title: Construction-conditioned rollback in total knee replacement: fluoroscopic results.
abstract: Firstly, the way of implementing approximatively the initial rollback of the natural tibiofemoral joint (TFJ) in a total knee replacement (AEQUOS G1 TKR) is discussed. By configuration of the curvatures of the medial and lateral articulating surfaces a cam gear mechanism with positive drive can be installed, which works under force closure of the femoral and tibial surfaces. Briefly the geometric design features in flexion/extension are described and construction-conditioned kinematical and functional properties that arise are discussed. Due to a positive drive of the cam gear under the force closure during the stance phase of gait the articulating surfaces predominantly roll. As a result of rolling, a sliding friction is avoided, thus the resistance to motion is reduced during the stance phase. Secondly, in vivo fluoroscopic measurements of the patella tendon angle during flexion/extension are presented. The patella tendon angle/ knee flexion angle characteristic and the kinematic profile in trend were similar to those observed in the native knee during gait (0°-60°).
authors.affiliation: Department of Trauma Surgery, Plastic and Reconstructive Surgery, University of Göttingen, Germany. martin.wachowski@web.de
authors.forename: Martin Michael
authors.initials: MM
authors.lastname: Wachowski
authors.forename: Christoph
authors.initials: C
authors.lastname: Fiedler
authors.forename: Tim Alexander
authors.initials: TA
authors.lastname: Walde
authors.forename: Peter
authors.initials: P
authors.lastname: Balcarek
authors.forename: Jan Philipp
authors.initials: JP
authors.lastname: Schüttrumpf
authors.forename: Stephan
authors.initials: S
authors.lastname: Frosch
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Frosch
authors.forename: Jochen
authors.initials: J
authors.lastname: Fanghänel
authors.forename: Riccardo
authors.initials: R
authors.lastname: Gezzi
authors.forename: Dietmar
authors.initials: D
authors.lastname: Kubein-Meesenburg
authors.forename: Hans
authors.initials: H
authors.lastname: Nägerl
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010329:Patella / Q000000981:diagnostic imaging / Q000503:physiopathology; D016059:Range of Motion, Articular / Q000502:physiology; D013710:Tendons / Q000000981:diagnostic imaging / Q000503:physiopathology