title: A surgical planning and guidance system for high tibial osteotomy.
abstract: OBJECTIVE
  To develop a three-dimensional pre-surgical planner and an intraoperative guidance system for high tibial osteotomy. The parameters that describe the placement and orientation of the osteotomy resection planes were to be transmitted to an accompanying guidance system that allowed the surgeon to reproducibly perform the planned procedure.
  
  
  METHODS
  The planning system and guidance system were coded using OpenGL on UNIX workstations. In vitro tests were performed to compare the reproducibility of the computer-enhanced technique to that of the traditional technique, and an in vivo pilot study was initiated.
  
  
  RESULTS
  In vitro, the computer-enhanced technique produced a significant reduction, by one half, in both the maximum error of correction and the standard deviation of the correction error. Preliminary in vivo results on six patients suggest that similar error diminution will occur during regular clinical application of the technique.
  
  
  CONCLUSIONS
  Both studies showed that the computer system is simple to use. The work suggests that three-dimensional planning and performance of high tibial osteotomy is essential for accurate correction of the alignment of the lower limb.
authors.affiliation: Department of Computing and Information Science, Queen's University at Kingston, Ontario, Canada. ellis@cs.queensu.ca
authors.forename: R E
authors.initials: RE
authors.lastname: Ellis
authors.forename: C Y
authors.initials: CY
authors.lastname: Tso
authors.forename: J F
authors.initials: JF
authors.lastname: Rudan
authors.forename: M M
authors.initials: MM
authors.lastname: Harrison
mesh_terms: D003198:Computer Simulation; D003199:Computer Systems; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007430:Intraoperative Care; D007592:Joint Diseases / Q000601:surgery; D007719:Knee Joint; D008953:Models, Anatomic; D010027:Osteotomy / Q000295:instrumentation / Q000379:methods*; D010347:Patient Care Planning; D010865:Pilot Projects; D015203:Reproducibility of Results; D013813:Therapy, Computer-Assisted / Q000295:instrumentation; D013977:Tibia / Q000000981:diagnostic imaging / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014584:User-Computer Interface