title: Is it possible to re-establish pre-operative patellar kinematics using a ligament-balanced technique in total knee arthroplasty? A cadaveric investigation.
abstract: OBJECTIVE
  Several authors emphasise that the appearance of patellar maltracking after total knee arthroplasty (TKA) is caused by rotational malalignment of the femoral and tibial components. Ligament-balanced femoral component rotation was not found to be associated with abnormal postoperative patellar position. We hypothesised that a ligament-balanced technique in TKA has the ability to best re-establish patellar kinematics.
  
  
  METHODS
  In ten cadaveric knees TKA was performed assessing femoral rotation in ligament-balanced and different femoral and tibial component rotation alignments. Patellar kinematics after different component rotations were analysed using a commercial computer navigation system.
  
  
  RESULTS
  Ligament-balanced femoral rotation showed the best re-establishment of patellar kinematics after TKA compared to the healthy pre-operative knee. In contrast to tibial component rotation, femoral component rotation had a major impact on patellofemoral kinematics.
  
  
  CONCLUSIONS
  This investigation suggests that a ligament-balanced technique in TKA is most likely to re-establish natural patellofemoral kinematics. Tibial component rotation did not influence patellar kinematics.
authors.affiliation: Department of Orthopaedic Surgery, University of Regensburg, Kaiser-Karl-V Allee 3, 93077, Bad Abbach, Germany, keshmiri_armin@yahoo.de.
authors.forename: Armin
authors.initials: A
authors.lastname: Keshmiri
authors.forename: Hans
authors.initials: H
authors.lastname: Springorum
authors.forename: Clemens
authors.initials: C
authors.lastname: Baier
authors.forename: Florian
authors.initials: F
authors.lastname: Zeman
authors.forename: Joachim
authors.initials: J
authors.lastname: Grifka
authors.forename: Günther
authors.initials: G
authors.lastname: Maderbacher
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D001696:Biomechanical Phenomena; D002102:Cadaver; D005269:Femur / Q000601:surgery; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology / Q000601:surgery*; D007720:Knee Prosthesis; D008022:Ligaments / Q000601:surgery*; D010329:Patella / Q000601:surgery*; D012399:Rotation; D013977:Tibia / Q000601:surgery