Clinical Features Post–Anterior Cruciate Ligament Reconstruction Associated With Structural Alterations in the Corticospinal Tract

Context Structural evidence for corticospinal tract (CST) abnormality in patients with anterior cruciate ligament reconstruction (ACLR) compared with healthy controls and the relationships between CST structure and clinical features of the patients (eg, objective sensorimotor outcomes and postoperative duration) are lacking. Objective To investigate whether the structural features of the CST differ between patients with ACLR and healthy controls and are associated with clinical features in patients after ACLR. Design Cross-sectional study. Setting Sports medicine laboratory. Patients or Other Participants A total of 26 patients who had undergone ACLR (age = 36.35 ± 6.39 years, height = 173.88 ± 5.97 cm, mass = 74.80 ± 10.61 kg) and 26 healthy controls (age = 32.85 ± 9.20 years, height = 173.35 ± 7.19 cm, mass = 72.88 ± 11.06 kg) participated. Main Outcome Measure(s) Using the CST as the region of interest, we performed diffusion tensor imaging to measure the microstructure of white matter tracts. Between-groups comparisons and correlation analyses with clinical features in patients with ACLR were performed. Results Patients with ACLR had moderately lower fractional anisotropy (Cohen d = −0.666; 95% CI = −1.221, −0.104; P = .01), lower axial diffusivity (Cohen d = −0.526; 95% CI = −1.077, 0.030; P = .03), higher radial diffusivity (RD; Cohen d = 0.514; 95% CI = −0.042, 1.064; P = .04), and smaller Y-Balance Test anterior-reach distance (Cohen d = −0.743; 95% CI = −1.302, −0.177; P = .005) compared with healthy controls. The RD values were correlated with the postoperative duration (r = 0.623, P < .001) after controlling for age, sex, and body mass index in patients with ACLR. Conclusions Patients with ACLR had impaired integrity (lower fractional anisotropy values and higher RD values) in the CST contralateral to the ACLR injured limb in comparison with healthy controls. Decreased integrity (higher RD) of the CST in patients was associated with longer postoperative duration, which hinted that impaired structural integrity of the CST may be a maladaptive process of neuroplasticity in ACLR.