title: Kinematic factors affecting postoperative knee flexion after cruciate-retaining total knee arthroplasty.
abstract: OBJECTIVE
  The purpose of this study was to investigate kinematic factors affecting postoperative knee flexion after cruciate-retaining (CR) total knee arthroplasty (TKA) by analysing pre- and postoperative knee kinematics.
  
  
  METHODS
  We retrospectively analysed 58 patients with osteoarthritis who received the same implant series. Pre- and postoperative kinematics were measured intraoperatively using a navigation system. As a clinical outcome, we measured the knee flexion angle before and one year after surgery. Correlations among pre- and postoperative kinematics and postoperative flexion were analysed using simple linear regression analyses.
  
  
  RESULTS
  Preoperative knee kinematics, including tibial internal rotation and anterior translation (R = 0.87, P < 0.001; R = 0.53, P < 0.001, respectively), were significantly correlated with postoperative kinematics. Preoperative varus-valgus movements improved significantly postoperatively; however, tibial internal rotation remained unchanged. Furthermore, postoperative knee flexion angle was significantly correlated with postoperative tibial internal rotation (R = 0.45, P < 0.001).
  
  
  CONCLUSIONS
  Preoperative knee kinematics were unchanged even after CR-TKA. Postoperative tibial internal rotation is one of the most important factors affecting postoperative knee flexion.
authors: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan.
authors: Tokio
authors: T
authors: Matsuzaki
authors: Tomoyuki
authors: T
authors: Matsumoto
authors: Hirotsugu
authors: H
authors: Muratsu
authors: Seiji
authors: S
authors: Kubo
authors: Takehiko
authors: T
authors: Matsushita
authors: Yohei
authors: Y
authors: Kawakami
authors: Kazunari
authors: K
authors: Ishida
authors: Shinya
authors: S
authors: Oka
authors: Ryosuke
authors: R
authors: Kuroda
authors: Masahiro
authors: M
authors: Kurosaka
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000534:rehabilitation*; D001696:Biomechanical Phenomena / Q000502:physiology; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000502:physiology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000503:physiopathology / Q000601:surgery; D016119:Posterior Cruciate Ligament / Q000601:surgery*; D011183:Postoperative Complications; D016059:Range of Motion, Articular; D020127:Recovery of Function; D012189:Retrospective Studies; D012399:Rotation; D013977:Tibia / Q000502:physiology