Assessment of anterior cruciate laxity using the Genucom System

One hundred subjects with normal knees and 47 patients with chronic rupture of the anterior cruciate ligament were tested in the Genucom Knee Analysis System; the 13 different laxity tests were carried out on both knees. Measurements on right and left knees in normal subjects showed that only the lateral pivot shift test, performed at 25 degrees of knee flexion, had a good side-to-side correlation, but did not differentiate the involved and uninvolved knees in the patients with anterior cruciate ligament deficiency. The sensitivity of the lateral pivot shift was 30% and specificity 91%. The corresponding figures for the anterior drawer test at 30 degrees flexion using 93 N force were 45% and 88%. Measurements showed great variation. Care should be taken in interpreting the results from the Genucom System. It should be considered as an experimental device with little value in assessing patients with anterior cruciate ligament deficiency.