CORRELATION BETWEEN THE MODIC I SIGN AND IMAGES OF VERTEBRAL INSTABILITY

ABSTRACT The lumbar region is highly affected by degenerative diseases and can be symptomatic as a result of inflammatory processes of the disc or segmental vertebral instability (SVI), according to concepts by White and Panjabi. Magnetic resonance imaging (MRI) and dynamic radiographs can be used to evaluate it. Objective: To determine whether images of Modic type I lesions are compatible with radiological vertebral instability. Methods: The MRIs and dynamic radiographs of 100 patients with a mean age of 46.94 years, 65 of whom were women and 35 of whom were men, were studied to evaluate the reaction of endplates according to Modic and SVI at levels L2-L3, L3-L4, L4-L5 and L5-S1. They were divided into 3 groups: A- Modic I and SVI; B- Modic I without SVI; and C- Without Modic I and SVI. Sex, age and type of disc were evaluated. Result: 46 Modic I lesions and 24 cases of SVI were recognized. There were 5 patients in Group A (OR 0.23, p=0.006), 38 in Group B; and 19 in Group C. No direct relationship between age and Modic I and/or SVI was observed. Pfirrmann grade 5 discs are 4.6 times more likely to present a Modic I signal. The most affected disc was L3-L4 for the Modic signal and L4-L5 with respect to the SVI, translational instability being more frequent. Conclusions: Modic type changes, identified by magnetic resonance, are clinically relevant in relation to low back pain, but their presence does not confirm either translational or angular instability. Level of evidence III; Cross-sectional cohort.

Deep Learning Approach for Evaluating Lumbar Intervertebral Disc Degeneration: Achieving High Accurate Segmentation for Quantitative Analysis on MRI

Purpose: Using deep learning and image processing technology, a standardized automatic segmentation and quantitation network of lumbar disc degeneration based on T2MRI was proposed to help residents accurately evaluate the intervertebral disc (IVD) degeneration.Materials and Methods: A semantic segmentation network (BianqueNet) consist of self-attention mechanism skip connection module and deep feature extraction module was proposed to achieve high-precision segmentation of IVD related areas. A quantitative method was used to calculate the signal intensity difference (∆SI) in IVD, average disc height (DH), disc height index (DHI), and disc height-to-diameter ratio (DHR). Quantitative ranges for these IVD parameters in a larger population was established among the 1051 MRI images collected from four hospitals around China.Results: The average dice coefficients of BianqueNet for vertebral bodies and intervertebral discs segmentation are 97.04% and 94.76%, respectively. This procedure was suitable for different MRI centers and different resolution of lumbar spine T2MRI (ICC=.874~.958). These geographic parameters of IVD degeneration have a significant negative correlation with the modified Pfirrmann Grade, while signal intensity in IVD degeneration had excellent reliability according to the modified Pfirrmann Grade (macroF1=90.63%~92.02%).Conclusion: we developed a fully automated deep learning-based lumbar spine segmentation network, which demonstrated strong versatility and high reliability to assist residents on IVD degeneration evaluating by means of IVD degeneration quantitation.Implication for Patient Care: Deep learning–based approaches have the potential to maximize diagnostic performance for detecting disc degeneration and assessing risk of disc herniation while reducing subjectivity, variability, and errors due to distraction and fatigue associated with human interpretation.

Kinematics of an intervertebral disc with type 1 Modic change: mechanical and non-mechanical causes

BackgroundType 1 Modic change (MC) is associated with chronic low back pain and attributed to segmental instability. However, the relationship between type 1 MC and segmental instability is unclear. This study sought to clarify the role of mechanical abnormalities in type 1 MC.MethodReview of magnetic resonance images obtained for 727 patients over a 1-year period at our institution revealed 161 cases of type 1 MC. In 86 of these, the following indicators of mechanical abnormality could be evaluated on dynamic radiographs: segmental scoliosis (> 5°), forward slippage (> 1%), and posterior disc opening in flexion. Patients with one or more of these abnormalities were allocated to a mechanical group (n = 62, 70%) and those with no abnormality to a non-mechanical group (n = 26, 30%). The Pfirrmann grade of disc degeneration at the affected level was compared between the groups.ResultsSegmental scoliosis, slippage, and posterior opening was observed in 34, 21 and 37 cases, respectively. Severe disc degeneration (grade IV or V) was present in 43 cases (69%) in the mechanical group and in 12 cases (46%) in the non-mechanical group; the difference was statistically significant (p = 0.04).ConclusionWe propose that there are mechanical and non-mechanical variants of type 1 MC.

Selective Retention of Bone Marrow Stromal Cells with Gelatin Sponge for Repair of Intervertebral Disc Defects after Microendoscopic Discectomy: A Prospective Controlled Study and 2-Year Follow-Up

Objective. Discectomy remains the classic procedure for treating lumbar intervertebral disc (IVD) herniation, but the occurrence of defects after discectomy is thought to be an important cause generating recurrent and accelerated IVD degeneration. Previous studies attempted suture of the annulus fissure, but the validity of this technique on restraining the degenerative process is controversial. On the other hand, cell therapies have been shown in multiple clinical and basic studies. Our purpose was to investigate the effectiveness of selective retention of autologous Bone Marrow Stromal Cells (BMSCs) with gelatin sponge in combination with annulus fibrosus suture (AFS) for the repair of IVD defects following mobile microendoscopic discectomy (MMED). Methods. This prospective, two-armed, and controlled clinical study was conducted from December 2016 to December 2018. Written informed consent was obtained from each patient. Forty-five patients with typical symptoms, positive signs of radiculopathy, and obvious lumbar disc herniation observed by MRI were enrolled. Patients were divided into 3 groups with different treating methods: MMED ( n = 15 ), MMED+AFS ( n = 15 ), and MMED+AFS+BMSCs ( n = 15 ). A postoperative 2-year follow-up was performed to evaluate the patient-reported outcomes of VAS, ODI, and SF-36. The improvement rate of VAS and ODI was calculated as latest ‐ preoperative / preoperative to evaluate the therapeutic effect of the three groups. Assessment parameters included Pfirrmann grade, intervertebral disc height (IDH), and disc protrusion size (DPS), as measured by MRI to evaluate the morphological changes. Results. All patients enrolled had a postoperative follow-up at 3, 6, 12, and 24 months. VAS and ODI scores were significantly improved compared to the preoperative status in all three groups with a mean DPS reduction rate over 50%. At the final follow-up, the improvement rate of the VAS score in the MMED+AFS+BMSCs group was significantly higher than the MMED+AFS and MMED groups ( 80.1 % ± 7.6 % vs. 71.3 % ± 7.0 % vs. 70.1 % ± 7.8 % ), while ODI improvement showed a significant change ( 65.6 % ± 8.8 % vs. 59.9 % ± 5.5 % vs. 57.8 % ± 8.1 % ). All participants showed significant improvement in SF-36 PCS and MCS; the differences between each group were not significant. The mean IDH loss rate of the MMED+AFS+BMSCs group was also significantly lower than other groups ( − 17.2 % ± 1.3 % vs. − 27.6 % ± 0.7 % vs. − 29.3 % ± 2.2 % ). The Pfirrmann grade was aggravated in the MMED and MMED+AFS groups while maintained at the preoperative grade in the MMED+AFS+BMSCs group. No adverse events of cell transplantation or recurrence were found in all patients during the postoperative follow-up period. Conclusions. It is feasible and effective to repair lumbar IVD defects using SCR-enriched BMSCs with gelatin sponges, which warrants further study and development as a cell-based therapy for IVD repair.

Application study of 3D LAVA-Flex on lumbar intervertebral disc degeneration

Background Degeneration of the intervertebral discs are very common diseases, indicating the specific or malignant changes in intervertebral disc component, structure and function. Imaging examination is currently used to evaluate the severity of lumbar intervertebral disc degeneration. This study was designed to investigate the diagnostic value of 3D LAVA-Flex in lumbar intervertebral disc degeneration. Material and methods Sagittal 3D LAVA-Flex and T2WI scans were performed in 45 patients with lumbar intervertebral disc degeneration. On T2WI, the degenerated intervertebral disc in every patient was evaluated using Pfirrmann grade. Then, the patients were re-evaluated using 3D LAVA-Flex with considerations of the distinction of nucleus pulposus and annulus fibrosus, hypointense signal of intervertebral disc and height of intervertebral disc. The evaluation results were compared between 3D LAVA-Flex and T2WI. Virtual endoscopy was also performed to evaluate the degenerated intervertebral disc. Results The intermediate–intense signal of nucleus pulposus and complete ring-shaped hyperintense signal of annulus fibrosus were found and the distinction of nucleus pulposus and annulus fibrosus was clear in the normal intervertebral disc on 3D LAVA-Flex. The incidence of linear hypointensity of narrowed intervertebral space (65/91) was higher than that of normal intervertebral space (4/134) (P = 0.000). A good consistency was shown between the LAVA-Flex grade and T2WI-based Pfirrmann grade. Virtual endoscopy based on 3D LAVA-Flex could help clearly show the anatomic relationship between the degenerated disc and intervertebral foramen. Conclusions 3D LAVA-Flex and T2WI show similar efficacy in evaluating lumbar intervertebral disc degeneration. 3D LAVA-Flex-based virtual endoscopy possesses great potential in the study of intervertebral disc abnormalities.

Development and validation of a nomogram predicting the risk of recurrent lumbar disk herniation within 6 months after percutaneous endoscopic lumbar discectomy

Objective To develop and validate a nomogram useful in predicting recurrent lumbar disk herniation (rLDH) within 6 months after percutaneous endoscopic lumbar discectomy (PELD). Methods Information on patients’ lumbar disk herniation (LDH) between January 2018 and May 2019 in addition to 26 other features was collected from the authors’ hospital. The least absolute shrinkage and selection operator (LASSO) method was used to select the most important risk factors. Moreover, a nomogram was used to build a prediction model using the risk factors selected from LASSO regression. The concordance index (C-index), the receiver operating characteristic (ROC) curve, and calibration curve were used to assess the performance of the model. Finally, clinical usefulness of the nomogram was analyzed using the decision curve and bootstrapping used for internal validation. Results Totally, 352 LDH patients were included into this study. Thirty-two patients had recurrence within 6 months while 320 showed no recurrence. Four potential factors, the course of disease, Pfirrmann grade, Modic change, and migration grade, were selected according to the LASSO regression model. Additionally, the C-index of the prediction nomogram was 0.813 (95% CI, 0.726-0.900) and the area under receiver operating characteristic curve (AUC) value was 0.798 while the interval bootstrapping validation C-index was 0.743. Hence, the nomogram might be a good predictive model. Conclusion Each variable, the course of disease, Pfirrmann grade, Modic change, and migration grade in the nomogram had a quantitatively corresponding risk score, which can be used in predicting the overall recurrence rate of rLDH within 6 months.

SIRT1 Inhibits Apoptosis by Promoting Autophagic Flux in Human Nucleus Pulposus Cells in the Key Stage of Degeneration via ERK Signal Pathway

Background. The application of biomolecular interventions in the early stage of intervertebral disc degeneration (IVDD) is considered an ideal method for the treatment of IVDD. However, the precise definition of the “early stage” of IVDD is unclear. Silent information regulation 2 homologue-1 (SIRT1) can protect human degenerative nucleus pulposus (NP) cells from apoptosis by activating autophagy. However, the mechanism of this effect is still unclear. This study tried to confirm the “early stage” of IVDD and the role of NP cell autophagy during IVDD as well as to determine the mechanism by which SIRT1 protects NP cells. Methods. The characteristics of the NP in various stages of degeneration were assessed to confirm the “early stage” of IVDD. Then, autophagy and apoptosis were detected in NP cells after SIRT1 upregulation/downregulation. Finally, LY294002 and PD98059 were used to inhibit the AKT/ERK pathway to determine the mechanism by which SIRT1 regulates autophagy in NP cells. Results. Our data showed that mildly degenerative (Pfirrmann grade III with normal height of intervertebral disc) NP cells may be the key target for biomolecular interventions in IVDD and that SIRT1 protects human mildly degenerative NP cells from apoptosis by activating autophagy via the ERK signalling pathway. Conclusion. Our data showed that SIRT1 inhibits apoptosis by promoting the autophagic flux in NP cells via the ERK signalling pathway during the key stage of degeneration. These findings will assist in the development of novel therapeutic approaches for IVDD treatment.

Short-Term Effect of Lumbar Traction on Intervertebral Discs in Patients with Low Back Pain: Correlation between the T2 Value and ODI/VAS Score

Objective The effect of lumbar traction on low back pain (LBP) patients is controversial. Our study aims to assess changes in the intervertebral disc water content after lumbar traction using T2 mapping and explore the correlation between changes in the T2 value and Oswestry Disability Index (ODI)/visual analogue scale (VAS) score. Design Lumbar spine magnetic resonance imaging was performed, and the ODI/VAS scores were recorded in all 48 patients. Midsagittal T2-weighted imaging and T2 mapping were performed to determine the Pfirrmann grade and T2 value. Then, the T2 values were compared between pre- and posttraction, and the correlation between changes in the T2 value and ODI/VAS scores were examined. Results In the traction group, the changes in the nucleus pulposus (NP) T2 values for Pfirrmann grades II-IV and the annulus fibrosus (AF) T2 values for Pfirrmann grade II were statistically significant after traction ( P < 0.05). Changes in the mean NP T2 value of 5 discs in each patient and in the ODI/VAS score showed a strong correlation ( r = 0.822, r = 0.793). Conclusion T2 mapping can be used to evaluate changes in the intervertebral disc water content. Ten sessions of traction resulted in a significant increase in quantitative T2 measurements of the NP in discs for Pfirrmann grade II-IV degeneration and remission of the patients’ clinical symptoms in the following 6 months. Changes in the mean NP T2 value of 5 discs in each patient were strongly correlated with changes in the ODI/VAS score.

Correlation between the Expression of Inflammatory Factors and the Degree of Intervertebral Disc Degeneration

Objective: To investigate the relationship between the expression of IL-6, IL-8, IL-15, IFN-a, TNF-a and TRPC6 in the disc tissue of patients with cervical disc degeneration. Methods: The expression levels of inflammatory factors IL-6, IL-8, IL-15, IFN-a, TNF-a and TRPC6 were analyzed by RT-PCR, and the correlation between inflammatory factors and Pfirrmann grade and inflammatory factors was analyzed. Results: The mRNA expression levels of IL-6, IL-8, IL-15, TNF - a and TRPC6 were significantly higher in Pfirrmann grade IV-V than in Pfirrmann grade II-III (P< 0.05), and IFN-a expression level in IV-V intervertebral disc samples was significantly lower than that in II-III discs (P<0.05); The mRNA expression levels of IL-6, IL-8, IL-15, TNF - a and TRPC6 were positively correlated with pfirmann grading (P<0.05), IFN - a was negatively correlated with pfirmann grading (P<0.05), IL-6, IL-8, IL-15, TNF - a and TRPC6 were positively correlated with each other(P<0.05), IFN - a was negatively correlated with IL-6, IL-8, IL-15, TNF-a and TRPC6(P<0.05). Conclusion: IL-6, IL-8, IL-15, IFN-a, TNF- a and TRPC6 are closely related to the degree of cervical disc degeneration.

Morphological and radiographic parameters of facet joints and their dependence on the grade of intervertebral disc degeneration

Objective To study morphological and radiological parameters of facet joints depending on the grade of the intervertebral disk degeneration. Materials and methods To study the facet joints of the lumbar spine in 145 patients with various grades of degeneration according to Pfirrmann and treated using rigid fixation and TLIF technology, MSCT in 2-energy mode and morphological investigation of the intraoperative material were performed. Results In Pfirrmann grade 2, an increase in the volumetric content of chondrocytes, Hounsfield density of the cartilage plate, and the level of Ca in the facet joints was visualized. They indicate that the joint remains functional. In Pfirrmann grade 5, deep pathological changes occurred with violation of the architectonics of the cartilage formations of the facet joints, formation of bone elements and connective tissue growth into the cartilage and bone structures of the joint, which correlated with the results of MSCT. Conclusion The data obtained show that there is a close relationship between morphological and radiological changes in the facet joints. Modulating the data obtained allows us to obtain objective criteria for evaluating the grade of pathological processes in facet joints and use them as a diagnostic component when planning decompression and stabilizing operations in patients with degenerative diseases of the lumbar spine.