Electrocortical activity in ACL patients

Rationale: Nowadays, the (operative and conservative) treatment and the rehabilitation after an anterior cruciate ligament (ACL) injury focuses on the restoring of mechanical stability. However, despite the restored mechanical stability a lot of patients have re-ruptures or remaining symptoms of instability. A possible explanation for this large number of re-ruptures is the lack of, or change of, sensory input from the affected knee. As a result, the central nervous system receives adjusted information and adapts to the new situation, a process called neural plasticity.



The biomechanical function of ACL patients is extensively investigated, yet neural plasticity is hardly studied. Biomechanical research shows that postural control and landing tasks are executed comparable by ACL patients and healthy controls with eyes open. However, when eyes are closed the execution is significantly diminished in ACL patients. This implies the additional need of visual feedback in ACL patients. Earlier research, which examines the brain activity in ACL reconstructed and ACL deficient patients, has shown an increased activation of the visual cortex during simple movements with the affected leg compared to legs of healthy controls.



Objective:

Primary objective: Examining the hypothesis that patients with ACL deficiency and patients with ACL reconstructions, despite comparable force-reproduction capacities with the affected, dominant leg, have a significant altered EEG Theta-activity in the motor cortex during a repetitive force-reproduction task compared to the dominant leg of the healthy controls.



Study design: A cross-sectional, three-armed case-control study, consisting of twelve healthy controls, twelveACL deficient patients and twelveACL reconstructed patients.



Study population: All subjects are sportively active persons (Tegner score ≥ 5) aged between 18 and 30 years old. Additionally, the subjects in the ACL reconstruction group have to be one year +/- three months after reconstruction surgery. The subjects in the ACL deficient group have to be one year +/- five months after their rupture. Most important exclusion criteria are the presence of additional ligament damage and/or brain disorders.
Main study parameters/endpoints:



Primary endpoint: The primary endpoint of this study is the difference in EEG Theta activity during the force-reproduction task between the ACL deficient group, the ACL reconstructed group and the healthy controls. The Theta-power consists of all waves in the frequency spectrum between 4.75 Hz en 6.75 Hz in the repetition period (where no visual feedback is present) in both measurement blocks. Thereafter, a logarithmic transformation of the power values is done to stabilize the power values for the statistical analysis. The stabilized Theta-value in both measurement blocks is then compared between the ACL deficient patients, ACL reconstructed patients and the healthy controls.

Patients with an ACL deficiency and patients with an ACL reconstruction have a significant changed EEG Theta-actvity during a force-reproduction task compared to healthy controls, despite comparable force-reproduction capacities.

One timepoint one-year after ACL rupture (ACL deficient group) or ACL surgery (ACL reconstruction group).

not applicable