title: Kinematics of successful knee prostheses during weight-bearing: three-dimensional movements and positions of screw axes in the Tricon-M and Miller-Galante designs.
abstract: Using roentgen stereophotogrammetric analysis we recorded the three-dimensional movements in six knees with implanted Tricon-M prostheses and ten knees with Miller-Galante prostheses as the patients ascended a platform. Fourteen patients with normal knees were used as controls. The two prosthetic designs displayed decreased internal tibial rotation and the Tricon-M increased valgus rotation. A central point on the tibial articular surface had a more lateral position in the Tricon-M design and a more distal one in the Miller-Galante design compared to normal knees. Increased posterior displacement with increasing flexion was observed in both designs. When the normal knees were extended at full weight-bearing the helical axes mainly shifted inclination in the frontal plane. In the prosthetic knees there was a tendency to anterior-posterior displacement of the axes as extension proceeded, especially in the Miller-Galante design. Translations along the helical axes were larger than normal in the Miller-Galante and smaller in the Tricon-M knees, reflecting differences in constraint of the two designs.
authors.affiliation: Department of Orthopaedics, Sahlgren Hospital, Gothenburg, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Kärrholm
authors.forename: H
authors.initials: H
authors.lastname: Jonsson
authors.forename: K G
authors.initials: KG
authors.lastname: Nilsson
authors.forename: I
authors.initials: I
authors.lastname: Söderqvist
mesh_terms: D000368:Aged; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D007720:Knee Prosthesis; D008297:Male; D010003:Osteoarthritis / Q000503:physiopathology / Q000601:surgery; D010780:Photogrammetry; D011474:Prosthesis Design; D012399:Rotation; D016474:Weight-Bearing