2025, Number 2
Biomechanics of proximal adjacent segment posterior to a lumbar interbody fusion in the previously degenerated disc: a finite element study
Valdez-Aguilar JE, Victoria-Buitimea CJ, Lomelí-Zamora D, Rojas-Ayala A, Sotelo-Valencia D, León-Salguero EU
Language: Spanish
References: 14
Page: 78-83
PDF size: 285.29 Kb.
ABSTRACT
Introduction: adjacent segment disease has become a major problem following fusion surgery. It refers to degenerative changes in the segment adjacent to those fused in an instrumentation. It can lead to recurrence of low back pain and radiculopathy, affecting the long-term effectiveness of surgery and leading to reintervention in some patients. Studies have been carried out in order to understand the factors that contribute to the development of this pathology, and thus take measures to avoid it or at least delay it. Objective: determine the biomechanical behavior of the adjacent lumbar intervertebral disc in finite element models subjected to posterior fixation in different stages of degeneration. Material and methods: a finite element model of an intact lumbar spine was built, which was validated by comparing with in vitro studies. The modified models that included different degrees of degeneration (loss of disc height, facet osteoarthritis and formation of anterior vertebral osteophyte), were subjected to physiological loads and subsequently in the same way, but with posterior fixation from L4 to S1. Stress variations in the L3 disc were measured in all models. Results: levels with different degrees of degeneration presented biomechanical alterations in the adjacent segment. The statistical results showed that the difference in stress to which the L3 disc was subjected was significant in all models to flexion-extension movements. Conclusions: the loads after instrumentation will cause spondyloarthrosis and consequently adjacent segment disease in the healthy disc, and in a significantly greater proportion to the previously degenerated disc.REFERENCES