title: Effect of tibial slope changes on femorotibial contact kinematics after cruciate-retaining total knee arthroplasty.
abstract: OBJECTIVE
  The present study was undertaken to evaluate the effect of tibial slope (TS) changes on the femorotibial articular contact kinematics in subjects undergoing posterior cruciate-retaining total knee arthroplasty (CRTKA).
  
  
  METHODS
  Eighteen knees in nine patients with medial osteoarthritis who underwent CRTKA using the same size prosthesis were analysed preoperatively and 2 years after TKA. TS changes were calculated on lateral radiographs taken before and after TKA. Knees were classified into two groups according to the change in TS obtained by subtracting the post-operative value from the preoperative value: group 1 (>3°) and group 2 (<3°). The femorotibial articular contact kinematics of knees during weight-bearing flexion were compared between the two groups by two-dimensional/three-dimensional registration.
  
  
  RESULTS
  Group 1 showed a continuous posterior translation of the medial femoral condyle during the process of knee flexion, whereas in group 2 the medial femoral condyle experienced paradoxical anterior motion from 20° to 90° of knee flexion. The lateral femoral condyle continuously moved posteriorly in both groups.
  
  
  CONCLUSIONS
  A greater reduction in TS after TKA compared with preoperative TS reduces paradoxical medial femoral condylar movement. This may contribute to improved patient satisfaction after CR TKA.
  
  
  METHODS
  III.
authors.affiliation: Department of Joint Surgery, Third Hospital of Hebei Medical University, 139 Ziqiang Road, Shijiazhuang, 050051, Hebei, China.
authors.forename: Xi-Qing
authors.initials: XQ
authors.lastname: Pan
authors.affiliation: Department of Orthopaedic Surgery, Third Hospital of Hebei Medical University, 139 Ziqiang Road, Shijiazhuang, 050051, Hebei, China.
authors.forename: A-Qin
authors.initials: AQ
authors.lastname: Peng
authors.affiliation: Department of Joint Surgery, Third Hospital of Hebei Medical University, 139 Ziqiang Road, Shijiazhuang, 050051, Hebei, China. wangfeiprofessor@126.com.
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Joint Surgery, Third Hospital of Shijiazhuang, 15 Sports South Street, Shijiazhuang, 050011, Hebei, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.affiliation: Department of Joint Surgery, Third Hospital of Shijiazhuang, 15 Sports South Street, Shijiazhuang, 050011, Hebei, China.
authors.forename: Xi-Zeng
authors.initials: XZ
authors.lastname: Nie
authors.affiliation: Hospital for Special Surgery, 535 E. 70th Street, New York, NY, 10021, USA.
authors.forename: Xi
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Joint Surgery, Third Hospital of Hebei Medical University, 139 Ziqiang Road, Shijiazhuang, 050051, Hebei, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Ji
authors.affiliation: Department of Joint Surgery, Third Hospital of Hebei Medical University, 139 Ziqiang Road, Shijiazhuang, 050051, Hebei, China.
authors.forename: Xiao-Meng
authors.initials: XM
authors.lastname: Wang
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D001696:Biomechanical Phenomena; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D007720:Knee Prosthesis; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D016059:Range of Motion, Articular; D013977:Tibia / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D016474:Weight-Bearing
keywords: Cruciate-retaining total knee arthroplasty; Kinematics; Tibial slope; Two-dimensional/three-dimensional registration