title: Survivorship of UKA in the middle-aged.
abstract: BACKGROUND
  Unicompartmental knee arthroplasty (UKA) is known to be a viable procedure allowing for preservation of the intact compartments and delivering excellent function at long-term follow-up. The primary purpose of this single-surgeon study was to analyse the survivorship of a fixed bearing UKA in patients younger than 60 years.
  
  
  METHODS
  From all UKAs implanted between 1993 and 2005 at the senior authors' centre, 223 patients <60 years at operation with a minimum follow-up of 5 years were identified including all-poly and metal-backed tibiae. They were evaluated applying the Knee Society Score (KSS) at latest follow-up. Survivorship was calculated using Kaplan-Meier analysis, which considered the following variables: gender, type of tibial implant, medial vs. lateral UKA, and age.
  
  
  RESULTS
  Average age at index operation was mean 53.7 (SD 5.8, range 30-60) years at a mean follow-up of 10.8 (SD 3.5, range 5-17) years. From the KSS, the knee score was 94.3 (SD 7.8) and the function score was 94.9 (SD 6.8). At latest follow-up, the implant survival rate was 94.3%. Survivorship for the entire cohort was 93.5% at 10 years (medial UKA 94.1% vs. lateral 91.8%), and 86.3% at 15 years (85.1% medial vs. 91.7% lateral)
  
  
  CONCLUSIONS
  In conclusion, excellent survival and function outcomes were noted in this subgroup of patients younger than 60 years. Revision rates were comparable to those studies in which UKA was performed on an elderly patient population. UKA can successfully be performed in patients younger than 60 years with appropriate patient selection.
authors.affiliation: Department of Orthopedics and Rheumatology, University Hospital Marburg, Germany. heyse@med.uni-marburg.de
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Heyse
authors.forename: Ahmed
authors.initials: A
authors.lastname: Khefacha
authors.forename: Geert
authors.initials: G
authors.lastname: Peersman
authors.forename: Philippe
authors.initials: P
authors.lastname: Cartier
mesh_terms: D000328:Adult; D000367:Age Factors; D019645:Arthroplasty, Replacement, Knee / Q000401:mortality*; D005260:Female; D005500:Follow-Up Studies; D005858:Germany / Q000453:epidemiology; D006801:Humans; D053208:Kaplan-Meier Estimate; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000401:mortality / Q000601:surgery*; D011474:Prosthesis Design; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D016896:Treatment Outcome