title: Influence of intra-operative joint gaps on post-operative flexion angle in posterior cruciate-retaining total knee arthroplasty.
abstract: OBJECTIVE
  The purpose of this study is to examine the joint component gap and its relationship with post-operative flexion angles in posterior cruciate-retaining (CR) total knee arthroplasty (TKA). In posterior-stabilized (PS) TKA, an inverse correlation between the joint component gap and the post-operative flexion angle was reported. However, the kinematics of the joint component gap has a different pattern in PS and CR TKA. It was hypothesised that CR TKA has a different correlation between the joint component gap and the post-operative flexion angle compared to PS TKA.
  
  
  METHODS
  The joint component gap was measured with an offset-type tensor. The joint component gaps were measured at 0°, 10°, 30°, 60°, 90° and 120° knee flexion angle and various values of the change in the joint component gap were calculated; 10°-0°, 30°-0°, 60°-0°, 90°-0° and 120°-0°. Multivariate regression analysis was used to determine the influencing of these parameters to post-operative knee flexion angle.
  
  
  RESULTS
  The post-operative flexion angle was positively correlated with a joint component gap of 90° and 120° and the values of the change in the joint component gap of 90°-0° and 120°-0°. Multivariate regression analysis demonstrated pre-operative knee flexion angle, and the values of the change in the joint component gap of 90°-0° had a significant independent factor of post-operative knee flexion angle.
  
  
  CONCLUSIONS
  Post-operative flexion angle is multi-factorial. However, it is important to avoid flexion component gap tightness as well as excessive flexion component gap looseness for acquisition of better flexion angle in CR TKA.
  
  
  METHODS
  IV.
authors: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan.
authors: Koji
authors: K
authors: Takayama
authors: Tomoyuki
authors: T
authors: Matsumoto
authors: Seiji
authors: S
authors: Kubo
authors: Hirotsugu
authors: H
authors: Muratsu
authors: Kazunari
authors: K
authors: Ishida
authors: Takehiko
authors: T
authors: Matsushita
authors: Masahiro
authors: M
authors: Kurosaka
authors: Ryosuke
authors: R
authors: Kuroda
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000033:anatomy & histology / Q000503:physiopathology*; D008297:Male; D015999:Multivariate Analysis; D020370:Osteoarthritis, Knee / Q000503:physiopathology / Q000601:surgery*; D010027:Osteotomy; D016059:Range of Motion, Articular