Executive Editor: Peter Trafton

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

Acetabulum - Both column with ilioinguinal

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Glossary

1 Reduction by axial traction top

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Axial traction

The ilioinguinal approach is done with the patient supine on a radiolucent table or, preferably, a specially designed fracture table which is radiolucent and can apply adjustable traction laterally and distally.

Traction can be applied in several ways with:

  • the use of a fracture table that allows axial and lateral traction
  • the intermittent help of an assistant. This can be unreliable in long procedures

Apply axial traction to the lower limb, and lateral traction through the greater trochanter.
Both these forces should be tuned until the best effect is obtained.

Note
Excessive traction may limit fracture fragment mobility and interfere with reduction.

 

2 Reduction of the anterior column top

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Reduction of the iliac wing

Start reduction from the proximal aspect of the iliac wing. Reduce accessory fragments of the iliac wing, if present.
Reduction must be perfect, without even small step-offs, gaps, or angulation. Check the outer aspect of the iliac crest.
It is important to restore the normal curvature of the iliac wing, and not to straighten it excessively.
Pointed reduction forceps applied to the iliac crest can serve as handles for reduction, and also for temporary fixation.
Alternatively, apply a Farabeuf clamp over screws placed into the crest on each side of a fracture line.


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Fixation of the iliac wing

Iliac wing fractures can be fixed with lag screws (3.5 mm) near the crest.
Alternatively, one can use pelvic reconstruction plates applied to the inner surface of the iliac crest.


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Important free fragments

A free fragment, particularly in a posterior location, may act as a cornerstone. It may be used as a reference point for the anterior column. Such a fragment may be located near the SI joint.
Such fragments must be reduced anatomically. Manipulation with a dental pick and pressure with a ball tip pusher are helpful.
When successfully reduced, apply a short 3.5 mm lag screw fixing the ancillary fragment in its anatomical position.


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Restore the iliac fossa concavity

Restore the iliac fossa concavity by correcting external rotation and medial displacement of the deeper part of the anterior column fragment.
Rotate the iliac wing internally using a ball-tip pusher applied to the proximal posterior portion, near the pelvic brim, of the anterior column and a Farabeuf clamp positioned on the ASIS.
If indicated, use a Schanz screw that is driven into the AIIS combined with lateral traction on the femur to obtain the complete reduction.


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Use of a large symmetric reduction forceps (“King Tong”)

Additionally, or as an alternative, apply a large symmetric “King Tong” clamp around the anterior column and the fixed portion of the iliac wing to obtain correct rotation of the iliac wing and to restore the iliac fossa concavity.

 

Note
Excessive internal rotation will open the fracture on the opposite side.


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Option: Plate as a reduction aid

An alternative or supplementary aid to reduction is a plate attached to the stable, posterior part of the ilium. As its screws are tightened, the plate presses the anterior fragment into alignment. Use a precontoured 3-hole 3.5 mm LC-DC plate.
Place the distal part of the plate over the free anterior column fragment.
Fix the plate with two cortical screws into the stable portion of the iliac wing.


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Tightening the distal screws will reduce the anterior column to its anatomical position.


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Occasionally the reduction plate can be used for fixation by adding the third screw in the free anterior column fragment.

Final fixation with a long reconstruction plate along the pelvic brim may permit removal of the reduction plate.


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Usually the reduction plate is assisted with lateral femoral traction and the use of a Farabeuf clamp in the ASIS to obtain correct reduction.

3 Fixation of the anterior column top

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Components of fixation

One or more of the following fixation methods may be used, depending on the fracture configuration:

  • One or more long small fragment lag screws.
  • Small fragment lag screw(s) from the inner aspect of the fossa to the outer iliac wing fragment, crossing an oblique fracture. Fixation with such short screws may be tenuous.

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  • In the majority of cases, a pelvic brim buttress plate completes the construct.

 


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Iliac body screw

Stabilize the anatomically reduced anterior column to the iliac wing with one or more position or lag screws between the inner and outer cortex.
The trajectory of these screws begins lateral to the anterior inferior iliac spine (AIIS) and is directed into the posterior innominate bone, just lateral to the sacroiliac joint.


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Alternative screw placement

 

Note
Fixation stability may be compromised by screws perforating the inner or outer cortex too close to the fracture line. Remember the S-shape of the iliac wing.

4 Reduction of the posterior column top

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Introduction

Reduction of the posterior column can be achieved utilizing multiple techniques. Preliminary reduction is normally achieved by ligamentotaxis with distal and lateral traction through the femur. This can be augmented by placement of a small bone hook in the lesser sciatic notch. The hook can be used to laterally and anteriorly displace the posterior column. Further techniques are listed below.


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Use of asymmetric reduction forceps

Use asymmetric forceps to reduce the posterior column. Normally, this clamp is utilized through the first window of the ilioinguinal approach. The short arm of the forceps is placed on the stable anterior column through the interspinous notch or over the iliac crest.


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Clamp pressure on the quadrilateral surface is applied with the long arm of the forceps through a disk or reconstruction plate. This prevents clamp perforation in osteoporotic bone.
The plate can be used temporarily, or be incorporated into the final fixation.


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Additional reduction maneuvers

Posterior column reduction can also be achieved utilizing exposure through the second window. The most useful clamp for this application is the large offset quadrangular clamp.


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Third window reduction techniques are equivalent to those used with the modified Stoppa approach. The most direct technique uses pointed reduction forceps (Weber clamp) which spans from the pelvic brim to the quadrilateral surface portion of the posterior column.

5 Reduction of the low anterior column top

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Once the posterior column is definitively reduced, check and reduce the associated fracture lines of the distal portion of the anterior column, if indicated.
In cases where the anterior column fracture is segmental, careful reduction of the medial articular part is also needed. This is normally accomplished utilizing pointed reduction forceps as shown.


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To reduce the low anterior column, place pointed reduction forceps between the pubis and the outer iliac bone.

6 Fixation of the posterior column top

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Contour neutralization plate

Once the posterior column is reduced, a reconstruction plate is contoured to fit the pelvic brim. The plate must be long enough to provide adequate fixation of both posterior and anterior injuries. This typically requires extension to the pubic body. When the symphysis is disrupted, the plate is extended to the contralateral pubis.
Use of a malleable template aids plate contouring.
Because the primary purpose of this plate is to buttress the anterior column, posterior contouring is most critical. For this reason, plate fixation normally starts posteriorly and proceeds anteriorly. Final adjustment of the plate profile can be achieved in situ, due to plate malleability.

Tools for in-situ plate contouring include the ball spike for pushing, ...


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... and large and small fragment screwdrivers for torsional adjustment.

Apply the plate along the pelvic brim spanning from the innominate bone adjacent to the sacroiliac joint to the pubis.


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Plate fixation

The posterior screws are placed parallel to the SI joint, anchor the plate to the sciatic buttress, and provide an additional reduction-assist as well as definitive buttress function.


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Stabilize the posterior column with a lag screw

When possible, it is desirable to place the posterior column fixation through the pelvic brim plate. The most posterior screw (ca. 80 mm) is directed toward the ischial spine. It is usually possible to place a second screw (ca. 100 mm) in the next anterior plate hole, directed toward the ischial tuberosity.

7 Evaluation of posterior column screw position top

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AP view

In this view, the screw should be parallel and very close to the ilioischial line.


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Iliac oblique view

In this projection, the screw lies inside the posterior column.
It is clearly outside the joint, although very close to the acetabular fossa.


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Obturator oblique view

The projection of the screw should aim at the ischium.
The most common mistake is to drive the screw in the direction of the posterior wall.
Screws that penetrate the posterior column cortex may injure the sciatic nerve.

8 Anterior fixation of pelvic brim plate top

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After the anterior portion of the pelvic brim plate has been satisfactorily contoured, it can be used to stabilize the low anterior column fracture extension (extraarticular).


Additional screws in the medial superior ramus and pubic body are inserted as needed.

9 Fixation of the posterior wall fragment top

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The association of a posterior wall fracture with a primary both-column pattern is a relatively common variant.
Posterior wall fractures with supraacetabular extension in some cases can be reduced by limited external iliac exposure and clamp or ball spike placement. Rarely, percutaneous reduction is successful. To do this, insert a ball spike through the soft tissues until it reaches the fragment.

Verify the reduction with obturator oblique imaging.

Once the fragment is reduced, place an interfragmentary screw from the internal iliac fossa into the posterior wall fragment.
If a satisfactory reduction of the posterior wall can not be achieved with these techniques, a second posterior approach is required.

v1.0 2007-07-22