Authors of section

Authors

Alex Vaccaro, Frank Kandziora, Michael Fehlings, Rajasekaran Shanmughanathan

Executive Editor

Luiz Vialle

General Editor

German Ochoa (in memoriam)

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Percutaneous posterior approach for pedicle screw placement

1. Skin incision

The skin incision is lateral to the image projection of the pedicle. The distance from the skin incision to the image projection varies depending on the various levels of the spine. It also depends on the convergence of the pedicles.

It is necessary to confirm the correct level of the approach with fluoroscopy.

mis posterior short segment fixation with schanz pins

In the middle thoracic spine, the skin incision is close to the image projection of the pedicle in the upper thoracic, and in the lumbar spine it is more lateral.

percutaneous posterior approach for pedicle screw placement

2. Exposure

Using scissors, a blunt dissection of the subcutaneous tissue, the fascia, and the muscles is performed down to the bony structures of the vertebra.

percutaneous posterior approach for pedicle screw placement

Cannulated needles are inserted both at a 3 o' clock on the right side and a 9 o' clock position on the left side.

percutaneous posterior approach for pedicle screw placement

The cannulated needles are tapped in until they reach the medial border of the pedicle image projection.

percutaneous posterior approach for pedicle screw placement

A lateral X-ray is then performed.

If the tip of the needle has not passed the posterior wall of the vertebral body in the lateral projection, retract and reposition the needle.

percutaneous posterior approach for pedicle screw placement

If the tip of the needle has passed the posterior wall of the vertebral body in the lateral projection, the needle can be advanced to the center of the vertebral body.

percutaneous posterior approach for pedicle screw placement

A K-wire is introduced via the cannulated needle. Then, the cannulated needle is removed leaving the K-wire in place.

percutaneous posterior approach for pedicle screw placement

After dilatation of the soft tissue, the cannulated pedicle screw is inserted over the k-wire.

percutaneous posterior approach for pedicle screw placement

These steps are repeated, depending on the number of vertebrae that have to be instrumented.

percutaneous posterior approach for pedicle screw placement

3. Rod placement

The rod is placed percutaneously. Depending on the used instrumentation, different techniques are in use.

percutaneous posterior approach for pedicle screw placement

4. Wound closure

The wound is closed in layers.

percutaneous posterior approach for pedicle screw placement