Finite element analysis on inferior cervical spine biomechanics after semi-constrained cervical intervertebral disc arthroplasty and anterior cervical discectomy and fusion / 医用生物力学

ABSTRACT

Objective To study biomechanical properties such as range of motion (ROM), intervertebral disc stress, ligament tension of inferior cervical spinal segment after the treatment of Discover, Prodisc-C artificial intervertebral disc replacement, and anterior cervical discectomy and fusion (ACDF), as well as mechanical property changes of the prosthesis after implantation. Methods Three kinds of operation plan on C5-6 cervical disc degeneration were established Discover model, Prodisc-C model and ACDF model, as well as C4-7 segment original model of cervical vertebra. Biomechanical property changes after operation in cervical spine C4-7 segment in sagittal, coronal and transverse section were analyzed. Results ROM changes of cervical segment C5-C6 were as following in Discover model it increased by 12.7%-73.1%, Prodisc-C model increased by 74%-98%, ACDF decreased by 55.8%-71.8%. The stress of C4-5 intervertebral disc after Discover artificial disc replacement showed no obvious increase, while the stress of C6-7 intervertebral disc decreased by 33.2%-54.2% under flexion, extension and axial rotation conditions. The amplification of ligament tension in Discover model decreased by 30%-40% as compared to that in Prodisc-C model. The maximum stress of Discover model (36.72 MPa) appeared under flexion condition, which was smaller than that in Prodisc-C model. Conclusions Artificial disc replacement can help to keep movement performance for segment after surgery. As a newly developed artificial intervertebral disc prosthesis, Discover makes some progress in the aspect of decreasing ligament stress and maintaining spinal stability. The research findings will provide theoretical basis for the clinical study on ACDF and artificial cervical intervertebral disc replacement surgeries.