Article
Percutaneous pedicle screw placement in thoracic an lumbar spine – results of two centers
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Authors
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K. Seidel
- Klinik für Neurochirurgie der Universität Ulm am BKH Günzburg
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C. Wimmer
- Klinik für Wirbelsäulenchirurgie und Skoliosezentrum BHZ Vogtareuth
| Published: | May 20, 2009 |
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Outline
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Objective: Minimally invasive or percutaneous pedicle screw placement are now common techniques in spine surgery. In first publications a screw misplacement rates from 6,6% up to 12 % were described. Also extreme medial placements (>6mm) with resulted in a nerve root injuries are published.
Methods: Between 2004 and 2008 in both centers 235 patients (BKH 60, BHZ 175) with mono- or bisegmental spinal pathologies (degenerative, tumor, trauma, infection) underwent a percutaneous instrumentation. All pedicle screws were placed percutaneously via four or six 15 mm incisions under biplanar fluoroscopy. For instrumentation we used the DePuy Expedium™ LIS system. 978 (BKH 254, BHZ 724) pedicle screws were placed between Th 1 and S1. All patients underwent a postoperative CT scan with coronal and sagittal reconstructions.
Results: A total of 978 screws were analysed in 235 patients, and 960 screws were placed without a violation of the pedicle wall. Only 18/978 (1,8%) screws were misplaced. There were only 5 medial breaches of the pedicle wall. Two screws had to be revised because of a new radicular pain. No neurologic deficit resulted. All medial misplacements were found at the level S1. 14 screws were placed laterally without compromising stability. None of them had to be corrected.
Conclusions: Percutaneous pedicle screw placement is a safe procedure in spine surgery. All in all 98,1% of all screws were placed correct. Only 2 (0,2%) had to be revised. Compared to open techniques there is a no higher risk of screw misplacement. The most dangerous level is S1 because of the limitation of the iliac crest and the need of a high angle of the trajectory.
