[Anterior knee laxity in a healthy patient sample]

A prospective study investigates anterior knee laxity in 100 healthy subjects (mean age 24.5 years). Testing was performed by two examiners either clinically by Lachman test or by means of KT-1000 arthrometer. Mean anterior tibial translation was 4 mm for the right and 4.3 mm for the left knee when tested clinically. With use of KT-1000 at 89 Newton results were 4.6 mm and 4.0 mm, respectively. Clinical measurements revealed an inter-examiner difference of 0 to 1 mm in 77% of right and 80% of left knees. In the remainder difference was more than 1 mm. On apparative testing the two examiners obtained similar results at 67 Newton. Measurements differed increasingly, however, at 89 Newton and 134 Newton. In conclusion, the use of KT-1000 arthrometer in routine assessment of anterior knee laxity offers no advantage over clinical testing alone.