title: Prevalence of knee arthroplasty in the state of São Paulo between 2003 and 2010.
abstract: The volume of knee arthroplasty procedures has increased over the last decade. The aim of this study was to estimate the frequency of these procedures performed within the public healthcare system of the state of São Paulo between 2003 and 2010.
  Cross-sectional study conducted in the state of São Paulo by researchers at Hospital do Servidor Público do Estado de São Paulo.
  A sample of 10,952 patients (7,891 females and 3,061 males) who underwent primary total knee arthroplasty (TKA) and revision of total knee arthroplasty (RTKA) in the state of São Paulo between 2003 and 2010 was evaluated. The patients were cataloged using the public healthcare service's TABNET software. All of the patients presented primary osteoarthritis of the knee. The variables of gender, number of primary TKA procedures and number of RTKA procedures were evaluated.
  A total of 10,952 TKA procedures were performed (annual average of 1369), of which 9,271 (85%) were TKA and 1,681 (15%), RTKA. Of the TKA procedures, 72% were carried out on females (P < 0.0001), while 70% of the RTKA procedures were on females (P < 0.0001). The average ratio of TKA to RTKA was 5.5:1 (P < 0.0001); the ratios in 2003 and 2010 were 9.0:1 and 4.4:1 (P < 0.0001), respectively.
  The number and frequency of TKA and RTKA procedures increased in the state of São Paulo between 2003 and 2010. This increase was relatively greater in RTKA than in TKA and was predominantly in female patients.
authors.affiliation: MD. Attending Physician in the Knee Group, Orthopedics and Traumatology Service, Hospital do Servidor Público do Estado de São Paulo, São Paulo (SP), Brazil.
authors.forename: Rogério Teixeira de
authors.initials: RT
authors.lastname: Carvalho
authors.affiliation: MD. Fellow in the Knee Group, Orthopedics and Traumatology Service, Hospital do Servidor Público do Estado de São Paulo, São Paulo (SP), Brazil.
authors.forename: Jonny Chaves Lima
authors.initials: JC
authors.lastname: Canté
authors.affiliation: MSc. Statistician, Orthopedics and Traumatology Service, Hospital do Servidor Público do Estado de São Paulo, São Paulo (SP), Brazil.
authors.forename: Juliana Hoss Silva
authors.initials: JH
authors.lastname: Lima
authors.affiliation: MD. Fellow in the Pediatric Orthopedics Group, Orthopedics and Traumatology Service, Hospital do Servidor Público do Estado de São Paulo, São Paulo (SP), Brazil.
authors.forename: Luiz Alberto Barbosa
authors.initials: LA
authors.lastname: Tavares
authors.affiliation: MD. Attending Physician in the Hip Group, Orthopedics and Traumatology Service, Hospital do Servidor Público do Estado de São Paulo, São Paulo (SP), Brazil.
authors.forename: Marcelo Itiro
authors.initials: MI
authors.lastname: Takano
authors.affiliation: MD. Attending Physician in the Knee Group, Orthopedics and Traumatology Service, Hospital do Servidor Público do Estado de São Paulo, São Paulo (SP), Brazil.
authors.forename: Fernando Gomes
authors.initials: FG
authors.lastname: Tavares
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000379:methods / Q000706:statistics & numerical data*; D001938:Brazil; D003430:Cross-Sectional Studies; D003695:Delivery of Health Care / Q000706:statistics & numerical data*; D005260:Female; D006779:Hospitals, Public / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D017678:Sex Distribution; D012737:Sex Factors; D018709:Statistics, Nonparametric; D013997:Time Factors