title: The effect of weight-bearing condition on kinematics of a high-flexion, posterior-stabilized knee prosthesis.
abstract: The objective of this study was to investigate the effects of weight-bearing (WB) condition on the kinematics of total knee arthroplasty. We investigated 17 patients (20 knees) implanted with a high-flexion posterior-stabilized total knee arthroplasty using 2- to 3-dimensional registration techniques. In vivo kinematics of dynamic deep knee flexion under WB and non-WB (NWB) conditions were compared. Six degree-of-freedom kinematics and articular contacts including post-cam contact were evaluated. At midflexion, femorotibial contact points were located significantly more anteriorly under NWB than WB conditions. As a result, post-cam engagement occurred significantly earlier under NWB than WB conditions. With NWB conditions, early engagement of the femoral cam engages at the top part of tibial post, which puts it at risk of jumping the tibial post particularly if there is instability in midflexion.
authors: Department of Orthopedic Biomaterial Science, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors: Norimasa
authors: N
authors: Shimizu
authors: Tetsuya
authors: T
authors: Tomita
authors: Takaharu
authors: T
authors: Yamazaki
authors: Hideki
authors: H
authors: Yoshikawa
authors: Kazuomi
authors: K
authors: Sugamoto
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee; D001696:Biomechanical Phenomena; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D007720:Knee Prosthesis; D008875:Middle Aged; D016059:Range of Motion, Articular; D016474:Weight-Bearing