Intraoperative measurement of knee kinematics in reconstruction of the anterior cruciate ligament

Abstract

Our objectives were to establish the envelope of passive movement and to demonstrate the kinematic behaviour of the knee during standard clinical tests before and after reconstruction of the anterior cruciate ligament (ACL). An electromagnetic device was used to measure movement of the joint during surgery. Reconstruction of the ACL significantly reduced the overall envelope of tibial rotation (10 degrees to 90 degrees flexion), moved this envelope into external rotation from 0 degrees to 20 degrees flexion, and reduced the anterior position of the tibial plateau (5 degrees to 30 degrees flexion) (p < 0.05 for all). During the pivot-shift test in early flexion there was progressive anterior tibial subluxation with internal rotation. These subluxations reversed suddenly around a mean position of 36 +/- 9 degrees of flexion of the knee and consisted of an external tibial rotation of 13 +/- 8 degrees combined with a posterior tibial translation of 12 +/- 8 mm. This abnormal movement was abolished after reconstruction of the ACL.

Optimal measurement of clinical rotational test for evaluating anterior cruciate ligament insufficiency

“…Increased anterior tibial translation without significant difference in knee rotation during pivot shift test in ACL deficient knee was previously demonstrated using non-invasive electromagnetic system [17] and reaffirmed by the other measurement system in which the sensors were fixed to the bones [4,10]. Kanamori et al [19] detected the rotational angle change as well as increased anterior tibial translation against pure rotational loading in ACL deficient knees by use of robotic system, but the rotational angle difference was so small that they suggest the coupled anterior tibial translation for evaluating ACL function [19].…”

“…The variation of the resultant knee kinematics is highly expected by manual pivot shift tests [10,34]. The magnitude of the pivot shift could be varied depending on the maneuver, such as hip position [3], applied rotational stress [20] and axial compression, and each knee has individually different loading condition to exert the maximum pivot shift [9,30].…”

“…To exclude the effect of the manual procedure variability, a single surgeon performed the testing, similarly to previous reports [10,23,24]. The external or internal pure rotational stress test was done by flexing the knees from full extension to more than 90°while applying manual maximum external or internal rotational torque by holding foot in the same manner as the report from Bull et al [10] (Fig. 1).…”

Development of a simple device for measurement of rotational knee laxity

“…While uncoupled rotation may not be significantly different after isolated rupture of the ACL [17], it has been shown that more complex tests such as the flexion rotation drawer or pivot shift tests will be positive [18]. Bull et al [11] intended to quantify the motion that occurs with reduction of the pivot shift and reported a combination of posterior translation and external rotation in 80% of their subjects.…”

“…Electromagnetic tracking systems also have high reported accuracy of <0.3% of the distance between the sensors and <1.0° [10]. These systems have been successfully used to describe kinematics, such as during a pivot shift test [11,12]. However, placing electromagnetic sensors on the skin produces undesired artifacts and can lead to measurement inconsistencies [13,14].…”