Comparison of knee kinematics between meniscal tear and normal control during a step-down task.

Abstract

Difficulty descending stairs is a common functional complaint reported by patients with meniscal tears. Abnormal knee movement patterns, such as dynamic valgus of the knee or decreased knee flexion during step down, have been reported by clinicians, but 3D knee kinematics descending stairs has never been described in this population. The objective of this study is to compare 3D knee kinematics of individuals with a meniscal tear to that of control individuals during a step-down task. Ten participants (6 men and 4 women) diagnosed with a meniscal tear and eleven healthy participants (3 men and 8 women) were recruited. Three-dimensional knee kinematic data were recorded during five step-down task trials with a VICON™ motion analysis system. The following parameters were extracted from the stance phase period only: maximum angle, minimum knee angle, and range of motion (maximum minus minimum) values for sagittal, frontal, and transverse planes. A group comparison was performed by ANOVA using the velocity of the step-down task as the control variable. Significant reductions in the mean maximum knee flexion angle, knee flexion/extension range of motion, and knee abduction/adduction were observed among the participants with a meniscal tear compared to the control group (mean differences and P values were 4.7°, P=0.02; 5.4°, P=0.02 and 1.6°, P=0.03 respectively). Differences in rotation movement were not significant. This study is the first to describe and compare 3D knee kinematics of persons with a meniscal tear during a step-down task. These findings support that significant kinematic changes occur in the sagittal and frontal plane in individuals with a meniscal tear compared to normal controls.