title: Assessing the Intraoperative Accuracy of Pedicle Screw Placement by Using a Bone-Mounted Miniature Robot System through Secondary Registration.
abstract: BACKGROUND
  Pedicle screws are commonly employed to restore spinal stability and correct deformities. The Renaissance robotic system was developed to improve the accuracy of pedicle screw placement.
  
  
  OBJECTIVE
  In this study, we developed an intraoperative classification system for evaluating the accuracy of pedicle screw placements through secondary registration. Furthermore, we evaluated the benefits of using the Renaissance robotic system in pedicle screw placement and postoperative evaluations. Finally, we examined the factors affecting the accuracy of pedicle screw implantation.
  
  
  RESULTS
  Through use of the Renaissance robotic system, the accuracy of Kirschner-wire (K-wire) placements deviating <3 mm from the planned trajectory was determined to be 98.74%. According to our classification system, the robot-guided pedicle screw implantation attained an accuracy of 94.00% before repositioning and 98.74% after repositioning. However, the malposition rate before repositioning was 5.99%; among these placements, 4.73% were immediately repositioned using the robot system and 1.26% were manually repositioned after a failed robot repositioning attempt. Most K-wire entry points deviated caudally and laterally.
  
  
  CONCLUSIONS
  The Renaissance robotic system offers high accuracy in pedicle screw placement. Secondary registration improves the accuracy through increasing the precision of the positioning; moreover, intraoperative evaluation enables immediate repositioning. Furthermore, the K-wire tends to deviate caudally and laterally from the entry point because of skiving, which is characteristic of robot-assisted pedicle screw placement.
authors.affiliation: Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Department of Neurosurgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
authors.forename: Keng-Liang
authors.initials: KL
authors.lastname: Kuo
authors.affiliation: Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Department of Neurosurgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
authors.forename: Yu-Feng
authors.initials: YF
authors.lastname: Su
authors.affiliation: Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Department of Neurosurgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
authors.forename: Chieh-Hsin
authors.initials: CH
authors.lastname: Wu
authors.affiliation: Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Department of Neurosurgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
authors.forename: Cheng-Yu
authors.initials: CY
authors.lastname: Tsai
authors.affiliation: Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Department of Neurosurgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
authors.forename: Chih-Hui
authors.initials: CH
authors.lastname: Chang
authors.affiliation: Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Department of Neurosurgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
authors.forename: Chih-Lung
authors.initials: CL
authors.lastname: Lin
authors.affiliation: Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Department of Neurosurgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
authors.forename: Tai-Hsin
authors.initials: TH
authors.lastname: Tsai
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D065289:Pedicle Screws; D012107:Research Design; D012189:Retrospective Studies; D012371:Robotics; D013122:Spinal Diseases / Q000601:surgery*; D013123:Spinal Fusion / Q000379:methods*; D013168:Spondylolisthesis / Q000601:surgery*; D025321:Surgery, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed; D055815:Young Adult