title: The cemented twin-peg Oxford partial knee replacement survivorship: a cohort study.
abstract: BACKGROUND
  A new twin-peg version of the Oxford knee was introduced in 2003. However, until now there has been no information about its survivorship. The aim of this study was to determine the survivorship, and the patients' perception of outcome over time.
  
  
  METHODS
  A cohort of all patients treated from 2003 until 2009 using the twin-peg Oxford partial knee was contacted. The main indication for treatment was anteromedial osteoarthritis (AMOA). The Oxford Knee Score (OKS), American Knee Society Functional (AKS-F) score and satisfaction rate were obtained, and the time-to-failure was used to perform a survival analysis.
  
  
  RESULTS
  There were 249 patients treated, with 288 medial cemented implants. Of these, 248 patients with 287 implants could be contacted and implant survival or failure was verified. Their mean age was 67years (range: 34-94). The mean follow-up time was 5.1years (maximum: 9.2). The nine years cumulative implant survival rate for all cases using revision for any reason to define failure was 98% (95% CI, 84 to 100). There were no cases of femoral loosening. The mean OKS was 22 pre-operatively, 41 at two years, and 41 at final review, at which point 96% of patients were very or fairly pleased with the result.
  
  
  CONCLUSIONS
  The survivorship of the twin-peg knee was better than that of the single peg knee at our centre, and appeared no worse than the results of the single peg knee at the originating centre. It can offer secure femoral fixation, sustained clinical benefit and patient satisfaction.
  
  
  METHODS
  Level IV case-series.
authors.affiliation: The Robert Jones and Agnes Hunt Orthopaedic Hospital NHS Foundation Trust, Oswestry, Shropshire SY10 7AG, United Kingdom. Electronic address: Stephen.White@rjah.nhs.uk.
authors.forename: Stephen H
authors.initials: SH
authors.lastname: White
authors.affiliation: The Robert Jones and Agnes Hunt Orthopaedic Hospital NHS Foundation Trust, Oswestry, Shropshire SY10 7AG, United Kingdom. Electronic address: Sharon.Roberts@rjah.nhs.uk.
authors.forename: Sharon
authors.initials: S
authors.lastname: Roberts
authors.affiliation: The Robert Jones and Agnes Hunt Orthopaedic Hospital NHS Foundation Trust, Oswestry, Shropshire SY10 7AG, United Kingdom; Institute for Science and Technology in Medicine, Keele University, United Kingdom. Electronic address: jan.kuiper@nhs.net.
authors.forename: Jan Herman
authors.initials: JH
authors.lastname: Kuiper
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D001843:Bone Cements; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology* / Q000601:surgery; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000503:physiopathology / Q000601:surgery*; D017060:Patient Satisfaction; D011474:Prosthesis Design; D016059:Range of Motion, Articular / Q000502:physiology*; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D001843:Bone Cements
keywords: Anteromedial osteoarthritis; Oxford twin-peg cemented knee replacement; Patient reported outcome measures (PROMs); Survival analysis; Unicompartmental knee replacement