title: Preoperative surgical planning versus navigation system in valgus tibial osteotomy: a cross-sectional study.
abstract: OBJECTIVE
  The objective of this study was to verify whether the correction obtained using a navigation system (NS) corresponds to the wedge calculated by the Dugdale method (DM) in high tibial osteotomy (HTO).
  
  
  METHODS
  We included 17 patients with primary varus and HTO indication, consecutively admitted to a public university hospital. All patients underwent panoramic radiography with bipedal load for the wedge calculation by DM. They underwent HTO with an opening wedge, fixed with an HTO plate and monitored by the OrthoPilot NS. Bone grafts were used in every case. The wedge opening obtained by the NS was compared to that calculated in the radiographs.
  
  
  RESULTS
  The mean opening by DM was 9.53° and by the NS 11.8° (p < 0.045).
  
  
  CONCLUSIONS
  There was a significant difference in the calculation of the wedge opening between the DM and NS. HTO without the aid of the NS could theoretically lead to undercorrection of the deformity.
authors.affiliation: Knee Surgery Division, Department of Orthopaedics and Traumatology, Faculdade de Ciências Médicas da Santa Casa de São Paulo (FCMSCSP), São Paulo, Brazil. alelorenti@yahoo.com.br
authors.forename: Cristiano Hossri
authors.initials: CH
authors.lastname: Ribeiro
authors.forename: Nilson Roberto
authors.initials: NR
authors.lastname: Severino
authors.forename: Patricia Maria de Moraes Barros
authors.initials: PM
authors.lastname: Fucs
mesh_terms: D000328:Adult; D017760:Bone Malalignment / Q000000981:diagnostic imaging / Q000601:surgery; D016025:Bone Transplantation; D003430:Cross-Sectional Studies; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000601:surgery*; D010027:Osteotomy / Q000379:methods*; D057234:Preoperative Period; D011446:Prospective Studies; D011859:Radiography; D012189:Retrospective Studies; D025321:Surgery, Computer-Assisted / Q000379:methods*; D013977:Tibia / Q000000981:diagnostic imaging / Q000601:surgery*