title: Are the long term results of a high-flex total knee replacement affected by the range of flexion?
abstract: OBJECTIVE
  The purpose of this study was to examine the effect of deep flexion on the long-term durability of a high-flex ceramic implant in total knee arthroplasty.
  
  
  METHODS
  Five hundred and five consecutive knees replaced with a Bi-Surface knee system (Kyocera Medical, Osaka, Japan) were divided into two groups according to the range of flexion by 135° postoperatively. Comparison of implant durability was made between the high- and low-flexion groups after a minimum ten year follow-up.
  
  
  RESULTS
  With revision for any surgery as the end point, the survival rates at ten years were 95.5% and 96.2% in the high- and low-flexion group, respectively (p = 0.63). With revision for mechanical failure as the end point, survival rates were 98.7% and 98.5%, respectively (p = 0.94).
  
  
  CONCLUSIONS
  Implant survival rate was similar for both groups. Deep flexion seemed not to affect long-term durability.
authors.affiliation: Department of Orthopedic Surgery, Kyoto University, Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto, 606-8507, Japan, shnk@kuhp.kyoto-u.ac.jp.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Nakamura
authors.forename: Hiromu
authors.initials: H
authors.lastname: Ito
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Kenji
authors.initials: K
authors.lastname: Nakamura
authors.forename: Ueo
authors.initials: U
authors.lastname: Toyoji
authors.forename: Richard D
authors.initials: RD
authors.lastname: Komistek
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakamura
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D007720:Knee Prosthesis; D008297:Male; D009068:Movement / Q000502:physiology*; D011474:Prosthesis Design; D016059:Range of Motion, Articular; D016896:Treatment Outcome