Comparative Analysis of the Biomechanical Characteristics After Different Minimally Invasive Surgeries for Cervical Spondylopathy: A Finite Element Analysis

Abstract

Minimally invasive surgeries, including posterior endoscopic cervical foraminotomy (PECF), microsurgical anterior cervical foraminotomy (MACF), anterior transdiscal approach of endoscopic cervical discectomy (ATd-ECD), and anterior transcorporeal approach of endoscopic cervical discectomy (ATc-ECD), have obtained positive results for cervical spondylotic radiculopathy. Nonetheless, there is a lack of comparison among them regarding their biomechanical performance. The purpose of this study is to investigate the biomechanical changes of operated and adjacent segments after minimally invasive surgeries compared to a normal cervical spine. A three-dimensional model of normal cervical vertebrae C3–C7 was established using finite element analysis. Afterwards, four surgical models (PECF, MACF, ATd-ECD, and ATc-ECD) were constructed on the basis of the normal model. Identical load conditions were applied to simulate flexion, extension, lateral bending, and axial rotation of the cervical spine. We calculated the range of motion (ROM), intradiscal pressure (IDP), annulus fibrosus pressure (AFP), uncovertebral joints contact pressure (CPRESS), and facet joints CPRESS under different motions. For all circumstances, ATc-ECD was close to the normal cervical spine model, whereas ATd-ECD significantly increased ROM and joints CPRESS and decreased IDP in the operated segment. PECF increased more the operated segment ROM than did the MACF, but the MACF obtained maximum IDP and AFP. Except for ATc-ECD, the other models increased joints CPRESS of the operated segment. For adjacent segments, ROM, IDP, and joints CPRESS showed a downward trend in all models. All models showed good biomechanical stability. With their combination biomechanics, safety, and conditions of application, PECF and ATc-ECD could be appropriate choices for cervical spondylotic radiculopathy.

Biomechanical performance of the novel assembled uncovertebral joint fusion cage in single-level anterior cervical discectomy and fusion: A finite element analysis

“…The material properties should be re-assessed if the objective of the study changes. Analogously, several recent studies have adopted similar methods for developing a finite element cervical spine model and provided satisfactory results ( He et al, 2021 ; Hua et al, 2020a ; Hua et al, 2020b ; Lin et al, 2021 ; Wo et al, 2021 ; Shen et al, 2022 ; Zhang et al, 2022b ). Given that material properties such as hyperelastic, viscoelastic, or poroelastic materials within the intervertebral disc can result in better biomechanical predictions, a more realistic model has to be developed in future studies.…”

Anterior percutaneous full-endoscopic transcorporeal decompression of the spinal cord via one vertebra with two bony channels for adjacent two-segment cervical spondylotic myelopathy: a technical note

“…We considered the question of whether the creation of two oblique bony channels through the same access portal on one vertebral body would have an impact on the biomechanical stability of the cervical spine. Some studies have demonstrated that the physiological state of the anterior transcorporeal approach procedure is closer to the normal cervical spine model, with better biomechanical stability and the ability to maintain better cervical mobility [ 29 – 31 ]. The results of a finite element analysis of the biomechanical stability of the C4 single bony channel showed that the diameter of the bony channel should be < 8 mm at the time of partial endplate excision [ 32 ].…”