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.

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.

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 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.

Ecto-5'-nucleotidase (CD73) attenuates inflammation after spinal cord injury by promoting macrophages/microglia M2 polarization in mice.

BACKGROUND: Immune activation, specifically activation of macrophages and resident microglia, leading to inflammation is a key component in the progression of spinal cord injury (SCI). Macrophages/microglia exist in two states-the classically activated M1 phenotype that confers pro-inflammatory effects or the alternatively activated M2 phenotype that confers anti-inflammatory effects. Ecto-5'-nucleotidase (CD73) is an immunosuppressive molecule intricately involved in adaptive and innate immune responses and is able to dephosphorylate AMP to adenosine. However, it is not known if CD73 is able to modulate the macrophages/microglia transformation between the M1 and M2 phenotypes. METHODS: We used gene-deficient mice to determine the role of CD73 in macrophages/microglia polarization post-SCI in vivo. We used small interference RNA (siRNA) or pcDNA3.1 to inhibit or overexpress CD73 in BV2 cells to verify anterior discovery in vitro. A combination of molecular and histological methods was used to detect the macrophages/microglia polarization and explore the mechanism both in vivo and in vitro. RESULTS: We found that SCI induced the upregulation of CD73 expression. CD73 deficient mice were noted to demonstrate overwhelming immune responses, few anti-inflammatory phenotype macrophages/microglia, and had a poorer locomotor recovery in comparison to wild-type mice that were also inflicted with SCI. In vitro studies found that CD73 suppression inhibited the expression of characteristic microglial anti-inflammatory polarization markers in BV2 cells, while the converse was noted in CD73 overexpression. Subsequent experiments confirmed that CD73 promoted microglia alternative activation by stimulating p38 MAPK. CONCLUSION: We were able to conclude that CD73 imparts neuroprotective effects by mediating macrophages/microglia polarization. These findings allow for better understanding of the modulatory factors involved in triggering the change in macrophages/microglia phenotypes, therefore uncovering additional molecules and pathways that may be targeted in the innovation of novel SCI therapies.

F-waves of peroneal and tibial nerves in the differential diagnosis and follow-up evaluation of L5 and S1 radiculopathies.

PURPOSE: To investigate F-wave as a method to identify a specific root lesion of L5 or S1 and to quantitatively evaluate the severity and progression of motor root lesions in lumbosacral radiculopathies (LR). METHODS: Both peroneal and tibial F-waves were performed bilaterally in 142 patients with unilateral L5 or S1 radiculopathies and 37 controls along with Medical Research Council (MRC) evaluation, and soleus H-reflexes were tested bilaterally in 78 of these 142 cases. Both F-wave and MRC were re-evaluated approximately 1 year after initial examination in 65 patients. RESULTS: Abnormal peroneal F-waves were found in 34 patients with L5 radiculopathy (34/67, 50.7%) along with normal tibial F-waves and soleus H-reflexes in all tested cases. By contrast, 27 patients with S1 radiculopathy presented abnormal tibial F-waves (27/76, 36.0%) along with normal peroneal F-waves in all 76 cases and abnormal soleus H-reflexes in 38 of 47 (80.9%) cases. There were significant differences in involved side F-duration among different MRC scales in both radiculopathy groups (P < 0.05). Follow-up analysis demonstrated slow progression of both F-wave abnormalities and muscle weakness in patients undergoing conservative treatment (P < 0.05). CONCLUSIONS: Comparisons of F-waves between the same nerve on both sides and between peroneal and tibial nerves in the same leg may clearly increase the validity of F-waves for evaluating a specific motor root lesion of L5 or S1. Furthermore, a quantitative comparison of F-waves may provide additional information on the severity of individual root lesions and their progression even in the early stages of disease. These slides can be retrieved under Electronic Supplementary Material.

Can a Nomogram Help to Predict the Overall and Cancer-specific Survival of Patients With Chondrosarcoma?

BACKGROUND: Many factors have been reported to be associated with the prognosis of patients with chondrosarcoma, but clinicians have few tools to estimate precisely an individual patient's likelihood of surviving the illness. We therefore sought to develop effective nomograms to better estimate the survival of patients with chondrosarcoma. QUESTIONS/PURPOSES: (1) Which clinicopathologic features are independent prognostic factors for patients with chondrosarcoma? (2) Can we develop a nomogram to predict 3- and 5-year overall and cancer-specific survival of individual patients with chondrosarcoma based on personalized information? METHODS: We collected information on patients diagnosed with chondrosarcoma between 1988 and 2011 from the Surveillance, Epidemiology, and End Results (SEER) database. The SEER database consists of 18 cancer registries and covers approximately 30% of the total United States population. One thousand thirty-four adult patients with grade II or III chondrosarcoma were included in the cohort (patients with grade I chondrosarcoma were not evaluated in this study), while 327 patients were excluded from the study owing to missing data regarding tumor size or metastasis. Nine hundred nineteen patients (89%) in the cohort had complete followup for at least 1 year. The X-tile program was used to determine optimal cutoff points. Univariate and multivariate analyses were applied to identify independent factors that were further included in the nomograms predicting 3- and 5-year overall survival and cancer-specific survival. Records of 1034 patients were collected and randomly divided into training (n = 517) and validation (n = 517) cohorts. The nomograms were developed based on training cohort. Data for the training cohort were obtained for internal validation of the nomograms, whereas data for the validation cohort were obtained for external validation of the nomograms. Bootstrapped validation, which used a resample with 500 iterations, was applied to validate the nomograms internally and externally. RESULTS: Six independent prognostic factors for overall survival and six for cancer-specific survival were identified and incorporated to construct nomograms for 3- and 5-year overall and cancer-specific survival. These nomograms can easily be used by providers in the office to estimate a patient's prognosis; the only clinical details a provider needs to use these nomograms effectively are age, histologic subtype, tumor grade, whether surgery was performed, tumor size, and the presence or absence of metastases. Internal and external calibration plots for the probability of 3- and 5-year overall survival and cancer-specific survival showed good agreement between nomogram prediction and observed outcomes. The concordance indices (C-indices) for internal validation of overall survival and cancer-specific survival prediction were 0.803 and 0.829, respectively, whereas the C-indices for external validation were 0.753 and 0.759, respectively. CONCLUSIONS: We were able to develop effective nomograms to predict overall survival and cancer-specific survival for patients with chondrosarcoma; these nomograms require only basic information, which should be available to all providers in the office setting. If these observations can be validated in different registries or databases, the nomograms can assist clinicians in counseling patients regarding therapeutic choices. LEVEL OF EVIDENCE: Level III, prognostic study.

Quantitative analysis of near-implant magnesium accumulation for a Si-containing coated AZ31 cage from a goat cervical spine fusion model.

BACKGROUND: Magnesium (Mg) released from Mg-based implants degradation is believed to be effective in improving osteogenesis, however, studies focusing on Mg-based interbody cages are limited and fusion success was never reported. As excessive Mg accumulation can inhibit new bone formation, this study is designed to explain the possible reasons for the fusion failure of Mg-based cages by analyzing the relationships between the intervertebral Mg accumulation and the resulting interbody fusion. METHODS: The experimental cage was consisted of magnesium alloy (AZ31) substrate and Silicon (Si) -containing coating. C3/C4 and C5/C6 of 24 goats were implanted with cage or autologous iliac crest bone graft (Control group), which were analyzed at 3, 6, 12, and 24 weeks post-operatively. Intervertebral Mg concentrations, Mg-related Calcium (Ca)/ Phosphorus (P) ratios, radiological evaluations and histological findings were recorded for analyzing the relationships between the three of cage corrosion, Mg accumulation, and interbody fusion. RESULTS: Intervertebral Mg levels were significantly increased after cage implantation, especially in the areas that were closer to the cages at 3 weeks post-operatively, and these increased concentrations could persist up to 12 weeks post-operatively, indicating a relatively rapid corrosion process. Significantly lower Mg levels were only found at 24 weeks post-operatively, but these levels were still higher than those of the control group. In addition, Mg was found to be widely distributed at the intervertebral space since high Mg concentrations could even be detected at the posterior boundary of the vertebral body. Under this Mg accumulation profile, interbody fusion was not achieved, as indicated by the decreased Ca/P ratios, low CT fusion scores and negative histological results. CONCLUSIONS: Intervertebral excessive Mg accumulation might be the primary reason for interbody fusion failure. Quantitative Mg analysis can offer insight into the association between cage degeneration and biological response.

Risk factors for metastasis at presentation with conventional chondrosarcoma: a population-based study.

PURPOSE: The aim of the study was to investigate risk factors for metastasis at diagnosis. METHODS: We collected patients diagnosed with conventional chondrosarcoma between 1983 and 2014 from the Surveillance, Epidemiology, and End Results (SEER) database. Each patient was classified as having metastatic or localized disease. Univariate and multivariate logistic regression analyses were applied to determine which characteristics were risk factors for metastasis at diagnosis. RESULTS: Two thousand three hundred forty-nine patients were collected and 180 patients had metastasis at presentation. Data on age, gender, primary site, grade, and tumour size were enrolled into the multivariate logistic analysis. Greater age (60 years or older: OR = 1.872, 95% CI, 1.206 to 2.904), axial or craniofacial location (spine: OR = 1.775, 95% CI, 1.188 to 2.651; thoracic cage: OR = 2.034, 95% CI, 1.321 to 3.134; craniofacial bones: OR = 5.507, 95% CI, 3.001 to 10.107), higher grade (grade II: OR = 1.849, 95%CI, 1.181 to 2.895; grade III: OR = 4.016, 95%CI, 2.513 to 6.418), and larger tumour size (size over 10 cm: OR = 7.135, 95%CI, 2.130 to 23.893) were associated with an increased risk of metastasis at presentation. CONCLUSIONS: Conventional chondrosarcoma patients with greater age, axial or craniofacial tumour location, higher grade, and larger tumor size were more likely to have metastasis at diagnosis.

Spinal Rosai-Dorfman disease: case report and literature review.

OBJECTIVE: Sinus histiocytosis with massive lymphadenopathy or Rosai-Dorfman disease (RDD) is a rare benign disease of dubious etiology that arises predominantly in lymph nodes with generalized fever and malaise. Isolated intraspinal involvement has its unique characteristics. The purpose of this study is to present the largest series of cases in the spinal Rosai-Dorfman disease literature to increase familiarity with its clinicopathologic features, diagnosis, and treatment of RDD from spine. METHODS: We present the case of a 34-year-old man who presented with paraplegia secondary to an isolated thoracic vertebral lesion. On physical exam, the patient displayed progressive weakness and tendon hyperreflexia of the lower limbs. After a totally section, symptoms of the patient were obviously relieved and the patient remained asymptomatic and no signs of recurrences were observed after follow-up for 5 months. We also retrospectively analyzed 60 cases of patients with spinal RDD published in English since 1969. Clinical date, histopathology, and radiological feature were retrospectively analyzed. RESULTS: Spinal RDD should no longer be considered rare and it may occupy an increasingly prominent place in the list of differential diagnoses for intraspinal lesions. Only elaborate histopathology was diagnostic for RDD. Most of the patients were surgically treated and marked improvements were observed in their clinical conditions. CONCLUSIONS: RDD with spinal involvement is uncommon and it is challengeable in making a certain diagnosis. Histopathologic characteristics and immunohistochemical findings are considered as the key points for the diagnosis of this disease. The optimal treatment remains controversial, and more efforts should be focused on the investigation of etiology and adjuvant therapy for relapsing cases or subresected lesions.

Repetitive nerve stimulation as a diagnostic aid for distinguishing cervical spondylotic amyotrophy from amyotrophic lateral sclerosis.

PURPOSE: To identify and compare the features of compound muscle action potential (CMAP) decrements in repetitive nerve stimulation (RNS) in patients with cervical spondylotic amyotrophy (CSA) and in patients with amyotrophic lateral sclerosis (ALS). METHODS: The cohort consisted of 43 CSA (distal-type to proximal-type ratio: 27-16) and 35 ALS patients. Five muscles, including abductor pollicis brevis (APB), abductor digiti minimi (ADM), biceps brachii (BB), middle deltoid (Del), and upper trapezius (Trap), were tested by 3-Hz RNS. Decrements greater than cutoff values (APB > 5.8%; ADM > 4.8%; BB > 5.2%; Del > 6%; Trap > 5.1%) determined using receiver operating characteristic (ROC) curves were defined as abnormal, and the conventional criterion (≥10%) was also considered. RESULTS: A significant CMAP decrement (>cutoff values) was recorded from at least one tested muscle in 91.4% of ALS patients, and was most common in the proximal muscle, a finding that differed significantly from CSA patients (32.6%, P < 0.05). The application of cutoff values greatly improved the sensitivity of RNS over the conventional criterion (≥10%) for the detection of ALS (P < 0.05). The specificity of this technique remained higher when performing RNS in the proximal muscles, especially in the upper trapezius (AUC = 0.864, sensitivity = 0.643, and specificity = 1.000). The decrement percentages were significantly greater in the proximal muscles of ALS patients than in those of the CSA patients (P < 0.05). In addition, illness duration was not correlated with decrement percentage in either patient group, and no difference in the frequency of decrement among different ALS diagnostic categories was observed (P > 0.05). CONCLUSIONS: The application of RNS, especially in proximal muscles, may provide a simple accurate and noninvasive supplementary test for distinguishing CSA from ALS, even in the early stage of these diseases. A combination of RNS, needle EMG, clinical features and cervical magnetic resonance imaging may yield sufficient diagnostic information to differentiate CSA and ALS.

Does right lateral decubitus position change retroperitoneal oblique corridor? A radiographic evaluation from L1 to L5.

PURPOSE: To determine if the retroperitoneal oblique corridor will be affected by right lateral decubitus position. METHODS: Forty volunteers were randomly enrolled and MRI scan was performed from L1 to L5 in supine and right lateral decubitus positions, respectively. In images across the center of each disc, O was defined as the center of a disc and A (supine) or A' (right lateral decubitus) was located in left lateral border of the aorta or the iliac artery; B (supine) or B' (right lateral decubitus) was on the anterior medial border of the psoas. The distance of AB and A'B' (Recorded as A-Ps and A-Pr, respectively) at each level was recorded and compared to each other. The relationships between A-Pr, sex, BMI and relative psoas cross-sectional area (PCSA) at each level were also evaluated. RESULTS: A-Pr was significantly smaller than A-Ps at L1/2, L2/3 and L3/4 (All p < 0.05); there was no significantly difference of A-Pr between all levels (p = 0.105), but L1/2 seemed to be larger than L3/4, followed by L2/3 and L4/5; A-Pr at each level was not affected by sex (All p > 0.05); linear relationships were found between A-Pr, BMI and PCSA at L1/2 and L3/4. CONCLUSIONS: ROC at L1/2, L2/3 and L3/4 will significantly decrease from supine to right lateral decubitus position and the reason may be due to the relaxed psoas deformation. Using MRI images in supine position for pre-operatively ROC evaluation is not accurate. Spine surgeon should also be more cautious when OLIF is performed at L4/5 where ROC is the smallest. Patients from Asia and those with strong psoas major at L1/2 and L3/4 are also associated with relatively narrow ROC.

The value of applying a melatonin antagonist (Luzindole) in improving the success rate of the bipedal rat scoliosis model.

BACKGROUND: An ideal animal model has always been the key to research the pathogenesis and treatment of adolescent idiopathic scoliosis (AIS), while available methods have obvious disadvantages. The deficiency of melatonin has been proved relating to AIS. In this research, we intended to apply Luzindole, the melatonin antagonist, in bipedal rat model, for the block of combination of melatonin and its receptor, to inhibit the melatonin effect, and then to understand whether this method can effectively improve the scoliosis rate of bipedal rat model, and investigate the role of melatonin in scoliosis. To investigate the feasibility of improving the success rate of bipedal rat scoliosis model via intraperitoneal injection of melatonin antagonist (Luzindole). METHODS: A total of 60 3-weeks-old Sprague-Dawley rats were included in this study, and were divided into 3 groups (A, B and C). Each group included 20 rats. Osteotomy of the bilateral proximal humerus and proximal tailbone was performed in group A and group B; intraperitoneal injection of Luzindole (0.2 mg/kg) was performed in group A and group C. X-rays were taken before the surgery, 1 month after the surgery, 3 months after the surgery, and 6 months after the surgery, to calculate the Cobb's angle of the spine (>10° was considered scoliosis). The weight of every rat was also measured at the same time. Rats were euthanized 6 months after surgery to determine the calmodulin level in thrombocytes. RESULTS: The rate of scoliosis in group A (14/20) was significantly higher than those in group B (6/20) and group C (0/20) (P < 0.05). The differences in the weights of the 3 groups were non-significant; as were differences in the calmodulin level in thrombocytes. CONCLUSION: The application of the melatonin antagonist of Luzindole can improve the success rate of the bipedal rat scoliosis model. Meanwhile, this study indicates that a decreased melatonin level is not the primary cause of scoliosis, but that it may increase the likelihood and severity of scoliosis.

Trans-synaptic degeneration of motoneurons distal to chronic cervical spinal cord compression in cervical spondylotic myelopathy.

OBJECTIVE: To assess the effect of chronic cervical spinal cord compression upon remote motor unit function in patients with cervical spondylotic myelopathy (CSM). METHODS: Fifty-three CSM patients and 47 healthy subjects were included. Bilateral motor unit number estimations (MUNEs) were recorded from both abductor digiti minimi and abductor pollicis brevis, and bilateral flexor carpi radialis (FCR) H-reflexes were examined in all subjects along with the nine-hole peg test (NHPT). The main outcome measures included the number of motor units, the average single motor unit potential (SMUP) area, the FCR Hmax/Mmax ratios and the NHPT time. RESULTS: Statistically significant results compared to healthy controls included increased average SMUP area, increased FCR Hmax/Mmax ratio and increased NHPT time (p < 0.05). Abnormal SMUP was observed in 10/53 (18.9%) CSM patients along with reduced motor units in 3 of these 10 patients, while the FCR Hmax/Mmax ratios in the CSM patients with abnormal MUNE were higher than those in others (p < 0.05). There was a positive correlation between the NHPT time and the average SMUP area, and a negative correlation was noted between the NHPT time and the number of motor units (p < 0.05). CONCLUSION: In CSM patients, the motor units below the level of compression may exhibit dysfunction, which is likely a result of trans-synaptic degeneration. Both cervical spinal cord compressive injury and this trans-synaptic degeneration contribute to the impairment of fine motor ability in CSM patients. Therefore, treatment and rehabilitation efforts should account for these two dysfunctions.

The prevalence of tarsal tunnel syndrome in patients with lumbosacral radiculopathy.

PURPOSE: Tarsal tunnel syndrome (TTS) is a painful foot condition. Lumbosacral radiculopathy (LR) may also present with symptoms occurring in TTS. However, no studies have been reported to determine the possible coexistence of these two conditions. The aim of our study was to identify the prevalence of TTS in patients with confirmed LR and to analyze the clinical and electrodiagnostic features of patients with both TTS and LR. METHODS: Medial and lateral plantar nerve mixed studies, peroneal motor studies and deep peroneal sensory studies were performed in 81 normal subjects and 561 patients with LR. The Tinel's test and other provocative tests were performed in the LR patient group, and the clinical symptoms of TTS were also analyzed. The frequency of TTS was investigated in all radiculopathy group patients with different nerve root lesions. RESULTS: Concomitant TTS was found in 27 (4.8%) patients with LR. Abnormal results of sensory/mixed conduction tests were observed in 25/27 (92.6%) patients, and 11/27 (40.7%) patients had abnormal results of motor conduction tests. Positivity for the Tinel's test and special provocative tests was found in 15/27 (55.6%) and 17/27 (63.0%) patients, respectively. Overall, 9/27 (33.3%) patients had typical symptoms, and suspicious clinical symptoms were found in the other 14/27 (51.9%) patients. The frequency of coexisting TTS was not statistically different among the single-level L4, L5 or S1 radiculopathy, or between the single-level and multi-level radiculopathies (P > 0.05). CONCLUSIONS: The findings suggest that the prevalence of TTS is significant in patients with LR. Thus, more caution should be paid when diagnosing and managing patients with LR due to the possible existence of TTS, as their management strategies are quite different.

Analysis of the correlative factors in the selection of interbody fusion cage height in transforaminal lumbar interbody fusion.

BACKGROUND: Selecting an interbody cage with appropriate height is one of the key steps in lumbar interbody fusion, and has an important impact on clinical efficacy. How to choose the appropriate height of the cage becomes one of the core problems of lumbar interbody fusion for spine surgeons. However, studies about objective selection criteria on interbody cage height was rare. METHODS: One hundred fifty-seven patients with single segment lumbar degenerative diseases treated by TLIF surgery from January 2011 to July 2013 were retrospectively analyzed. Parameters analyzed included: gender, age, body height, clinical diagnosis, pathological segment location and the intervertebral height of pathological segment, pathological segment activity, the intervertebral height of the adjacent segments. And further to analyze the correlation between these parameters and interbody cage height. By measuring the intervertebral height of pathological segment and normal segment to calculate the regression equation of interbody cage height. RESULTS: The average interbody cage height of male patients (12.38 ± 1.43) mm was significantly higher than female (11.62 ± 1.45) mm (p < 0.001). The L4-5 segment interbody cage height (12.11 ± 1.38) mm was significantly greater than the L5-S1 (11.25 ± 1.32) mm (p = 0.04). Body height, the intervertebral height of pathological segment, and the middle intervertebral heigh of upper adjacent segment were highly positively correlated to the interbody cage height. The range of interbody cage height used in transforaminal lumbar interbody fusion for Chinese patients with lumbar degenerative diseases was: L3-4 (11.28 ± 3.29) mm ~ (12.76 ± 2.40) mm, L4-5 (11.62 ± 2.89) mm ~ (13.18 ± 1.91) mm, L5-S1 (10.52 ± 2.22) mm ~ (11.90 ± 2.80) mm. The regression equation of interbody cage height was: interbody cage height = 11.123-0.563 * (gender) + 0.149 * (the middle intervertebral height of pathological segment). CONCLUSIONS: The selection of interbody cage height was influenced by sex, body height, pathological segment location, the intervertebral height of pathological segment and other factors. The interbody cage height for the lower lumbar spine mostly selected 11,12,13 mm, L3-4, L4-5 segment highly selective in general should not be less than 10 mm, and L5-S1 segments height was relatively small, usually not more than 13 mm. The interbody cage height might be selected based on the regression equation of interbody cage height. But, the regression equation maybe need to be verified in a prospective study.

Electrophysiological differences between Hirayama disease, amyotrophic lateral sclerosis and cervical spondylotic amyotrophy.

BACKGROUND: Hirayama disease (HD), amyotrophic lateral sclerosis (ALS) or cervical spondylotic amyotrophy (CSA) may result in atrophy of intrinsic hand and forearm muscles. The incidence of HD is low, and it is rarely encountered in the clinical setting. Consequently, HD is often misdiagnosed as ALS or CSA. It is important to differentiate these diseases because HD is caused by a benign focal lesion that is limited to the upper limbs. METHODS: The thenar and hypothenar compound muscle action potential (CMAP) amplitude of the upper limbs of 100 HD, 97 ALS and 32 CSA cases were reviewed; 35 healthy individuals were included as controls. Seventy-eight percent, 38% and 69% of patients with HD, ALS or CSA had unilateral involvement; the remaining patients were affected bilaterally. Thenar and hypothenar CMAP amplitude evoked by ulnar stimulation was compared with CMAP evoked by median stimulation. RESULTS: The ulnar/median CMAP ratio was found to be lower in HD (0.55 ± 0.41, P<0.0001), higher in ALS (2.28 ± 1.15, P<0.0001) and no different in CSA (1.21 ± 0.53, P>0.05) compared with the normal range from previous studies (0.89-1.60) and with the healthy controls (1.15 ± 0.23). Conduction velocities of the sensory and motor nerves, the amplitude of the sensory nerve action potential, and the CMAP amplitude of the unaffected limb were all normal. CONCLUSIONS: The hand muscles were differentially affected between patients with HD, ALS and CSA. The ulnar/median CMAP ratio could be used to distinguish these three diseases.

HIF-1α-induced expression of the m6A reader YTHDF1 inhibits the ferroptosis of nucleus pulposus cells by promoting SLC7A11 translation.

The nucleus pulposus is in a hypoxic environment in the human body, and when intervertebral disc degeneration (IVDD) occurs, the hypoxic environment is disrupted. Nucleus pulposus cell (NPC) ferroptosis is one of the causes of IVDD. N6-methyladenosine (m6A) and its reader protein YTHDF1 regulate cellular activities by affecting RNA metabolism. However, the regulation of ferroptosis in NPCs by m6A-modified RNAs under hypoxic conditions has not been as well studied. In this study, through in vitro and in vivo experiments, we explored the underlying mechanism of HIF-1α and YTHDF1 in regulating ferroptosis in NPCs. The results indicated that the overexpression of HIF-1α or YTHDF1 suppressed NPC ferroptosis; conversely, the knockdown of HIF-1α or YTHDF1 increased ferroptosis levels in NPCs. Luciferase reporter assays and chromatin immunoprecipitation demonstrated that HIF-1α regulated YTHDF1 transcription by directly binding to its promoter region. Polysome profiling results showed that YTHDF1 promoted the translation of SLC7A11 and consequently the expression of the anti-ferroptosis protein GPX4 by binding to m6A-modified SLC7A11 mRNA. In conclusion, HIF-1α-induced YTHDF1 expression reduces NPC ferroptosis and delays IVDD by promoting SLC7A11 translation in a m6A-dependent manner.

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.

Diagnostic advantage of S1 foramen-evoked H-reflex for S1 radiculopathy in patients with diabetes mellitus.

Hoffmann reflex to tibial nerve stimulation at the popliteal fossa (tibial H-reflex) is routinely used to evaluate S1 radiculopathy. However, it lacks sensitivity because other lesions along this reflex circuit affect the H-reflex bilaterally. This study was undertaken to determine whether the H-reflex evoked by stimulating proximally at the S1 foramen (S1 foramen H-reflex) could improve S1 root lesion evaluation sensitivity in patients with diabetes mellitus. A randomized paired study was designed to evaluate tibial and S1 foramen H-reflexes; bilateral H-M interval (HMI) and H-reflex latency were compared in 22 diabetic patients with unilateral S1 radiculopathy. Other electrophysiological evaluations included standard tibial conduction studies, sural conduction studies and needle electromyography (EMG). The S1 foramen H-reflex had a significantly higher sensitivity (91.0%, 20 of 22) in evaluating S1 radiculopathy than the conventional tibial H-reflex (63.6%, 14 of 22, p < 0.05). Bilateral tibial compound muscle action potential amplitudes were reduced in 3 patients, and sural sensory nerve action potential amplitudes decreased in 7 patients. Needle EMG revealed denervation restricted to the paraspinal muscle and myotomes supplied by the S1 nerve root on the ipsilateral side in 18 patients, and multiple lumbosacral nerve roots were involved bilaterally in the other 4 patients. Our results demonstrate that the S1 foramen H-reflex is a more sensitive assessment of S1 compressive radiculopathy in patients with diabetes mellitus.