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Percutaneous Transpedicular Fixation: Technical tips and Pitfalls of Sextant and Pathfinder Systems.

Mohi Eldin MM, Hassan AS - Asian Spine J (2016)

Bottom Line: Fluoroscopy-guided percutaneous placement of pedicle screws is effective.Operative techniques are discussed and the results compared.Fluoroscopy-guided percutaneous pedicular screws are feasible and can be safely done.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurosurgery, Faculty of Medicine, Cairo University, Cairo, Egypt.

ABSTRACT

Study design: The efficacy of the operative techniques, possible benefits as well as pitfalls and limitations of the techniques are discussed. Potential drawbacks are also detected.

Purpose: This study aims to report indications, techniques, and our experience with the use of the Sextant and PathFinder percutaneous transpedicular screw fixation systems.

Overview of literature: Percutaneous pedicle screw insertion is a novel technique. Successful percutaneous placement of pedicle screws requires surgical skill and experience because of lack of anatomic surface landmarks. Fluoroscopy-guided percutaneous placement of pedicle screws is effective. Many systems are now available.

Methods: We conducted a prospective operative and postoperative analysis of 40 patients with absolute indication for thoracic or lumbar instability between January 2009 and June 2013. All procedures were performed with the Sextant (group A) and PathFinder (group B) systems under fluoroscopic guidance. Operative techniques are discussed and the results compared.

Results: Percutaneous transpedicular screw fixation minimizes the morbidity associated with open techniques without compromising the quality of fixation. A total of 190 screws were inserted. There was no additional morbidity. Postoperative computed tomography images and plain X-rays were analyzed. Reduction of visual analog scale scores of back pain was evident.

Conclusions: Fluoroscopy-guided percutaneous pedicular screws are feasible and can be safely done. Current systems allow multi-segmental fixation with significantly less difficulties. The described techniques have acceptable intra- and postoperative complication rates, and overall sufficient pain control with early mobilization of patients.

No MeSH data available.


Related in: MedlinePlus

The instruments are removed and skin incisions closed.
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Figure 9: The instruments are removed and skin incisions closed.

Mentions: The patient is positioned prone on a radiolucent frame. Attention is paid to ensure that lordosis is maintained, that all bony prominences are padded, and that the abdomen remains freely suspended. The arms are abducted and placed on padded boards. The legs are maintained in extension. A standard dose of Ceftriaxone (Rocephin) 1 g is administered intravenously before the skin incision. Anteroposterior (AP) and lateral fluoroscopic images are obtained, and the vertebrae to be instrumented are determined with the C-Arm and the midline, lateral pedicular, and interpedicular lines marked on the skin. We recommend a more lateral incision lateral to the border of the pedicle on AP imaging for percutaneous transpedicular placement, especially in lumbar vertebrae, to create the right trajectory for placement of instrumentation. The incision should be sufficient to accommodate the screw extender used with the system. A transpedicular channel is created using the Jamshidi needle under AP and lateral fluoroscopic guidance into the upper outer quadrant of the pedicle. The needle is advanced using a mallet into the pedicle approximately 30 mm into the bone, with care taken not to advance across the medial border (Fig. 2). Guide wires are subsequently inserted into the pedicles through the needles. Insertion is confirmed fluoroscopically. After removal of the needles, atraumatic dilatation of the paraspinal muscles is done using special serial dilators followed by screw extenders over the guide wires. The small and medium dilators are removed, leaving the final dilator (screw extenders) in place. The pedicles and proximal half of the vertebral body are tapped with a cannulated tap. Subsequently, the dilators are removed and the cannulated screws are introduced over the guide wires into their trajectory (Fig. 3). The guide wires are removed, possibly using a Kocher, after the pedicle screw is placed beyond the pedicle. All procedures are done under lateral fluoroscopy. For the Sextant system, the screw extenders are lined up, and a rod measuring device is used to measure the appropriate rod length (Fig. 4). The rod inserter is attached to the screw extenders and the rods are inserted percutaneously using the free-hand technique through a small incision rostral to the proximal screw incision, and passing through the screw head extenders of the proximal and caudal screws (Figs. 5, 6). The screws are then compressed, tightened, and broken off according to the appropriate torque of the locking caps (Fig. 7). For the PathFinder system, bending of the rod prior to implantation is required. The screws are attached to C-shaped towers, a slotted extender sleeve that attaches securely to the screw heads and extends above the skin. The rod is then passed down and implanted through connecting the screw snap incisions into one single incision on each side. It is through those towers that the rod is delivered into the screw head deep in the tissue and tightened in place with set screws (Fig. 8). Reduction and compression can then be performed. Finally, the instruments are removed and skin incisions closed (Fig. 9). When decompression of neural structures is needed, it is limited to the affected levels using the miniopen approach. In this approach, percutaneous instrumentation minimizes the skin incision length and muscle dissection (Fig. 10).


Percutaneous Transpedicular Fixation: Technical tips and Pitfalls of Sextant and Pathfinder Systems.

Mohi Eldin MM, Hassan AS - Asian Spine J (2016)

The instruments are removed and skin incisions closed.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4764522&req=5

Figure 9: The instruments are removed and skin incisions closed.
Mentions: The patient is positioned prone on a radiolucent frame. Attention is paid to ensure that lordosis is maintained, that all bony prominences are padded, and that the abdomen remains freely suspended. The arms are abducted and placed on padded boards. The legs are maintained in extension. A standard dose of Ceftriaxone (Rocephin) 1 g is administered intravenously before the skin incision. Anteroposterior (AP) and lateral fluoroscopic images are obtained, and the vertebrae to be instrumented are determined with the C-Arm and the midline, lateral pedicular, and interpedicular lines marked on the skin. We recommend a more lateral incision lateral to the border of the pedicle on AP imaging for percutaneous transpedicular placement, especially in lumbar vertebrae, to create the right trajectory for placement of instrumentation. The incision should be sufficient to accommodate the screw extender used with the system. A transpedicular channel is created using the Jamshidi needle under AP and lateral fluoroscopic guidance into the upper outer quadrant of the pedicle. The needle is advanced using a mallet into the pedicle approximately 30 mm into the bone, with care taken not to advance across the medial border (Fig. 2). Guide wires are subsequently inserted into the pedicles through the needles. Insertion is confirmed fluoroscopically. After removal of the needles, atraumatic dilatation of the paraspinal muscles is done using special serial dilators followed by screw extenders over the guide wires. The small and medium dilators are removed, leaving the final dilator (screw extenders) in place. The pedicles and proximal half of the vertebral body are tapped with a cannulated tap. Subsequently, the dilators are removed and the cannulated screws are introduced over the guide wires into their trajectory (Fig. 3). The guide wires are removed, possibly using a Kocher, after the pedicle screw is placed beyond the pedicle. All procedures are done under lateral fluoroscopy. For the Sextant system, the screw extenders are lined up, and a rod measuring device is used to measure the appropriate rod length (Fig. 4). The rod inserter is attached to the screw extenders and the rods are inserted percutaneously using the free-hand technique through a small incision rostral to the proximal screw incision, and passing through the screw head extenders of the proximal and caudal screws (Figs. 5, 6). The screws are then compressed, tightened, and broken off according to the appropriate torque of the locking caps (Fig. 7). For the PathFinder system, bending of the rod prior to implantation is required. The screws are attached to C-shaped towers, a slotted extender sleeve that attaches securely to the screw heads and extends above the skin. The rod is then passed down and implanted through connecting the screw snap incisions into one single incision on each side. It is through those towers that the rod is delivered into the screw head deep in the tissue and tightened in place with set screws (Fig. 8). Reduction and compression can then be performed. Finally, the instruments are removed and skin incisions closed (Fig. 9). When decompression of neural structures is needed, it is limited to the affected levels using the miniopen approach. In this approach, percutaneous instrumentation minimizes the skin incision length and muscle dissection (Fig. 10).

Bottom Line: Fluoroscopy-guided percutaneous placement of pedicle screws is effective.Operative techniques are discussed and the results compared.Fluoroscopy-guided percutaneous pedicular screws are feasible and can be safely done.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurosurgery, Faculty of Medicine, Cairo University, Cairo, Egypt.

ABSTRACT

Study design: The efficacy of the operative techniques, possible benefits as well as pitfalls and limitations of the techniques are discussed. Potential drawbacks are also detected.

Purpose: This study aims to report indications, techniques, and our experience with the use of the Sextant and PathFinder percutaneous transpedicular screw fixation systems.

Overview of literature: Percutaneous pedicle screw insertion is a novel technique. Successful percutaneous placement of pedicle screws requires surgical skill and experience because of lack of anatomic surface landmarks. Fluoroscopy-guided percutaneous placement of pedicle screws is effective. Many systems are now available.

Methods: We conducted a prospective operative and postoperative analysis of 40 patients with absolute indication for thoracic or lumbar instability between January 2009 and June 2013. All procedures were performed with the Sextant (group A) and PathFinder (group B) systems under fluoroscopic guidance. Operative techniques are discussed and the results compared.

Results: Percutaneous transpedicular screw fixation minimizes the morbidity associated with open techniques without compromising the quality of fixation. A total of 190 screws were inserted. There was no additional morbidity. Postoperative computed tomography images and plain X-rays were analyzed. Reduction of visual analog scale scores of back pain was evident.

Conclusions: Fluoroscopy-guided percutaneous pedicular screws are feasible and can be safely done. Current systems allow multi-segmental fixation with significantly less difficulties. The described techniques have acceptable intra- and postoperative complication rates, and overall sufficient pain control with early mobilization of patients.

No MeSH data available.


Related in: MedlinePlus