title: Cervical screw placement using rapid prototyping drill templates for navigation: a literature review.
abstract: OBJECTIVE
  Due to the high screw malposition rate and the potential risk of neurovascular injury in cervical fixation surgeries, guided tools, mainly computer-assisted surgery navigation systems and rapid prototyping drill templates (RPDTs) have increasingly been developed to help surgeons improve screw placement accuracy. Although RPDTs have been used in cervical surgeries for almost 2 decades, no specific review has been performed detailing the state of this technique. Thus, in the current review, we fully discuss the status of applying RPDTs in cervical surgeries.
  
  
  METHODS
  Studies that tested the accuracy and reliability of RPDTs in guiding cervical screw placements were included in this review. The fabrication workflow and usage of RPDTs, the accuracy and reliability of using RPDTs for screw and plate placement, the advantages and disadvantages of RPDTs and their prospects for future applications as a part of cervical fixation instrumentation are discussed.
  
  
  RESULTS
  As the design of RPDTs becomes more rational, the accuracy and reliability of these devices have significantly improved in cervical fixation surgeries. Moreover, RPDTs decrease the intraoperative radiation exposure for surgeons and patients relative to conventional methods. However, some disadvantages also exist. The fabrication of RPDTs is time-consuming, and the time required to learn the related software is long.
  
  
  CONCLUSIONS
  We believe that because of their merits, the RPDT technique is worth promoting for use in cervical surgeries. However, the time-consuming fabrication workflow and the long period required to learn the related software might limit its widespread use. In the future, the workflow should be simplified to reduce the extra workload for surgeons. Moreover, more clinical studies with high-level evidence are still needed to further test its accuracy and feasibility.
authors.affiliation: Department of Orthopaedics, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, Shaanxi Province, China.
authors.forename: Teng
authors.initials: T
authors.lastname: Lu
authors.affiliation: Department of Neurology, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, Shaanxi Province, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Liu
authors.affiliation: Department of Orthopaedics, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, Shaanxi Province, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Dong
authors.affiliation: Department of Orthopaedics, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, Shaanxi Province, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Lu
authors.affiliation: Department of Orthopaedics, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, Shaanxi Province, China.
authors.forename: Haopeng
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Orthopaedics, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, Shaanxi Province, China. He_Xijing@126.com.
authors.forename: Xijing
authors.initials: X
authors.lastname: He
mesh_terms: D000328:Adult; D001268:Atlanto-Axial Joint / Q000000981:diagnostic imaging* / Q000601:surgery; D001863:Bone Screws; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging* / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D013123:Spinal Fusion / Q000295:instrumentation; D025321:Surgery, Computer-Assisted / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: Cervical screw; Computer-assisted; Drill template; Rapid prototyping; Screw placement accuracy