title: Single-radius, multidirectional total knee replacement.
abstract: OBJECTIVE
  The present study was designed to evaluate the mid-term (5- to 8-year) survival rate of a new total knee replacement (TKR) with a single-radius femoral component and a multidirectional, highly congruent tibial component, in comparison with an historical group (TKR with multi-radius design and fixed bearing).
  
  
  METHODS
  Four hundred and thirty patients were included, of which 369 patients (86 %) completed the 5-year follow-up with Knee Society Score evaluation and radiograph examination (study group = 387, control group = 83).
  
  
  RESULTS
  There was a significant improvement for all analysed items between pre-operative status and late follow-up. Mean knee score was 93 ± 9 points in the study group and 88 ± 16 points in the control group (p < 0.001). Mean flexion angle was not different (118 ± 11 vs. 114 ± 13 degrees). Mean functional score was 87 ± 16 points in the study group and 71 ± 24 points in the control group (p < 0.001). Survival rate at 5-year follow-up was 98.8 % (vs. 98.0 %) for mechanical revisions only, and 96.4 % (vs. 98.1 %) for all revisions.
  
  
  CONCLUSIONS
  The new TKR allowed obtaining significantly better results than the fixed-bearing TKR. These results are in line with the best series published in the current literature, but there was no evidence of any superiority of this TKR against already published standards.
authors.affiliation: Center for Orthopedic and Hand Surgery, University Hospital Strasbourg, 10 avenue Baumann, 67400, Illkirch, France, jean-yves.jenny@chru-strasbourg.fr.
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Jenny
authors.forename: Rolf
authors.initials: R
authors.lastname: Miehlke
authors.forename: Dominique
authors.initials: D
authors.lastname: Saragaglia
authors.forename: Robert
authors.initials: R
authors.lastname: Geyer
authors.forename: Numa
authors.initials: N
authors.lastname: Mercier
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Schoenahl
authors.forename: Birger
authors.initials: B
authors.lastname: Thiel
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D005260:Female; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D011474:Prosthesis Design; D011475:Prosthesis Failure; D016059:Range of Motion, Articular / Q000502:physiology; D012086:Reoperation; D016896:Treatment Outcome