Neural Markers of Knee Disability in Patients with Anterior Cruciate Ligament Reconstruction: A Multicenter fMRI Study (108)

Abstract

Objectives:Anterior cruciate ligament (ACL) rupture is a common knee injury among athletes and physically active adults. Despite surgical reconstruction and extensive rehabilitation, reinjury rates remain high and patient-reported disability continues even years after therapy and return to activity. Prolonged knee dysfunction has been attributed, in part, to unresolved neuromuscular deficits of the surrounding joint musculature in response to injury. Recent reports have identified widespread cortical and spinal cord changes to engage the quadriceps following injury, which may explain why a considerable proportion of patients exhibit persistent levels of knee disability. While these reports have provided evidence for consequences of injury that extend beyond the joint, there is a paucity of studies exploring the link between nervous system functioning and patient-reported measures of disability. The objective of this study was to determine the relationship between patient-reported knee disability and neural activity for knee control in patients with ACL reconstruction (ACL-R).Methods:In this multicenter cross-sectional study, twenty-five participants with unilateral ACL-R (18 left, 7 right; 10 males, 15 females; age, 21.8 ± 2.6 years; height, 169.7 ± 19.2 cm; weight, 69.6 ± 14.8 kg; Tegner activity level scale, 8.4 ± 1.2; IKDC, 84.9 ± 10.8; graft type, 15 quadrupled hamstring tendon / 10 bone-patellar-tendon-bone; time from surgery, 51.6 ± 32.0 months) underwent functional magnetic resonance imaging (fMRI) testing. fMRI testing consisted of repeated cycles of open-chain knee flexion/extension movement (Figure 1A). Neural activation patterns were quantified using blood-oxygen-level-dependent (BOLD) signals for all participants during the movement task at a cluster corrected z-threshold >2.3, p