title: Monitoring the quality of robot-assisted pedicle screw fixation in the lumbar spine by using a cumulative summation test.
abstract: METHODS
  Prospective randomized controlled trial.
  
  
  OBJECTIVE
  The aim of this study was to monitor the quality control of robot-assisted pedicle screw fixation accuracy by using a cumulative summation (CUSUM) test at the initial stage of its application.
  
  
  BACKGROUND
  Although robot-assisted pedicle screw fixation reduces screw misplacement rates and provides critical support for minimally invasive surgical procedures, there have been no reports relating to the monitoring of quality control of the accuracy of this robot-assisted pedicle screw fixation procedure.
  
  
  METHODS
  Patients with lumbar spinal stenosis scheduled to undergo surgery were randomly and equally assigned through 1:1 allocation to a robot-assisted minimally invasive posterior lumbar interbody fusion (Rom-PLIF) group or a conventional open posterior PLIF using freehand technique group. The accuracy of pedicle screw placement was evaluated using postoperative computed tomography. The primary outcome was the CUSUM analysis for monitoring the quality control of the accuracy of pedicle screw insertion between the Rom-PLIF and conventional open posterior PLIF using freehand technique groups.
  
  
  RESULTS
  Of the 80 pedicle screws inserted in each group, 4 screws in the Rom-PLIF group, and 7 in the conventional open PLIF group, breached the pedicle. Of these 11 offending screws, 4 cases were categorized as grade B in the Rom-PLIF group, whereas 6 were grade B and 1 case was grade C in the Com-PLIF group, using the Gertzbein and Robbins classification. Throughout the monitoring period, there was no CUSUM test-derived indication that the quality of performance of the pedicle screw fixation procedure was inadequate in either group.
  
  
  CONCLUSIONS
  First, this study demonstrates the adequacy of quality control of robot-assisted pedicle screw fixation even early in the application period based on the CUSUM analysis. Second, the CUSUM test can be a useful tool for monitoring of the quality of procedures related with spine surgery.
authors.affiliation: *Spine Center and Department of Orthopaedic Surgery, Seoul National University College of Medicine and Seoul National University Bundang Hospital, Sungnam, Republic of Korea †Department of Orthopaedic Surgery, Seoul National University College of Medicine and Seoul National University Hospital, Seoul, Republic of Korea ‡ClinResearch Sdn Bhd and §Stats Consulting Sdn Bhd, Petaling Jaya, Selangor, Malaysia; and ¶Department of Orthopaedic Surgery, Kangwon National University Hospital, Gangwon-do, Korea.
authors.forename: Ho-Joong
authors.initials: HJ
authors.lastname: Kim
authors.forename: Seung Hoo
authors.initials: SH
authors.lastname: Lee
authors.forename: Bong-Soon
authors.initials: BS
authors.lastname: Chang
authors.forename: Choon-Ki
authors.initials: CK
authors.lastname: Lee
authors.forename: Teck Onn
authors.initials: TO
authors.lastname: Lim
authors.forename: Ling Ping
authors.initials: LP
authors.lastname: Hoo
authors.forename: Je-Min
authors.initials: JM
authors.lastname: Yi
authors.forename: Jin S
authors.initials: JS
authors.lastname: Yeom
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000295:instrumentation* / Q000379:methods; D065289:Pedicle Screws; D012371:Robotics; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods; D013130:Spinal Stenosis / Q000601:surgery*; D016896:Treatment Outcome