Biomechanical effects of different approaches and titanium mesh in combined anterior cervical corpectomy decompression and fusion：a finite element study

Abstract

Background: Anterior Cervical Corpectomy and Fusion(ACCF), which is one of the common surgeries used to treat cervical spine diseases, has been widely applied in clinical practice. The commonly used internal fixation forms in ACCF surgery include the traditional anterior vertebral body screw-plate (AVBSP) structure and the anterior cervical pedicle screw-plate (APSP) structure, both of which are combined with titanium mesh to achieve support and bone fusion. Objetives: The purpose was to investigate the effects of different surgical plans on cervical spine biomechanics and the interplay between internal fixation instruments after surgery. Methods: In this study, a finite element model of the human lower cervical spine (C3-C7) after ACCF surgery was established. The surgical plan consisted of two internal fixation forms (AVBSP and APSP) and two titanium mesh forms (linear and curved), combined in different ways. Results: The mechanical sensitivity of adjacent intervertebral disc nuclei to different surgical plans was significantly different. The stress concentration areas on the vertebral body entry surface varied with different entry methods, and the stress values were greatly affected by cervical movements. The related instrument studies showed that the choice of anterior fixation method would affect the stress level and distribution of the titanium mesh. Theoretically, the combination of curved titanium mesh and AVBSP is beneficial to reducing the overall stress level of the internal fixation instruments and titanium mesh. Conclusion:The research provides theoretical basis for the selection of clinical surgical plans. It is advantageous in enhancing postoperative stability of cervical vertebrae while reducing the risk of recurrence or other complications such as adjacent segment disease. Clinically, when selecting the excision fusion surgical plan based on the condition of the patient's cervical lesion, consideration should also be given to the matching characteristics between internal fixation methods and titanium mesh forms, as well as their effects on the biomechanics of adjacent segments.