title: The Mark Coventry Award: Trabecular metal tibial components were durable and reliable in primary total knee arthroplasty: a randomized clinical trial.
abstract: BACKGROUND
  Although highly porous metals have demonstrated excellent bone ingrowth properties and so are an intriguing option for fixation in total knee arthroplasty (TKA), some surgeons are skeptical about the durability of uncemented tibial fixation and the potential for soft tissues to adhere to these porous metals and perhaps cause knee stiffness or pain.
  
  
  OBJECTIVE
  The purpose of this study was to compare, in the context of a randomized clinical trial, a highly porous metal tibia compared with a traditional modular cemented tibia in terms of survivorship, Knee Society scores, range of motion (ROM), and complications.
  
  
  METHODS
  From 2003 to 2006, 397 patients (age 67.8 ± 8.7 years; 54% female) were randomized to three groups: (1) traditional modular cemented tibia; (2) cemented highly porous metal tibia; and (3) uncemented highly porous metal tibia. The same posterior-stabilized femoral component and patella component were cemented in every case. Stratified randomization was done for surgeon, patient's age, sex, and body mass index. Survivorship at 5 years was compared between the groups, as were Knee Society scores, ROM, and complications. Radiographic assessment included alignment, radiolucency, and implant migration/loosening. Patients were followed until death, revision, or for a minimum of 2 years (mean, 5 years; range, 2-9 years). Four patients were lost to followup before 2 years.
  
  
  RESULTS
  Highly porous metal tibias (both uncemented and cemented) were no different from traditional cemented modular tibial modular components in terms of survivorship at 5 years using a intention-to-treat analysis (96.8% [1]; 97.6% [2]; 96.7% [3]; p = 0.59). A per-protocol analysis revealed that no highly porous metal tibia was revised for aseptic loosening. Highly porous metal tibias performed comparably to traditional cemented modular tibias in terms of Knee Society scores, ROM, and the frequency of complications.
  
  
  CONCLUSIONS
  At 5 years this randomized clinical trial demonstrated that highly porous metal tibias provided comparably durable fixation and reliable pain relief and restoration of function when compared with a traditional cemented modular tibia in TKA.
  
  
  METHODS
  Level I, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
authors.affiliation: Department of Orthopaedic Surgery, Mayo Clinic, Rochester, MN, 55902, USA, pulidosierra.luis@mayo.edu.
authors.forename: Luis
authors.initials: L
authors.lastname: Pulido
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Abdel
authors.forename: David G
authors.initials: DG
authors.lastname: Lewallen
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Stuart
authors.forename: Joaquin
authors.initials: J
authors.lastname: Sanchez-Sotelo
authors.forename: Arlen D
authors.initials: AD
authors.lastname: Hanssen
authors.forename: Mark W
authors.initials: MW
authors.lastname: Pagnano
mesh_terms: D000328:Adult; D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000295:instrumentation*; D001363:Awards and Prizes; D001696:Biomechanical Phenomena; D001843:Bone Cements / Q000627:therapeutic use; D005260:Female; D006801:Humans; D057194:Intention to Treat Analysis; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D007720:Knee Prosthesis; D008297:Male; D008670:Metals; D008875:Middle Aged; D008910:Minnesota; D016062:Porosity; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D016059:Range of Motion, Articular; D020127:Recovery of Function; D012086:Reoperation; D013977:Tibia / Q000503:physiopathology / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D001843:Bone Cements; D008670:Metals