title: No Differences Identified in Transverse Plane Biomechanics Between Medial Pivot and Rotating Platform Total Knee Implant Designs.
abstract: Total knee arthroplasties (TKAs) using well-designed, fixed bearing prostheses, such as medial pivot (MP), have produced good long-term results. Rotating-platform, posterior-stabilized (RP-PS) mobile bearing implants were designed to decrease polyethylene wear. Sagittal and coronal plane TKA biomechanics are well examined and correlated to polyethylene wear. However, limited research findings describe this relationship in transverse plane. We assumed that although axial plane biomechanics might not be the most destructive parameters on polyethylene wear, it is important to clarify their role because both joint kinematics and kinetics in all 3 planes are important input parameters for TKA wear testing (International Organization for Standardization 14243-1 and 14343-3). Our hypothesis was that transverse plane overall range of motion (ROM) and/or peak moment show differences that reflect on wear advantages when compared RP-PS implants to MP designs.
  
  
  
  Two groups (MPs = 24 and RP-PSs = 22 subjects) were examined by using 3D gait analysis. The variables were total internal-external rotation (IER) ROM and peak IER moments.
  
  
  
  No statistically significant difference was demonstrated between the 2 groups in kinetics (P = .389) or kinematics (P = .275).
  
  
  
  In the present study, no wear advantages were found between 2 TKAs. Both designs showed identical kinetics at the transverse plane in level-ground walking. Kinematic analysis could not illustrate any statistically significant difference in terms of overall IER ROM. Nevertheless, kinematic gait pattern differences observed possibly reflect different patterns of joint surface motion or abnormal gait patterns. Thus, wear testing with various input waveforms combined with functional data analysis will be necessary to identify the actual effects of gait variability on polyethylene wear.
authors.affiliation: Biomechanics and Gait Analysis Laboratory "Sylvia Ioannou", Orthopaedic Research and Education Center "P.N.Soukakos", "Attikon" University Hospital, 1st Department of Orthopaedics, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Georgios I
authors.initials: GI
authors.lastname: Papagiannis
authors.affiliation: Biomechanics and Gait Analysis Laboratory "Sylvia Ioannou", Orthopaedic Research and Education Center "P.N.Soukakos", "Attikon" University Hospital, 1st Department of Orthopaedics, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Ilias M
authors.initials: IM
authors.lastname: Roumpelakis
authors.affiliation: Biomechanics and Gait Analysis Laboratory "Sylvia Ioannou", Orthopaedic Research and Education Center "P.N.Soukakos", "Attikon" University Hospital, 1st Department of Orthopaedics, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Athanasios I
authors.initials: AI
authors.lastname: Triantafyllou
authors.affiliation: Biomechanics and Gait Analysis Laboratory "Sylvia Ioannou", Orthopaedic Research and Education Center "P.N.Soukakos", "Attikon" University Hospital, 1st Department of Orthopaedics, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Ioannis N
authors.initials: IN
authors.lastname: Makris
authors.affiliation: 2nd Department of Orthopaedics, Medical School, National and Kapodistrian University of Athens, Konstantopouleio General Hospital, Nea Ionia, Greece.
authors.forename: George C
authors.initials: GC
authors.lastname: Babis
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D001696:Biomechanical Phenomena; D005260:Female; D005684:Gait; D006801:Humans; D007719:Knee Joint / Q000601:surgery*; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020959:Polyethylene; D011474:Prosthesis Design; D011475:Prosthesis Failure; D016059:Range of Motion, Articular; D016138:Walking
chemical_list: D020959:Polyethylene
keywords: TKA gait analysis; TKA kinematics; knee rotation moments; total knee arthroplasty; total knee biomechanics