title: A new mechanical testing device for measuring anteroposterior knee laxity.
abstract: BACKGROUND
  The authors assessed a new instrument, the Rolimeter, for the measurement of anteroposterior translation in the knee; it was compared to the KT-1000 arthrometer.
  
  
  OBJECTIVE
  To determine if the Rolimeter offers a valid method for the measurement of anteroposterior translation that is as reproducible and reliable as the KT-1000 arthrometer.
  
  
  METHODS
  Two of 3 observers examined 16 normal subjects (32 knees) and 36 patients (72 knees) with ligament ruptures twice, using both the Rolimeter and the KT-1000 arthrometers, 30 minutes apart. Total anteroposterior translation (manual maximal Lachman test) was recorded at 20 degrees and 80 degrees of knee flexion.
  
  
  RESULTS
  On average, the Rolimeter measured approximately 1 mm less anteroposterior displacement than the KT-1000 arthrometer at manual maximum stress. Rolimeter measurements were more consistent than the KT-1000 measurements as measured by our observers. Specificity and sensitivity were equivalent between the Rolimeter and the KT-1000 arthrometer.
  
  
  CONCLUSIONS
  The Rolimeter is as reproducible and reliable as the KT-1000 arthrometer. It offers a valid method for the measurement of anteroposterior translation in the knee. Higher accuracy was obtained at 20 degrees of flexion for the KT-1000 arthrometer and at 80 degrees of flexion for the Rolimeter.
authors.affiliation: Department of Orthopaedic Surgery, Hôpital Cantonal, Fribourg, Switzerland. andreas.schuster@spitalbern.ch <andreas.schuster@spitalbern.ch>
authors.forename: Andreas J
authors.initials: AJ
authors.lastname: Schuster
authors.forename: Mike J
authors.initials: MJ
authors.lastname: McNicholas
authors.forename: Stefan W
authors.initials: SW
authors.lastname: Wachtl
authors.forename: Douglas W
authors.initials: DW
authors.lastname: McGurty
authors.forename: Roland P
authors.initials: RP
authors.lastname: Jakob
mesh_terms: D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena; D006801:Humans; D007593:Joint Instability; D007718:Knee Injuries / Q000175:diagnosis*; D007719:Knee Joint / Q000502:physiology*; D009985:Orthopedics / Q000379:methods; D016119:Posterior Cruciate Ligament / Q000293:injuries*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity