Radiological and functional assessment in patients with lumbar spinal stenosis

Quantification of cauda equina nerve root dispersion through radiomics features in weight-bearing MRI in normal subjects and spinal canal stenosis patients

OBJECTIVE

To quantify the distribution of cauda equina nerve roots in supine and upright positions using manual measurements and radiomics features both in normal subjects and in lumbar spinal canal stenosis (LSCS) patients.

METHODS

We retrospectively recruited patients who underwent weight-bearing MRI in supine and upright positions for back pain. 3D T2-weighted isotropic acquisition (3D-HYCE) sequences were used to develop a 3D convolutional neural network for identification and segmentation of lumbar vertebrae. Para-axial reformatted images perpendicular to the spinal canal and parallel to each vertebral endplate were automatically extracted. From each level, we computed the maximum antero-posterior (AP) and latero-lateral (LL) dispersion of nerve roots; further, radiomics features were extracted to quantify standardized metrics of nerve root distribution.

RESULTS

We included 16 patients with LSCS and 20 normal subjects. In normal subjects, nerve root AP dispersion significantly increased from supine to upright position (p < 0.001, L2-L5 levels), and radiomics features showed an increase in non-uniformity. In LSCS subjects, in the upright position AP dispersion of nerve roots and entropy-related features increased caudally to the stenosis level (p < 0.001) and decreased cranially (p < 0.001). Moreover, entropy-related radiomics features negatively correlated with pre-operative Pain Numerical Rating Scale. Comparison between normal subjects and LSCS patients showed a difference in AP dispersion and increase of variance cranially to the stenosis level (p < 0.001) in the upright position.

CONCLUSIONS

Nerve root distribution inside the dural sac changed between supine and upright positions, and radiomics features were able to quantify the differences between normal and LSCS subjects.

CLINICAL RELEVANCE STATEMENT

The distribution of cauda equina nerve roots and the redundant nerve root sign significantly varies between supine and upright positions in normal subjects and spinal canal stenosis patients, respectively. Radiomics features quantify nerve root dispersion and correlates with pain severity.

KEY POINTS

• Weight-bearing MRI depicts spatial distribution of the cauda equina in both supine and upright positions in normal subjects and spinal stenosis patients. • Radiomics features can quantify the effects of spinal stenosis on the dispersion of the cauda equina in the dural sac. • In the orthostatic position, dispersion of nerve roots is different in lumbar spinal stenosis patients compared to that in normal subjects; entropy-related features negatively correlated with pre-operative Pain Numerical Rating Scale.

Full endoscopic percutaneous stenoscopic lumbar decompression and discectomy: An outcome and efficacy analysis on 606 lumbar stenosis patients

Introduction

Laminectomy has long been a "gold standard" to treat symptomatic lumbar spinal stenosis (LSS). Minimal invasive spine surgery (MISS) is widely developed to overcome the limitations of conventional laminectomy to achieve a better outcome with minimal complications. Full endoscopic percutaneous stenoscopic lumbar decompression (FE-PSLD) is the newest MISS technique for spinal canal decompression. We aimed to evaluate and analyze the significance of FE-PSLD in reducing pain and its association with age, duration of symptoms, stenosis level, and operative time (OT).

Materials and Methods

A longitudinal cross-sectional study was conducted on 606 LSS patients who underwent FE-PSLD and enrolled from 2020 to 2022. Three-month evaluation of the Visual Analog Scale (VAS) and the modified MacNab criteria were assessed. The significance of changes was analyzed using the Wilcoxon signed-ranks test. Spearman's correlation test was performed to evaluate the significant correlation of several variables (pre-PSLD-VAS, age, symptoms duration, OT, and level of LSS) to post-PSLD-VAS, and multiple regression analysis was conducted.

Results

The reduction of VAS was statistically significant (P ≤ 0.005) with an average pre-PSLD-VAS of 6.75 ± 0.63 and post-PSLD-VAS of 2.24 ± 1.04. Pre-PSLD-VAS, age, and stenosis level have a statistically significant correlation with post-PSLD-VAS, while the duration of the symptoms and OT have an insignificant correlation. Multiple regression showed the effect of pre-PSLD-VAS (β =0.4033, P = 0.000) and stenosis level (β =0.0951, P = 0.021) are statistically significant with a positive coefficient.

Conclusions

FE-PSLD is an efficacious strategy with favorable outcomes for managing LSS, shown by a significant reduction of pain level with a relatively short follow-up time after the procedure. Preoperative pain level, age, and stenosis level are significantly correlated with postoperative pain level. Based on this experimental study, PSLD can be considered a good strategy for treating lumbar canal stenosis in all age groups and all LSS levels.

Mechanical Needling With Sterile Water Versus Lidocaine Injection for Lumbar Spinal Stenosis

Study Design: This was a retrospective observational study that assessed the clinical outcome of ageing patients who received ultrasound-guided (USG) mechanical needling with sterile water injection. In addition, the clinical outcome of age-and gender matched patients randomly selected from patients who received needling with sterile water was compared to the patients injected with lidocaine in a 1:1 ratio.Objective: This present study aimed to explore the clinical effects of USG mechanical needling with sterile water injection for lumbar spinal stenosis (LSS).Methods: The data was extracted from the medical records of ageing patients with LSS who received USG injection at the lumbosacral spine by the first author. Low back pain or axial pain, and leg pain or radicular pain were assessed by the visual analogue scale, and gait ability with walking distance were obtained at six different time points.Results: A total of 4328 medical records were examined. Four thousand two hundred and twenty-eight ageing patients received mechanical needling with sterile water injection and found the efficacy lasted up to 6 months. One hundred patients were compared with 100 patients who received lidocaine injection. Those who received lidocaine had pain returned at 3 months and 6 months post-injection.Conclusions: USG mechanical needling with sterile water injection could help relieve axial and radicular pain for at least 6 months. Removal of calcification and fibrosis as well as reduction of sensitization are all possible mechanisms.