Beitragstitel | Patient-specific template-guided versus free-hand lumbar pedicle screw implantation – a randomized controlled trial |
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Beitragscode | P030 |
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Präsentationsform | Poster |
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Abstract |
Introduction Pedicle screw misplacement is biomechanically disadvantageous and carries the risk of neurovascular sequelae. Patient-specific template-guided pedicle screw placement has the highest yet reported accuracy in cadaveric and early clinical studies. However, a randomized controlled trial eliminating potential biases is lacking. We aimed to compare patient-specific template-guided (TG) versus free-hand (FH) lumbar pedicle screw implantation in a randomized controlled trial to illuminate aspects of accuracy and safety. Methods Patients scheduled for lumbar fusion surgery were randomized to either the TG or FH pedicle screw insertion group. An immediate postoperative computer tomography (CT) was performed to assess accuracy of pedicle screws by grading perforations rate using a 2 mm increment grading scale. Time of surgical exposure and blood loss, time of screw insertion and overall surgery, as well as intraoperative radiation dose and complications were recorded and compared. Results 24 patients (9 male, 15 female) with a mean age of 64 years underwent either FH (n=13) or TG (n=11) pedicle screw insertion with a mean follow-up of 13.4 months. A total of 108 screws (FH-screws/TG-screws = 62/46) were implanted. There was no significant difference in surgical exposure time (31.6 ± 8.7 min versus 40.7 ± 12.1 min; p=0.062), screw insertion time (27.0 ± 11.0 min versus 33.6 ± 13.6 min; p=0.234), overall surgical time (157.7 ± 32.7 min versus 177.8 ± 36.4 min; p=0.168) and blood loss (353.8 ± 187.6 ml versus 518.2 ± 355.2 ml; p=0.161) between the FH and the TG group, respectively. Radiation exposure was significantly less in the TG group (230.8 ± 132.7 cGy) vs the FH group (67.8 ± 31.0 cGy) (p=0.001). There were 4 pedicle screw perforations (6%) in the FH group and 2 (4%) in the TG group (p=1.000). All perforations were less than 2 mm and had no clinical consequences. Clinically relevant complications were 1 postoperative pedicle fracture in the FH group (p=1.000), 2 infections in the FH group and 1 infection in the TG group (p=1.000). Conclusion Patient-specific template-guided pedicle screw insertion provides a similar accuracy, but less intraoperative radiation exposure than the FH technique. However, for the lumbar region it requires more surgical time and blood loss by tendency. Other screw trajectories such as cortical bone trajectory might amplify the potential benefits of patient-specific guides, but need further evaluation. |