title: In vivo three-dimensional motion analysis of osteoarthritic knees.
abstract: OBJECTIVE
  The purpose of this study is to investigate the three-dimensional (3D) kinematics of preoperative osteoarthritic (OA) knees, and to clarify the validity of the findings in comparison with previous studies of kinematics in normal and OA knees.
  
  
  METHODS
  Fifteen preoperative OA knees were scanned by 3D computed tomography (CT) at three positions. We created 3D bone models and quantitatively evaluated motion of the knee joint using a markerless volume-based registration technique. Assessment categories comprised rotation angles and anterior-posterior (AP) translation. The Pearson correlation test was used to analyze correlations between rotational angle and femorotibial angle.
  
  
  RESULTS
  From maximum extension to 90° flexion, 11 femurs displayed internal rotation relative to the tibia. In 10 knees, the sulcus moved >1 mm more backward than the lateral epicondyle. Significant differences were apparent between movement of the sulcus and lateral epicondyle. A correlation of -0.42 was found between the rotational angle and femorotibial angle.
  
  
  CONCLUSIONS
  The kinematics of OA knees differed from that of normal knees in that femurs did not present external rotation with flexion. One reason for this movement is that the medial condyle of the femur tended to move backward in knee flexion due to disruption of the tibial joint surface.
authors: Department of Orthopaedic Surgery, Itami City Hospital, Itami, Japan.
authors: Kunihiko
authors: K
authors: Kawashima
authors: Tetsuya
authors: T
authors: Tomita
authors: Masashi
authors: M
authors: Tamaki
authors: Tsuyoshi
authors: T
authors: Murase
authors: Hideki
authors: H
authors: Yoshikawa
authors: Kazuomi
authors: K
authors: Sugamoto
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena / Q000502:physiology; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D007717:Knee / Q000000981:diagnostic imaging / Q000503:physiopathology; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D008953:Models, Anatomic; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology*