Spinal surgery uses a wide range of instrumentation devices to provide comfort to the patient, stabilize the spine, and enhance the bony healing process after surgery. In order to improve upon the effectiveness of these devices, the interaction between the spine and the implant devices needs to be studied from both medical and engineering perspectives. This paper investigates the effect of an anterior interbody fusion cage on lumbar spine stabilization, by means of numerical analysis using the finite element technique and experimental testing. Specifically, the relative displacement within an intact L4-L5 motion segment has been simulated and measured, under a range of compression, flexion, extension, torsion, and lateral bending loads. Subsequently, the effect of a single anterior lumbar fusion cage implanted into the segment was simulated and experimentally validated, under similar loading conditions. Comparison between the intact and cage-implanted segments indicated varying stabilizing ability of the fusion cage, which is highly dependent upon the cage position and the type of loading.
Concurrent Use of Lumbar Total Disc Arthroplasty and Anterior Lumbar Interbody Fusion
