Orientation of the facet joints in degenerative rotatory lumbar scoliosis: an MR study on 52 patients

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.

Preliminary study on the effect of lumbar axial rotation on bone mineral density measured by DXA and QCT

Currently, the relationship between axial rotation of the vertebrae and bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) and quantitative computed tomography (QCT) remains controversial. The aim of this study is to quantitatively assess the effect of vertebral rotation on volumetric bone mineral density (v-BMD) and areal bone mineral density (a-BMD), further to propose the corrected strategies. To achieve this, a phantom, which was rotated from 0° to 25° in 5° increments, was utilized. Bone mineral content (BMC), a-BMD, v-BMD, and projected area (p-AREA) were measured. The Kruskal-Wallis non-parametric test or one-way ANOVA was used to examine the differences in variables between the different groups. The Pearson and Spearman correlation was used to test the relationships between quantitative parameters and rotated angles. Linear regression analysis was used to evaluate the relationship between angles and quantitative parameters. The findings indicate that, as the angle increased, a-BMD and v-BMD decreased (P < 0.001) , and the p-AREA increased (P < 0.001), but the BMC stays constant. The rotated angle was negative correlated (r = - 0.925, P < 0.001) with a-BMD and v-BMD (r = - 0.880, P < 0.001), positive (r = 0.930, P =  < 0.001) correlated with p-AREA. The linear regression analysis showed that a-BMD = 0.808-0.01 × Angle and v-BMD = 151.808-1.588 × Angle. This study showed that, axial rotation might lead to a lower measured for a-BMD and v-BMD, it should be modified. This gives clinicians some insights into how to deal with osteoporosis in scoliosis patients. It's essential for clinicians to incorporate these findings into their diagnostic processes to prevent potential misdiagnosis and over-treatment of osteoporosis.

Prevalence, distribution characteristic and risk factors of lumbar vertebral axial rotation in patients with lumbar disc herniation: a retrospective study

This retrospective study aimed to investigate the impact of lumbar disc herniation (LDH) on vertebral axial rotation (VAR) in the lumbar spine, focusing on both close and distant neighboring vertebrae. A total of 516 patients with LDH and an equal number of healthy individuals were included in the study, matched for age and gender. The degree of axial rotation for each lumbar spine vertebra was assessed using the Nash-Moe index. The results revealed that the prevalence of VAR in the lumbar spine was significantly higher in the LDH group compared to the Control group (65.7% vs 46.7%, P < 0.001). Among the LDH group, the L2 vertebra had the highest frequency of VAR (49.5%), followed by L1 (45.1%), and then L3 to L5 (33.6%, 8.9%, 3.1%, respectively). A similar pattern was observed in the Control group (L2, 39.8%; L1, 34.6%; L3, 23.2%; L4, 3.1%; L5, 0.8%). Furthermore, the study found that disc herniation was associated with a higher incidence of VAR not only in close neighboring vertebrae but also in distant neighboring vertebrae. This indicates that the biomechanical influence of LDH extends beyond just the immediate adjacent vertebrae. To identify potential risk factors for VAR in LDH patients, multivariate analysis was performed. The results revealed that age was an independent risk factor for VAR (OR 1.022, 95% CI [1.011, 1.034], P < 0.001). However, the duration of symptoms and presence of back pain were not found to be significant risk factors for VAR.

The effects of vertebral rotation on the position of the aorta relative to the spine in patients with adult degenerative scoliosis

Aims

This study aimed to explore the effects of vertebral rotation on the position of the aorta relative to the thracolumbar and lumbar spine, and to identify risk factors for vertebral rotation in patients with adult degenerative scoliosis (ADS).

Methods

A total of 71 patients with ADS were divided into left scoliosis (LS) group (n = 40 cases) and right scoliosis (RS) group (n = 31cases) with well-matched demographics. Apical vertebrae, Cobb angle (°), coronal horizontal movement, thoracolumbar kyphosis (TLK) and Nash-Moe rotation classification were measured on X-ray. The Cartesian coordinate system was established on T2-MRI for each level of intervertebral disc on thracolumbar and lumbar spine, where aorta-vertebrae angle (α), aorta-vertebrae distance (d), and vertebral rotation angle (γ) for each level of T12-L1 to L3-L4 on MRI were defined within the Cartesian coordinate system.

Results

There was no statistical difference in the distribution of apical vertebrae between LS and RS groups. Nash-Moe classification was of no significance between the two groups. When there was a larger Cobb angle and coronal horizontal movement, a greater γ in LS group and a lower γ in RS group were noted (both p < 0.001). There was no correlation among γ, α, and d in LS group (p = 0.908 and 0.661, respectively) nor in RS group (p = 0.738 and 0.289, respectively). In LS group, Nash-Moe classification correlated to Cobb angle, coronal movement and TLK. In RS group, it correlated to Cobb angle and coronal movement. Cobb angle was the risk factor for Nash-Moe classification in RS group while no factors were identified in LS group. Coronal movement was independent risk factor for γ (p = 0.003) in LS group. Moreover, γ was affected by Cobb angle (p = 0.001) and coronal horizontal movement (p = 0.006) in RS group.

Conclusion

Vertebral rotation could be predicted by Cobb angle or coronal horizontal movement measured on X-ray in ADS patients and aorta maintained in a relatively normal position in patients with ADS.

Exploring the pathological role of intervertebral disc and facet joint in the development of degenerative scoliosis by biomechanical methods

BACKGROUND

To investigate the biomechanical changes in the development of scoliosis due to intervertebral disc and facet joint degeneration.

METHODS

We enrolled 39 cases of fresh-frozen lumbar spine specimens and underwent CT scanning and 3D reconstruction. An Osirix Dicom imaging system was to assess the degeneration of the intervertebral disc and facet joints, and mechanical loading was conducted using a spine mechanical instrument with the frequency set at plus/minus 7.5 NM, 0.005 Hz. Range of motion (ROM) and neutral zone (NZ) of 39 cadaveric lumbar spines were tested.

FINDINGS

Degeneration existed in all 39 cases of the lumbar specimens: the Cobb angle >10° in 5 cases (degenerative scoliosis (DS) group), between 3° and 10° in 9 cases (pre-degenerative scoliosis (PS) group) and <3° in 25 cases (no scoliosis (NS) group). The axial torsion (AT) range of motion (ROM_AT) and the NZ of the DS and PS groups was greater than in the NS group and increased with increasing Cobb angle. A significant correlation was found between the degeneration of the intervertebral disc and the AT and the AT correlated with the Cobb angle and facet joint degeneration.

INTERPRETATION

The AT correlated with intervertebral disc and facet joint degeneration, which might be a mechanic factor in the occurrence and development of degenerative scoliosis.