AOSpine Needs Assessment

Help shape the future of AOSpine education

If you are not a member but would like to contribute by telling us about your educational needs, please enter your e-mail address by using the button below and we will contact you.
Thank you for your valuable input.

Pipsa Ylanko, AOSpine Global Education Manager

General Editor: Luiz Vialle

Authors: Carlo Bellabarba

Sacral trauma - C3 Spinopelvic fixation

back to Spine overview

Glossary

1 Introduction top

enlarge

NOTE: This procedure should only be performed by highly trained surgeons.

Lumbo-sacral dissociation is caused by high energy and is commonly associated with other fractures as well as neurological deficit.

It is essentially a multiplanar sacral fracture with vertical and horizontal components (C3 fractures), which results in detachment of the lumbo-sacral spine from the pelvic ring.

This injury can be viewed as having two primary fracture "fragments":

  1. The upper central sacrum and remainder of the spine
  2. Lower and peripheral sacrum and the attached pelvis

The sacrum is the lowest part of the spine and the fracture has the characteristics of spinal fractures.

A multidisciplinary approach is highly advisable.

For the fixation, knowledge of both spinal and pelvis fixation techniques is necessary. In cases of neurological deficit, decompression of sacral nerve roots is mandatory.


enlarge

The fixation should ideally allow early mobilization; even for patients with neurological deficits.

In cases of large displacement, reduction is difficult and great care should be taken to avoid further damage to the neurological structures.

With minimal displacement in the absence of neurological deficit, fixation in situ is recommended.

Spino-pelvic fixation allows a complete exclusion of the fractured sacrum from weight bearing.

The essence of this procedure is to provide a rigid fixation to protect healing, allow rapid mobilization and avoid pseudoarthrosis.

Although some malunion can be accepted, care should be taken to avoid significant leg length discrepancy and spinal sagittal malalignment.

2 Neural decompression top

enlarge

If open reduction and foraminotomy are required, after exposure is completed, identify and remove small bony fragments from the comminuted fracture zone. They may be located in the transforaminal region and may hinder fracture reduction.


enlarge

The complete fracture line has to be cleaned out and inspected.

Enhance the exposure by using a lamina (bone) spreader.

Extract fragments that may compromise the sacral nerve roots.


enlarge

Additional foraminal patency can be achieved with the use of Kerrison rongeurs or high speed rotational burr to expand the nerve root channel.

3 Reduction top

enlarge

ISS fixation requires an essentially anatomically reduced sacral fracture. Significant residual displacement renders this procedure unsafe.

Displacement may make it impossible to accomplish ISS fixation without causing nerve root injury or resulting in an extraosseous screw that threatens adjacent neurovascular structures.

If displacement remains significant after closed reduction, open reduction should be considered.


enlarge

Reduction of type C3 injuries depend on the ability to obtain appropriate fracture length and alignment.


enlarge

Restoration of length

Approximately 10 Kg of traction applied to a distal femoral traction pin usually suffices.

It is important to avoid pressure by the traction bow on the peroneal nerve at the level of the fibular head.

  • ####More details on skeletal traction can be found here.####

enlarge

If additional length across the spinopelvic junction is needed, Schanz pins are inserted into the L5 pedicle and ilium, with the same technique and trajectory as the final spinopelvic fixation screws. The universal distractor is placed over these pins to achieve the desired length.

Note

Good bone quality is required for this technique to be effective. It is not recommended for patients with metabolic bone disease.


enlarge

Reduction of anterior dislocation

After ####sacral laminectomy####, elevators are placed between the sacral nerve roots into the fracture.


enlarge

The fracture is further mobilized by prying apart.


enlarge

A 4.0 mm Schanz pin is placed in between the S1 and S2 nerve roots into the upper sacrum to act as a joystick.


enlarge

The Schanz pin can be used to translate and rotate the upper sacrum as desired to achieve reduction.


enlarge

Reduction of posterior dislocation

After ####sacral laminectomy####, elevators are placed between the sacral nerve roots into the fracture.

The fracture is further mobilized by prying apart.

Once the curved elevator has accessed the length of the fracture it may be rotated 180 ° around its axis before prying to further improve alignment.


enlarge

A 4.0 mm Schanz pin is placed in between the S1 and S2 nerve roots into the upper sacrum to act as a joystick.


enlarge

A ball spike pusher is placed between the nerve roots onto the dorsum of the lower sacrum to translate the lower sacrum anteriorly while the Schanz pin is used to translate the upper sacrum posteriorly and rotate as desired to achieve reduction.

4 Insertion of the IS screws top

enlarge

Before beginning an ISS screw fixation procedure, appropriate preoperative planning for screw type and location needs to be completed.

Following reduction, the IS screw is inserted.

5 Insertion of the pedicle screws top

enlarge

Pedicle screws are inserted bilaterally in L5 and connected with the rod. If there is concern regarding fixation to L5, then more cranial fixation levels can be added.

6 Iliac screw insertion top

enlarge

Iliac screws are inserted in either of the three potential locations

7 Insertion of the connection rod top

enlarge

It is important that the iliac screw heads and connecting rods lie flush to the bone. Avoiding prominent hardware prevents soft tissue irritation.

With a sacral entry point for the iliac screw there is less concern with screw prominence compared to iliac starting points.

Cut the permanent rods to the appropriate length. Attach it to the screws per the hardware system.

This technique is most reliable when reduction has already been achieved and provisionally stabilized for example with iliosacral screws. Spinopelvic fixation is therefore primarily being used as neutralization construct.

However, additional contouring of the rod may be necessary to achieve indirect reduction. This might consist of both under and over bending.

The final rod is prepared and attached to the pedicle screws bilaterally.


enlarge

The construct should be further stabilized by the insertion of 1-2 transverse connectors at the level of the sacrum.

8 X-rays top

enlarge

After completion of internal fixation, confirm the final reduction and hardware position intraoperatively by AP, inlet and outlet radiographic imaging.

v1.0 2016.01.01