title: Cementless second-generation hydroxyapatite CaP-coated tibial component: an 8.7-year follow-up.
abstract: BACKGROUND
  This is the first study that reports on the mid-term results of 81 patients suffering from arthritis of the knee, treated with a cementless second-generation hydroxyapatite calcium phosphate (CaP)-coated tibial component.
  
  
  METHODS
  Seventy-six knees with osteoarthritis were evaluated according to the Knee Society clinical, functional and radiological score, the Hospital for Special Surgery Rating System and the Patella Score. The clinical and radiological parameters were assessed preoperatively and after a mean follow-up of 8.7 years.
  
  
  RESULTS
  All the three score systems revealed excellent clinical outcomes after the follow-up period. The mean preoperative Knee Society clinical Score was 124.41 ± 12.99 and the mean postoperative score was 187.07 ± 14.59 at the time of the final consultation (p = 0.0008). The survival rate was 97.5 %. Radiolucency of <1 mm around the uncemented hydroxyapatite CaP-coated tibial component without accompanying pain symptoms was seen in fewer than 6 % of cases. In two cases, a medial cyst, also without other clinical symptoms, was observed beside the tip of the tibial fixation screw.
  
  
  CONCLUSIONS
  These findings indicate that the uncemented second-generation hydroxyapatite CaP-coated tibial component performed well at mid-term follow-up, and provides sufficiently stable bone ingrowth fixation.
authors.affiliation: Department of Orthopedic and Trauma Surgery, St. Barbara Hospital, Barbara Str. 1, 45964 Gladbeck, Germany. christian.wedemeyer@uni-duisburg-essen.de
authors.forename: Christian
authors.initials: C
authors.lastname: Wedemeyer
authors.forename: Max Daniel
authors.initials: MD
authors.lastname: Kauther
authors.forename: Miralay
authors.initials: M
authors.lastname: Bülbül
authors.forename: Marcus
authors.initials: M
authors.lastname: Jäger
authors.forename: Ralf
authors.initials: R
authors.lastname: Peppmüller
authors.forename: Thomas
authors.initials: T
authors.lastname: Bredendiek
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002130:Calcium Phosphates; D020099:Coated Materials, Biocompatible; D017886:Durapatite; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery*; D011474:Prosthesis Design; D013977:Tibia; D013997:Time Factors
chemical_list: D002130:Calcium Phosphates; D020099:Coated Materials, Biocompatible; D017886:Durapatite; C020243:calcium phosphate