title: What is the optimal alignment of the tibial and femoral components in knee arthroplasty?
abstract: BACKGROUND
  Surgeon-dependent factors such as optimal implant alignment are thought to play a significant role in outcome following primary total knee arthroplasty (TKA). Exact definitions and references for optimal alignment are, however, still being debated. This overview of the literature describes different definitions of component alignment following primary TKA for (1) tibiofemoral alignment in the AP plane, (2) tibial and femoral component placement in the AP plane, (3) tibial and femoral component placement in the sagittal plane, and (4) rotational alignment of tibial and femoral components and their role in outcome and implant survival.
  
  
  METHODS
  We performed a literature search for original and review articles on implant positioning following primary TKA. Definitions for coronal, sagittal, and rotational placement of femoral and tibial components were summarized and the influence of positioning on survival and functional outcome was considered.
  
  
  RESULTS
  Many definitions exist when evaluating placement of femoral and tibial components. Implant alignment plays a role in both survival and functional outcome following primary TKA, as component malalignment can lead to increased failure rates, maltracking, and knee pain.
  
  
  CONCLUSIONS
  Based on currently available evidence, surgeons should aim for optimal alignment of tibial and femoral components when performing TKA.
authors.affiliation: Department of Orthopaedic Surgery.
authors.forename: Kirill
authors.initials: K
authors.lastname: Gromov
authors.forename: Mounim
authors.initials: M
authors.lastname: Korchi
authors.forename: Morten G
authors.initials: MG
authors.lastname: Thomsen
authors.forename: Henrik
authors.initials: H
authors.lastname: Husted
authors.forename: Anders
authors.initials: A
authors.lastname: Troelsen
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D005269:Femur / Q000601:surgery*; D006801:Humans; D010043:Outcome and Process Assessment, Health Care; D011475:Prosthesis Failure; D013977:Tibia / Q000601:surgery*