Biomechanical evaluation of a dynamic fusion cage design for cervical spine: A finite element study

• Main Authors: Jung-Tung Liu, Wen-Chuan Chen, Hung-Wen Wei
• Format: Article
• Language: English
• Published: SAGE Publishing 2017-05-01
• Series: Advances in Mechanical Engineering
• Online Access: https://doi.org/10.1177/1687814017698881

Spinal interbody fusion is the most common surgery for treatment of disc degeneration, but the increased stress and compensatory range of motion at adjacent level have been noted. The dynamic cage design becomes an alternative strategy for dealing with problem of disc degeneration while the bony fusion is eventually required. Concept from a commercial cervical cage product with a ‘Z’-shaped dynamic feature has been evaluated and compared with intact cervical spine and conventional cage design by finite element method. Physiological loadings have been applied for evaluating the effect of cage design on biomechanical performances including adjacent disc stress and segmental range of motion. Results revealed that dynamic characteristic of the dynamic cage design shall effectively reduce the stress and range of motion at the adjacent disc, compared with conventional solid cage design, by providing sufficient mobility by itself. Torsional mobility was constrained due to its geometrical restriction. The dynamic function of cervical cage design may protect the disc adjacent to treat level from over-stressed and excessive mobility in early stage after fusion surgery. Further clinical investigation is required to determine the efficacy of cervical fusion by certain cervical cage with ‘Z’-shaped dynamic feature.