title: En Bloc Resection of Primary Malignant Bone Tumor in the Cervical Spine Based on 3-Dimensional Printing Technology.
abstract: OBJECTIVE
  To investigate the feasibility and safety of en bloc resection of cervical primary malignant bone tumors by a combined anterior and posterior approach based on a three-dimensional (3-D) printing model.
  
  
  METHODS
  Five patients with primary malignant bone tumors of the cervical spine underwent en bloc resection via a one-stage combined anteroposterior approach in our hospital from March 2013 to June 2014. They comprised three men and two women of mean age 47.2 years (range, 26-67 years). Three of the tumors were chondrosarcomas and two chordomas. Preoperative 3-D printing models were created by 3-D printing technology. Sagittal en bloc resections were planned based on these models and successfully performed. A 360° reconstruction was performed by spinal instrumentation in all cases. Surgical margins, perioperative complications, local control rate and survival rate were assessed.
  
  
  RESULTS
  All patients underwent en bloc excision via a combined posterior and anterior approach in one stage. Mean operative time and estimated blood loss were 465 minutes and 1290 mL, respectively. Mean follow-up was 21 months. Wide surgical margins were achieved in two patients and marginal resection in three; these three patients underwent postoperative adjuvant radiation therapy. One vertebral artery was ligated and sacrificed in each of three patients. Nerve root involved by tumor was sacrificed in three patients with preoperative upper extremity weakness. One patient (Case 3) had significant transient radiculopathy with paresis postoperatively. Another (Case 4) with C 4 and C 5 chordoma had respiratory difficulties and pneumonia after surgery postoperatively. He recovered completely after 2 weeks' management with a tracheotomy tube and antibiotics in the intensive care unit. No cerebrovascular complications and wound infection were observed. No local recurrence or instrumentation failure were detected during follow-up.
  
  
  CONCLUSIONS
  Though technically challenging, it is feasible and safe to perform en bloc resection of cervical primary bone tumors. This is the most effective means of managing cervical spine tumors. Preoperative 3-D printing modelling enables better anatomical understanding of the relationship between the tumor and cervical spine and can assist in planning the surgical procedure.
authors.affiliation: Department of Orthopaedic Oncology, Spine Tumor Center, Changzheng Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Jian-Ru
authors.initials: JR
authors.lastname: Xiao
authors.affiliation: Department of Orthopaedics, 411th Hospital of the People's Liberation Army, Shanghai, China.
authors.forename: Wen-Ding
authors.initials: WD
authors.lastname: Huang
authors.affiliation: Department of Orthopaedic Oncology, Spine Tumor Center, Changzheng Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Xing-Hai
authors.initials: XH
authors.lastname: Yang
authors.affiliation: Department of Orthopaedic Oncology, Spine Tumor Center, Changzheng Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Wang-Jun
authors.initials: WJ
authors.lastname: Yan
authors.affiliation: Department of Orthopaedic Oncology, Spine Tumor Center, Changzheng Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Dian-Wen
authors.initials: DW
authors.lastname: Song
authors.affiliation: Department of Orthopaedic Oncology, Spine Tumor Center, Changzheng Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Hai-Feng
authors.initials: HF
authors.lastname: Wei
authors.affiliation: Department of Orthopaedic Oncology, Spine Tumor Center, Changzheng Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Tie-Long
authors.initials: TL
authors.lastname: Liu
authors.affiliation: Department of Orthopaedic Oncology, Spine Tumor Center, Changzheng Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Zhi-Peng
authors.initials: ZP
authors.lastname: Wu
authors.affiliation: Department of Orthopaedic Oncology, Spine Tumor Center, Changzheng Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Yang
mesh_terms: D000328:Adult; D000368:Aged; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging* / Q000601:surgery; D002681:China / Q000453:epidemiology; D002813:Chondrosarcoma / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000379:methods*; D066330:Printing, Three-Dimensional; D013125:Spinal Neoplasms / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D025321:Surgery, Computer-Assisted / Q000379:methods*; D015996:Survival Rate / Q000639:trends; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome
keywords: 3D-printing model; Cervical spine; Complication; En bloc resection; Primary tumor