title: Better functional outcome after single-radius TKA compared with multi-radius TKA.
abstract: OBJECTIVE
  To determine whether the design of the femoral component influenced patient outcomes.
  
  
  METHODS
  Two hundred and thirty-seven patients were randomized to compare functional outcomes between single-radius TKA (SR, 118 patients) and multi-radius TKA (MR, 119 patients) with a minimum follow-up of 5 years. Prospective pre- and postoperative assessments were performed by the clinical and radiological criteria of the Knee Society Score (KSS), WOMAC and Short-Form 12 (SF12) questionnaires. The extension mechanism was assessed based on the quadriceps strength and chair test. Patient satisfaction was also assessed.
  
  
  RESULTS
  The median follow-up was 5.7 (range 5-7) years. At last follow-up, significant better KSSs (p = 0.001), range of motion (p = 0.001), extension lag (p = 0.020), quadriceps strength (p = 0.004), chair test (p = 0.032) and WOMAC pain (p = 0.002) were found in the SR group. Moreover, the improvements of these variables were early in the SR group (from 6 postoperative months). There were no significant differences in WOMAC function or SF12 physical and mental components. The revision rate and implant survival were similar in both groups. Satisfaction rate was significantly higher in SR group (p = 0.032).
  
  
  CONCLUSIONS
  This study shows better results with SR cruciate-retaining femoral component than MR component. The use of SR system is recommended because, although the clinically relevant differences were moderate, the functional improvement was earlier and the patient satisfaction higher with this design.
  
  
  METHODS
  Therapeutic study, Level I.
authors: Department of Orthopaedic Surgery, Elda University Hospital, Ctra Elda-Sax s/n, 03600, Elda, Alicante, Spain.
authors: Isabel
authors: I
authors: Collados-Maestre
authors: Department of Orthopaedic Surgery, Elda University Hospital, Ctra Elda-Sax s/n, 03600, Elda, Alicante, Spain. lizaur1@telefonica.net.|Traumatology and Orthopaedia, Faculty of Medicine, Miguel Hernandez University, Elche, Alicante, Spain. lizaur1@telefonica.net.
authors: Alejandro
authors: A
authors: Lizaur-Utrilla
authors: Department of Orthopaedic Surgery, Elda University Hospital, Ctra Elda-Sax s/n, 03600, Elda, Alicante, Spain.
authors: Blanca
authors: B
authors: Gonzalez-Navarro
authors: Department of Orthopaedic Surgery, Elda University Hospital, Ctra Elda-Sax s/n, 03600, Elda, Alicante, Spain.
authors: Francisco A
authors: FA
authors: Miralles-Muñoz
authors: Department of Orthopaedic Surgery, Elda University Hospital, Ctra Elda-Sax s/n, 03600, Elda, Alicante, Spain.
authors: Luis
authors: L
authors: Marco-Gomez
authors: Traumatology and Orthopaedia, Faculty of Medicine, Miguel Hernandez University, Elche, Alicante, Spain.
authors: Fernando A
authors: FA
authors: Lopez-Prats
authors: Clinical Research Unit, Elda University Hospital, Elda, Alicante, Spain.
authors: Vicente
authors: V
authors: Gil-Guillen
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D005260:Female; D005269:Femur / Q000601:surgery*; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000601:surgery*; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D011446:Prospective Studies; D011474:Prosthesis Design; D016059:Range of Motion, Articular; D020127:Recovery of Function; D016037:Single-Blind Method; D016896:Treatment Outcome
keywords: Multi-radius; Outcomes; Quadriceps strength; Single-radius; Total knee arthroplasty