title: Results after Cementless Medial Oxford Unicompartmental Knee Replacement - Incidence of Radiolucent Lines.
abstract: OBJECTIVE
  Tibial radiolucent lines (RL) are commonly seen in cemented unicompartmental knee replacement (UKR). In the postoperative course, they can be misinterpreted as signs of loosening, thus leading to unnecessary revision. Since 2004, a cementless OUKR is available. First studies and registry data have shown equally good clinical results of cementless OUKR compared to the cemented version and a significantly reduced incidence of RL in cementless implants.
  
  
  METHODS
  This single-centre retrospective cohort study includes the first 30 UKR (27 patients) implanted between 2007 and 2009 with a mean follow-up of 5 years. Clinical outcome was evaluated using the OKS, AKS, range of movement (ROM) and level of pain (VAS). Standard radiologic evaluation was performed at three months, one and five years after surgery. The results five years after implantation were compared to a group of 27 cemented Oxford UKR (OUKR) in a matched-pair-analysis.
  
  
  RESULTS
  Tibial RL were seen in 10 implants three months after operation, which significantly decreased to five after one year and to three after five years (p = 0.02). RL did not have a significant influence on revision (p = 1.0) or clinical outcome after five years. RL were always partial, never progressive and strictly limited to the tibia. There was no significant difference in the incidence of tibial RL five years after implantation between cemented and cementless implants (cemented: 4, cementless: 3, p = 1.0).
  
  
  CONCLUSIONS
  After cementless implantation RL were limited to the tibia, partial and never progressive. During short term follow-up the incidence of RL decreased significantly. RL seem to have no influence on clinical outcome and revision.
authors.affiliation: Clinic of Orthopedic and Trauma Surgery, University of Heidelberg, Heidelberg, Germany.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Panzram
authors.affiliation: Clinic of Orthopedic and Trauma Surgery, University of Heidelberg, Heidelberg, Germany.
authors.forename: Ines
authors.initials: I
authors.lastname: Bertlich
authors.affiliation: Clinic of Orthopedic and Trauma Surgery, University of Heidelberg, Heidelberg, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Reiner
authors.affiliation: Clinic of Orthopedic and Trauma Surgery, University of Heidelberg, Heidelberg, Germany.
authors.forename: Tilman
authors.initials: T
authors.lastname: Walker
authors.affiliation: Clinic of Orthopedic and Trauma Surgery, University of Heidelberg, Heidelberg, Germany.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Hagmann
authors.affiliation: Clinic of Diagnostic and Interventional Radiology, University of Heidelberg, Heidelberg, Germany.
authors.forename: Marc-André
authors.initials: MA
authors.lastname: Weber
authors.affiliation: Clinic of Orthopedic and Trauma Surgery, University of Heidelberg, Heidelberg, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Gotterbarm
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000379:methods*; D001843:Bone Cements; D015331:Cohort Studies; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000601:surgery; D011475:Prosthesis Failure / Q000209:etiology; D012189:Retrospective Studies; D013977:Tibia / Q000000981:diagnostic imaging
chemical_list: D001843:Bone Cements