title: Robotic guidance for en bloc sacrectomy: a case report.
abstract: METHODS
  Case report of a patient with primary osteosarcoma of the sacrum who underwent en bloc sacrectomy.
  
  
  OBJECTIVE
  To describe a novel approach using robotic guidance for sacral tumor resection.
  
  
  BACKGROUND
  En bloc sacrectomy for aggressive primary malignancies or metastatic tumors of the sacrum can be technically challenging. Although imaging can delineate appropriately planned resection margins, the complex anatomy of the spinopelvic junction poses a challenge for the exact intraoperative execution of the preoperative plan.
  
  
  METHODS
  The patient was a 22-year-old male who was diagnosed with a primary sacral osteosarcoma. The mass extended to the left sacroiliac joint requiring a transiliac osteotomy. Preoperative robotic-guidance software was used allowing for virtual planning of the transiliac osteotomy.
  
  
  RESULTS
  During surgery, the robot was attached and synchronized with the preoperative imaging. Pilot holes were drilled along the planned iliac resection margin. With rigid tubes placed in the left iliac pilot holes, we passed a series of osteotomes parallel to the tubes to the same depth as our drillings and completed our left iliac osteotomy. Negative tumor margins were achieved and the postoperative course was uneventful.
  
  
  CONCLUSIONS
  We report the first case of robotic-guided en bloc transiliac resection of a primary sacral osteosarcoma with extension to the sacroiliac joint. Robotic guidance for tumor resection can be a useful tool in such challenging surgical procedures to fully resect the tumor, while minimizing disruption of the surrounding healthy anatomy.
  
  
  METHODS
  5.
authors.affiliation: *Department of Orthopaedic Surgery, University of California Irvine, Irvine, CA †Musculoskeletal Tumor Center, People's Hospital, Peking University, Beijing, China; and ‡Department of Orthopaedic Surgery, Montefiore/Albert Einstein College of Medicine, Bronx, NY.
authors.forename: S Samuel
authors.initials: SS
authors.lastname: Bederman
authors.forename: Gregory
authors.initials: G
authors.lastname: Lopez
authors.forename: Tao
authors.initials: T
authors.lastname: Ji
authors.forename: Bang H
authors.initials: BH
authors.lastname: Hoang
mesh_terms: D001859:Bone Neoplasms / Q000175:diagnosis* / Q000601:surgery; D006801:Humans; D008297:Male; D012516:Osteosarcoma / Q000175:diagnosis* / Q000601:surgery; D012371:Robotics / Q000379:methods*; D012447:Sacrum / Q000473:pathology* / Q000601:surgery; D013125:Spinal Neoplasms / Q000175:diagnosis* / Q000601:surgery; D055815:Young Adult