[Classification and diagnosis of lumbar spinal stenosis]

Case report: Thoracolumbar spinal stenosis associated with alkaptonuria

Background

Alkaptonuria is a rare autosomal genetic disorder with an incidence of about 1 in 1 million per year. Spinal involvement often manifests in the later stages of the disease. However, this is the first report of the presentation of thoracolumbar spinal stenosis.

Case presentation

We report the case of a 61-year-old female patient with significant thoracolumbar stenosis symptoms. The patient had obvious kyphosis with preoperative lower extremity muscle strength grade 2/5. Symptoms and imaging signs initially suggested ankylosing spondylitis. This patient was classified into motor incomplete injury (ASIA C). However, the patient was found to have melanin deposits on the sclera and skin, and the urine was darkened at rest. CT and MRI both suggested no bone bridge connection between vertebrae, which was the key difference between ankylosing spondylitis and alkaptonuria in imaging. Most importantly, urine specimen testing and intraoperative pathology demonstrated alkaptonuria. The patient underwent spinal decompression and vertebral body fixation. Postoperative recovery was good: the patient had significantly relieved pain and could stand and walk.

Conclusion

This case is the first report of thoracolumbar spinal stenosis associated with alkaptonuria involving the spine.

Relationship between Severity of Lumbar Spinal Stenosis and Ligamentum Flavum Hypertrophy and Serum Inflammatory Factors

Objective

This study is aimed at investigating the correlation between lumbar spinal stenosis (LSS) severity, ligamentum flavum hypertrophy, and the upregulation of inflammatory markers.

Methods

From March 2019 and May 2022, eighty-five inpatients with LSS were enlisted as the study's research group, while sixty-five patients hospitalized for lumbar intervertebral disc herniation over the same time period served as the study's control group. Moreover, mild, moderate, and severe subgroups of patients were created within the research population based on their LSS severity. The ligamentum flavum thickness and the positive expression rates of TNF-α, TGF-β1, and IL-1α were compared between the study group and the control group. The levels of TNF-α, TGF-β1, and IL-1α that were found to be positively expressed were compared between the mild, moderate, and severe groups. Patients with LSS had their ligamentum flavum thickness and their positive expression rates of TNF-α, TGF-β1, and IL-1α analyzed using Spearman correlation analysis. We evaluated the diagnostic utility of the positive expression rates of IL-α1, TGF-β1, and TNF-α and ligamentum flavum thickness in distinguishing the severity of LSS using a receiver operating characteristic (ROC) curve.

Results

The rates of both lower limb pain (40.00%) and intermittent claudication (80.00%) in the LSS group were higher than those in the lumbar disc herniation group (15.38%, 12.31%), with statistical significance (P < 0.05). However, no substantial disparity was observed in left lower limb pain, right lower limb pain, low back pain, lower limb sensation, muscle strength, and reflex abnormalities between the two groups (P > 0.05). Positive expressions of TGF-β1, TNF-α, and IL-1α and thicker ligamentum flavum were more prevalent in the LSS group than in the lumbar intervertebral disc herniation group. All indexes were significantly (P < 0.05) higher in the moderate stenosis group than in the severe stenosis group. Additionally, the thickness of the ligamentum flavum and the positive expression rates of TNF-α, TGF-β1, and IL-1α were higher in the mild and moderate stenosis groups than in the severe stenosis group. The expression levels of TNF-α, TGF-β1, and IL-1α were favorably linked with ligamentum flavum thickness (P < 0.05). ROC curve analysis showed that the thickness of ligamentum flavum, the expression of IL-1α, the expression of TGF-β1, and the expression of TNF-α could effectively diagnose mild, moderate, and severe LSS (P < 0.05).

Conclusion

Ligamentum flavum hypertrophy and positive expression rates of IL-1α, TGF-β1, and TNF-α are closely linked to LSS, which can effectively identify mild, moderate, and severe LSS.

Minimally invasive microsurgical decompression in patients with monosegmental lumbar spinal stenosis

Surgical treatment of degenerative lumbar spinal stenosis is an actual problem of modern spinal surgery and orthopedics.

OBJECTIVE

To analyze the results of minimally invasive microsurgical decompression (MI-MD) in patients with monosegmental lumbar spinal stenosis.

MATERIAL AND METHODS

A retrospective observational cohort study was performed. We analyzed medical records of patients who underwent MI-MD for monosegmental degenerative lumbar spinal stenosis. Clinical and objective results of MI-MD, as well as the types and prevalence of adverse clinical events were studied.

RESULTS

The study included 96 medical records (50 (52%) males and 46 (48%) females aged 18-84 years). Analysis of pain in lower back and lower extremities in 3, 6, 9, 12 and 24 months after MI-MD showed a significant decrease of this indicator (p<0.001). There was significant improvement of capacity according to ODI score up to 5-12% in 72.9% of patients in early postoperative period (p=0.055). In delayed postoperative period, we also observed significant improvement of working capacity according to ODI score and gradual decrease in disability index (p<0.001). Adverse clinical events occurred in 6 (6.2%) patients.

CONCLUSION

MI-MD is a highly effective surgical method for monosegmental lumbar spinal stenosis with minimal incidence of adverse clinical events.

The identification of novel gene mutations for degenerative lumbar spinal stenosis using whole-exome sequencing in a Chinese cohort

BACKGROUND

Degenerative lumbar spinal stenosis (DLSS) is a common lumbar disease that requires surgery. Previous studies have indicated that genetic mutations are implicated in DLSS. However, studies on specific gene mutations are scarce. Whole-exome sequencing (WES) is a valuable research tool that identifies disease-causing genes and could become an effective strategy to investigate DLSS pathogenesis.

METHODS

From January 2016 to December 2017, we recruited 50 unrelated patients with symptoms consistent with DLSS and 25 unrelated healthy controls. We conducted WES and exome data analysis to identify susceptible genes. Allele mutations firstly identified potential DLSS variants in controls to the patients' group. We conducted a site-based association analysis to identify pathogenic variants using PolyPhen2, SIFT, Mutation Taster, Combined Annotation Dependent Depletion, and Phenolyzer algorithms. Potential variants were further confirmed using manual curation and validated using Sanger sequencing.

RESULTS

In this cohort, the major classification variant was missense_mutation, the major variant type was single nucleotide polymorphism (SNP), and the major single nucleotide variation was C > T. Multiple SNPs in 34 genes were identified when filtered allele mutations in controls to retain only patient mutations. Pathway enrichment analyses revealed that mutated genes were mainly enriched for immune response-related signaling pathways. Using the Novegene database, site-based associations revealed several novel variants, including HLA-DRB1, PARK2, ACTR8, AOAH, BCORL1, MKRN2, NRG4, NUP205 genes, etc., were DLSS related.

CONCLUSIONS

Our study revealed that deleterious mutations in several genes might contribute to DLSS etiology. By screening and confirming susceptibility genes using WES, we provided more information on disease pathogenesis. Further WES studies incorporating larger DLSS patient cohorts are required to comprehend the genetic landscape of DLSS pathophysiology fully.

Decompression with fusion versus decompression in the treatment of lumbar spinal stenosis: A systematic review and meta-analysis

OBJECTIVE

The goal of this study was to review relevant studies in order to determine the efficacy of decompression with fusion versus decompression in the treatment of lumbar spinal stenosis.

METHODS

Using appropriate keywords, we identified relevant studies using PubMed, the Cochrane library, and Embase. Key pertinent sources in the literature were also reviewed, and all articles published through October 2019 were considered for inclusion. For each study, we used odds ratios, mean difference (MD), and 95% confidence interval (95% CI) to assess and synthesize outcomes.

RESULTS

We found 13 studies that were consistent with this meta-analysis with a total of 29066 patients. Compared with decompression, decompression with fusion significantly increased the incidence of complications (RR: 1.41, 95%CI: 1.26-1.57), the length of hospital stay (WMD: 1.868, 95%CI: 1.394-2.343), operative time (WMD: 80.399, 95%CI: 44.397-116.401), estimated blood loss (WMD: 309.356, 95%CI: 98.008-520.704) and Zurich claudication questionnaire in symptom severity (WMD: 0.200, 95%CI: 0.006-0.394). The reoperation rate was lower in the decompression with fusion group than the decompression group but without significant difference (RR: 0.91, 95%CI: 0.82-1.00). There was no significant difference between 2 groups in visual analog scale (leg pain and back pain), ODI, Short Form 36 Health Survey physical component summary, Short Form 36 Health Survey mental component summary, and Zurich claudication questionnaire physical function.

CONCLUSION

Decompression with fusion has no significant clinical advantages in treatment of lumbar spinal stenosis when compared with decompression.