited external iliac exposure.

It is frequently necessary to use several of these reduction techniques in concert to achieve an anatomic reduction.

The image shows a Schanz screw inserted through the first window.


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Picador inserted through first window


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Weber clamp inserted through first window


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Tong inserted through first window


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Reduction with plate

Lastly, plate reduction techniques are extremely useful in this fracture pattern.

A pelvic brim plate is applied initially posteriorly, exerting a reduction force on the anterior column as the screws are tightened.


Note

It is frequently necessary to use several of these reduction techniques in concert to achieve an anatomic reduction.

4 Anterior column: fixation top

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Plate and screw fixation

Stabilization of the anterior column normally starts peripherally, with the crest, and can be achieved with either screws or reconstruction plates.

This is usually augmented by a buttress plate placed along the pelvic brim extending from the area lateral to the sacroiliac joint to the superior pubic ramus.


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Use of lag screws as single fixation technique

In some cases it is possible to achieve stable fixation with lag screw technique alone.

 

 

5 Posterior column: reduction strategies top

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Instruments for reducing the posterior column

Following reduction and provisional or definitive stabilization of the anterior column, the posterior column can then be addressed.
Preliminary correction of the posterior column displacement is achieved with lateral traction in most cases, but it usually must be adjusted to be truly anatomical.

The final reduction usually involves a clamp which straddles the iliac crest, from the quadrilateral surface internally to the lateral aspect of the ilium, or the anterolateral surface of the iliopectineal eminence.

A number of clamps are useful for this purpose, including the pointed reduction (Weber) clamp, the offset quadrangular clamps, or the large asymmetric pelvic reduction forceps.


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A number of clamps are useful for this purpose, including the pointed reduction (Weber) clamp, the offset quadrangular clamps, or the large asymmetric pelvic reduction forceps.

The image shows a quadrangular clamp through the second window.


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Weber clamp inserted through the third window.


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Access

The soft tissue access for application of these clamps is dependent to some degree on the positioning of the patient and use of the fracture table.

The exposure through the first window of the ilioinguinal is limited on the fracture table by the inability to flex the hip beyond 25 degrees.

This makes it impossible to release the tension on the iliopsoas and gain optimum access to the quadrilateral surface.

Clamps through 1st ilioinguinal window

The asymmetric tong reduction clamp is usually used in the first window.

The articulated disk may (be needed to prevent) may prevent the clamp perforation of osteoporotic bone.

Note
In cases where first window exposure is inadequate, the asymmetric clamp can be used to span to the second window.


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Clamps through 2nd ilioinguinal window

In this case, the reduction clamps can be placed completely within the second window or from the lateral ilium to the quadrilateral surface.

Caution
Placement of clamps through the second window requires the utmost caution and should be limited to brief periods.


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Reduction forceps through 3rd ilioinguinal window

Lastly, it is possible to reduce the posterior column from the third window of the ilioinguinal approach by passing a pointed reduction forceps from the midline laterally to span from the internal iliac fossa to the quadrilateral surface.

6 Posterior column: fixation top

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Screw fixation

Fixation of the posterior column is usually provided by lag or position screws which are inserted from the pelvic brim into the safe zone that extends from the cranial limit of the greater sciatic notch distally to the ischium, depending on the starting point.

 


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Screw directions

The location of the posterior column fracture line relative to the iliopectineal line will affect screw placement and direction. Generally, screws will be placed through the pelvic brim plate and perpendicular to the fracture plane.

In some cases with fracture obliquity, it is best for the screws to actually perforate the quadrilateral surface, or even be inserted percutaneously from the lateral aspect of the ilium.


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Spring plate

Quadrilateral surface comminution can be stabilized with the use of a supplemental spring plate.

This plate is generally applied beneath a spanning pelvic brim plate.


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Pelvic buttress plate

A plate can be placed on the quadrilateral surface to buttress comminution or counteract posterior column medial displacement.

This plate is mutually fixed into the dense bone in the sciatic buttress just anterior to the SI-joint.

In addition, one or two screws can also be placed in the posterior portion of the plate taking care to avoid joint penetration.

This plate is placed under direct visualization thought the third window of the ilioinguinal approach.

v1.0 2007-07-22