title: VALUE OF PREOPERATIVE RADIOGRAPHIC EVALUATIONS ON KNEE BONE DEFECTS FOR REVISION ARTHROPLASTY.
abstract: OBJECTIVE
  To evaluate the value of preoperative radiographic evaluations for total knee arthroplasty (TKA) revision.
  
  
  METHODS
  Thirty-one knees that were operated between 2006 and 2008, in a consecutive series of cases of TKA revision surgery were analyzed retrospectively. The following criteria were evaluated: number of wedges or structured bone grafts used for filling the bone defects; locations of the wedges and bone grafts used; and mean thickness of the polyethylene used. The AORI classification was previously established based on preoperative radiographs, using preestablished criteria. After the analysis, the knees were divided into four groups (I, IIA, IIB and III).
  
  
  RESULTS
  The mean number of wedges or grafts used in each knee progressively increased among the groups (group I: 1.33; group IIA: 2; group IIB: 4.33; and group III: 4.83) (P = 0.0012). The commonest locations were medial in the tibia and posteromedial in the femur. There were no statistically significant differences in the thickness of the polyethylene used.
  
  
  CONCLUSIONS
  The AORI classification for bone defects in the knee, based on preoperative radiographs, showed a correlation with increasing need to use wedges and/or structured grafts in TKA revisions. However, up to 46% of the knees in groups I and IIA presented bone defects of up to 5 mm that were not diagnosed by means of preoperative radiographs.
authors.affiliation: Orthopedist and Preceptor, Knee Group, Institute of Orthopedics and Traumatology, HC/FMUSP - São Paulo, Brazil.
authors.forename: Mauricio Masasi
authors.initials: MM
authors.lastname: Iamaguchi
authors.affiliation: Resident, Knee Group, Institute of Orthopedics and Traumatology, HC/FMUSP - São Paulo, Brazil.
authors.forename: Camilo Partezani
authors.initials: CP
authors.lastname: Helito
authors.affiliation: Assistant Physician, Knee Group, Institute of Orthopedics and Traumatology, HC/FMUSP - São Paulo, Brazil.
authors.forename: Riccardo Gomes
authors.initials: RG
authors.lastname: Gobbi
authors.affiliation: Assistant Physician, Knee Group, Institute of Orthopedics and Traumatology, HC/FMUSP - São Paulo, Brazil.
authors.forename: Marco Kawamura
authors.initials: MK
authors.lastname: Demange
authors.affiliation: Orthopedist and Preceptor, Knee Group, Institute of Orthopedics and Traumatology, HC/FMUSP - São Paulo, Brazil.
authors.forename: Luiz Eduardo Passarelli
authors.initials: LE
authors.lastname: Tirico
authors.affiliation: Assistant Physician and Head, Knee Group, Institute of Orthopedics and Traumatology, HC/FMUSP - São Paulo, Brazil.
authors.forename: Jose Ricardo
authors.initials: JR
authors.lastname: Pecora
authors.affiliation: Full Professor, Department of Orthopedics, USP School of Medicine - São Paulo, Brazil.
authors.forename: Gilberto Luis
authors.initials: GL
authors.lastname: Camanho
keywords: Bone Defects; Radiography/classification; Total Knee Arthroplasty Revision/classification