Biomechanical comparison of transdiscal fixation and posterior fixation with and without transforaminal lumbar interbody fusion in the treatment of L5–S1 lumbosacral joint

Abstract

Transdiscal screw fixation is generally performed in the treatment of high-grade L5-S1 spondylolisthesis. The main thought of the study is that the biomechanical performances of the transdiscal pedicle screw fixation can be identical to standard posterior pedicle screw fixations with or without transforaminal lumbar interbody fusion cage insertion. Lumbosacral portions and pelvises of 45 healthy lambs' vertebrae were dissected. Animal cadavers were randomly and equally divided into three groups for instrumentation. Three fixation systems, L5-S1 posterior pedicle screw fixation, L5-S1 posterior pedicle screw fixation with transforaminal lumbar interbody fusion cage insertion, and L5-S1 transdiscal pedicle screw fixation, were generated. Axial compression, flexion, and torsion tests were conducted on test samples of each system. In axial compression, L5-S1 transdiscal fixation was less stiff than L5-S1 posterior pedicle screw fixation with transforaminal lumbar interbody fusion cage insertion. There were no significant differences between groups in flexion. Furthermore, L5-S1 posterior fixation was stiffest under torsional loads. When axial compression and flexion loads are taken into consideration, transdiscal fixation can be alternatively used instead of posterior pedicle screw fixation in the treatment of L5-S1 spondylolisthesis because it satisfies enough stability. However, in torsion, posterior fixation is shown as a better option due to its higher stiffness.

Influence of posterior pedicle screw fixation at L4–L5 level on biomechanics of the lumbar spine with and without fusion: a finite element method

“…It has many assets, such as a high fusion rate, maintenance of the original disc height, and maintenance of lumbar spine stability [5,6]. Nevertheless, the PS fixation method with interbody fusion has some complications including PS failure, rod breakage, and adjacent segment disease (ASD) as a result of restricting the range of motion (ROM) of the lumbar spine [7][8][9][10]. Many experimental and numerical studies have been conducted based on fusion surgery to benefit from these advantages more efficiently and avoid the disadvantages [11][12][13][14].…”

The effects of pre-stressed rods contoured by different bending techniques on posterior instrumentation of L4-L5 lumbar spine segment: A finite element study

“…30,43 Nevertheless, it also entails complications such as PS failure and rod breakage. 44–46 In this study, it has been shown that the regions of maximum stress concentration for rods and PSs were usually the middle region of the rods and the neck region of the PSs. In the related literature, Guo and Wang 47 demonstrated the same trend for stress concentration regions with rods and PSs.…”

Sacrolumbar Interbody Fusion (SLIF): Feasibility, Technical Nuances, Biomechanical Assessment, and Clinical Outcomes

“…This technique (and its modifications) was adopted by other authors and has shown encouraging results [4][5][6][7][8][9][10] . Additionally, several studies demonstrated similar biomechanical profiles of transdiscal and classical pedicle screw-based constructs [11][12][13] . In cadaveric biomechanical testing, Minamide et al demonstrated that L5-SLTS pedicle screw-rod system provided a 1.6-1.8 stiffer construct than conventional L5-S1 BPSS.…”