title: PLATEAU-PATELLA ANGLE: AN OPTION FOR ASSESSING PATELLAR HEIGHT ON PROXIMAL TIBIA OSTEOTOMY.
abstract: OBJECTIVE
  To compare the plateau-patella angle method to the methods already established for patellar height measurement in patients undergoing high tibial osteotomy.
  
  
  METHODS
  This is a retrospective study of 13 patients undergoing medial opening tibial osteotomy. The patellar height was measured in pre and post-operative radiographs by the methods from Insall-Salvati, Caton-Deschamps, Blackburne-Peel and patella-plateau angle, as well as the tibial slope and length of the patellar tendon. Measurements were performed by two knee surgeons at two different times.
  
  
  RESULTS
  The mean age was 41.33 ± 01.09 years old. The average rates of Caton-Deschamps, Blackburne-Peel, Insall-Salvati and plateau-patella angle were, respectively, 1.00; 0.89; 1.10; and 23.15° preoperatively, and 0.89; 0.78; 1.11; and 20.46°, postoperatively. The correlation of Caton-Deschamps, Blackburne-Pell, and Insall-Salvati indexes and plateau-patellar angle interobserver was 0.72 (p <0.001), 0:54 (p <0.001), 0.65 (p <0.001), and 0.67 (w <0.001), respectively.
  
  
  CONCLUSIONS
  The plateau-patella angle method undergoes changes that are correlated with changes in tibial slope after osteotomy, unlike the classical methods. This fact may lead to overestimate the reduction of patellar height after osteotomy. Level of evidence IV. Case Series.
authors.affiliation: . Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Instituto de Ortopedia e Traumatologia, Knee Group, São Paulo, SP, Brazil.
authors.forename: Marcelo Batista
authors.initials: MB
authors.lastname: Bonadio
authors.affiliation: . Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Instituto de Ortopedia e Traumatologia, Knee Group, São Paulo, SP, Brazil.
authors.forename: Júlio Augusto Do Prado
authors.initials: JA
authors.lastname: Torres
authors.affiliation: . Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Instituto de Ortopedia e Traumatologia, Knee Group, São Paulo, SP, Brazil.
authors.forename: Vicente
authors.initials: V
authors.lastname: Mazzaro
authors.affiliation: . Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Instituto de Ortopedia e Traumatologia, Knee Group, São Paulo, SP, Brazil.
authors.forename: Camilo Partezani
authors.initials: CP
authors.lastname: Helito
authors.affiliation: . Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Instituto de Ortopedia e Traumatologia, Knee Group, São Paulo, SP, Brazil.
authors.forename: Riccardo Gomes
authors.initials: RG
authors.lastname: Gobbi
authors.affiliation: . Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Instituto de Ortopedia e Traumatologia, Knee Group, São Paulo, SP, Brazil.
authors.forename: Marco Kawamura
authors.initials: MK
authors.lastname: Demange
keywords: Knee.; Osteotomy; Patellar ligament