title: Kinematic analysis of kneeling in cruciate-retaining and posterior-stabilized total knee arthroplasties.
abstract: Kneeling is an important function of the knee for many activities of daily living. In this study, we evaluated the in vivo kinematics of kneeling after total knee arthroplasty (TKA) using radiographic based image-matching techniques. Kneeling from 90 to 120 degrees of knee flexion produced a posterior femoral rollback after both cruciate-retaining and posterior-stabilized TKA. It could be assumed that the posterior cruciate ligament and the post-cam mechanism were functioning. The posterior-stabilized TKA design had contact regions located far posterior on the tibial insert in comparison to the cruciate-retaining TKA. Specifically, the lateral femoral condyle in posterior-stabilized TKA translated to the posterior edge of the tibial surface, although there was no finding of subluxation. After posterior-stabilized TKA, the contact position of the post-cam translated to the posterior medial corner of the post with external rotation of the femoral component. Because edge loading can induce accelerated polyethylene wear, the configuration of the post-cam mechanism should be designed to provide a larger contact area when the femoral component rotates.
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hamai
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Miura
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Higaki
authors.forename: Shuichi
authors.initials: S
authors.lastname: Matsuda
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shimoto
authors.forename: Kousuke
authors.initials: K
authors.lastname: Sasaki
authors.forename: Masaaki
authors.initials: M
authors.lastname: Yoshizumi
authors.forename: Ken
authors.initials: K
authors.lastname: Okazaki
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Tsukamoto
authors.forename: Yukihide
authors.initials: Y
authors.lastname: Iwamoto
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000502:physiology*; D008297:Male; D016119:Posterior Cruciate Ligament / Q000502:physiology*; D011859:Radiography