title: No difference between standard and high flexion cruciate retaining total knee arthroplasty: a prospective randomised controlled study.
abstract: OBJECTIVE
  The purpose of this prospective, randomised, double-blind study was to test the hypotheses that patients with high-flexion total knee arthroplasty (TKA) have (1) a wider/greater range of motion (ROM) post-operatively and (2) higher levels of knee society score (KSS) and WOMAC score post-operatively compared to standard TKA.
  
  
  METHODS
  In this study, 28 high flexion with 31 standard TKAs were compared. We measured ROM, pre-operatively, on day 3, 7, 28, and after 6 and 36 months post-operatively as well as KSS and WOMAC score pre-operatively, on day 28 and after 6 and 36 months post-operatively.
  
  
  RESULTS
  No statistically significant differences were found between both groups with regard to the target parameters. The mean ROM was 113° (range 80°-140°, SD 13.4°) in the control group (standard TKA) and 117° (range 90°-140°, SD 12.3) in the study group (high-flexion TKA) at 36 months follow-up [p = not significant (n.s.)]. The KSS pre-operatively was 38.2 (range 8-64, SD 15.8) in the control group and 45.9 (range 8-74, SD 16.0) in the study group (n.s.) increasing to 157.6 in the control group and 156.7 in the study group (p = n.s) at 36 months follow-up.
  
  
  CONCLUSIONS
  This study could not confirm significant benefits of high-flexion TKA compared to standard TKA with regard to ROM and higher levels of KSS and WOMAC score.
  
  
  METHODS
  I.
authors.affiliation: Department of Orthopaedic Surgery, University of Regensburg, Kaiser-Karl-V Allee 3, 93077, Bad Abbach, Germany.
authors.forename: Hans Robert
authors.initials: HR
authors.lastname: Springorum
authors.forename: Günther
authors.initials: G
authors.lastname: Maderbacher
authors.forename: Benjamin
authors.initials: B
authors.lastname: Craiovan
authors.forename: Christian
authors.initials: C
authors.lastname: Lüring
authors.forename: Clemens
authors.initials: C
authors.lastname: Baier
authors.forename: Joachim
authors.initials: J
authors.lastname: Grifka
authors.forename: Armin
authors.initials: A
authors.lastname: Keshmiri
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation / Q000379:methods*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology / Q000601:surgery; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D063868:Patient Outcome Assessment; D011446:Prospective Studies; D011474:Prosthesis Design; D016059:Range of Motion, Articular / Q000502:physiology