title: Joint-preserving tumor resection and reconstruction using image-guided computer navigation.
abstract: BACKGROUND
  Joint-preserving surgery is performed in select patients with bone sarcomas of extremities and allows patients to retain the native joint with better joint function. However, recurrences may relate to achieving adequate margins and there is frequently little room for error in tumors close to the joint surface. Further, the tumor margin on preoperative CT and/or MR images is difficult to transpose to the actual extent of tumor in the bone in the operating room.
  
  
  OBJECTIVE
  We therefore determined whether joint-preserving tumor surgery could be performed accurately under image-guided computer navigation and determined local recurrences, function, and complications.
  
  
  METHODS
  We retrospectively studied eight patients with bone sarcoma of extremities treated surgically by navigation with fused CT-MR images. We assessed the accuracy of resection in six patients by comparing the cross sections at the resection plane with complementary prosthesis templates. Mean age was 17 years (range, 6-46 years). Minimum followup was 25 months (mean, 41 months; range, 25-60 months).
  
  
  RESULTS
  The achieved resection was accurate, with a difference of 2 mm or less in any dimension compared to that planned in patients with custom prostheses. We noted no local recurrence at latest followup. The mean Musculoskeletal Tumor Society score was 29 (range, 28-30). There were no complications related to navigation planning and procedures. There was no failure of fixation at the remaining epiphysis.
  
  
  CONCLUSIONS
  In selected patients, the computer-assisted approach facilitates precise planning and execution of joint-preserving tumor resection and reconstruction. Further followup assessment in a larger study population is required in these patients.
  
  
  METHODS
  Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.
authors.affiliation: Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong. skcwong@ort.cuhk.edu.hk
authors.forename: Kwok Chuen
authors.initials: KC
authors.lastname: Wong
authors.forename: Shekhar Madhukar
authors.initials: SM
authors.lastname: Kumta
mesh_terms: D000293:Adolescent; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D002648:Child; D002813:Chondrosarcoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D017076:Computer-Aided Design; D005260:Female; D006801:Humans; D007596:Joints / Q000473:pathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D012516:Osteosarcoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D010027:Osteotomy / Q000009:adverse effects / Q000379:methods*; D011474:Prosthesis Design; D019919:Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted; D019651:Plastic Surgery Procedures / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D012189:Retrospective Studies; D025321:Surgery, Computer-Assisted / Q000009:adverse effects / Q000295:instrumentation; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D055815:Young Adult