Comparative Analysis of Knee-laxity Measurements by a Left-handand a Right-hand-dominant Physiotherapist in Patients with Anterior Cruciate Ligament Injuries and Healthy Control Group

The purpose of the study was to analyze and compare KT-1000 knee laxity as examined by a left-hand- and a right-hand-dominant physiotherapist in a group of patients with an anterior cruciate ligament (ACL) injury and a group of patients, 2 years after ACL reconstruction. The other aim was to measure and analyze knee laxity in a group of persons without any known knee problems. A crosssectional examination of two groups of patients preoperatively and post-operatively after ACL reconstruction and examination of healthy controls on two different occasions was performed. 22 patients who were scheduled for ACL reconstruction and 20 patients who attended a 2- year follow-up examination were included in the study. In the ACL-deficient group, 14 patients had a right-sided ACL injury and 08 patients a left-sided ACL injury. The corresponding figures in the post-operative group were 13 patients with a right-sided ACL injury and 07 patients with a left-sided ACL injury. 20 healthy persons without any known knee problems served as controls. One left-hand- and one right-hand-dominant experienced physiotherapist performed all the examinations. To be able to evaluate the intra and inter-reliability of the examiners the controls were examined at two occasions. The left-hand-dominant physiotherapist measured significantly higher absolute laxity values in the left knee, both injured and non-injured ones, compared with the right-hand-dominant physiotherapist. This was found irrespectively of whether the patients belonged to the ACL deficient or the post-operative group. In the healthy control group, the right-hand-dominant physiotherapist measured significantly higher knee-laxity values in the right knee compared with the left-handdominant physiotherapist. Correspondingly, the left-handdominant physiotherapist measured significantly higher knee laxity values in the left knee. We conclude that KT- 1000 arthrometer laxity measurements can be affected by the hand dominance of the examiner. This might affect the reliability of KT-1000 arthrometer measurements.