Morphological Evaluation of The Anterolateral Ligament at Varying Knee Flexion Angles Using Wireless Meta Surface Technology: Implications for Clinical Reconstruction

Abstract

Anterolateral ligament (ALL) reconstruction alongside the anterior cruciate ligament (ACL) improves recovery, stability, and reduces complications. However, the optimal knee position for ALL reconstruction remains debated. This study uses magnetic resonance imaging (MRI) to assess ALL morphology at various knee flexion angles, providing insights for better preoperative planning. In October 2022 and February 2023, 30 healthy adult participants underwent MRI scans of the left knee at 0°, 45°, and 90° flexion. Exclusion criteria included a history of knee surgery, injury, or lateral knee ligament tears. Two experienced radiologists independently evaluated the visibility of the ALL on multiplanar MRI reconstruction images, categorizing it as either fully or partially visible. Statistical analyses were performed to assess the differences in ALL length and thickness across flexion angles. Correlations between ALL dimensions and participant age, height, and weight were also analysed. The ALL was visible in 27 participants (90%), with visibility rates of 86.7% at 0°, and 83.3% at 45° and 90° flexion. Knee flexion was associated with an increase in ALL length (30.86 ± 3.45 mm at 0° to 33.57 ± 3.51 mm at 90°) and a decrease in its thickness (1.18 ± 0.16 mm at 0° to 0.93 ± 0.13 mm at 90°), both of which were statistically significant (P < 0.05). Additionally, a positive correlation was found between ALL thickness and participant weight. This study reveals significant variations in ALL length and thickness across knee flexion angles, offering insights to optimize diagnostics, surgery, and rehabilitation.