Outcome-Based Classification for Assessment of Thoracic Pedicular Screw Placement
- 1 February 2008
- journal article
- Published by Ovid Technologies (Wolters Kluwer Health) in Spine
- Vol. 33 (4), 384-390
- https://doi.org/10.1097/brs.0b013e3181646ba1
Abstract
Prospective cohort study. We propose a simple outcome-based classification for assessment of pedicle screw positions based on postoperative computed tomography scan. This bridges the gap between high rates of pedicle screw misplacement and minimal complications reported. The main deterrent for the use of thoracic pedicular screws is the feared neurovascular complications due to screw "misplacements." The literature shows that only a small fraction of the misplaced screws actually causes any complication, and some misplacements can be acceptable both in terms of safety and their biomechanical strength. Sixty patients with various spinal disorders were included in the study. The mean age was 29.6 years (range, 12-72 years). The patients were divided into 2 groups for assessment of pedicle screw placements using postoperative computed tomography scans: scoliosis group with 24 patients and the nonscoliosis group with 34 patients. Placements of screws were assessed using the outcome-based classification and the Rongming Xu criteria of screw placement. A total of 341 screws were assessed from 60 patients with various spinal disorders (scoliosis and nonscoliosis groups). Using the Rongming Xu criteria, the overall screw misplacement in scoliosis group was 50.72% (68 of 138) and that in nonscoliosis group was 45.45% (80 of 176 screws). Assessment of these screws using the outcome-based classification showed a high percentage of acceptable screw placements (type 1) - 89.85% (124 of 138 screws) in the scoliosis group and 86.93% (153 of 176 screws) in the nonscoliosis group. The literature shows consensus over high rates of pedicle screw misplacement, but low clinical complications, in the hands of the best of spine surgeons. The concept of acceptable screw placements and the outcome classification makes the pedicle screw assessment results correlate better with the clinical outcome.Keywords
This publication has 17 references indexed in Scilit:
- Volumetric Spinal Canal IntrusionSpine, 2004
- Accuracy of Thoracic Pedicle Screws in Patients with and Without Coronal Plane Spinal DeformitiesSpine, 2002
- Comparative analysis of pedicle screw and hook instrumentation in posterior correction and fusion of idiopathic thoracic scoliosisEuropean Spine Journal, 2002
- Zur Definition der PedikelfehllageDer Orthopäde, 2002
- In Vivo Accuracy of Thoracic Pedicle ScrewsSpine, 2001
- Thoracic Pedicle Screw Fixation in Spinal DeformitiesSpine, 2001
- Fatal Cardiac Tamponade Associated With Posterior Spinal InstrumentationSpine, 1998
- Anatomic Considerations of Pedicle Screw Placement in the Thoracic SpineSpine, 1998
- Pedicle Screw Instrumentation of the Thoracic Spine in Idiopathic ScoliosisSpine, 1997
- Accuracy of Pedicular Screw Placement In VivoSpine, 1990