title: Influence of the anterior-posterior femoral translation on the range of motion in cruciate-retaining total knee arthroplasty.
abstract: OBJECTIVE
  The purpose of this study is to evaluate the post-operative range of motion (ROM) of the knee related to the anterior-posterior femoral translation on the tibia observed during surgery in cruciate-retaining total knee arthroplasty (TKA) using a navigation system. Our hypothesis is that the intraoperative anterior-posterior femoral translation is correlated with the post-operative ROM in patients undergoing cruciate-retaining TKA.
  
  
  METHODS
  The subjects were 20 patients involving 23 joints. The passive maximum ROM was measured before and 1 year after surgery. In addition, we evaluated the intraoperative anterior-posterior femoral translation that was measured after inserting a tensor device from 10° to 120° of knee flexion. The starting point of the anterior-posterior femoral translation was defined as when the femur started to move posteriorly. The anterior-posterior femoral translation 120 was set as the amount of femoral movement from 10° to 120°.
  
  
  RESULTS
  The subjects were divided into those with an increased or maintained ROM (group A) and those with a decreased ROM (group B). There were no significant differences between the two groups in terms of the age or pre-operative ROM. The starting point of the anterior-posterior femoral translation was significantly earlier in group B (58.0 ± 5.7° for group A, 48.7 ± 3.2° for group B) (P < 0.05). Regarding the anterior-posterior femoral translation 120, Group B showed a larger amount of femoral movement posteriorly than group A (13.0 ± 6.5 mm for group A, 19.0 ± 6.2 mm for group B) (P < 0.05).
  
  
  CONCLUSIONS
  The present study shows that intraoperative anterior-posterior femoral translation has a significant correlation with the post-operative ROM in patients undergoing cruciate-retaining TKA. If the starting point of the anterior-posterior femoral translation is early and the anterior-posterior femoral translation 120 is large, there is likely to be a decrease in the post-operative ROM.
  
  
  METHODS
  III.
authors.affiliation: Department of Orthopaedic Surgery, Gunma University Graduate School of Medicine, 3-39-15 Showa-machi, Maebashi, Gunma, 371-8511, Japan, yanashin87@yahoo.co.jp.
authors.forename: Shinya
authors.initials: S
authors.lastname: Yanagisawa
authors.forename: Naoki
authors.initials: N
authors.lastname: Sato
authors.forename: Takashi
authors.initials: T
authors.lastname: Ohsawa
authors.forename: Kenichi
authors.initials: K
authors.lastname: Saito
authors.forename: Masaki
authors.initials: M
authors.lastname: Shimizu
authors.forename: Kenji
authors.initials: K
authors.lastname: Takagishi
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee; D001696:Biomechanical Phenomena; D005260:Female; D005269:Femur / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology* / Q000601:surgery; D008297:Male; D009068:Movement; D020370:Osteoarthritis, Knee / Q000503:physiopathology* / Q000601:surgery; D016059:Range of Motion, Articular; D025321:Surgery, Computer-Assisted; D013977:Tibia / Q000503:physiopathology* / Q000601:surgery