title: Navigated cementless total knee arthroplasty - medium-term clinical and radiological results.
abstract: OBJECTIVE
  The objective of this prospective study was to evaluate the medium-term clinical and radiological results after navigated cementless implantation, without patella resurfacing, of a total knee endoprosthesis with tibial and femoral press-fit components, with a focus on survival rate and clinical outcome. The innovation is the non-cemented fixation together with the use of a navigation system.
  
  
  METHODS
  Sixty patients with gonarthrosis were included consecutively in this study. In all cases, the cementless Columbus total knee endoprosthesis with a coating out of pure titanium was implanted, using a navigation system. The Knee Society Score showed a statistically significant increase from 75 (± 21.26) before surgery to 180 (± 16.15) after a mean follow-up of 5.6 (± 0.25) years. The last radiological examination revealed no osteolysis. No radiolucent lines were seen at any time in the area of the femoral prosthetic components. In the tibial area, radiolucent lines were seen in 24.4 % of the cases, mostly in the distal uncoated part of the stem. During follow-up, no prosthesis had to be replaced because of aseptic loosening while in 2 cases revision surgery was necessary due to septic loosening and in 1 case due to unexplainable pain.
  
  
  CONCLUSIONS
  Navigated cementless implantation of the Columbus total knee endoprosthesis yielded good clinical and radiological results in the medium term. The excellent radiological osteointegration of the prosthetic components, coated with a microporous pure titanium layer and implanted with a press-fit technique, should be emphasized.
authors.affiliation: Department of Trauma Surgery, Plastic and Reconstructive Surgery, University Medicine Göttingen, D-37099 Göttingen, Germany.
authors.forename: Jan P
authors.initials: JP
authors.lastname: Schüttrumpf
authors.forename: Peter
authors.initials: P
authors.lastname: Balcarek
authors.forename: Stephan
authors.initials: S
authors.lastname: Sehmisch
authors.forename: Stephan
authors.initials: S
authors.lastname: Frosch
authors.forename: Martin M
authors.initials: MM
authors.lastname: Wachowski
authors.forename: Klaus M
authors.initials: KM
authors.lastname: Stürmer
authors.forename: Hans-Joachim
authors.initials: HJ
authors.lastname: Walde
authors.forename: Tim A
authors.initials: TA
authors.lastname: Walde