title: Surgical technique: Computer-generated custom jigs improve accuracy of wide resection of bone tumors.
abstract: BACKGROUND
  Manual techniques of reproducing a preoperative plan for primary bone tumor resection using rudimentary devices and imprecise localization techniques can result in compromised margins or unnecessary removal of unaffected tissue. We examined whether a novel technique using computer-generated custom jigs more accurately reproduces a preoperative resection plan than a standard manual technique.
  
  
  METHODS
  Using CT images and advanced imaging, reverse engineering, and computer-assisted design software, custom jigs were designed to precisely conform to a specific location on the surface of partially skeletonized cadaveric femurs. The jigs were used to perform a hemimetaphyseal resection.
  
  
  METHODS
  We performed CT scans on six matched pairs of cadaveric femurs. Based on a primary bone sarcoma model, a joint-sparing, hemimetaphyseal wide resection was precisely outlined on each femur. For each pair, the resection was performed using the standard manual technique on one specimen and the custom jig-assisted technique on the other. Superimposition of preoperative and postresection images enabled quantitative analysis of resection accuracy.
  
  
  RESULTS
  The mean maximum deviation from the preoperative plan was 9.0 mm for the manual group and 2.0 mm for the custom-jig group. The percentages of times the maximum deviation was greater than 3 mm and greater than 4 mm was 100% and 72% for the manual group and 5.6% and 0.0% for the custom-jig group, respectively.
  
  
  CONCLUSIONS
  Our findings suggest that custom-jig technology substantially improves the accuracy of primary bone tumor resection, enabling a surgeon to reproduce a given preoperative plan reliably and consistently.
authors.affiliation: Department of Orthopaedics, Stony Brook University School of Medicine, Stony Brook, NY, USA.
authors.forename: Fazel A
authors.initials: FA
authors.lastname: Khan
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Lipman
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Pearle
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Boland
authors.forename: John H
authors.initials: JH
authors.lastname: Healey
mesh_terms: D001859:Bone Neoplasms / Q000601:surgery*; D002102:Cadaver; D017076:Computer-Aided Design; D005269:Femur / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging; D010027:Osteotomy / Q000379:methods*; D015203:Reproducibility of Results; D012509:Sarcoma / Q000601:surgery*; D025321:Surgery, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed