title: Trabecular metal tibia still stable at 5 years: an RSA study of 36 patients aged less than 60 years.
abstract: OBJECTIVE
  Clinical results of total knee replacement (TKR) are inferior in younger patients, mainly due to aseptic loosening. Coating of components with trabecular metal (TM) is a new way of enhancing fixation to bone. We have previously reported stabilization of TM tibial components at 2 years. We now report the 5-year follow-up of these patients, including RSA of their TM tibial components.
  
  
  METHODS
  22 patients (26 knees) received an uncemented TM cruciate-retaining tibial component and 19 patients (21 knees) a cemented NexGen Option cruciate-retaining tibial component. Follow-up with RSA, and clinical and radiographic examinations were done at 5 years. In bilaterally operated patients, the statistical analyses included only the first-operated knee.
  
  
  RESULTS
  Both groups had most migration within the first 3 months, the TM implants to a greater extent than the cemented implants. After 3 months, both groups stabilized and remained stable up to the 5-year follow-up.
  
  
  CONCLUSIONS
  After a high initial degree of migration, the TM tibia stabilized. This stabilization lasted for at least 5 years, which suggests a good long-term performance regarding fixation. The cemented NexGen CR tibial components showed some migration in the first 3 months and then stabilized up to the 5-year follow-up. This has not been reported previously.
authors.affiliation: Department of Orthopaedics and Center for Clinical Research, Falu General Hospital, Falun, Sweden. anders.henricson@itdalarna.se
authors.forename: Anders
authors.initials: A
authors.lastname: Henricson
authors.forename: Dan
authors.initials: D
authors.lastname: Rösmark
authors.forename: Kjell G
authors.initials: KG
authors.lastname: Nilsson
mesh_terms: D000328:Adult; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000379:methods*; D002484:Cementation / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000601:surgery*; D007720:Knee Prosthesis / Q000009:adverse effects / Q000706:statistics & numerical data*; D008297:Male; D008670:Metals; D008875:Middle Aged; D011474:Prosthesis Design / Q000379:methods*; D011475:Prosthesis Failure; D059869:Radiostereometric Analysis; D013977:Tibia / Q000601:surgery*; D016896:Treatment Outcome
chemical_list: D008670:Metals