title: [The application of computer aided design and computer aided engineering technique in separation of Pygopagus conjoined twins].
abstract: OBJECTIVE
  To explore the effect of CAD and CAE related technique in separation of Pygopagus Conjoined Twins.
  
  
  METHODS
  CT images of Pygopagus conjoined twins were obtained and reconstructed in three-dimensional by Mimics software. 3D entity model of skin and spine of conjoined twins were made by fast plastic technique and equipment according to 3D data model. The circumference and area of fused and independent dural sac were measured by software of AutoCAD.
  
  
  RESULTS
  The entity model is real reflection of skin and spine of Pygopagus. It was used in the procedures of discussion, sham operation, skin flap design and informed consent. In the measure of MRI, the circumference and area of fused dural sac was more than of independent dural sac, that is to say, the defect of dural sac can be repaired by direct suture. The intraoperative finding match with imaging measure results.
  
  
  CONCLUSIONS
  The application of CAD and CAE in the procedure of preoperative plan have gave big help to successful separation of Pygopagus Conjoined Twins.
authors.affiliation: Department of Orthopedic Surgery, Beijing Army General Hospital, Beijing 100700, China.
authors.forename: Zhi-cheng
authors.initials: ZC
authors.lastname: Zhang
authors.forename: Tian-sheng
authors.initials: TS
authors.lastname: Sun
authors.forename: Fang
authors.initials: F
authors.lastname: Li
authors.forename: Guo-lin
authors.initials: GL
authors.lastname: Tang
mesh_terms: D017076:Computer-Aided Design; D006801:Humans; D021621:Imaging, Three-Dimensional; D007223:Infant; D008297:Male; D012984:Software; D025321:Surgery, Computer-Assisted; D016896:Treatment Outcome; D014428:Twins, Conjoined / Q000601:surgery*