Yeungnam Univ J Med.  2003 Dec;20(2):160-168. 10.12701/yujm.2003.20.2.160.

Analysis of Compression Behavior on Intervertebral Disc L4-5 in Pedicle Screw System Instrumented Lumbar Spine under Follower Load

• Ahn MW
• Ahn JC
• Lee SH
• Chung IS
• Lee CY
• Lee JW

• KMID: 2049761
• DOI: http://doi.org/10.12701/yujm.2003.20.2.160

Abstract

BACKGROUND: Confirm the stability of intervertebral disc sustaining each fused lumbar spine cases, comparing vertical compression, A-P shear force and rotational moment on intervertebral disc of instrumented lumbar spine with simple vertical compression load and follower load using finite element analysis.
MATERIALS AND METHODS
We analyze the stability of intervertebral disc L4-5 supporting fused lumbar spine segments. After performing finite element modelling about L1-L5 lumbar vertebral column and L1-L4 each fusion level pedicle screw system for fused lumbar spine fine element model. Intervertebral discs with complex structure and mechanical properties was modeled using spring element that compensate stiffness and tube-to-tube contact element was employed to give follower load. Performing geometrical non-linear analysis.
RESULTS
The differences of intervertebral disc L4-5 behavior under the follower compression load in comparision with vertical compression load are as follows.
CONCLUSION
As a result of finite element interpretation of instrumented lumbar spine, the stability of L4-5 sustaining fused lumbar segment, the long level fused lumbar spine observed hing stability under follower load. This research method can be the basis tool of effects prediction for instrumentation, a invention of a more precious finite element interpretation model which consider the role of muscle around the spine is loaded.

Keyword

Finite element method; Follower load; Fusion level; Lumbar spine; Stability

MeSH Terms

Finite Element Analysis
Intervertebral Disc*
Inventions
Spine*