A new mechanical testing device for measuring anteroposterior knee laxity.
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.
Schuster
Andreas J
AJ
Department of Orthopaedic Surgery, Hôpital Cantonal, Fribourg, Switzerland. andreas.schuster@spitalbern.ch <andreas.schuster@spitalbern.ch>
McNicholas
Mike J
MJ
Wachtl
Stefan W
SW
McGurty
Douglas W
DW
Jakob
Roland P
RP
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