title: Function and activity in patients with knee arthroplasty: validity and reliability of a German version of the Lysholm Score and the Tegner Activity Scale.
abstract: OBJECTIVE
  The Lysholm score and the Tegner activity scale are widely used for assessing knee function and activity level after knee ligament injuries. This study aimed to asses validity and reliability of the German versions of the Lysholm score (Lysholm-G) and the Tegner activity scale (Tegner-G) in patients after total knee arthroplasty (TKA).
  
  
  METHODS
  Two patient groups (<3 months postoperative; 3 to 12 months postoperative) and a healthy control group completed both questionnaires twice within 3 to 7 days. On the first occasion, the SF-12 questionnaire was also administered. The instruments' absolute and relative reliability, internal consistency, construct validity (discriminative validity and exploratory factor analysis), criterion validity, and floor/ceiling effects were determined.
  
  
  RESULTS
  Both instruments showed acceptable relative reliability (Lysholm-G: ICC2,1 = 0.87; Tegner-G: ICC2,1 = 0.79), and the Lysholm-G had a Cronbach's alpha of 0.93. Kruskal-Wallis test and post-hoc Mann-Whitney U tests showed significant differences in both scores among the groups. Factor analysis of Lysholm-G yielded three factors that together explained 76% of the variance. Correlations between the Lysholm-G/Tegner-G and the physical component of the SF-12 were moderate (ρ = 0.60/0.59). Item analysis of the Lysholm-G revealed a low relative reliability for the item "instability" and low discriminative validity for the items "locking" and "instability".
  
  
  CONCLUSIONS
  This study demonstrated acceptable psychometric performances for the Lysholm-G and the Tegner-G scales as outcome measures for patients with TKA. A short version of the Lysholm score without the "locking" and "instability" items might be more appropriate for TKA patients.
authors.affiliation: Department of Physiotherapy, Balgrist University Hospital, Zurich, Switzerland; Physiotherapy and Occupational Therapy Research, Directorate of Research and Education, University Hospital Zurich, Switzerland; Department of Chiropractic Medicine, Faculty o.
authors.forename: Jaap
authors.initials: J
authors.lastname: Swanenburg
authors.affiliation: Department of Orthopaedics, Balgrist University Hospital, Zurich, Switzerland.
authors.forename: Peter P
authors.initials: PP
authors.lastname: Koch
authors.affiliation: Department of Physiotherapy, Balgrist University Hospital, Zurich, Switzerland; Institute of Human Movement Sciences and Sport, ETH Zurich, Switzerland.
authors.forename: Nadja
authors.initials: N
authors.lastname: Meier
authors.affiliation: Institute of Human Movement Sciences and Sport, ETH Zurich, Switzerland.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Wirth
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D007802:Language; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D011594:Psychometrics; D020127:Recovery of Function; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires