title: [The MyKnee® patient-specific system. Rationale, Technique and Results].
abstract: BACKGROUND
  Adequate three-dimensional component positioning and restoration of overall limb alignment are primary goals in total knee arthroplasty. Patient-specific instrumentation (PSI) is a potential way to improve accuracy of knee reconstruction surgery. However, currently available literature regarding the reliability of PSI shows inconsistent results for limb alignment restoration and component positioning.
  
  
  OBJECTIVE
  The purpose of this article is to illustrate the rationale for using PSI in total knee arthroplasty, to demonstrate the surgical technique, and to present our outcome with the MyKnee(®) system.
  
  
  METHODS
  We illustrate in detail the logistics and workflow involved in PSI for total knee arthroplasty. Finally, we present clinical and radiological results of patients undergoing knee arthroplasty using the MyKnee(®) system compared to a conventional instrumentation group.
  
  
  RESULTS
  PSI significantly improved accuracy and reduced the number of outliers regarding neutral mechanical alignment restoration as well as three-dimensional component positioning compared to conventional instrumentation. The early clinical outcome was comparable between the two instrumentation groups. However, clinical outcome in the subgroup of patients within ± 3° from neutral mechanical limb alignment was superior to limb alignment outliers.
  
  
  CONCLUSIONS
  The MyKnee(®) PSI system presents a reliable way to improve the accuracy of mechanical limb alignment restoration and three-dimensional component positioning in total knee arthroplasty. Nonetheless, an adequate surgical technique remains the crucial factor for successful total knee reconstruction.
authors.affiliation: Abteilung für Orthopädie, Krankenhaus der Barmherzigen Schwestern Wien, Stumpergasse 13, 1060, Wien, Österreich. werner.anderl@bhs.at.
authors.forename: W
authors.initials: W
authors.lastname: Anderl
authors.affiliation: Abteilung für Orthopädie, Krankenhaus der Barmherzigen Schwestern Wien, Stumpergasse 13, 1060, Wien, Österreich.
authors.forename: L
authors.initials: L
authors.lastname: Pauzenberger
authors.affiliation: Abteilung für Orthopädie, Krankenhaus der Barmherzigen Schwestern Wien, Stumpergasse 13, 1060, Wien, Österreich.
authors.forename: E
authors.initials: E
authors.lastname: Schwameis
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation* / Q000379:methods; D019544:Equipment Failure Analysis; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000295:instrumentation; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000601:surgery; D007720:Knee Prosthesis; D015207:Osteoarthritis, Hip / Q000000981:diagnostic imaging / Q000601:surgery*; D018579:Patient Selection; D057285:Precision Medicine / Q000295:instrumentation / Q000379:methods; D066330:Printing, Three-Dimensional / Q000295:instrumentation; D011474:Prosthesis Design; D017755:Prosthesis Fitting / Q000295:instrumentation* / Q000379:methods; D025321:Surgery, Computer-Assisted / Q000295:instrumentation* / Q000379:methods*; D016896:Treatment Outcome
keywords: Bone malalignment; Osteoarthritis; Patient-specific instrumentation (PSI); Prosthesis design; Total knee arthroplasty