Comparison of Anterior Laxity Measurements in Anterior Cruciate Deficient Knees with Two Instrumented Testing Devices

Abstract

We measured anterior tibial displacements in 21 anterior cruciate ligament deficient patients using two instrumented testing devices, the KT-1000 and the KSS. A comparison of values obtained from testing was done using statistical analysis. The two tests common to both devices were the 20 lb pull and the manual maximum. The involved normal (I-N) values showed that there was no significant difference between the two devices for both the manual maximum and the 20 lb force level. There was also no significant difference between devices for the manual maximum absolute values. The significant difference between the absolute values for the 20 lb force level is probably due to the different testing techniques for both devices. When testing with the KSS, the patella remains free; testing with the KT-1000 requires that the examiner maintain pressure to hold the patella down. The manual maximum absolute values showed no significant difference because the testing techniques for both devices were identical. Comparable data for both devices are the I-N values for the 20 lb and manual maximum values.