title: Irregular osteotomy in limb salvage for juxta-articular osteosarcoma under computer-assisted navigation.
abstract: BACKGROUND
  Joint-preserving limb salvage surgery has been expected to have good functional outcomes. However, it is still a unsolved problem to perform a joint preserving resection for patients with juxta-articular osteosarcoma invading epiphyseal line. We determined whether irregular osteotomy under image-guided navigation make joint-saving resection possible for juxta-articular osteosarcoma while adhering oncological principles.
  
  
  METHODS
  We performed joint-preserving limb salvage surgeries on six patients with juxta-articular osteosarcoma of the long bone. Three lesions located in humerus, two in tibia and one in femur. Two tumors extend to and four beyond the epiphyseal line. CT and MRI data fusion images were applied for intraoperative navigation. Planned irregular osteotomy under image-guided navigation was employed for obtaining clear surgical margin while maximizing host tissue preservation. All tumors were en bloc removed and intercalary defect were reconstructed by allograft in one and combination of allograft with vascularized fibula graft in five patients. All specimens were examined for resection margin. Patients were followed up for average of 17.5 months for evaluating of functional and oncology outcomes.
  
  
  RESULTS
  Entire joint were preserved in three patients and part of joint were saved in another three patients. Clear surgical margin was obtained in all specimens with a minimum of 6-mm distance between tumor and osteotomy line. No patient experienced a local recurrence. One patient developed lung metastasis and had no evidence of disease at the most recent follow-up. All allografts but one healed during the study period. The MSTS average score was 88.8% at final follow-up.
  
  
  CONCLUSIONS
  With careful patient selection, the irregular osteotomy under navigation guidance was proved to be an effective and safe technique for precise tumor resection in joint preserving limb salvage procedures for treating patients with juxta-articular osteosarcomas.
authors.affiliation: Orthopaedic Oncology Department, Xi Jing Hospital Affiliated to the Fourth Military Medical University, Xi'an, People's Republic of China. ljfmmu@sina.com.cn
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wang
authors.forename: Zheng
authors.initials: Z
authors.lastname: Guo
authors.forename: Guo-Jing
authors.initials: GJ
authors.lastname: Chen
authors.forename: Ming
authors.initials: M
authors.lastname: Yang
authors.forename: Guo-Xian
authors.initials: GX
authors.lastname: Pei
mesh_terms: D000293:Adolescent; D000328:Adult; D001859:Bone Neoplasms / Q000601:surgery*; D002648:Child; D005260:Female; D006801:Humans; D023821:Limb Salvage / Q000379:methods*; D008297:Male; D012516:Osteosarcoma / Q000601:surgery*; D010027:Osteotomy / Q000379:methods*; D025321:Surgery, Computer-Assisted / Q000379:methods*