title: Courses of change in knee adduction moment and lateral thrust differ up to 1 year after TKA.
abstract: OBJECTIVE
  In total knee arthroplasty (TKA), dynamic knee loading may loosen the artificial joint and bone or cause polyethylene wear after prolonged use. TKA decreases knee adduction moment at 6 months, but this effect is lost by 1 year post-operatively. However, lateral thrust after TKA has not been clarified. We hypothesized that like knee adduction moment, lateral thrust would return to baseline levels by 1 year post-operatively.
  
  
  METHODS
  Participants were 15 patients who underwent TKA for medial knee OA. Japanese Orthopaedic Association (JOA) score, numeric rating scale, and gait analysis (measurement of peak knee adduction moment, knee varus angle at peak knee adduction moment, lateral thrust, and gait speed) were performed preoperatively (baseline) and 3 weeks, 3 and 6 months, and 1 year post-operatively.
  
  
  RESULTS
  JOA score improved from 55 ± 9.8 to 78 ± 12.1 at 1 year post-operatively, and pain decreased significantly from baseline at each follow-up (p < 0.001). Significant increases in gait speed were observed at 6 months and 1 year (p < 0.001). Peak knee adduction moment during stance phase was significantly lower at 3 weeks, 3 months, and 6 months compared to baseline (p < 0.05), but no significant changes were seen at 1 year. Knee varus at peak knee adduction moment did not differ significantly between any measurement points, while lateral thrust was decreased at 6 months and 1 year compared to baseline (p < 0.05).
  
  
  CONCLUSIONS
  Temporal courses of changes up to 1 year after TKA differed between knee adduction moment and lateral thrust, so our hypothesis was rejected.
  
  
  METHODS
  IV.
authors.affiliation: Clinical Practice and Support Department, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Noboru
authors.initials: N
authors.lastname: Shimada
authors.affiliation: Institute of Biomedical and Health Sciences, Graduate School of Health Sciences, Hiroshima University, Hiroshima, Japan. snm3@hiroshima-u.ac.jp.
authors.forename: Masataka
authors.initials: M
authors.lastname: Deie
authors.affiliation: Clinical Practice and Support Department, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Hirata
authors.affiliation: Clinical Practice and Support Department, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Hiate
authors.affiliation: Clinical Practice and Support Department, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Naoya
authors.initials: N
authors.lastname: Orita
authors.affiliation: Clinical Practice and Support Department, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Iwaki
authors.affiliation: Clinical Practice and Support Department, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Ito
authors.affiliation: Department of Rehabilitation Medicine, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kimura
authors.affiliation: Discipline of Physiotherapy, Faculty of Health Sciences, The University of Sydney, Sydney, Australia.
authors.forename: Evangelos
authors.initials: E
authors.lastname: Pappas
authors.affiliation: Department of Orthopedic Surgery, Hiroshima University, Hiroshima, Japan.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Ochi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D001696:Biomechanical Phenomena; D005260:Female; D005684:Gait; D006801:Humans; D007719:Knee Joint / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology*; D020370:Osteoarthritis, Knee / Q000601:surgery*; D020959:Polyethylene
chemical_list: D020959:Polyethylene
keywords: Knee adduction moment; Lateral thrust; Temporal course; Total knee arthroplasty