title: The natural history of a newly developed flexion contracture following primary total knee arthroplasty.
abstract: OBJECTIVE
  We investigated the incidence, natural history, and functional consequences of a newly developed flexion contracture after total knee arthroplasty (TKA).
  
  
  METHODS
  Forty patients with full knee extension preoperatively who developed a postoperative flexion contracture were match-paired 1:2 with 80 patients who had full extension. The incidence of a newly developed flexion contracture, ROM, and Knee Society scores (KSS) at six weeks, four months, and one year were analysed.
  
  
  RESULTS
  The incidence of a new flexion contracture at six weeks was 14%, but diminished to 5% and 0.3% at four months and one year, respectively. One year after surgery, there was no difference in the KSS (p = 0.5).
  
  
  CONCLUSIONS
  This study showed that the majority of patients who developed a new flexion contracture after TKA have full knee extension one year postoperatively. Moreover, knee extension and KSS at one year are equivalent to those patients who did not developed a flexion contracture.
authors.affiliation: Department of Orthopaedic Surgery, Hospital Naval "Pedro Mallo", Buenos Aires, Argentina.
authors.forename: Andres
authors.initials: A
authors.lastname: Anania
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Abdel
authors.forename: Yuo-yu
authors.initials: YY
authors.lastname: Lee
authors.forename: Stephen
authors.initials: S
authors.lastname: Lyman
authors.forename: Alejandro
authors.initials: A
authors.lastname: González Della Valle
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D016022:Case-Control Studies; D003286:Contracture / Q000000981:diagnostic imaging / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000502:physiology / Q000601:surgery; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery*; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000453:epidemiology*; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology; D012189:Retrospective Studies; D016896:Treatment Outcome