A new pathological classification of lumbar disc protrusion and its clinical significance

Animal Models of Intervertebral Disc Diseases: Advantages, Limitations, and Future Directions

Animal models are valuable tools for studying the underlying mechanisms of and potential treatments for intervertebral disc diseases. In this review, we discuss the advantages and limitations of animal models of disc diseases, focusing on lumbar spinal stenosis, disc herniation, and degeneration, as well as future research directions. The advantages of animal models are that they enable controlled experiments, long-term monitoring to study the natural history of the disease, and the testing of potential treatments. However, they also have limitations, including species differences, ethical concerns, a lack of standardized protocols, and short lifespans. Therefore, ongoing research focuses on improving animal model standardization and incorporating advanced imaging and noninvasive techniques, genetic models, and biomechanical analyses to overcome these limitations. These future directions hold potential for improving our understanding of the underlying mechanisms of disc diseases and for developing new treatments. Overall, although animal models can provide valuable insights into pathophysiology and potential treatments for disc diseases, their limitations should be carefully considered when interpreting findings from animal studies.

The effect of annulus fibrosus incision and foraminoplasty on lumbar biomechanics in percutaneous endoscopic lumbar discectomy: a finite element analysis

The objective of this study was to analyze the effects of annulus fibrosus incision and foraminoplasty on lumbar biomechanics during posterior lateral approach translaminar percutaneous endoscopic lumbar discectomy (PELD) using a lumbar 4/5 segment model and three-dimensional finite element analysis (FEA). We created a model of the L4 to L5 segment and performed simulated foraminoplasty, annulus fibrosus incision, and a combined operation. The models were tested under six working conditions, and we recorded the deformation and equivalent strain/stress of each group. Results showed that foraminoplasty can affect the stability and rotation axis of the segment during rotation without significantly impacting discal stress. Conversely, annulus fibrosus incision significantly increases discal stress except for when the patient is doing a forward flexion movement. We recommend that surgical maneuvers minimize the removal and destruction of the annulus fibrosus and that rotation movements are avoided during the short-term recovery period following PELD surgery.

Development of a predictive model for 1-year postoperative recovery in patients with lumbar disk herniation based on deep learning and machine learning

Background

The aim of this study is to develop a predictive model utilizing deep learning and machine learning techniques that will inform clinical decision-making by predicting the 1-year postoperative recovery of patients with lumbar disk herniation.

Methods

The clinical data of 470 inpatients who underwent tubular microdiscectomy (TMD) between January 2018 and January 2021 were retrospectively analyzed as variables. The dataset was randomly divided into a training set (n = 329) and a test set (n = 141) using a 10-fold cross-validation technique. Various deep learning and machine learning algorithms including Random Forests, Extreme Gradient Boosting, Support Vector Machines, Extra Trees, K-Nearest Neighbors, Logistic Regression, Light Gradient Boosting Machine, and MLP (Artificial Neural Networks) were employed to develop predictive models for the recovery of patients with lumbar disk herniation 1 year after surgery. The cure rate score of lumbar JOA score 1 year after TMD was used as an outcome indicator. The primary evaluation metric was the area under the receiver operating characteristic curve (AUC), with additional measures including decision curve analysis (DCA), accuracy, sensitivity, specificity, and others.

Results

The heat map of the correlation matrix revealed low inter-feature correlation. The predictive model employing both machine learning and deep learning algorithms was constructed using 15 variables after feature engineering. Among the eight algorithms utilized, the MLP algorithm demonstrated the best performance.

Conclusion

Our study findings demonstrate that the MLP algorithm provides superior predictive performance for the recovery of patients with lumbar disk herniation 1 year after surgery.

Predicting the Need for Surgery in Patients with Lumbar Disc Herniation: A New Internally Validated Scoring System

STUDY DESIGN

Prospective study.

PURPOSE

To propose a scoring system for predicting the need for surgery in patients with lumbar disc herniation (LDH).

OVERVIEW OF LITERATURE

The indications for surgery in patients with LDH are well established. However, the exact timing of surgery is not. According to surgeons, patients with failed conservative treatment who underwent delayed surgery, often after 6 months postsymptom initiation, have poor functional recovery and outcome.

METHODS

The current study included patients with symptomatic LDH. Patients with an indication for emergent surgery such as profound or progressive motor deficit, cauda equina syndrome, and diagnoses other than single-level LDH were excluded from the analysis. All patients followed a conservative treatment regimen (a combination of physical therapy, pain medications, and/or spinal epidural steroid injections). Surgery was indicated for patients who continuously experienced pain despite maximal conservative therapy.

RESULTS

In total, 134 patients met the inclusion and exclusion criteria. Among them, 108 (80.6%) responded to conservative management, and 26 (19.4%) underwent unilateral laminotomy and microdiscectomy. The symptom duration, disc degeneration grade on magnetic resonance imaging (Pfirrmann disc grade), herniated disc location and type, fragment size, and thecal sac diameter significantly differed between patients who responded to conservative treatment and those requiring surgery. The area under the receiver operating characteristic curve of the scoring system based on the anteroposterior size of the herniated disc fragment and herniated disc location and type was 0.81.

CONCLUSIONS

A scoring system based on herniated disc/fragment size, location, and type can be applied to predict the need for surgery in patients with LDH. In the future, this tool can be used to prevent unnecessarily prolonged conservative management (>4-8 weeks).

Association of LINC-PINT polymorphisms with lumbar disc herniation risk among Chinese Han population: a case control study

BACKGROUND

Lumbar disc herniation (LDH) is a complex spinal disease, with multiple genetic polymorphisms being related to its risk. Nevertheless, the role of LINC-PINT polymorphisms in LDH risk has remained unknown. Therefore, this study aimed to investigate the association between LINC-PINT polymorphisms and LDH risk.

METHODS

DNA was extracted from 504 LDH patients and 500 healthy controls. Three single nucleotide polymorphisms (SNPs) in LINC-PINT were selected and genotyped using Agena MassARRAY. We used logistic regression analysis to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs) under multiple genetic models to evaluate the association between LINC-PINT polymorphisms and LDH risk. Haploview 4.2 and SNPStats software were used to evaluate the linkage strength of SNPs and the correlation between haplotypes and LDH risk. The impact of SNP-SNP interactions on LDH risk was analyzed using multi-factor dimensionality reduction (MDR).

RESULTS

Results showed that rs157916 (G vs. A: OR = 1.23, FDR-p = 0.029) and rs7801029 (G vs. C: OR = 1.39, FDR-p = 0.006; GG vs. CC: OR = 2.34, FDR-p = 0.038; recessive: OR = 2.13, FDR-p = 0.045; additive: OR = 1.39, FDR-p = 0.030) were associated with an increased risk of LDH. Furthermore, LINC-PINT rs157916 and rs780129 were found to be significantly associated with LDH risk in males. The "GGG" haplotype was associated with increased LDH risk (OR = 1.41, FDR-p = 0.006). MDR analysis indicated that the interaction between rs7801029 and rs16873842 was associated with an increased risk of LDH (OR = 1.47, p = 0.004). Additionally, there were significant differences in C-reactive protein levels among different genotypes of rs157916 and rs780129 (p < 0.05).

CONCLUSION

This study suggests that LINC-PINT gene polymorphisms (rs157916 and rs7801029) are considered risk factors for LDH in the Chinese Han population and provide a scientific basis for early screening, prevention, and diagnosis of LDH.

Novel MRI signs of ruptured disc in the cervical spine with intraoperative comparisons

OBJECTIVES

To evaluate the diagnostic performance of two novel MRI signs for extruded disc (ED) and uncontained ED (ruptured disc, RD) in the cervical spine using intraoperative findings as reference.

METHODS

This retrospective study included patients who underwent cervical spine MRI and surgery for disc pathology with intraoperative confirmation of RD from September 1, 2016, to January 31, 2021. Two radiologists determined whether the disc was extruded or ruptured with and without the aid of two novel MRI signs suggesting RD (sign 1: blurred margin of the disc; sign 2: mushroom-shaped disc). The diagnostic performance was analyzed using surgical findings as reference. Intra- and interobserver agreements were measured for each MRI sign.

RESULTS

A total of 91 patients totaling 131 discs were enrolled (mean age: 56.02 ± 12.93; range: 26-88; 62 men and 29 women), of whom 62 were surgically confirmed with RD. When the diagnosis was based exclusively on existing ED definitions, ED was diagnosed with 62.9-79.0% sensitivity and 80.2% accuracy, whereas RD was diagnosed with 35.5-45.2% sensitivity and 67.9-71.0% accuracy. However, when the two novel MRI signs were used as an aid in the diagnosis, ED was diagnosed with 95.2-96.8% sensitivity and 84.0-88.5% accuracy, while RD was diagnosed with 95.2-96.8% sensitivity and 84.0-89.3% accuracy. Intra- and interobserver agreement was substantial (k = 00.77-0.86, 0.69-0.79, respectively, p < 0.001).

CONCLUSIONS

The detection of two novel MRI signs on preoperative MRI can lead to a more accurate RD diagnosis.

KEY POINTS

• The diagnostic sensitivity of MRI for cervical ruptured disc is very low (about 35-45 %) using the standardized definition of lumbar disc nomenclature. • Two novel MRI signs can lead to a more accurate diagnosis of the surgically confirmed ruptured disc in the cervical spine. • These two novel MRI signs showed substantial intra-and interobserver reliabilities.

Preoperative Magnetic Resonance Imaging Abnormalities Predictive of Lumbar Herniation Recurrence After Surgical Repair

OBJECTIVE

There are currently no standard criteria for evaluating the risk of recurrent disk herniation after surgical repair. This study investigated the predictive values of 5 presurgical imaging parameters: paraspinal muscle quality, annular tear size, Modic changes, modified Phirrmann disk degeneration grade, and presence of sacralization or fusion.

METHODS

Between 2015 and 2018, 188 patients (89 female, 99 male, median age 50) receiving first corrective surgery for lumbar disk herniation were enrolled. Microdiskectomy was performed in 161 of these patients, and endoscopic translaminar diskectomy approach was performed in 27 patients. Clinical status was evaluated before surgery and 4, 12, and 24 months post surgery using a visual analog scale, Oswestry Disability Index, and Short Form 36.

RESULTS

Recurrent disk herniation was observed in 21 of 188 patients. Seventeen of the recurrent disk herniations were seen in those who underwent microdiskectomy and 4 in those who underwent endoscopic translaminar diskectomy. There were significant differences in visual analog scale, Oswestry Disability Index, and Short Form 36 scores at 4, 12, and 24 months between patients with recurrence and the 167 no-recurrence patients. The median annular tear length was significantly greater in patients with recurrence than without recurrence. In addition, there were significant differences in recurrence rate according to Modic change type distribution, sacralization or fusion presence, Pfirmann disk; degeneration grade distribution, dichotomized annular tear size, dichotomized Modic change; and type and simplified 3-tier muscle degeneration classification distribution.

CONCLUSIONS

Patients with poor clinical scores and recurrence exhibited additional radiologic abnormalities before surgery, such as poor paraspinal muscle quality, longer annular tears, higher Modic change type, higher modified Phirrmann disk degeneration grade, and sacralization or fusion. This risk evaluation protocol may prove valuable for patient selection, surgical planning, and choice of postoperative recovery regimen.

efficacy of the therapeutic exercises on Evminov board with use of the Glisson loop in patients with degenerative spine diseases

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Does Size Matter? An Analysis of the Effect of Lumbar Disc Herniation Size on the Success of Nonoperative Treatment

STUDY DESIGN

Retrospective study.

OBJECTIVE

In this study, we examined whether the size of a lumbar disc herniation (LDH) is predictive of the need for surgical intervention within 2 years after obtaining an initial magnetic resonance imaging (MRI) scan. We hypothesized that a fragment that occupied a larger percentage of the spinal canal would not predict which patients failed conservative management.

METHODS

Using the ICD-10 code M51.26, we identified patients at a single academic institution, across the 2-year period from 2015 to 2016, who received a diagnosis of primary lumbar radicular pain, had MRI showing a disc herniation, and underwent at least 6 weeks of nonoperative management. Patients experiencing symptoms suggesting cauda equina syndrome and those with progressive motor neurological deficits were excluded from analysis, as were patients exhibiting "hard" disc herniations. Within the axial view of an MRI, the following measurements were made on AGFA-IMPACS for a given disc herniation: the length of both the canal and the herniated disc along the anterior-posterior axis, the average width of the disc within the canal; the total canal area, and the area of the disc herniation. Data analysis was conducted in SPSS and a 2-tailed reliability analysis using Cronbach's alpha as a measure of reliability was obtained.

RESULTS

A total of 368 patients met the inclusion and exclusion criteria for this study. Of these, 14 (3.8%) had L3-L4 herniations, 185 had L4-L5 herniations (50.3%), and 169 had L5-S1 herniations (45.9%). Overall, 336 (91.3%) patients did not undergo surgery within 1 year of the LDH diagnosis. Patients who did not receive surgery had an average herniation size that occupied 31.2% of the canal, whereas patients who received surgery had disc herniations that occupied 31.5% of the canal on average. A Cronbach's alpha of .992 was observed overall across interobserver measurements. After controlling for age, race, gender, and location of herniation through a logistic regression, it was found that the size of the herniation and the percentage of the canal that was occupied had no predictive value with regard to failure of conservative management, generating an odds ratio for surgery of 1.00.

CONCLUSIONS

The percentage of the spinal canal occupied by a herniated disc does not predict which patients will fail nonoperative treatment and require surgery within 2 years after undergoing a lumbar spine MRI scan.

Factors associated with lumbar disc hernia recurrence after microdiscectomy

INTRODUCTION

Lumbar disc hernias are a common cause of spinal surgery. Hernia recurrence is a prevalent complication.

OBJECTIVE

To analyse the risk factors associated with hernia recurrence in patients undergoing surgery in our institution.

MATERIALS AND METHODS

Lumbar microdiscectomies between 2010 and 2014 were analysed, patients with previous surgeries, extraforaminales and foraminal hernias were excluded. Patients with recurrent hernia were the case group and those who showed no recurrence were the control group.

RESULTS

177 patients with lumbar microdiscectomy, of whom 30 experienced recurrence (16%), and of these 27 were reoperated. Among the risk factors associated with recurrence, we observed a higher rate of disc height, higher percentage of spinal canal occupied by the hernia and presence of degenerative facet joint changes; we observed no differences in sex, body mass index or age.

DISCUSSION

Previous studies show increased disc height and young patients as possible factors associated with recurrence.

CONCLUSION

In our series we found that the higher rate of disc height, the percentage of spinal canal occupied by the hernia and degenerative facet joint changes were associated with hernia recurrence.