title: Soft-tissue balancing in total knee arthroplasty: cruciate-retaining versus posterior-stabilised, and measured-resection versus gap technique.
abstract: OBJECTIVE
  The purpose of this study was to prove the hypothesis that soft tissues are well balanced using the gap technique with a navigation system in cruciate-retaining (CR) and posterior-stabilised (PS) total knee arthroplasty (TKA), leading to better clinical outcomes compared with the measured-resection technique.
  
  
  METHODS
  One hundred and thirty-five TKAs (90 CR and 45 PS) were performed in patients with varus-type osteoarthritis using the gap technique guided by the offset-type tensor and a navigation system. Soft-tissue balance (joint-component gap and ligament balance) were intraoperatively assessed with the tensor under 40 lb of joint-distraction force. The achievement in the equalised rectangular gap at extension and flexion was assessed and retrospectively compared with the previous series in which the measured-resection technique was used (20 CR and 100 PS TKAs). In addition, clinical outcomes, including range of motion and Knee Society Score were assessed at a minimum two year follow-up.
  
  
  RESULTS
  In achieving equalised rectangular gaps at extension and flexion, CR TKAs met criteria in more cases [66.7% (64/90) vs. 44.4% (20/45) of PS TKA] with the gap technique, which was superior to that with the measured-resection technique [50.0% (10/20) of CR TKA and 28.0% (28/100) of PS TKA]. However, clinical outcomes showed no significant differences among groups at minimum two year follow-up.
  
  
  CONCLUSIONS
  The superiority of CR TKA with the gap technique in achieving equalised rectangular gaps at extension and flexion does not directly reflect two year postoperative clinical outcomes.
authors.affiliation: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan, mastun@m4.dion.ne.jp.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Muratsu
authors.forename: Yohei
authors.initials: Y
authors.lastname: Kawakami
authors.forename: Koji
authors.initials: K
authors.lastname: Takayama
authors.forename: Kazunari
authors.initials: K
authors.lastname: Ishida
authors.forename: Takehiko
authors.initials: T
authors.lastname: Matsushita
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Akisue
authors.forename: Kotaro
authors.initials: K
authors.lastname: Nishida
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Kuroda
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kurosaka
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D001696:Biomechanical Phenomena; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007593:Joint Instability / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery*; D057071:Patellofemoral Joint / Q000503:physiopathology / Q000601:surgery*; D016119:Posterior Cruciate Ligament / Q000601:surgery*; D011184:Postoperative Period; D016059:Range of Motion, Articular / Q000502:physiology; D012189:Retrospective Studies; D025321:Surgery, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome