title: Joint-preserving limb salvage surgery under navigation guidance.
abstract: BACKGROUND
  Recently, the navigation system has been introduced to orthopedic oncology. It can apply MRI and/or CT images to intraoperative visualization. We performed navigation-assisted limb salvage surgeries on patients with a malignant bone tumor of the metaphysis of the long bone or the iliac bone while preserving the adjacent joint.
  
  
  METHODS
  When preoperative chemotherapy was estimated to be effective by imaging studies and the residual remaining epiphysis was expected to be more than 1 cm long after tumor resection with 1-2 cm of surgical margin, joint-preserving surgery was performed under navigation guidance. We carried out CT and MRI data fusion to use MR images as an intraoperative guide. A deep frozen strut allograft was placed in the defect for the restoration of anatomical continuity.
  
  
  RESULTS
  Resection margin measured on pathological examination was in accordance with that of the preoperative plan. The functional scores of all patients were satisfactory. There was no evidence of recurrence on the regional radiographs and CT on the chest until the last follow-up.
  
  
  CONCLUSIONS
  Navigation-assisted surgery can be indicated for limb salvage and it can help to preserve the adjacent joint in selected cases.
authors.affiliation: Department of Orthopaedic Surgery, Kyungpook National University College of Medicine, Daegu, Korea.
authors.forename: Hwan Seong
authors.initials: HS
authors.lastname: Cho
authors.forename: Joo Han
authors.initials: JH
authors.lastname: Oh
authors.forename: Ilkyu
authors.initials: I
authors.lastname: Han
authors.forename: Han-Soo
authors.initials: HS
authors.lastname: Kim