A Radiological Study of the Association of Facet Joint Tropism and Facet Angulation With Degenerative Spondylolisthesis

Facet joint tropism in degenerative lumbar scoliosis: a retrospective case-control study

BACKGROUND

To investigate the association between lumbar degenerative scoliosis and the dural sac cross-sectional area (DSCA), the lumbar canal anterior-posterior (LCAP) diameter, and the neural foraminal cross-sectional area (NFCA) in relation to facet joint tropism (FJT).

METHODS

In a retrospective case-control study, we analyzed data from 160 patients referred for lumbar magnetic resonance imaging (MRI) between January 2020 and December 2022. Cobb's angle on anteroposterior lumbosacral X-ray is served to identify the presence of degenerative lumbar scoliosis-Cobb's angle exceeding 10 degrees-, and axial T2W MRI is implemented to evaluate facet joint angles and tropism-defined as a difference exceeding 10 degrees between the facet joint angles at each level-, DSCA, LCAP, and NFCA.

RESULTS

FJT was much more common in patients with degenerative lumbar scoliosis (69%) than in controls (14%). The frequency of FJT also incremented with the increasing severity of the scoliotic curve. We observed that LCAP and NFCA were significantly smaller in cases with FJT. However, no statistically significant difference was found in DSCA related to FJT. Age and gender did not exhibit significant associations with degenerative lumbar scoliosis, and no correlation was detected between different Cobb's angle groups and age.

CONCLUSIONS

These findings underscore the importance of considering FJT as a potential contributing factor to degenerative lumbar scoliosis and may have implications for clinical diagnosis and management. Prospective research with larger and more diverse cohorts is needed to further investigate this complex relationship and its impact on lumbar spinal health.

Different Degeneration Patterns of Paraspinal Muscles Between Double-Level and Single-Level Lumbar Spondylolisthesis: An Magnetic Resonance Imaging Analysis of 140 Patients

OBJECTIVE

To evaluate the degeneration patterns of paraspinal muscles in double-level degenerative lumbar spondylolisthesis (dl-DLS) versus single-level degenerative lumbar spondylolisthesis (sl-DLS).

METHODS

A total of 67 dl-DLS and 73 sl-DLS patients were included. Multifidus (MF), erector spinae (ES), and psoas major (PM)'s fatty infiltration (FI) and relative cross-sectional area (rCSA) were measured. Sagittal parameters such as lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS) were also assessed. Comparisons and correlation analysis were performed between the 2 groups.

RESULTS

MF atrophy is worse in dl-DLS patients from L3-4 to L5-S1, with higher FI from L1-2 to L5-S1 compared to sl-DLS patients. ES atrophy and FI are more pronounced in dl-DLS patients from L1-2 to L5-S1. PM atrophy is more significant in dl-DLS patients at L2-3 to L5-S1, with heavier FI from L1-2 to L3-4, though no difference in FI from L4-5 to L5-S1. The rCSA and FI of MF and ES show significant differences between adjacent segments in both groups, except for MF rCSA between L3-4 and L4-5 in dl-DLS. In dl-DLS, PM rCSA negatively correlates with PT from L4-5 to L2-3, while FI of MF and ES in L5-S1 positively correlates with LL. In sl-DLS, PM FI in L4-5 and L5-S1 negatively correlates with LL.

CONCLUSION

Degeneration of MF, ES, and PM is more severe in dl-DLS patients, particularly at the spondylolisthesis level. Severe paraspinal muscle degeneration can lead to spinal force imbalance and progression from sl-DLS to dl-DLS. The degradation of PM and ES correlates negatively with PT and SVA, indicating a link to pelvic decompensation and SVA abnormalities, potentially causing disproportionate degenerative changes in dl-DLS patients.

Exploration of the correlation between facet joints cross-sectional area asymmetry and cervical disc herniation

PURPOSE

To evaluate the association between facet joints cross-sectional area asymmetry (FCAA) and cervical intervertebral disc herniation (CDH).

METHODS

Overall, we retrospectively recruited 390 consecutive patients with CDH who underwent surgical treatment at our institution and 50 normal participants. Clinical variables and radiological findings related to CDH were collected.

RESULTS

Patients with CDH were more likely to have a higher absolute value of the facet asymmetry factor (FAF) (p  < .001), in which the FAF value of the left group was significantly higher than the other groups (p  < .001) and the right group was lower than the central group (p  < .001). 9.62% (C3/4), 12.19% (C4/5), 8.70% (C5/6), and 8.14% (C6/7) were determined as cutoff values for each variable that maximized sensitivity and specificity. Furthermore, multivariate analysis showed that cross-sectional area asymmetry of the facet joint (FCAA) was an independent risk factor for the occurrence of CDH. Also, the Chi-square test showed a significant difference in the distribution of the degeneration classification of the disc between the facet-degenerated group and the nondegenerated group at C5/6 (p = 0.026) and C6/7 (p = 0.005) in the facet asymmetry (FA) group.

CONCLUSIONS

FCAA is evaluated as an independent risk factor for CDH and associated with the orientation of disc herniation. And facet joint orientation may also play a role in cervical spine degeneration rather than facet joint tropism.

Mechanical Basis of Lumbar Intervertebral Disk Degeneration

The etiology of degenerative disk disease (DDD) is multifactorial. Among the various factors, mechanical processes contributing to endplate or discal injuries have been discussed as the initiating events in the degenerative cascade. DDD encompasses the multitudinous changes undergone by the different structures of the spinal segment, namely intervertebral disk (IVD), facet joints, vertebral end plate (VEP), adjoining marrow (Modic changes), and vertebral body. It has been etiologically linked to a complex interplay of diverse mechanisms. Mechanically, two different mechanisms have been proposed for intervertebral disk degeneration (IVDD): endplate-driven, especially in upper lumbar levels, and annulus-driven degeneration. VEP is the weakest link of the lumbar spine, and fatigue damage can be inflicted upon them under physiological loads, leading to the initiation of DDD. Disk calcification has been put forth as another initiator of inflammation, stiffening, and abnormal stresses across the IVD. The initial mechanical disruption leads to secondary IVDD through unfavorable loading of the nucleus pulposus and annulus fibrosis. The final degenerative cascade is then propagated through a combination of biological, inflammatory, autoimmune, or metabolic pathways (impaired transport of metabolites or nutrients). Abnormal spinopelvic alignment, especially pelvic incidence, also significantly impacts the degenerative process. Hence, the etiology of DDD is multifactorial. Mechanical pathways, including VEP injuries, increased disk stiffness, and abnormal spinopelvic alignment, play a significant role in the initiation of IVDD.

Biomechanical response of decompression alone in lower grade lumbar degenerative spondylolisthesis--A finite element analysis

BACKGROUND

Previous studies have demonstrated the clinical efficacy of decompression alone in lower-grade spondylolisthesis. A higher rate of surgical revision and a lower rate of back pain relief was also observed. However, there is a lack of relevant biomechanical evidence after decompression alone for lower-grade spondylolisthesis.

PURPOSE

Evaluating the biomechanical characteristics of total laminectomy, hemilaminectomy, and facetectomy for lower-grade spondylolisthesis by analyzing the range of motion (ROM), intradiscal pressure (IDP), annulus fibrosus stress (AFS), facet joints contact force (FJCF), and isthmus stress (IS).

METHODS

Firstly, we utilized finite element tools to develop a normal lumbar model and subsequently constructed a spondylolisthesis model based on the normal model. We then performed total laminectomy, hemilaminectomy, and one-third facetectomy in the normal model and spondylolisthesis model, respectively. Finally, we analyzed parameters, such as ROM, IDP, AFS, FJCF, and IS, for all the models under the same concentrate force and moment.

RESULTS

The intact spondylolisthesis model showed a significant increase in the relative parameters, including ROM, AFS, FJCF, and IS, compared to the intact normal lumbar model. Hemilaminectomy and one-third facetectomy in both spondylolisthesis and normal lumbar models did not result in an obvious change in ROM, IDP, AFS, FJCF, and IS compared to the pre-operative state. Moreover, there was no significant difference in the degree of parameter changes between the spondylolisthesis and normal lumbar models after undergoing the same surgical procedures. However, total laminectomy significantly increased ROM, AFS, and IS and decreased the FJCF in both normal lumbar models and spondylolisthesis models.

CONCLUSION

Hemilaminectomy and one-third facetectomy did not have a significant impact on the segment stability of lower-grade spondylolisthesis; however, patients with LDS undergoing hemilaminectomy and one-third facetectomy may experience higher isthmus stress on the surgical side during rotation. In addition, total laminectomy changes the biomechanics in both normal lumbar models and spondylolisthesis models.

Quantitative Radiological Characteristics of the Facet Joints in Patients with Lumbar Foraminal Stenosis

Purpose

This study aimed to evaluate the degeneration patterns of the facet joints (FJs) in patients with lumbar foraminal stenosis (LFS) and investigate the correlation between quantitative parameters and FJ osteoarthritis (FJ OA).

Patients and Methods

A total of 171 patients with LFS at the L4/5 level and 146 control patients were enrolled in this study. The severity of FJ OA was graded according to the Weishaupt classification. The FJ orientation, FJ tropism, superior articular process cross-sectional area (SAPA), and FJ area were measured at the L3/4, L4/5, and L5/S1 spinal levels. Associations among the parameters were assessed using Pearson's correlation coefficients. Independent sample t-tests and Pearson's chi-square tests were used for univariate analyses. The association between LFS and the quantitative parameters was also analyzed using multivariate logistic regression models adjusted for age, gender, and body mass index.

Results

Patients with LFS had more sagittal FJ orientation (37.9 vs 45.0, p < 0.001), more FJ tropism (5.6 vs 3.8, p < 0.001), larger SAPA (129.0 vs 97.8, p < 0.001), and less FJ area (21.7 vs 23.3, p = 0.016). Logistic regression analysis showed that LFS was significantly associated with FJ tropism (odds ratio [OR]: 1.153; p = 0.003) and SAPA (OR: 1.113; p < 0.001). The SAPA showed the largest area under the curve (0.908, 95% confidence interval: 0.875-0.942) for the diagnosis of LFS. The optimal cutoff value was 114.75 mm2 with 85.4% sensitivity and 87.0% specificity. Additionally, a significant correlation was observed between FJ OA and SAPA and FJ area at each studied spinal level.

Conclusion

This study confirmed that LFS is significantly associated with FJ hypertrophy and tropism. FJ hypertrophy and joint space narrowing correlated with the severity of FJ OA. These results are helpful in understanding the morphology and pathology of FJs.

A Systematic Review and Meta-Analysis of the Facet Joint Orientation and Its Effect on the Lumbar

Facet tropism is recognized as the difference in the positioning of the facet joints in association with each other in the sagittal plane. This guides to an imbalanced biomechanical force over the facet joints and the intervertebral disc during rotation and other physiological activities. A systematic review and meta-analysis of Web of Science, EMBASE, PubMed, Cochrane Library, SCOPUS, and CINHAL from 2004 to 2021 to recognize the related research studies was performed. The data for meta-analysis were obtained from multiple studies to get the combined effect of the facet tropism on the lumbar disc herniation (LDH) and the degenerative lumbar spondylolisthesis (LDS). 117 articles were incorporated in the systematic review, where 41 studies were selected for meta-analysis, out of which 7 studies were found eligible as per the inclusion criteria. When degenerative lumbar spondylolisthesis was compared with the normal group, 95% CI was observed at 1.94 (1.59, 2.28). There was a comparison of disc herniation with the normal group in L4/L5, with a 95% CI of 0.60 (0.05, 1.14). The L5/S1 disc herniation was compared with the normal group and was found to be 0.21 (-0.48, 0.90). Therefore, it was observed that facet tropism is related to lumbar disc herniation and degenerative lumbar spondylolisthesis. Our meta-analysis demonstrated a unique link between the facet tropism and the lumbar disk degeneration along with degenerative lumbar spondylolisthesis.

Associations between facet tropism and vertebral rotation in patients with degenerative lumbar disease

Background

Vertebral rotation and facet tropism are very common in various lumbar degenerative diseases. Facet tropism means the presence of asymmetric angles on both sides of the facet joints. Studies have shown that facet tropism contributes to lumbar degenerative disease, and also inevitably leads to the asymmetry of movement and the imbalance of force, which may be possible to rotate the vertebral body. The aim of this study was to explore the correlation between lumbar vertebral rotation and facet tropism in patients with lumbar degenerative diseases.

Methods

A total of 198 patients with lumbar degenerative diseases from 2018 to 2019 were enrolled. Five hundred and seventy vertebral rotation angles and 1140 facet angles were measured. The vertebral bodies are divided into non-rotation group (Group A) and rotation group (Group B) with the vertebral rotation angle of 3° as the boundary. The information including gender, age, BMI (body mass index), bone mineral density, history of smoking, drinking, hypertension, diabetes, diagnosis, segment distribution, and degree of facet degeneration were also counted. Using inter-class correlation coefficients (ICC) to test the reliability of measurement results. Univariate and multivariate logistic regression analysis were used to analyze the relationship between vertebral rotation and facet tropism.

Results

The consistency of the ICC within the groups of the observers is above 0.8, with good agreement. The results of univariate analysis showed that facet tropism was significantly different between group A and group B (OR (odds ratio)  = 3.30, 95% CI  =  2.03–5.35, P  < 0.0001). Other significant factors were included as adjustment variables into the multivariate regression model. Three models were analyzed separately (Model 1: non-adjusted. Model 2: adjust for age; facet degeneration; Model 3: adjust for age; disease distribution; segment distribution; facet degeneration). The results showed that after adjusting the confounders, the correlation between facet tropism and vertebral rotation did not change (Model 1: OR  = 3.30, 95% CI  = 2.03–5.35, P  < 0.0001; Model 2: adjusted OR  = 2.87, 95% CI  = 1.66–4.97, P  = 0.0002, Model 3: adjusted OR  = 2.84, 95% CI  = 1.56–5.17, P  = 0.0006).

Conclusion

Current research demonstrates that there is an association between vertebral rotation and facet tropism, suggesting that vertebral rotation may also have a certain degree of correlation with lumbar degenerative diseases.

Facet Tropism in Lumbar Spine and Cervical Spine: A Systematic Review and Meta-Analysis

BACKGROUND

Facet tropism (FT) refers to the difference in the orientation of facet joints with respect to each other in the sagittal plane. FT leads to unequal biomechanical forces on facet joint and intervertebral disc during rotation and other physiologic movements. Most of the studies have reported the incidence of FT in the lumbar spine to vary between 40% and 70%, with L4-5 level being the most commonly afflicted level. The objective of this study was to find the association between FT and various lumbar and cervical degenerative disorders.

METHODS

A systematic search of PubMed was performed with the keywords "facet tropism" and "facet asymmetry." Data for meta-analysis were extracted from the studies to obtain pooled impact of FT on lumbar disc herniation (LDH) and lumbar degenerative spondylolisthesis (LDS).

RESULTS

Eighty-two articles were included in the systematic review and 18 studies had the required data to be included in the meta-analysis. The pooled standard mean difference between FT angles in patients with or without LDH was 0.31 with (P = 0.04). The pooled odds ratio for FT in patients with LDH was 3.27 with (P = 0.02). Subgroup analysis showed that there is no significant difference in the L3/4, L4/5, and L5S1 subgroups. The pooled standard mean difference between FT angles in patients with or without LDS was 0.54 (P = 0.009).

CONCLUSIONS

FT is significantly associated with LDH and LDS along with various other lumbar and cervical degenerative diseases.

Lumbar Vertebral Endplate Defects on Magnetic Resonance Imaging in Degenerative Spondylolisthesis: Novel Classification, Characteristics, and Correlative Factor Analysis

BACKGROUND

Endplate defects are commonly seen in patients with lumbar degenerative disease. However, little is known about the presence of endplate defects in patients with degenerative spondylolisthesis (DS). In the present study, we have introduced a classification system for endplate defects in patients with DS using routine magnetic resonance imaging findings and explored the correlative factors.

METHODS

Endplate defects were classified into 3 major categories (rim defects, focal defects, and erosive defects) and 5 subtypes (anterior type, posterior type, arc type at the anterior rim, notch type, and Schmorl's nodes). The incidence rates of the endplate defects were compared between the slippage and nonslippage levels. The correlations between the endplate defects and age, sex, disc degeneration, Modic changes (MCs), body mass index, slippage segment, and slippage degree were analyzed.

RESULTS

Endplate defects were present in 47.43% of the endplates in DS. The most common endplate defects were rim defects. The occurrence of endplate defects, especially anterior defects, was more common at the slippage levels. Endplate defects were associated with age and closely related to MCs and the severity of disc degeneration. The slippage degree, slippage segment, body mass index, and sex differences were not associated with endplate defects in our study. The results obtained using this novel classification system were stable and consistent.

CONCLUSIONS

The results from the present study have shown that the novel radiological classification system of endplate defects is reliable. Endplate defects were associated with slippage but not with the slippage degree or slippage segment differences in DS. The correlation between endplate defects and age and between MCs and disc degeneration were important features on the magnetic resonance imaging scans of patients with DS.