A Study on Interobserver and Intraobserver Reliability of the Huashan Radiologic Classification System for Cervical Spinal Cord Injury Without Fracture and Dislocation.

STUDY DESIGN: Observational study. OBJECTIVE: To assess the reproducibility and reliability of the system. BACKGROUND: The Huashan radiologic classification system for cervical spinal cord injury without fracture and dislocation (CSCIWFD) was recently proposed and found useful for clinical practice. PATIENTS AND METHODS: Patients diagnosed with CSCIWFD between 2015 and 2021 were recruited. Six spine surgeons from different institutions, three experienced and other inexperienced respectively, were trained as observers of the system, and these surgeons classified the recruited patients using the system. Then, 8 weeks later, they repeated the classification on the same patients in a different order. The interobserver and intraobserver agreement between the results was analyzed using percentage agreement, weighted kappa, and Cohen kappa (κ) statistics. RESULTS: A total of 60 patients were included in the analysis. Type I was the most frequent type (29 cases, 48.3%), followed by type II (13 cases, 21.7%), type III (12 cases, 20%), and type IV (6 cases, 10%). For all the observers, experienced observers, and inexperienced observers, the overall agreement percentages were 77.6% (κ = 0.78), 84.4% (κ = 0.84), and 72.8% (κ = 0.74), respectively, indicating substantial to nearly perfect interobserver reproducibility. A higher level of agreement was found for differentiating type I from other types, with the percentage agreement ranging from 87.8% to 94.4% (κ= 0.74-0.88). For distinguishing compression on the spinal cord (types I and II vs types III and IV) among the different groups of observers, the percentage agreement was 97.8% (κ = 0.94), indicating nearly perfect reproducibility. As for intraobserver agreement, the percentage agreement ranged from 86.7% to 96.7% (κ = 0.78-0.95), indicating at least substantial reliability. CONCLUSIONS: The Huashan radiologic classification system for CSCIWFD was easy to learn and apply in a clinical environment, showing excellent reproducibility and reliability. Therefore, it would be promising to apply and promote this system for the precise evaluation and personalized treatment strategy.

Evaluation of the modified MRI vertebral bone quality score for bone quality in lumbar degenerative disorders.

OBJECTIVE: The traditional VBQ scoring method may lead to overestimation due to the concentration of intravertebral fat and vascular structures in the posterior half of vertebral bodies, potentially resulting in false-positive outcomes. This study aims to modify the measurement method of VBQ score (Modified-VBQ) and evaluate its effectiveness in evaluating bone quality of lumbar degenerative diseases. METHODS: Retrospective analysis was conducted on clinical data from patients undergoing lumbar surgery for degenerative diseases between September 2022 and September 2023. Preoperative lumbar t1-weighted Magnetic resonance imaging was used for both modified and traditional VBQ scoring. Computed tomography (CT) images and dual-energy X-ray absorptiometry (DEXA) data were collected through the picture archiving and communication system. The effectiveness of the modified VBQ score was evaluated, considering P < 0.05 as statistically significant. RESULTS: The study included 212 patients, revealing a significant difference between the modified VBQ and VBQ scores (P < 0.0001). Notably, patients with a history of hyperlipidemia exhibited a significant difference between the two scores (P = 0.0037). The area under the ROC curve (AUC) for the modified VBQ was 0.86, surpassing the VBQ score (AUC = 0.74). Linear regression analysis demonstrated a moderate to strong correlation between the modified VBQ and DEXA T-score (r = - 0.49, P < 0.0001) and a high correlation with CT Hounsfield units (HU) values (r = - 0.60, P < 0.0001). CONCLUSION: The modified VBQ score provides a simple, effective, and relatively accurate means of assessing bone quality in lumbar degenerative diseases. Preoperative implementation of the modified VBQ score facilitates rapid screening for patients with abnormal bone quality.

MSC-Derived Exosomes Ameliorate Intervertebral Disc Degeneration By Regulating the Keap1/Nrf2 Axis.

Bone marrow mesenchymal stem cell derived exosomes (BMSC-exos) are a crucial means of intercellular communication and can regulate a range of biological processes by reducing inflammation, decreasing apoptosis and promoting tissue repair. The process of intervertebral disc degeneration (IVDD) is accompanied by increased reactive oxygen species (ROS) because of a decrease in the expression of Nrf2, a critical transcription factor that resists excessive ROS. Our study demonstrated that BMSC-exos decreased ROS production by inhibiting Keap1 and promoting Nrf2 expression, attenuating the apoptosis, inflammation, and degeneration of nucelus pulposus (NP) cells. BMSC-exos promoted an increase in Nrf2 and nuclear translocation, while NF-κB expression was downregulated during this process. Additionally, the expression of antioxidative proteins was elevated after treatment with BMSC-exos. In vivo, we found more NP tissue retention in the BMSC-exos-treated group, along with more expression of Nrf2 and antioxidant-related proteins. Our findings demonstrated for the first time that BMSC-exos could restore the down-regulated antioxidant response system in degenerating NP cells by modulating the Keap1/Nrf2 axis. BMSC-exos could be used as an immediate ROS modulator in the treatment of intervertebral disc degeneration. When BMSC-exos were uptaken by NPCs, the expression of Keap1 decreased and this led to increased expression of Nrf2. Nuclear translocation of Nrf2 then promoted the synthesis of antioxidants against ROS and inhibited NF-kB signalling. Cellular inflammation, apoptosis, and ECM-related indicators were further reduced. Together, the process of IVDD was alleviated.

N6-methyladenosine hypomethylation of circGPATCH2L regulates DNA damage and apoptosis through TRIM28 in intervertebral disc degeneration.

Circular RNAs (circRNAs) are a class of noncoding RNAs that have been found to be involved in intervertebral disc degeneration (IVDD) progression, and N6-methyladenosine (m6A) broadly exists in circRNAs. Here, we identified circGPATCH2L with a low m6A methylation level to be upregulated in degenerative nucleus pulposus tissues. Mechanistically, as a protein decoy for tripartite motif containing 28 (TRIM28) within aa 402-452 region, circGPATCH2L abrogates the phosphorylation of TRIM28 and inhibits P53 degradation, which contributes to DNA damage accumulation and cellular apoptosis and leads to IVDD progression. Moreover, m6A-methylated circGPATCH2L is recognised and endoribonucleolytically cleaved by a YTHDF2-RPL10-RNase P/MRP complex to maintain the physiological state of nucleus pulposus cells. Thus, our data show the physiological significance of m6A modification in regulating circRNA abundance and provide a potentially effective therapeutic target for the treatment of IVDD.

Dihydroorotate dehydrogenase regulates ferroptosis in neurons after spinal cord injury via the P53-ALOX15 signaling pathway.

BACKGROUND: Spinal cord injury (SCI) is a highly disabling condition in spinal surgery that leads to neuronal damage and secondary inflammation. Ferroptosis is a non-apoptotic type of cell death that has only recently been identified, which is marked primarily by iron-dependent and lipid-derived reactive oxygen species accumulation, and accompanied by morphological modifications such as mitochondrial atrophy and increase in membrane density. Dihydroorotate dehydrogenase (DHODH) is a powerful inhibitor of ferroptosis and has been demonstrated to inhibit cellular ferroptosis in tumor cells, but whether it can inhibit neuronal injury following spinal cord injury remains ambiguous. METHODS: In this study, the effect of DHODH on neuronal ferroptosis was observed in vivo and in vitro using a rat spinal cord injury model and erastin-induced PC12 cells, respectively. A combination of molecular and histological approaches was performed to assess ferroptosis and explore the possible mechanisms in vivo and in vitro. RESULTS: First, we confirmed the existence of neuronal ferroptosis after spinal cord injury and that DHODH attenuates neuronal damage after spinal cord injury. Second, we showed molecular evidence that DHODH inhibits the activation of ferroptosis-related molecules and reduces lipid peroxide production and mitochondrial damage, thereby reducing neuronal ferroptosis. Further analysis suggests that P53/ALOX15 may be one of the mechanisms regulated by DHODH. Importantly, we determined that DHODH inhibits ALOX15 expression by inhibiting P53. CONCLUSIONS: Our findings reveal a novel function for DHODH in neuronal ferroptosis after spinal cord injury, suggesting a unique therapeutic target to alleviate the disease process of spinal cord injury.

Sulforaphane Delays Intervertebral Disc Degeneration by Alleviating Endoplasmic Reticulum Stress in Nucleus Pulposus Cells via Activating Nrf-2/HO-1.

Intervertebral disc degeneration (IVDD) is one of the main causes of low back pain, which brings heavy burdens to individuals and society. The mechanism of IVDD is complex and diverse. One of the important reasons is that the abnormal accumulation of reactive oxygen species (ROS) in nucleus pulposus cells (NPCs) leads to endoplasmic reticulum stress (ERS), which causes increased apoptosis of NPCs. Nuclear factor E2-related factor 2 (Nrf-2) and its downstream antioxidant proteins are key molecular switches for sensing oxidative stress and regulating antioxidant responses in cells. Sulforaphane (SFN), a natural compound derived from Brassicaceae plants, is a Nrf-2 agonist that displays potent antioxidant potential in vitro and in vivo. Here, we used advanced glycation end products (AGEs) to construct an in vitro degeneration model of NPCs, and we found that AGEs elevated ROS level in NPCs and caused severe ERS and apoptosis. While SFN can promote the entry of Nrf-2 into the nucleus and increase the expression level of heme oxygenase 1 (HO-1) in vitro, thus clearing the accumulated ROS in cells and alleviating ERS and cell apoptosis. Moreover, the protection of SFN on NPCs was greatly attenuated after HO-1 was inhibited. We also used AGEs to construct a rat IVDD model. Consistent with the in vitro experiments, SFN could attenuate ERS in NPCs in vivo and delay disc degeneration in rats. This study found that SFN can be used as a new and promising agent for the treatment of IVDD.

Do patients with Hirayama disease require surgical treatment? A review of the literature.

The main clinic characteristic of Hirayama disease (HD) is atrophy of the distal muscles in the upper limbs. Recently, an increasing number of HD cases have been reported. Many HD patients have persistently progressive symptoms and conservative treatments failed. This article aims to review the current status of the field and summarizes the main surgical treatment options for patients with HD. A comprehensive search of the PubMed and the Web of Science databases was conducted from their inception to September 15th, 2022. Search terms included "juvenile muscular atrophy of upper extremity", "Hirayama disease" and "surgery". A total of 169 relevant publications were identified and 29 articles were finally reviewed. Current surgical treatments for HD are either anterior cervical surgery or posterior cervical surgery. The two approaches can effectively stop the disease. However, no studies have compared the advantages and limitations of the two surgical methods. The previous view that HD can be improved with conservative treatment has been challenged. In many studies, surgical treatment has been shown to improve the hand function in patients with HD. However, there is still controversy about the methods of anterior and posterior cervical surgery. Future research could focus on exploring the advantages and limitations of different surgeries.

Can preoperative cervical spinal diffusion tensor imaging (DTI) indices predict surgical outcomes in patients with Hirayama disease? A retrospective cohort study.

Objective: Anterior cervical discectomy and fusion (ACDF) surgery can effectively prevent disease progression in patients with Hirayama disease (HD) and diffusion tensor imaging (DTI) can quantitatively assess spinal cord function. In this study, we aimed to evaluate the relationship between preoperative spinal DTI indices and the clinical outcomes of patients with HD when treated by ACDF. Methods: We retrospectively analyzed 35 HD patients treated by ACDF. We collated a range of DTI indices, including fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values, prior to surgery with patients in flexion and neutral positions. Patients were divided into improvement (Im) group and non-improvement (Nim) group according to the Odom score, and the difference in surgical outcomes between the two groups was confirmed by quick disabilities of the arm, shoulder and hand (Q-DASH) scores. The DTI indices in the two groups of patients were then compared. Receiver operating characteristic (ROC) curves and area under curve (AUC) were used to evaluate the predictive capability. The correlation between Q-DASH scores and DTI indices was also evaluated. Results: The FA values in the two groups of patients differed significantly in the cervical flexion position and the different segments were mainly located in the lower cervical spinal cord including the flexion C5/6 (Im group vs. Nim group: 0.501 ± 0.078 vs. 0.362 ± 0.087, P < 0.001) and C6/7 (Im group vs. Nim group: 0.455 ± 0.097 vs. 0.347 ± 0.102, P = 0.003) FA values, the mean FA value for C4/5-C6/7 (Im group vs. Nim group: 0.471 ± 0.067 vs. 0.372 ± 0.078, P < 0.001), mean FA value for C5/6-C6/7 (Im group vs. Nim group: 0.478 ± 0.076 vs. 0.354 ± 0.083, P < 0.001) and mean FA value for the two minimal segments (Im group vs. Nim group: 0.442 ± 0.078 vs. 0.341 ± 0.081, P = 0.001). The ADC values were similar to FA values. The ROC curve for DTI indices in the lower cervical spinal cord had an AUC > 0.7 including: flexion FA value and ADC value for C5/6 (0.877 and 0.931), flexion FA value and ADC value for C6/7 (0.778 and 0.761), flexion mean FA value and ADC value for C4/5-C6/7 (0.846 and 0.859), flexion mean FA value and ADC value for C5/6-C6/7 (0.861 and 0.905), flexion mean FA value and ADC value for the two minimal/maximal segments (0.815 and 0.892). DTI indices including FA value and ADC value were correlated with the preoperative score, final follow-up score and improvement percentage. Flexion ADC value was correlated with improvement score but flexion FA value was not correlated with improvement score. Conclusion: Preoperative DTI indices of the spinal cord, especially those of the lower cervical spinal cord with patients in the flexion position, can predict the clinical outcome of patients with HD post-surgery. In general, a larger FA value and a smaller ADC value indicate a better surgical outcome.

Association Between Roussouly Classification and Characteristics of Lumbar Degeneration.

OBJECTIVE: Different sagittal morphologies are associated with various lumbar degenerative diseases. In this paper, we aim to investigate the association between Roussouly classification and the characteristics of lumbar degeneration. METHODS: A total of 273 patients with lumbar degeneration diseases were included in this cross-sectional study. The patients were divided into 4 groups according to the Roussouly classification. The degeneration of intervertebral disc (IVD) and facet joint was evaluated by Pfirrmann and Pathria grading scales, respectively. Our goal was to elucidate the degenerative characteristics of diverse lumbar sagittal morphologies by comparing the degeneration degree of IVDs and facet joints between 4 groups. RESULTS: The differences in sacral slope and lumbar lordosis were significant between the 4 groups (P < 0.05). Type 2 lumbar spine had the highest proportion of high-grade disc degeneration compared with other subtypes (P < 0.05), types 1 and 2 had a higher proportion of high-grade degeneration than types 3 and 4 (P < 0.05). However, type 4 lumbar spine had the highest proportion of high-grade facet joint degeneration compared with other subtypes (P < 0.05), types 3 and 4 had a higher proportion of high-grade degeneration than types 1 and 2 (P < 0.05). CONCLUSIONS: Risks of advanced disc degeneration are higher for patients with lumbar spine morphologies of Roussouly type 1 or type 2, especially for patients with type 2 lumbar spine, whereas high-grade degeneration of facet joint tends to occur in type 3 and type 4 lumbar spine, especially for individuals with type 4 lumbar spine.

How to reconstruct the lordosis of cervical spine in patients with Hirayama disease? A finite element analysis of biomechanical changes focusing on adjacent segments after anterior cervical discectomy and fusion.

PURPOSE: To compare the biomechanical changes of adjacent segments between patients with Hirayama disease and non-pathological people after anterior cervical discectomy and fusion (ACDF) operation, and to explore the optimal degree of local lordosis reconstruction during surgery. METHODS: A young male volunteer was recruited to establish a three-dimensional finite element model of the lower cervical spine based on the CT data. By adjusting the bony structures and simulating the operation process, the models of non-pathological individuals before and after ACDF, patients with Hirayama disease before and after ACDF, and different local lordosis angles were established. Then, the postoperative range of motion (RoM) and stress of the adjacent segments under flexion, extension, left bending, right bending, left rotation and right rotation were recorded and compared. RESULTS: The RoM and stress of all segments of lower cervical spine in patients with Hirayama disease are higher than those in non-pathological individual, and this trend still exists after ACDF surgery. When the local lordosis angle is under physiological conditions, the RoM and stress of the adjacent segments are minimum. CONCLUSION: Compared with non-pathological people, Hirayama disease patients have differences in cervical biomechanics, which may lead to cervical hypermobility and overload. After ACDF, the possibility of adjacent segments degeneration is greater than that of non-pathological people. When the operation maintains the physiological local lordosis angle, it can slow down the degeneration.

A study of screw placement to obtain the optimal pull-out resistance of lumbar pedicle screws-analysis of Hounsfield units measurements based on computed tomography.

OBJECTIVE: The screw path of lumbar pedicle screws in the vertebral body has certain variability. It is not clear whether the screw paths in different directions can obtain the same pull-out resistance. This study intends to use CT (Computed Tomography) to measure the Hounsfield unit (HU value) around the screw paths in different parts of the lumbar vertebral body to obtain the bone mineral density value of the corresponding parts which will provide some reference for the direction of lumbar pedicle screw placement. METHODS: This retrospective study included 200 patients with lumbar degenerative diseases selected randomly from the case base and the patient's basic information was recorded. L1-L5 vertebral body was divided equally into the upper, middle and lower 1/3, which was consistent with the three sagittal entry directions of the pedicle screw head tilt, parallel endplate and caudal tilt, and the HU values were measured by CT cross-sectional scanning to indirectly reflect the local bone density values. The paired t-test (randomized block experiment) was used to compare the HU values of the upper, middle and lower 1 / 3 parts, with P < 0.05 being considered statistically significant. RESULTS: Comparison of HU values in different parts of each vertebral body revealed that HU values in the middle 1/3 of the L1,L2 (163.88 ± 58.44 and 152.94 ± 59.45) and in the lower 1/3 of the L4 (149.86 ± 60.18) were higher than in the other two parts of the vertebral body of the same segment(P < 0.0001,P = 0.0069 and P = 0.0024, respectively); According to the results of each stratification, patients with younger age and better bone condition had higher HU values in the middle 1/3 of L1 and L2, and higher HU values in the lower 1/3 of L3, L4 and L5; With the increase of age, the decrease of bone condition and the difference of HU value in each vertebral body gradually decreased. CONCLUSION: Although further follow-up studies are needed, based on the analysis of the statistical results, we speculate that from the perspective of obtaining the best pull-out resistance of the lumbar pedicle screws, the placement direction of L1 and L2 in the sagittal position may be as parallel to the endplate as possible; L3, L4, and L5 may be as appropriate as possible to the tail tilt theoretically.

Interobserver and Intraobserver Reproducibility and Reliability of the Huashan Clinical Classification System for Hirayama Disease.

Purpose: The Huashan clinical classification system for Hirayama disease has recently been proposed and has been found useful for diagnosis and treatment. So far, however, there has been little in-depth evaluation of its reliability. Thus, this study aimed to assess the reproducibility and reliability of the system. Methods: Patients diagnosed with Hirayama disease between 2019 and 2020 were recruited. Seven spine surgeons from four different institutions, including an experienced group of three and an inexperienced group of four, were trained as observers of the Huashan clinical classification system for Hirayama disease, and these surgeons classified the recruited patients using the system. Then, 2 months later, they repeated the classification on the same patients in a different order. The interobserver and intraobserver agreement between the results was analyzed using percentage agreement and weighted kappa (κ) statistics. Results: A total of 60 patients were included in the analysis. For all the observers, experienced observers, and inexperienced observers, the agreement percentages were, respectively, 78.5% (κ = 0.76), 80.0% (κ = 0.78), and 78.9% (κ = 0.77), indicating substantial interobserver reproducibility. For distinguishing typical (Types I and II) and atypical (Type III) Hirayama disease among the different groups of observers, the percentage agreement ranged from 95.6 to 98.9% (κ = 0.74-0.92), indicating substantial to nearly perfect reproducibility. For suggesting conservative treatment (Types I and III) or surgery (Type II), the percentage agreement ranged from 93.3 to 96.4% (κ = 0.81-0.90), indicating nearly perfect reproducibility. As for intraobserver agreement, the percentage agreement ranged from 68.3 to 81.7% (κ = 0.65-0.79), indicating substantial reliability. Conclusion: The Huashan clinical classification system for Hirayama disease was easy to learn and apply in a clinical environment, showing excellent reproducibility and reliability. Therefore, it would be promising to apply and promote this system for the precise and individualized future treatment of Hirayama disease.

Roles of circular RNAs in the pathogenesis of intervertebral disc degeneration (Review).

Lower back pain (LBP) is an extremely common symptom and is recognized as a leading contributor to disability and disease burden globally. Intervertebral disc degeneration (IDD) represents a major cause of LBP. However, the molecular mechanisms involved in the pathogenesis of IDD remain unclear, and currently available treatments, including conservative and surgical options, fail to effectively delay, stop or reverse the progression of IDD. Circular RNAs (circRNAs) are a newly discovered group of covalently closed, single-stranded and endogenous non-coding RNAs. A growing body of research has revealed that a number of circRNAs are widely and aberrantly expressed in IDD tissues. Furthermore, they play important roles in the pathogenesis of IDD, including proliferation, apoptosis, senescence, mitophagy, inflammation and extracellular matrix metabolism, mainly by acting as sponges for microRNAs. The present review aims to summarize the current understanding on the mechanisms of circRNA-mediated regulation in IDD.

Carbohydrate sulfotransferase 3 (CHST3) overexpression promotes cartilage endplate-derived stem cells (CESCs) to regulate molecular mechanisms related to repair of intervertebral disc degeneration by rat nucleus pulposus.

To investigate the regulatory effect of carbohydrate sulfotransferase 3 (CHST3) in cartilage endplate-derived stem cells (CESCs) on the molecular mechanism of intervertebral disc degeneration after nucleus pulposus repair in rats. We performed GO and KEGG analysis of GSE15227 database to select the differential genes CHST3 and CSPG4 in grade Ⅱ, Ⅲ and Ⅳ intervertebral disc degeneration, IHC and WB to detect the protein profile of CHST3 and CSPG4, Co-IP for the interaction between CHST3 and CSPG4. Then, immunofluorescence was applied to measure the level of CD90 and CD105, and flow cytometry indicated the level of CD73, CD90 and CD105 in CESCs. Next, Alizarin red staining, Alcian blue staining and TEM were performed to evaluate the effects of CESCs into osteoblasts and chondroblasts, respectively, CCK8 for the cell proliferation of osteoblasts and chondroblasts after induction for different times; cell cycle of osteoblasts or chondroblasts was measured by flow cytometry after induction, and WB for the measurement of specific biomarkers of OC and RUNX in osteoblasts and aggrecan, collagen II in chondroblasts. Finally, colony formation was applied to measure the cell proliferation of CESCs transfected with ov-CHST3 or sh-CHST3 when cocultured with bone marrow cells, WB for the protein expression of CHST3, CSPG4 and ELAVL1 in CSECs, transwell assay for the migration of CESCs to bone marrow cells, TEM image for the cellular characteristics of bone marrow cells, and WB for the protein profile of VCAN, VASP, NCAN and OFD1 in bone marrow cells. CHST3 and CSPG4 were differentially expressed and interacted in grade Ⅱ, Ⅲ and Ⅳ intervertebral disc degeneration; CD73, CD90 and CD105 were lowly expressed in CESCs, osteogenic or chondroblastic induction changed the characteristics, proliferation, cell cycle and specific biomarkers of osteoblasts and chondroblasts after 14 or 21 days,; CHST3 affected the cell proliferation, protein profile, migration and cellular features of cocultured CESCs or bone marrow cells. CHST3 overexpression promoted CESCs to regulate bone marrow cells through interaction with CSPG4 to repair the grade Ⅱ, Ⅲ and Ⅳ intervertebral disc degeneration.

The Short-Term to Midterm Follow-Up of Patients with Hirayama Disease After Anterior Cervical Discectomy and Fusion.

OBJECTIVE: Surgical treatment is widely used to treat patients with Hirayama disease (HD). However, postoperative follow-up with abundant samples is still scarce. This study investigated short-term to midterm clinical outcomes after anterior cervical discectomy and fusion (ACDF) among patients with HD. METHODS: We enrolled 115 patients with HD who had undergone ACDF. Radiographic parameters included cervical lordosis (CL), sagittal vertical axis, segment lordosis (SL), T1 slope (T1S), T1S minus CL, range of motion (ROM), upper/lower adjacent segment ROM, and upper adjacent SL. Electrophysiologic parameters included the maximal compound muscle action potentials (CMAPs) of abductor digit minimi and abductor pollicis brevis, the latency of the ulnar nerve F reaction, and abnormal spontaneous action potentials. Clinical assessment included the selected brief-Michigan Hand Questionnaire and Odom scale. RESULTS: The average age was 19.5 ± 4.5 years. The mean follow-up time was 16.35 ± 9.21 months. CL, SL, and T1S increased, whereas sagittal vertical axis and ROM decreased at the final follow-up (P < 0.001). Upper adjacent SL, upper adjacent ROM, and lower adjacent ROM were stable after ACDF (P > 0.05). The maximal CMAPs of abductor digit minimi and the latency of the ulnar nerve F reaction improved bilaterally (P < 0.05), whereas there was no significance in the maximal CMAPs of abductor pollicis brevis (P > 0.05). Abnormal spontaneous action potentials reduced remarkably. The selected brief-Michigan Hand Questionnaire score increased after surgery (P < 0.001). The Odom scale showed a ratio of 79.1% (excellent and good ratio). CONCLUSIONS: This study showed favorable radiologic, electrophysiologic, and clinical outcomes after ACDF among patients with HD.

Bioabsorbable high-purity magnesium interbody cage: degradation, interbody fusion, and biocompatibility from a goat cervical spine model.

BACKGROUND: Bioabsorbable Mg-based implants have been a focus of orthopedic researches due to their intrinsic advantages in orthopedics surgeries. This study aimed to investigate the performance of bioabsorbable high-purity magnesium (HP Mg, 99.98 wt.%) interbody cages in anterior cervical discectomy and fusion (ACDF) and to evaluate the degradation of HP Mg cages under an interbody microenvironment. METHODS: ACDF was performed at C2-3 and C4-5, and a HP Mg cage or autologous iliac bone was randomly implanted. At 3, 6, 12 and 24 weeks after surgery, the cervical specimens were harvested to evaluate the fusion status, degradation and biocompatibility by CT, micro-CT, histological examinations and blood tests. RESULTS: There was no significant difference in the CT fusion score between cage group and autogenous ilium group at 3 and 6 weeks. At 12 and 24 weeks, the mean CT fusion score in the cage group was markedly lower than in the autogenous ilium group. CT and histological examinations showed bony junctions formed through the middle hole of the cage between upper and lower vertebral bodies in the cage group, but the total fusion area was less than 30%. The degradation rate of cages was relatively rapid within the first 3 weeks and thereafter became stable and slow gradually. The HP Mg cage had good biosecurity and biomechanical characteristics. CONCLUSIONS: Implantation of Mg-based interbody cage achieves successful histological fusion, while the total fusion area needs to be improved. More studies are needed to improve the bone-cage interface.

CircERCC2 ameliorated intervertebral disc degeneration by regulating mitophagy and apoptosis through miR-182-5p/SIRT1 axis.

The molecular mechanism of intervertebral disc degeneration (IVDD) remains unclear. This study aimed to investigate the role of circular RNAs (circRNAs) in the pathogenesis of IVDD. We sued nucleus pulposus (NP) tissues of patients, tert-butyl hydroperoxide (TBHP) stimulated NP cells (NPCs), and IVDD rat model to explore the interaction between circERCC2 and miR-182-5p/SIRT1 axis. The results showed that downregulation of circERCC2 increased the level of miR-182-5p and decreased the level of SIRT1 in degenerative NP tissues in vivo as well as in TBHP-stimulated NPCs in vitro. Treatment of SIRT1-si activated apoptosis and inhibited mitophagy. Moreover, miR-182-5p-si could regulate the mitophagy and the apoptosis of NPCs by targeting SIRT1. The effects of circERCC2 on NPCs and IVDD rat model were mediated by miR-182-5p/SIRT1 axis. In conclusion, this study provides the first evidence that circERCC2 could ameliorate IVDD through miR-182-5p/SIRT1 axis by activating mitophagy and inhibiting apoptosis, and suggests that circERCC2 is a potentially effective therapeutic target for IVDD.

The evaluation on neural status of cervical spinal cord in normal and Hirayama disease using diffusion tensor imaging.

PURPOSE: To explore the changes in diffusion tensor imaging (DTI) parameters in cervical spinal cord in Hirayama disease (HD) patients and healthy volunteers and to compare these parameters between cervical flexion and neutral positions in HD patients. METHODS: Seventeen male patients with HD and eleven healthy young males were included to receive DTI scans in cervical flexion and neutral positions. The FA and ADC values of different levels were measured based on the region of interest drawn on the mid-sagittal plane. The dynamic compressed level's parameters were defined as the lowest and the second lowest FA and the highest and the second highest ADC, respectively. The clinical assessment of patients was obtained using their disabilities of the arm, shoulder and hand (DASH) scores. RESULTS: For the HD patients, the FA values in the cervical flexion position were lower and the ADC values were much higher than those in the cervical neutral position. Compared with the controls, the ADC values were significantly higher in the lower levels (C5/6-C7/T1) and the FA values obviously lower at C7/T1 in HD patients in cervical neutral position. The FA and ADC values of the dynamic compressed level in HD patients deviated significantly from the average of the lower levels in controls. Both the FA and ADC values of the dynamic compressed level correlated with the DASH scores (FA, R2 = 0.520, P = 0.001; ADC, R2 = 0.421, P = 0.005). CONCLUSIONS: DTI parameters can support a hypothesis of dynamic cervical flexion compression and noninvasively reveal the neural status of HD patients. These slides can be retrieved under Electronic Supplementary Material.

Adjacent Intervertebral Disk Height Decrease Phenomenon After Single-Level Transforaminal Lumbar Interbody Fusion of the Lumbar Spine.

BACKGROUND: The increase of intradiskal pressure on the upper segment resulting from intervertebral distraction after lumbar intervertebral fusion decreases intervertebral height and aggravates degeneration. However, the incidence rate and risk factors of the adjacent intervertebral disk height decrease phenomenon have not been studied. The purpose of this study was to identify the incidence rate and risk factors of the adjacent intervertebral disk height decrease phenomenon after single-level transforaminal lumbar interbody fusion (TLIF) of the lumbar spine. METHODS: A retrospection of 68 patients who underwent L4-5 TLIF. Patient age, sex, and body mass index were collected. Lumbar lordosis, facet sagittalization, Pfirrmann classification, L4-5 distraction height, and L3-4 reduction height were evaluated by radiologic image. The patients were divided into 2 groups based on whether their L3-4 intervertebral height decreased. RESULTS: Forty of 68 patients (58.8%) had L3-4 intervertebral height decrease. The patients' mean age was 62.05 ± 10.90 years in the L3-4 intervertebral height decrease positive (IHDP) group, significantly higher than the 56.14 ± 12.06 years in the L3-4 intervertebral height decrease negative (IHDN) group (P = 0.039). The mean facet sagittalization angle in the IHDP group was 67.5° ± 20.36°, significantly larger than the 55.43° ± 14.97° in the IHDN group (P = 0.010). The preoperative lumbar lordosis was significantly higher in the IHDP group (P = 0.049). No significant effects of other factors on L3-4 height decrease were observed (P > 0.05). CONCLUSIONS: Distraction of the L4-5 intervertebral space by cage insertion leads to a reduced height on the adjacent L3-4 segment in some patients. In addition, the decrease in L3-4 intervertebral height resulting from L4-5 distraction was correlated with age, preoperative lumbar lordosis, and facet joint sagittalization.

Snake-Eyes Appearance on MRI Occurs during the Late Stage of Hirayama Disease and Indicates Poor Prognosis.

PURPOSE: Because Hirayama disease is stereotyped as a self-limited disease in the absence of a definite pathology, we investigated the potential relationship between snake-eyes appearance (SEA) and Hirayama disease to bring a new perspective in the pathological process of Hirayama disease based on relevant radiological and clinical evidence. METHODS: A total of 30 cases observed SEA were selected from 293 patients with Hirayama disease to constitute the SEA group, and an equal number of cases were randomly selected from the remaining patients to form the non-SEA group. Cervical magnetic resonance imaging (MRI) was performed and subsequently used to measure the anteroposterior diameter and anterior shifting of the spinal cord. Additionally, clinical data, such as age, sex, duration of symptoms, symptoms, and signs, were collected and analyzed. RESULTS: Of 293 patients, 10.6% appeared with the SEA, which was mainly multisegmental (86.7%), particularly at the C5-6 segment (73.3%), and intense with a well-defined border (70.0%). The SEA group was an older population (p < 0.0001) with a longer duration (p < 0.0001) and a higher incidence of Hoffmann signs and knee hyperreflexia (p < 0.0001, p = 0.0038, respectively). The degree of spinal cord atrophy demonstrated a close association with the SEA, as it was significantly worse in the SEA group and SEA segment (p = 0.0008, p < 0.0001, respectively). The degree of spinal cord atrophy was positively related to both age and duration (p = 0.0095, p = 0.0176, respectively). CONCLUSIONS: Confirmed as an irreversible lesion and an indication of poor prognosis, SEA appears during the late stage of Hirayama disease and is closely related to pyramidal signs and spinal cord atrophy.