Biomechanical role of osteoporosis in the vibration characteristics of human spine after lumbar interbody fusion

Abstract

Lumbar vertebrae osteoporosis is the most common challenge for lumbar interbody fusion, and this challenge has been widely concerned by scholars for many years. However, under whole-body vibration, osteoporosis how to affect the vibration characteristics of the fusion lumbar spine, complications, and fusion outcomes is urgent to know. The L1-L5 finite element model of lumbar spine was modified to simulate the transforaminal lumbar interbody fusion model with the bilateral pedicle screw fixator at L4-L5 level. A 5 Hz, 40 N sinusoidal vertical load supplemented with a 400 N preload was used to simulate the vertical vibration of human body. The results showed that under wholebody vibration, osteoporosis of fused vertebrae may cause the adjacent segments more unstable and increase the risk of adjacent segment diseases, subsidence, cage failure, rod failure, and lumbar instability. Osteoporosis of the fused vertebrae may cause the vertebral cells an unstable, inhibited growth and lead to poorer fusion outcomes. The findings may assist us in understanding the effect of osteoporosis on the vibration characteristics of lumbar spine fusion and provide references to clinical treatments for lumbar interbody fusion and lumbar vertebrae osteoporosis.

Postoperative Sclerotic Modic Changes after Transforaminal Lumbar Interbody Fusion

“…In TLIF surgery, osteoporosis can lead to disc bulging in the adjacent intervertebral space, affecting the insertional torque and cyclic loading of pedicle screws, increasing the pressures on the upper and lower endplates and the internal fixation system, ultimately resulting in CS, screw loosening, broken screw or rod, and increased lumbar instability. 31,32 These complications at the fusion level can directly or indirectly lead to endplate damage and induce the occurrence of postoperative sclerotic MCs. Patients with osteopenia may also develop pseudarthrosis after LIF, 33 and the pseudarthrosis may experience a certain range of motion in the intervertebral space with lumbar spine movement.…”

“…Osteoporosis is characterized by osteopenia and the destruction of the trabecular and cortical bone microarchitecture. In TLIF surgery, osteoporosis can lead to disc bulging in the adjacent intervertebral space, affecting the insertional torque and cyclic loading of pedicle screws, increasing the pressures on the upper and lower endplates and the internal fixation system, ultimately resulting in CS, screw loosening, broken screw or rod, and increased lumbar instability 31,32 . These complications at the fusion level can directly or indirectly lead to endplate damage and induce the occurrence of postoperative sclerotic MCs.…”

Multibody Models of the Thoracolumbar Spine: A Review on Applications, Limitations, and Challenges

“…Simplifications are an integral part of any model and have to be taken into consideration when it comes to the interpretation of the results. To understand and evaluate their influence, MBS models have been used to systematically investigate common assumptions, such as the reduction of complex mechanics of the functional spine unit (FSU) [37,115]. Further, the sensitivity of the model accuracy to assumed positions of intervertebral centers of rotation [23,36] or muscle insertions [75] have been analyzed.…”

Recent advancement in finite element analysis of spinal interbody cages: A review

“…Furthermore, the surgeon must consider the limitations of the stand-alone (SA) and lateral plate-screw (LPS) fixations in OLIF, which may not provide adequate stability for osteoporotic patients ( Bereczki et al, 2021 ; Wang et al, 2021b ). Under whole-body vibration (WBV), the osteoporosis of the fused vertebrae may make the adjacent segments more unstable, increasing the risk of adjacent segment disease, subsidence, cage failure, rod failure, and lumbar instability ( Wang and Guo, 2020 ). These findings may contribute to a better understanding of the effect of osteoporosis on the static and vibration characteristics of lumbar spine fusion, as well as provide clinical treatment references for lumbar interbody fusion and lumbar vertebrae osteoporosis.…”