title: Females, younger patients and patients with high BMI have the highest pre-operative knee awareness measured using the Forgotten Joint Score.
abstract: OBJECTIVE
  The Forgotten Joint Score (FJS) is a novel measurement for patients' awareness of their knee in daily life. By identifying factors that could explain pre-operative FJS levels, the clinician could better prioritize and single out patients who would benefit most from TKA. The aim of this study was to identify possible factors that may explain the variance of pre-operative FJS levels and evaluate the relationship between pre-operative FJS and pre-operative Oxford Knee Score (OKS).
  
  
  METHODS
  Four-hundred and six individual knees undergoing primary TKA between 2014 and 2016 were included in the study. Age, gender, body mass index (BMI), pre-operative FJS and pre-operative OKS were obtained maximum 2 weeks prior to surgery. Kellgren-Lawrence (K-L) grade, alignment and joint space width (JSW) were evaluated on pre-operative radiographs.
  
  
  RESULTS
  Mean FJS was 21.1 ± 15.6. Females, younger patients and patients with high BMI had significantly the worst pre-operative FJS (p < 0.005). Females scored 6.5 FJS points lower than males. A 0.2-point increase in FJS for every added year indicated improvement in knee awareness with age. A 0.4-point decrease in FJS points for every added BMI point indicated worse knee awareness with higher BMI. There was a strong positive correlation between pre-operative FJS and pre-operative OKS according to the Spearman's rank order test (p < 0.005).
  
  
  CONCLUSIONS
  Females, younger patients and patients with high BMI had significantly the worst pre-operative joint awareness. FJS had a strong positive correlation to OKS in pre-operative patients for primary TKA. This information can be used for improved patient selection; clinically continuous low FJS despite weight loss and/or the passing of time may be indication for TKA.
  
  
  METHODS
  Prospective cohort study, Level II.
authors.affiliation: Department of Orthopedics, Hvidovre Hospital, University of Copenhagen, Kettegaard Alle 30, 2650, Hvidovre, Denmark. Dana_li88@yahoo.dk.|, Sallingvej 31, 2. tv, 2720, Vanløse, Denmark. Dana_li88@yahoo.dk.
authors.forename: Dana
authors.initials: D
authors.lastname: Li
authors.affiliation: Department of Orthopedics, Hvidovre Hospital, University of Copenhagen, Kettegaard Alle 30, 2650, Hvidovre, Denmark.
authors.forename: A
authors.initials: A
authors.lastname: Troelsen
authors.affiliation: Department of Orthopedics, Hvidovre Hospital, University of Copenhagen, Kettegaard Alle 30, 2650, Hvidovre, Denmark.
authors.forename: L
authors.initials: L
authors.lastname: Ingelsrud
authors.affiliation: Department of Orthopedics, Hvidovre Hospital, University of Copenhagen, Kettegaard Alle 30, 2650, Hvidovre, Denmark.
authors.forename: H
authors.initials: H
authors.lastname: Husted
authors.affiliation: Department of Orthopedics, Hvidovre Hospital, University of Copenhagen, Kettegaard Alle 30, 2650, Hvidovre, Denmark.
authors.forename: K
authors.initials: K
authors.lastname: Gromov
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D001364:Awareness; D015992:Body Mass Index; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000601:surgery; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000523:psychology* / Q000601:surgery; D011446:Prospective Studies; D011859:Radiography; D012737:Sex Factors
keywords: FJS; Forgotten Joint Score; Oxford Knee Score; Pre-operative; TKA