title: Navigated percutaneous lumbosacral interbody fusion: a feasibility study with three-dimensional surgical simulation and cadaveric experiment.
abstract: METHODS
  A feasibility study with three-dimensional surgical simulation and cadaveric experiment.
  
  
  OBJECTIVE
  To verify the feasibility of a new navigated surgical method for lumbosacral interbody fusion.
  
  
  BACKGROUND
  The advances in surgical navigation have opened new possibilities for lumbosacral interbody fusion procedure. We designed a novel navigated surgical method that enables lumbosacral discectomy and bone grafting to be performed percutaneously and safely.
  
  
  METHODS
  First, to prove that the newly designed surgical method is feasible from an anatomic perspective, the new method, navigated percutaneous lumbosacral interbody fusion (NPLSIF), was simulated on the three-dimensional models of lumbosacral spine. The three-dimensional models were established using the computed tomographic (CT) data of 60 patients. Feasibility could be verified if both working corridor and S1 pedicle screw could be accommodated in sacral ala without overlapping and without penetrating either the spinal canal or the anterior or upper sacral wall. Second, to verify the feasibility of the NPLSIF procedure in reality, cadaveric experiment was performed. Two cadavers were included; one was a 67-year-old male, and the other a 65-year-old female. CT scanning was performed with an intraoperative CT scanner before surgery, after the discectomy and after bone grafting. These three series of CT images were compared to evaluate the efficacy of the NPLSIF procedure. After the procedures, the lumbosacral spines were separated from the cadaver trunks in the department of anatomy. The lumbosacral disc of one cadaver was bisected coronally, while the lumbosacral disc of the other cadaver was bisected sagittally. The internal view of the lumbosacral discs helped to further evaluate the efficacy of the NPLSIF procedures.
  
  
  RESULTS
  In the three-dimensional surgical simulation experiment, the feasibility of the NPLSIF procedure was verified in every case. In the cadaveric experiment, the NPLSIF procedures were successfully executed. The surgical procedure on the first cadaver took 3 hours. After improving the workflow and having gained some experience, the procedure on the second cadaver took 1.5 hours. On the navigation workstation, the preoperative plan was completed in 3 to 5 minutes and each intraoperative CT scanning took 30 seconds. The quality of the intraoperative CT images was comparable to that of normal CT images. CT images and the internal view of the lumbosacral discs showed that the NPLSIF procedures had yielded satisfactory discectomy and endplate preparation.
  
  
  CONCLUSIONS
  The feasibility of NPLSIF was verified by the means of three-dimensional surgical simulation and cadaveric experiment. Clinical studies are needed to further investigate the efficacy and efficiency of NPLSIF in clinical practice.
authors.affiliation: Department of Orthopaedics E, Aarhus University Hospital, Norrebrogase 44, Aarhus, Denmark. yu.wang@ki.au.dk
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.forename: Dang Q S
authors.initials: DQ
authors.lastname: Le
authors.forename: Haisheng
authors.initials: H
authors.lastname: Li
authors.forename: Miao
authors.initials: M
authors.lastname: Wang
authors.forename: Cody Eric
authors.initials: CE
authors.lastname: Bünger
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001863:Bone Screws; D016025:Bone Transplantation; D002102:Cadaver; D003198:Computer Simulation; D017586:Diskectomy; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007403:Intervertebral Disc / Q000601:surgery; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D008953:Models, Anatomic; D012447:Sacrum / Q000000981:diagnostic imaging / Q000601:surgery*; D013123:Spinal Fusion / Q000295:instrumentation / Q000379:methods*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D055815:Young Adult