Prevalence of Lumbar Segmental Instability in Young Individuals with the Different Types of Lumbar Disc Herniation—Preliminary Report

Background A reduction in total lumbar range of motion (ROM) after lumbar fusion may offset the increase in intradiscal pressure (IDP) and facet joint force (FJF) caused by the abnormally increased ROM at adjacent segments. This study aimed to determine a relative total lumbar ROM rather than an ideal adjacent segment ROM to guide postoperative waist activities and further delay adjacent segment degeneration (ASD). Methods An intact L1-S1 finite element model was constructed and validated. Based on this, a surgical model was created to allow the simulation of L4/5 transforaminal lumbar interbody fusion (TLIF). Under the maximum total L1-S1 ROM, the ROM, IDP, and FJF of each adjacent segment between the intact and TLIF models were compared to explore the biomechanical influence of lumbar fusion on adjacent segments. Subsequently, the functional relationship between total L1-S1 ROM and IDP or total L1-S1 ROM and FJF was fitted in the TLIF model to calculate the relative total L1-S1 ROMs without an increase in IDP and FJF. Results Compared with those of the intact model, the ROM, IDP, and FJF of the adjacent segments in the TLIF model increased by 12.6-28.9%, 0.1-6.8%, and 0-134.2%, respectively. As the total L1-S1 ROM increased, the IDP and FJF of each adjacent segment increased by varying degrees. The relative total L1-S1 ROMs in the TLIF model were 11.03°, 12.50°, 12.14°, and 9.82° in flexion, extension, lateral bending, and axial rotation, respectively. Conclusions The relative total L1-S1 ROMs after TLIF were determined, which decreased by 19.6-29.3% compared to the preoperative ones. Guiding the patients to perform postoperative waist activities within these specific ROMs, an increase in the IDP and FJF of adjacent segments may be effectively offset, thereby alleviating ASD.

Section: Introductionmentioning

confidence: 99%

Determining a relative total lumbar range of motion to alleviate adjacent segment degeneration after transforaminal lumbar interbody fusion: a finite element analysis

Li,

Cao,

Chen

et al. 2024

“…Sustained loading on the cervical spine, such as prolonged use of smartphones or computers, can lead to disc degenerative disease and forward head posture (FHP) [ 4 ]. Kuligowski T [ 5 ] found that the overall incidence of lumbar segment instability was higher with severer disc damage. FHP affects the length–tension relationship in the suboccipital muscles and causes structural and functional changes in the surrounding muscles, which result in suboccipital muscle dysfunction [ 6 ].…”

Section: Introductionmentioning

confidence: 99%

The effect of suboccipital muscle dysfunction on the biomechanics of the upper cervical spine: a study based on finite element analysis

Li,

Liu,

Zhang

et al. 2024

Objective Muscle dysfunction caused by repetitive work or strain in the neck region can interfere muscle responses. Muscle dysfunction can be an important factor in causing cervical spondylosis. However, there has been no research on how the biomechanical properties of the upper cervical spine change when the suboccipital muscle group experiences dysfunction. The objective of this study was to investigate the biomechanical evidence for cervical spondylosis by utilizing the finite element (FE) approach, thus and to provide guidance for clinicians performing acupoint therapy. Methods By varying the elastic modulus of the suboccipital muscle, the four FE models of C0-C3 motion segments were reconstructed under the conditions of normal muscle function and muscle dysfunction. For the two normal condition FE models, the elastic modulus for suboccipital muscles on both sides of the C0-C3 motion segments was equal and within the normal range In one muscle dysfunction FE model, the elastic modulus on both sides was equal and greater than 37 kPa, which represented muscle hypertonia; in the other, the elastic modulus of the left and right suboccipital muscles was different, indicating muscle imbalance. The biomechanical behavior of the lateral atlantoaxial joint (LAAJ), atlanto-odontoid joint (ADJ), and intervertebral disc (IVD) was analyzed by simulations, which were carried out under the six loadings of flexion, extension, left and right lateral bending, left and right axial rotation. Results Under flexion, the maximum stress in LAAJ with muscle imbalance was higher than that with normal muscle and hypertonia, while the maximum stress in IVD in the hypertonic model was higher than that in the normal and imbalance models. The maximum stress in ADJ was the largest under extension among all loadings for all models. Muscle imbalance and hypertonia did not cause overstress and stress distribution abnormalities in ADJ. Conclusion Muscle dysfunction increases the stress in LAAJ and in IVD, but it does not affect ADJ.

“…LSI prevalence can be as high as 57% of patients with chronic LBP [ 5 ]. The LSI is related to the proper and balanced working of the three subsystems: active, passive, and neural control [ 6 ]. The abnormal function of one of them can lead to an overload of others and cause pain and reduced quality of life [ 7 ].…”

Section: Introductionmentioning

confidence: 99%

“…The abnormal function of one of them can lead to an overload of others and cause pain and reduced quality of life [ 7 ]. LSI symptoms might lead to spondylolisthesis [ 6 , 8 ]. However, LSI is difficult to define, whether or not spondylolisthesis is involved [ 9 ].…”

Section: Introductionmentioning

confidence: 99%

Lumbosacral transitional vertebra in spondylolisthesis: frequency, demographic findings, and clinical characteristics

Mahmoodkhani,

Naeimi,

Zohrevand

et al. 2024

Background The association of LSTV with low back pain has been debated in the literature for nearly a century, but the relationship between LSTV and spondylolisthesis is still under discussion. There is currently no valid information about LSTV’s prevalence in Iran. This study investigated the relationship between the presence of LSTV and lumbosacral spondylolisthesis regarding frequency, gender and age variation, grade and level of spondylolisthesis, and clinical signs and symptoms. Methods This cross-sectional study included spondylolisthesis patients admitted for surgery between March 2021 to December 2022. All patients underwent CT imaging. After evaluating medical records, the baseline data were collected. Patients were categorized into No LSTV, Sacralization, and Lumbarization groups. Demographic and clinical characteristics of the studied groups were compared using an independent T-test and Chi-Square. Multiple logistic regression was used to assess the age and sex variations between groups. Results 219 patients with a mean age of 57.07 ± 11.04 were included. A significant relationship was observed between the presence of sacralization and gender diversity with female predominance (P = 0.01). The level of spondylolisthesis and the presence of motor deficits (paresis) significantly differed among study groups (P < 0.05). Sacralization group exhibited a greater prevalence of higher grades of listhesis compared to the other groups. Conclusions LSTV is frequently seen in spondylolisthesis patients. Sacralization is the common type of LSTV in spondylolisthesis patients, possibly leading to an increased risk for higher grades of vertebral slip and higher rates of motor deficit signs and symptoms. The presence of sacralization results in a significant increase in the incidence of higher levels of spondylolisthesis, especially the L4-L5*(sacralized L5) level. There is no relationship between age and the presence of LSTV in spondylolisthesis.