title: [Osteotomy techniques close to the knee. Effect on wedge volume and bony contact surface].
abstract: BACKGROUND
  Bone geometry following osteotomy around the knee suggests that biplanar rather than uniplanar open wedge techniques simultaneously create smaller wedge volumes and larger bone surface areas. However, precise data on the bone surface area and wedge volume resulting from both open and closed wedge high tibial osteotomy (HTO) and distal femoral osteotomy (DFO) techniques remain unknown.
  
  
  OBJECTIVE
  It was hypothesized that biplanar rather than uniplanar osteotomy techniques better reflect the ideal geometrical requirements for bone healing, representing a large cancellous bone surface combined with a small wedge volume.
  
  
  METHODS
  Tibial and femoral artificial bones were assigned to four different groups of valgisation and varisation osteotomy consisting of open wedge and closed wedge techniques in a uniplanar and biplanar fashion. Bone surface areas of all osteotomy planes were quantified. Wedge volumes were determined using a prism-based algorithm and applying standardized wedge heights of 5 mm, 10 mm and 15 mm.
  
  
  RESULTS
  Both femoral and tibial biplanar osteotomy techniques created larger contact areas and smaller wedge volumes compared to the uniplanar open wedge techniques.
  
  
  CONCLUSIONS
  Although this idealized geometrical view of bony geometry excludes all biological factors that might influence bone healing, the current data suggest a general rule for the standard osteotomy techniques applied and all surgical modifications: reducing the amount of slow gap healing and simultaneously increasing the area of faster contact healing may be beneficial for osteotomy healing. Thus, biplanar rather than uniplanar osteotomy should be performed for osteotomy around the knee.
authors.affiliation: Orthopädische Klinik des Centre Hospitalier de Luxembourg, Akademisches Lehrkrankenhaus der Universitätskliniken des Saarlandes, 78, rue d` Eich, 1460, Luxembourg, Luxembourg, dietrichpape@yahoo.de.
authors.forename: D
authors.initials: D
authors.lastname: Pape
authors.forename: R
authors.initials: R
authors.lastname: van Heerwaarden
authors.forename: M
authors.initials: M
authors.lastname: Haag
authors.forename: R
authors.initials: R
authors.lastname: Seil
authors.forename: H
authors.initials: H
authors.lastname: Madry
mesh_terms: D005269:Femur / Q000033:anatomy & histology* / Q000601:surgery*; D006801:Humans; D007719:Knee Joint / Q000033:anatomy & histology* / Q000601:surgery*; D008953:Models, Anatomic; D009929:Organ Size; D010027:Osteotomy / Q000379:methods*; D013499:Surface Properties; D013977:Tibia / Q000033:anatomy & histology* / Q000601:surgery*