title: Lateral laxity in flexion increases the postoperative flexion angle in cruciate-retaining total knee arthroplasty.
abstract: Thirty-eight patients diagnosed with osteoarthritis underwent 41 cruciate-retaining total knee arthroplasties. In varus and valgus tests at flexion, subjects were seated on a table at 80° of knee flexion; 50 N was applied perpendicular to the lower leg. The factors affecting the postoperative flexion angle were investigated in a multiregression analysis. The mean joint angles of the flexion-valgus and flexion-varus tests were 3.4° ± 1.4° and 6.2° ± 2.5°, respectively. The flexion-varus angle was correlated with the postoperative flexion angle (P < .01). The mean postoperative flexion angles were 110.8° ± 9.6° and 118.1° ± 8.0° in the groups with the flexion-varus angle of 6° or less and more than 6°, respectively (P = .02). Slack lateral laxity in flexion had a significant effect during knee flexion in cruciate-retaining total knee arthroplasty.
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba City, Chiba, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Masahiko
authors.initials: M
authors.lastname: Suzuki
authors.forename: Takahisa
authors.initials: T
authors.lastname: Sasho
authors.forename: Koichi
authors.initials: K
authors.lastname: Nakagawa
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Tsuneizumi
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Takahashi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016118:Anterior Cruciate Ligament / Q000503:physiopathology*; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology*; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery; D016119:Posterior Cruciate Ligament / Q000503:physiopathology*; D011184:Postoperative Period; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology; D012044:Regression Analysis; D012189:Retrospective Studies; D016896:Treatment Outcome