title: Revision total knee arthroplasty: causes and outcomes.
abstract: BACKGROUND
  Local data on revision total knee arthroplasty (TKA) are limited. This study aims to assess the causes and outcomes of revision TKA in a single institution, with a 2-year follow-up.
  
  
  METHODS
  A retrospective review of case records of patients who underwent revision TKA in 2008 and 2009 in the authors' institution was performed. Outcome was assessed using SF-36, Oxford knee score and Knee Society Clinical Rating System preoperatively, at 6 months and at 2 years' follow-up.
  
  
  RESULTS
  Forty-one patients (41 knees) were included in the study. Indications for revision were aseptic loosening in 13 (31.7%), mechanical wear/component failure in 10 (24.4%), infection in 9 (22.0%), malalignment in 4 (9.8%), instability in 3 (7.3%), periprosthetic fracture in 1 (2.4%) and persistent stiffness in 1 (2.4%). Significant improvements were seen postoperatively in all 3 instruments used to evaluate clinical outcome. These improvements were seen at 6 months after surgery, and were maintained through the 2-year follow-up period. There were no significant changes in all scores between 6 months and 2 years follow-up. There was 100% survivorship of the implants with no postoperative complications requiring surgical intervention.
  
  
  CONCLUSIONS
  Indications for revision TKA locally are similar to those in other large centres. Revision total knee arthroplasty results in significantly improved function and quality of life for patients, which is maintained over a 2-year follow-up period. In our series, we obtained 100% implant survivorship.
authors.affiliation: Department of Orthopaedic Surgery, Singapore General Hospital, Singapore. k_s_tay@hotmail.com
authors.forename: Kae Sian
authors.initials: KS
authors.lastname: Tay
authors.forename: Ngai Nung
authors.initials: NN
authors.lastname: Lo
authors.forename: Seng Jin
authors.initials: SJ
authors.lastname: Yeo
authors.forename: Shi Lu
authors.initials: SL
authors.lastname: Chia
authors.forename: Darren K J
authors.initials: DK
authors.lastname: Tay
authors.forename: Pak Lin
authors.initials: PL
authors.lastname: Chin
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery*; D011183:Postoperative Complications / Q000453:epidemiology*; D011475:Prosthesis Failure; D012086:Reoperation; D012189:Retrospective Studies; D012846:Singapore / Q000453:epidemiology; D013997:Time Factors