ARE THERE OBJECTIVE BIOMECHANICAL SYMPTOMS OF KNEE INSTABILITY AFTER ANTERIOR CRUCIATE LIGAMENT INJURY OR IT’S RECONSTRUCTION?

Abstract

Background: Instability of the knee joint after rupture of the anterior cruciate ligament and even after its reconstruction remains a pressing problem. The use of a special functional test with fast walking can be considered as a potential tool for verifying instability. Aims: to find out whether there are biomechanical differences in joint function with and without instability, both in the period before and after anterior cruciate ligament reconstruction. Methods: A biomechanical study of the function of walking at fast speeds, including an electromyographic study, was used. 40 patients were examined, 22 underwent reconstruction of the anterior cruciate ligament. The patients were divided into two groups - with symptoms of instability - 33 people, and without them - 7 people and a control group (healthy) 20 people. Results: The time characteristics of the step cycle did not reveal significant differences between the groups and the control group. For the amplitudes of movements in the joints, there are also completely no significant differences between the parameters of one group from the other and the affected side from the intact side. Only for the intact side in the group with instability there is a significant increase in both amplitudes in the knee joint compared to the control. Electromyographic study also did not reveal significant differences. Conclusions: The use of a functional test with fast walking does not allow differentiating the state of instability. Thus, the instability of the knee joint during normal walking, even at high speed, does not manifest itself in any way. To detect it, it is necessary to develop special provocative tests.