title: Quality of life after bilateral total knee arthroplasty determined by a 3-year longitudinal evaluation using the Japanese knee osteoarthritis measure.
abstract: BACKGROUND
  Recently, the Japanese knee osteoarthritis measure (JKOM), a new disease-specific and patient-derived quality of life (QOL) measure, has been developed. The objectives of this study were to longitudinally evaluate QOL assessed by JKOM and objective outcomes including knee society score (KSS), range of motion (ROM), and timed up and go test (TUG) of patients who underwent bilateral total knee arthroplasties (TKAs) for osteoarthritis; to evaluate correlations between JKOM and those objective outcomes; and to test our hypothesis that increased maximum flexion leads to better JKOM.
  
  
  METHODS
  Forty patients with bilateral TKAs and ≥ 3-year follow-up were included. There were 35 female and 5 male patients with a mean patient age of 74 years. They were evaluated preoperatively (Pre), 5-29 months after unilateral TKA (after U), 12-21 months after bilateral TKAs (1 year after B), 24-34 months after bilateral TKAs (2 years after B), and 36-46 months after bilateral TKAs (3 years after B) using JKOM, KSS, TUG, and ROM.
  
  
  RESULTS
  Improvements in JKOM and TUG were statistically significant between "Pre" and "after U", and between the "after U" and "1 year after B". Improvements in the KSS function score were statistically significant between "after U" and "1 year after B" but not between "Pre" and "after U". The improvements in the JKOM scores, the KSS function score, and TUG did not increase after the 1-year follow-up but was maintained at "3 years after B". The maximum flexion value did not change among the evaluation time points. There were statistically significant correlations between JKOM with KSS and TUG but not with ROM.
  
  
  CONCLUSIONS
  There were statistically significant correlations between JKOM with KSS and TUG but not with ROM. Therefore, our hypothesis was false even in a Japanese population.
authors.affiliation: Department of Orthopaedic Surgery, Tohoku Orthopaedic Clinic, 4-9-22 Kamiyagari, Izumi-ku, Sendai, 981-3121, Japan, t-sugita@tohokuseikei.com.
authors.forename: Takehiko
authors.initials: T
authors.lastname: Sugita
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kikuchi
authors.forename: Toshimi
authors.initials: T
authors.lastname: Aizawa
authors.forename: Akira
authors.initials: A
authors.lastname: Sasaki
authors.forename: Naohisa
authors.initials: N
authors.lastname: Miyatake
authors.forename: Ikuo
authors.initials: I
authors.lastname: Maeda
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D044466:Asian People; D005260:Female; D006801:Humans; D007564:Japan; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000208:ethnology / Q000503:physiopathology / Q000601:surgery*; D011788:Quality of Life; D016059:Range of Motion, Articular / Q000502:physiology; D020127:Recovery of Function / Q000502:physiology; D011795:Surveys and Questionnaires; D013997:Time Factors; D016896:Treatment Outcome