title: Clinical outcome is not affected by total knee arthroplasty alignment.
abstract: OBJECTIVE
  This study aims to analyse the influence on total knee arthroplasty (TKA) clinical outcomes of biomechanical intra-operative computer-assisted surgery-measured parameters, together with radiographic and demographical data.
  
  
  METHODS
  Between 2007 and 2009, 227 computer-assisted surgery (CAS) primary TKAs were performed in 219 consecutive patients. Information about gender, age and body mass index (BMI) was collected for each patient. Before knee replacement, all patients underwent a complete radiographic examination and passive flexion-extension range of motion was recorded. All TKAs were implanted using an image-free knee navigation system. Patients included in the study were evaluated at 3, 6 and 12 months of follow-up and then yearly. At each follow-up, subjects were asked to answer the validated Italian version of the Knee Injury and Osteoarthritis Outcome Score.
  
  
  RESULTS
  One hundred and eighty patients (187 knees) had data available for analysis. Complications were reported in 13 patients (7.0 %). Intra-operative CAS-measured parameters, together with age, BMI, gender, pre- and post-operative radiographic alignment, did not influence TKA clinical results at a mean 2 years of follow-up. On the other hand, higher post-operative flexion arc of movement was suggestive of better clinical outcomes.
  
  
  CONCLUSIONS
  TKA clinical outcome is influenced by post-operative knee flexion, other than neutral mechanical limb alignment. Therefore, it is recommended to prefer TKA designs that allow high flexion and to encourage early physical rehabilitation.
  
  
  METHODS
  IV.
authors.affiliation: Department of Orthopaedics and Traumatology, University of Modena and Reggio Emilia, Via del Pozzo 71, 41124, Modena, Italy. raffaele.mugnai@gmail.com.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Mugnai
authors.affiliation: Department of Orthopaedics and Traumatology, University of Modena and Reggio Emilia, Via del Pozzo 71, 41124, Modena, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Zambianchi
authors.affiliation: Department of Orthopaedics and Traumatology, University of Modena and Reggio Emilia, Via del Pozzo 71, 41124, Modena, Italy.
authors.forename: Vitantonio
authors.initials: V
authors.lastname: Digennaro
authors.affiliation: Department of Orthopaedics and Traumatology, University of Modena and Reggio Emilia, Via del Pozzo 71, 41124, Modena, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Marcovigi
authors.affiliation: Department of Orthopaedics and Traumatology, University of Modena and Reggio Emilia, Via del Pozzo 71, 41124, Modena, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Tarallo
authors.affiliation: Department of Diagnostic, Clinical and Public Health Medicine, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Cinzia
authors.initials: C
authors.lastname: Del Giovane
authors.affiliation: Department of Orthopaedics and Traumatology, University of Modena and Reggio Emilia, Via del Pozzo 71, 41124, Modena, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Catani
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000502:physiology* / Q000601:surgery*; D008297:Male; D020370:Osteoarthritis, Knee / Q000503:physiopathology / Q000601:surgery; D011184:Postoperative Period; D016059:Range of Motion, Articular; D025321:Surgery, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome
keywords: Biomechanical; Computer-assisted; Knee injury; Navigation; Osteoarthritis outcome score; Outcome; Total knee arthroplasty