BIOMECHANICAL IMPACT OF CERVICAL LORDOSIS VARIATIONS ON ADJACENT INTERVERTEBRAL STRUCTURES IN ATHLETES UNDERGOING ANTERIOR CERVICAL DISCECTOMY FUSION: A FINITE ELEMENT ANALYSIS

Abstract

Objective: This study aims to assess biomechanical changes in athletes undergoing Anterior Cervical Discectomy and Fusion (ACDF) with varying degrees of cervical lordosis, particularly focusing on the stress distribution on adjacent intervertebral structures which could influence recovery and return to sport. Methods: Three-dimensional finite element models of the C2-C7 cervical spine were constructed based on CT images from two patients who underwent ACDF at C5/6, representing normal and straightened cervical curvatures. A 75-N follower load simulated head weight, and 1.0-N moments induced flexion, extension, lateral bending, and rotation. Range of Motion (ROM) and stress distribution on the annulus fibrosus and implant surfaces were analyzed under these conditions, with stress measured across four zones of the intervertebral annulus fibrosus. Results: The model demonstrated that normal cervical curvature exhibited less alteration in von Mises stress during extension and flexion compared to the straightened curvature, indicating a more favorable biomechanical environment post-surgery. In the straightened curvature group, increased stress concentrations on the titanium plate and screws were noted, particularly in extension, suggesting a higher risk of implant strain and adjacent segment degeneration. ROM and stress distribution comparisons suggest that maintaining or restoring natural cervical curvature during ACDF could be crucial for optimal biomechanical outcomes. Conclusions: The findings highlight the importance of considering cervical curvature in the surgical planning for athletes undergoing ACDF, as variations in curvature significantly affect stress distributions that are critical for long-term outcomes and prevention of adjacent segment degeneration. These biomechanical insights are vital for sports medicine professionals in planning rehabilitation and conditioning programs post-surgery to ensure a safe and effective return to athletic activities. Future studies should explore long-term clinical outcomes to further validate these biomechanical predictions.