title: Trabecular metal in total knee arthroplasty associated with higher knee scores: a randomized controlled trial.
abstract: BACKGROUND
  Porous tantalum is an option of cementless fixation for TKA, but there is no randomized comparison with a cemented implant in a mid-term followup.
  
  
  OBJECTIVE
  We asked whether a tibial component fixed by a porous tantalum system might achieve (1) better clinical outcome as reflected by the Knee Society Score (KSS) and WOMAC Osteoarthritis Index, (2) fewer complications and reoperations, and (3) improved radiographic results with respect to aseptic loosening compared with a conventional cemented implant.
  
  
  METHODS
  We randomized 145 patients into two groups, either a porous tantalum cementless tibial component group (Group 1) or cemented conventional tibial component in posterior cruciate retaining TKA group (Group 2). Patients were evaluated preoperatively and 15 days, 6 months, and 5 years after surgery, using the KSS and the WOMAC index. Complications, reoperations, and radiographic failures were tallied.
  
  
  RESULTS
  At 5-year followup the KSS mean was 90.4 (range, 68-100; 95% CI, ± 1.6) for Group 1, and 86.5 (range, 56-99; 95% CI, ± 2.4) for Group 2. The effect size, at 95% CI for the difference between means, was 3.88 ± 2.87. The WOMAC mean was 15.1 (range, 0-51; 95% CI, ± 2.6) for the Group 1, and 19.1 (range, 4-61; 95% CI, ± 2.9) for Group 2. The effect size for WOMAC was -4.0 ± 3.9. There were no differences in the frequency of complications or in aseptic loosening between the two groups.
  
  
  CONCLUSIONS
  Our data suggest there are small differences between the uncemented porous tantalum tibial component and the conventional cemented tibial component. It currently is undetermined whether the differences outweigh the cost of the implant and the results of their long-term performance.
authors.affiliation: Instituto de Cirugía Ortopédica y Traumatología de Barcelona, Río de Oro 37, 5º3ª, Barcelona, 08034, Spain, mferfai@gmail.com.
authors.forename: Mariano
authors.initials: M
authors.lastname: Fernandez-Fairen
authors.forename: Daniel
authors.initials: D
authors.lastname: Hernández-Vaquero
authors.forename: Antonio
authors.initials: A
authors.lastname: Murcia
authors.forename: Ana
authors.initials: A
authors.lastname: Torres
authors.forename: Rafael
authors.initials: R
authors.lastname: Llopis
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000295:instrumentation*; D001696:Biomechanical Phenomena; D001843:Bone Cements / Q000627:therapeutic use; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D016062:Porosity; D011183:Postoperative Complications / Q000209:etiology / Q000601:surgery; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D020127:Recovery of Function; D012086:Reoperation; D012307:Risk Factors; D013030:Spain; D013635:Tantalum; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D001843:Bone Cements; D013635:Tantalum