古矢 丈雄

＜文献概要＞Point ▼脊髄造影の適応,手技を提示する。▼神経根ブロックや神経根造影の適応,手技,治療効果を提示する。▼脊髄造影,神経根ブロック,神経根造影の合併症を提示する。

CASE: A 44-year-old man developed urinary retention due to a spontaneous spinal epidural hematoma (SSEH) at the cervicothoracic junction, without paraplegia. Symptoms improved with surgical treatment. CONCLUSION: SSEH is rare and causes acute neck or back pain and progressive paralysis. Patients with advanced myelopathy due to spinal cord compression lesion including SSEH often present with bladder and bowel disorders after exacerbation of quadriplegia. However, SSEH can cause predominant bladder and bowel disorders without paraplegia or quadriplegia. Physicians should consider that there can be a manifestation of myelopathy with bladder and bowel dysfunction without quadriplegia.

OBJECTIVE: The Hybrid Assistive Limb (HAL) has recently been used to treat movement disorders. Although studies have shown its effectiveness for chronic myelopathy, the immediate effects of HAL gait training on lower limb function have not been clarified. We conducted HAL gait training and examined its immediate effects on a 69-year-old man with re-deterioration of myelopathy in the chronic phase after surgery for compression myelopathy. The HAL intervention was performed every 4 weeks for 10 total sessions. Immediately before and after each session, we analyzed the patient's walking ability using the 10-m walk test. In the 4th HAL session, the gastrocnemius muscle activity was measured bilaterally using a synchronized motion capture-electromyogram system. RESULTS: The training effects became steady after the 2nd session. In sessions 2-10, the step length increased from 0.56 to 0.63 m (mean: 0.031 m) immediately after HAL training. The motion capture-electromyogram analyses showed that considerable amounts of gastrocnemius muscle activity were detected during the stance and swing phases before HAL training. During and immediately after HAL training, gastrocnemius activity during the swing phase was diminished. HAL gait training has an immediate effect for inducing a normal gait pattern with less spasticity in those with chronic myelopathy.

＜文献概要＞【目的】転移性骨腫瘍により脊椎の不安定性が高い症例に対し,骨転移キャンサーボード後に疼痛回避動作指導を中心とした理学療法が効果的であった症例について報告する.【対象】乳癌,脊椎多発転移を呈した52歳女性である.Spinal Instability Neoplastic Scoreによる脊椎の不安定性は16点であった.腰背部の疼痛が増悪し,ADLが困難となった.【方法】骨転移キャンサーボードで多職種連携し,疼痛回避動作指導を中心とした理学療法を施行した.【結果】骨転移キャンサーボードから23日間,骨関連事象が増悪せずにADLの拡大が図れた.【結語】脊椎の不安定性が高い症例に対し,骨転移キャンサーボードで多職種間の連携を強化し疼痛回避動作を中心とした理学療法を施行することで,疼痛を増悪させずにADLの拡大につなげた.

STUDY DESIGN: Retrospective observational study. PURPOSE: We investigated the correlation between T2 relaxation times and clinical symptoms in patients with cervical radiculopathy caused by cervical disk herniation. OVERVIEW OF LITERATURE: There are currently no imaging modalities that can assess the affected cervical nerve roots quantitatively. METHODS: A total of 14 patients with unilateral radicular symptoms and five healthy subjects were subjected to simultaneous apparent T2 mapping and neurography with nerve-sheath signal increased with inked rest-tissue rapid acquisition of relaxation enhancement signaling (SHINKEI-Quant) using a 3-Tesla magnetic resonance imaging. The Visual Analog Scale (VAS) score for neck pain and upper arm pain was used to evaluate clinical symptoms. T2 relaxation times of the cervical dorsal root ganglia of the brachial plexus were measured bilaterally from C4 to C8 in patients with radicular symptoms and from C5 to C8 in healthy controls. The T2 ratio was calculated as the affected side to unaffected side. RESULTS: When comparing nerve roots bilaterally at each spinal level, no significant differences in T2 relaxation times were found between patients and healthy subjects. However, T2 relaxation times of nerve roots in the patients with unilateral radicular symptoms were significantly prolonged on the involved side compared with the uninvolved side (p<0.05). The VAS score for upper arm pain was not significantly correlated with the T2 relaxation times, but was positively correlated with the T2 ratio. CONCLUSIONS: In patients with cervical radiculopathy, the SHINKEI-Quant technique can be used to quantitatively evaluate the compressed cervical nerve roots. The VAS score for upper arm pain was positively correlated with the T2 ratio. This suggests that the SHINKEI-Quant is a potential tool for the diagnosis of cervical nerve entrapment.

STUDY DESIGN: Prospective cohort study (open-label, single-arm, and non-blinded). PURPOSE: This study aims to determine the effects of systemic administration of tocilizumab, an anti-interleukin-6 (IL-6) receptor antibody on refractory low back pain and leg symptoms. OVERVIEW OF LITERATURE: IL-6 overexpression is associated with neuropathic pain pathogenesis, which is potentially followed by chronic low back pain, including leg pain and numbness. This finding suggest that inhibition of IL-6 at the site of pain or in the transmission pathway could provide novel therapeutic targets for chronic low back pain. METHODS: This prospective, single-arm study included 11 patients (eight men; mean age, 62.7 years) with ≥3-months' chronic pain history due to lumbar disease. Subcutaneous TCZ injections were administered twice, at a 2-week interval. We evaluated low back pain, leg pain, and leg numbness using numeric rating scales and the Oswestry Disability Index (ODI; baseline and 6 months postinjection); serum IL-6 and tumor necrosis factor-α levels (baseline and 1 month postinjection); and clinical adverse events. RESULTS: Intractable symptoms reduced after TCZ administration. Low back pain improved for 6 months. Improvements in leg pain and numbness peaked at 4 and 1 month, respectively. Improvements in ODI were significant at 1 month and peaked at 4 months. Serum IL-6 was increased at 1 month. IL-6 responders (i.e., patients with IL-6 increases >10 pg/mL) showed particularly significant improvements in leg pain at 2 weeks, 1 month, and 2 months compared with nonresponders. We observed no apparent adverse events. CONCLUSIONS: Systemic TCZ administration improved symptoms effectively for 6 months, with peak improvements at 1-4 months and no adverse events. Changing serum IL-6 levels correlated with leg pain improvements; further studies are warranted to elucidate the mechanistic connections between lumbar disorders and inflammatory cytokines.

＜文献概要＞【目的】転移性骨腫瘍により脊椎の不安定性が高い症例に対し,骨転移キャンサーボード後に疼痛回避動作指導を中心とした理学療法が効果的であった症例について報告する.【対象】乳癌,脊椎多発転移を呈した52歳女性である.Spinal Instability Neoplastic Scoreによる脊椎の不安定性は16点であった.腰背部の疼痛が増悪し,ADLが困難となった.【方法】骨転移キャンサーボードで多職種連携し,疼痛回避動作指導を中心とした理学療法を施行した.【結果】骨転移キャンサーボードから23日間,骨関連事象が増悪せずにADLの拡大が図れた.【結語】脊椎の不安定性が高い症例に対し,骨転移キャンサーボードで多職種間の連携を強化し疼痛回避動作を中心とした理学療法を施行することで,疼痛を増悪させずにADLの拡大につなげた.

STUDY DESIGN: Prospective, nationwide case series. OBJECTIVE: To identify preoperative factors associated with myelopathy and neurological impairment in patients with cervical ossification of the posterior longitudinal ligament (OPLL). SUMMARY OF BACKGROUND DATA: Various studies have reported clinical outcomes following the surgical treatment of OPLL. However, there has been no large-scale study of preoperative clinical features in patients with cervical OPLL. MATERIALS AND METHODS: Data were prospectively collected from 28 institutions nationwide in Japan. In total, 512 patients with neurological impairment caused by cervical OPLL requiring surgery were enrolled. Basic demographic and clinical data, including age, sex, diabetes status, body mass index, smoking history, and disease duration were collected. C2-7 lordotic angle, canal narrowing ratio, range of motion in flexion-extension at C2-7, and type of OPLL were evaluated on lateral radiographs to identify factors influencing the clinical features of patients with OPLL in whom surgery was planned. RESULTS: Complete documentation was available for 490 patients (362 male, 128 female). In total, 34 patients had the localized type, 181 had the segmental type, 64 had the continuous type, and 211 had the mixed type. Although there were no significant differences in age, body mass index, disease duration, Japanese Orthopedic Association (JOA) score, and lordotic angle at C2-7 according to the type of OPLL, significant differences were observed in a range of motion at C2-7 and the canal narrowing ratio among the 4 types. Multiple regression analysis revealed that the JOA score was significantly associated with age and signal intensity change on magnetic resonance imaging. CONCLUSIONS: This is the first large-scale, prospective, multicenter case series study to investigate factors influencing preoperative neurological status in patients with OPLL. Age and signal intensity change on magnetic resonance images were significantly associated with JOA score in patients requiring surgery. LEVEL OF EVIDENCE: Level II.

STUDY DESIGN: This was a retrospective study of prospectively collected data. OBJECTIVE: In this study, we aimed to characterize a population of patients with degenerative cervical myelopathy (DCM) and a history of poor postoperative neurological recovery and to identify risk factors associated with poor neurological recovery after laminoplasty. SUMMARY OF BACKGROUND DATA: Kyphotic cervical alignment has been considered a relative contraindication to laminoplasty in recent years; hence, laminoplasty has been decreasingly performed for the treatment of DCM in patients with cervical kyphosis. However, the effect of global spinal alignment on postoperative outcomes has not been extensively investigated. MATERIALS AND METHODS: We prospectively enrolled patients who were scheduled for laminoplasty for DCM. Outcome (at enrollment and 1 y after surgery) and risk factor analyses were performed by comparing the good recovery and poor recovery groups. The Spearman correlation coefficient was used to evaluate the relationships between the recovery rate and the preoperative radiographic factors. RESULTS: In total, 101 patients completed the 1-year follow-up. Regarding clinical outcomes, the Japanese Orthopedic Association score for the assessment of cervical myelopathy, European Quality of Life-5 Dimensions, and Neck Disability Index scores improved postoperatively. The recovery rate was significantly correlated with the preoperative sagittal vertical axis (SVA). The patients in the poor recovery group were older than those in the good recovery group. Univariate analyses showed that the SVA and T1 pelvic angle were significantly higher in the poor recovery group. Lastly, stepwise logistic regression analysis showed that a higher SVA was an independent predictor of poor recovery after laminoplasty. CONCLUSIONS: The SVA and T1 pelvic angle were significantly higher in the poor recovery group. A high preoperative SVA is an independent predictor for poor recovery after laminoplasty. Therefore, indications for laminoplasty in elderly DCM patients with a high preoperative SVA should be carefully considered. LEVEL OF EVIDENCE: Level III.

PURPOSES: To analyze T2 relaxation times of the facet joint by MRI T2-mapping in patients with degenerative lumbar disorders (DLD), and to determine the correlation with lumbar instability in radiographs. METHODS: We conducted a T2-mapping of the lumbar facet joint using a 1.5 T MRI system. We classified patients with degenerative lumbar disorders scheduled to undergo decompression surgery into groups with stability and instability using radiographs, and compared the T2 relaxation times of the lumbar facet. Lumbar instability was defined as the presence of anterior translation ratio > 5% or disk range of motion (ROM) > 5° in the sagittal plane of SLFE radiographs. RESULTS: Inclusion criteria were met by 22 patients (45 levels, mean age 64.3 years). Facet effusions had high sensitivity (90%) but had low specificity (28%) for diagnosis of lumbar instability. Mean T2 relaxation times of right and left facet joints are significantly longer (98.4 ms) in the instability group than they are (87.6 ms) in the stability group (p < 0.001). Anterior translation ratio was positively correlated with mean T2 relaxation times of facet joint (R2 = 0.493, p < 0.05). From a ROC analysis, the cutoff value of T2 relaxation times for lumbar instability was 98.65 ms (sensitivity 60.0%, specificity 95.7%, AUC 0.763). CONCLUSIONS: The T2 relaxation times were positively correlated with lumbar instability. This new quantitative evaluation of lumbar facet joint using MRI T2-mapping might be useful to determine lumbar instability.

This study investigated the effect of romosozumab on bone union in a rat posterolateral lumbar fixation model. Posterolateral lumbar fixation was performed on 8-week-old male Sprague Dawley rats (n=20). For bone grafting, autogenous bone (40 mg) was harvested from the spinous processes of the 10th thoracic vertebra until the 2nd lumbar vertebra and implanted between the intervertebral joints and transverse processes of the 4th and 5th lumbar vertebrae on both sides. Rats were matched by body weight and equally divided into two groups: R group (Evenity®, 25 mg/kg) and control (C) group (saline). Subcutaneous injections were administered twice a week until 8 weeks after surgery. Computed tomography was performed at surgery and week 8 after surgery. The area and percentage of bone trabeculae in the total area of bone fusion were calculated. Statistical analysis was performed using an unpaired t-test (P<0.05). We found that the R group rats had significantly higher mean bone union rate and volume than did the C group rats at all time courses starting week 4 after surgery. The R group had significantly higher increase rates than did the C group at weeks 4 and 6 after surgery. The percentage of bone trabeculae area in the R group was approximately 1.7 times larger than that in the C group. Thus, we demonstrated that romosozumab administration has stimulatory effects on bony outgrowth at bone graft sites. We attribute this to the modeling effect of romosozumab. This article is protected by copyright. All rights reserved.

In the current aging society, there has been a marked increase in the incidence of cervical spinal cord injury (CSCI) without major bone injury. This multicenter study aimed to identify predictors of neurological improvement in elderly patients with CSCI without major bone injury. The participants were 591 patients aged ≥65 years with CSCI without major bone injury and a minimum follow-up period of 3 months. Neurologic status was defined using the American Spinal Injury Association (ASIA) impairment scale (AIS). Univariate and multivariate analyses were performed to identify prognostic factors for walking recovery in AIS A-C cases and full upper extremity motor recovery in AIS D cases. In AIS A-C cases, body mass index (odds ratio (OR): 1.112), magnetic resonance imaging signal change (OR: 0.240), AIS on admission (OR: 3.497), comorbidity of dementia/delirium (OR: 0.365), and post-injury pneumonia (OR: 0.194) were identified as independent prognostic factors for walking recovery. The prevalence of ossification of the posterior longitudinal ligament (OR: 0.494) was also found to be an independent prognostic factor in AIS B and C cases only. In AIS D cases, age (OR: 0.937), upper extremity ASIA motor score on admission (OR: 1.230 [per 5 scores]), and operation (OR: 0.519) were independent prognostic factors for full motor recovery. The severity of AIS at admission was the strongest predictor of functional outcomes. However, promoting rehabilitation through measures to reduce cognitive changes, post-injury pneumonia, and unhealthy body weight changes can contribute to greater neurological improvement in AIS A-C cases.

OBJECTIVE: It is unclear whether anterior cervical decompression and fusion (ADF) or laminoplasty (LMP) results in better outcomes for patients with K-line-positive (+) cervical ossification of the posterior longitudinal ligament (OPLL). The purpose of the study is to compare surgical outcomes and complications of ADF versus LMP in patients with K-line (+) OPLL. METHODS: The study included 478 patients enrolled in the Japanese Multicenter Research Organization for Ossification of the Spinal Ligament and who underwent surgical treatment for cervical OPLL. The patients who underwent anterior-posterior combined surgery or posterior decompression with instrumented fusion were excluded. The patients with a follow-up period of fewer than 2 years were also excluded, leaving 198 patients with K-line (+) OPLL. Propensity score matching was performed on 198 patients with K-line (+) OPLL who underwent ADF (44 patients) or LMP (154 patients), resulting in 39 pairs of patients based on the following predictors for surgical outcomes: age, preoperative Japanese Orthopaedic Association (JOA) score, C2-7 angle, and the occupying ratio of OPLL. Clinical outcomes were assessed 1 and 2 years after surgery using the recovery rate of the JOA score. Complications and reoperation rates were also investigated. RESULTS: The mean recovery rate of the JOA score 1 year after surgery was 55.3% for patients who underwent ADF and 42.3% (p = 0.06) for patients who underwent LMP. Two years after surgery, the recovery rate was 53.4% for those who underwent ADF and 38.7% for LMP (p = 0.07). Although both surgical procedures yielded good results, the mean recovery rate of JOA scores tended to be higher in the ADF group. The incidence of surgical complications, however, was higher following ADF (33%) than LMP (15%; p = 0.06). The reoperation rate was also higher in the ADF group (15%) than in the LMP group (0%; p = 0.01). CONCLUSIONS: Clinical outcomes were good for both ADF and LMP, indicating that ADF and LMP are appropriate procedures for patients with K-line (+) OPLL. Clinical outcomes of ADF 1 and 2 years after surgery tended to be better than LMP, but the analysis did not detect any significant difference in clinical outcomes between the groups. Conversely, patients who underwent ADF had a higher incidence of surgery-related complications. When considering indications for ADF or LMP, benefits and risks of the surgical procedures should be carefully weighed.

This prospective multicenter study, established by the Japanese Ministry of Health, Labour and Welfare and involving 27 institutions, aimed to compare postoperative outcomes between laminoplasty (LM) and posterior fusion (PF) for cervical ossification of the posterior longitudinal ligament (OPLL), in order to address the controversy surrounding the role of instrumented fusion in cases of posterior surgical decompression for OPLL. 478 patients were considered for participation in the study; from among them, 189 (137 and 52 patients with LM and PF, respectively) were included and evaluated using the Japanese Orthopaedic Association (JOA) scores, the JOA Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), and radiographical measurements. Basic demographic and radiographical data were reviewed, and the propensity to choose a surgical procedure was calculated. Preoperatively, there were no significant differences among the participants in terms of patient backgrounds, radiographical measurements (K-line or cervical alignment on X-ray, OPLL occupation ratio on computed tomography, increased signal intensity change on magnetic resonance imaging), or clinical status (JOA score and JOACMEQ) after adjustments. The overall risk of perioperative complications was found to be lower with LM (odds ratio [OR] 0.40, p = 0.006), and the rate of C5 palsy occurrence was significantly lower with LM (OR 0.11, p = 0.0002) than with PF. The range of motion (20.91° ± 1.05° and 9.38° ± 1.24°, p < 0.0001) in patients who had PF was significantly smaller than in those who had LM. However, multivariable logistic regression analysis showed no significant difference among the participants in JOA score, JOA recovery rate, or JOACMEQ improvement at two years. In contrast, OPLL progression was greater in the LM group than in the PF group (OR 2.73, p = 0.0002). Both LM and PF for cervical myelopathy due to OPLL had resulted in comparable postoperative outcomes at 2 years after surgery.

PURPOSE: We investigated changes in skeletal muscle mass and bone mineral density in degenerative lumbar scoliosis (DLS) patients during a 2-year follow-up following diagnosis. METHOD: This study included 418 Japanese women, identifying 50 patients for the DLS group (mean age 76.4 years) and 368 patients for the control group (mean age 73.4 years). Whole-body skeletal muscle mass was measured using a Bioelectrical Impedance Analyzer. Bone mineral density (BMD) was measured using DXA. Skin autofluorescence (SAF), a marker of advanced glycation end products in the skin, was measured using a spectroscope. Spinal alignment, skeletal muscle mass, BMD, grip strength, and SAF were examined and the amount of change 1 and 2 years from the initial examination for each item was compared between groups. RESULTS: Height, body fat mass, grip strength, upper limb muscle mass, and trunk muscle mass in the DLS group were significantly lower, and lumbar spine BMD was significantly greater compared to controls at the first visit (p < 0.05). There was no significant difference in spinal alignment in the DLS group after 2 years compared with baseline. Trunk muscle mass also decreased significantly more in the DLS group (-2.7%) than in the control group (-1.1%) over the 2-year follow-up (p < 0.05). DISCUSSION: In this study, trunk muscle mass in the DLS group decreased about 2.4 times more in 2 years compared with the control group (p < 0.05). It may be possible to clarify the mechanism of kyphoscoliosis progression in the future with large-scale longitudinal studies.

It is challenging to predict neurological outcomes of acute spinal cord injury (SCI) considering issues such as spinal shock and injury heterogeneity. Deep learning-based radiomics (DLR) were developed to quantify the radiographic characteristics automatically using a convolutional neural network (CNN), and to potentially allow the prognostic stratification of patients. We aimed to determine the functional prognosis of patients with cervical SCI using machine learning approach based on MRI and to assess the ability to predict the neurological outcomes. We retrospectively analyzed the medical records of SCI patients (n=215) who had undergone MRI and had an American Spinal cord Injury Association Impairment Scale (AIS) assessment at 1 month after injury, enrolled with a total of 294 MR images. Sagittal T2-weighted MR images were used for the CNN training and validation. The deep learning framework TensorFlow was used to construct the CNN architecture. After we calculated the probability of the AIS grade using the DLR, we built the identification model based upon the random forest using 3 features: the probability of each AIS grade obtained by the DLR method, age, and the initial AIS grade at admission. We performed a statistical evaluation between the actual and predicted AIS. The accuracy, precision, recall and f1 score of the ensemble model based on the DLR and RF were 0.714, 0.590, 0.565 and 0.567, respectively. The present study demonstrates that prediction of the short-term neurological outcomes for acute cervical spinal cord injury based on MRI using machine learning is feasible.

Purpose Although the understanding of the mechanisms of low back pain due to spinopelvic sagittal imbalance has strengthened, the understanding of the mechanisms of neck pain remains insufficient. Thus, this study aimed to identify the factors associated with preoperative and postoperative neck pain in patients with degenerative cervical myelopathy who underwent laminoplasty. Methods In this prospective multicenter study, we prospectively enrolled patients who were scheduled for laminoplasty for degenerative cervical myelopathy. The associations between different variables and the Numerical Pain Rating Scale (NRS) scores for neck pain were investigated using univariate and multiple linear regression models. Results In total, 92 patients were included in the current study. The univariate analysis showed that age, sex, cervical lordosis in neutral and extension, and thoracic kyphosis were significantly associated with the preoperative NRS score for neck pain; moreover, preoperative cervical lordosis in extension and range of motion and postoperative cervical lordosis in neutral, flexion, and extension were significantly associated with the postoperative NRS Scale score for neck pain. Stepwise multiple regression analysis showed that the independent factors contributing to preoperative neck pain were preoperative cervical lordosis in extension, sex, and age. The independent preoperative predictor and contributor to postoperative neck pain were preoperative cervical lordosis in extension and postoperative cervical lordosis in extension, respectively. Conclusions Cervical lordosis in extension showed significant association with neck pain in patients with degenerative cervical myelopathy. Therefore, when performing laminoplasty for patients with a low cervical lordosis in extension, attention should be paid to residual postoperative neck pain.

Introduction Advanced glycation end-products (AGEs) have the potential to serve as biomarkers of aging and metabolic diseases; however, how their expression relates to clinical symptoms is not well defined. In this study, we sought to determine whether the accumulation of pentosidine, one type of AGE, at the peripheral nerve is associated with cutaneous pain or hypersensitivity caused by ovariectomy (OVX). Methods We assigned 12-week-old female Sprague Dawley rats into either the OVX group (n = 6) or the sham group (n = 6). Cutaneous hindpaw sensitivity to mechanical stimuli was measured with von Frey filaments, using Chaplan's adapted method, and the 50% withdrawal threshold was calculated. Then, the accumulation of pentosidine, which represents AGEs, was measured in sciatic nerve fibers after staining with an anti-pentosidine antibody. Results OVX rats showed significantly increased plantar hypersensitivity to mechanical stimuli compared to sham rats 8 weeks after OVX (P = 0.017). Pentosidine-positive sciatic nerves were detected at a higher rate in OVX rats than in sham rats (P = 0.035). The pentosidine positivity rate in sciatic nerve fibers showed a negative correlation with withdrawal threshold (P < 0.001). Conclusions This study showed that higher levels of pentosidine in sciatic nerve fibers are associated with higher plantar hypersensitivity. Accumulation of pentosidine at the sciatic nerve, caused by OVX, may result in cutaneous hindpaw hypersensitivity.

STUDY DESIGN: A retrospective analysis of prospectively collected data. OBJECTIVE: This study aimed to create a prognostic model for surgical outcomes in patients with cervical ossification of the posterior longitudinal ligament (OPLL) using machine learning (ML). SUMMARY OF BACKGROUND DATA: Determining surgical outcomes helps surgeons provide prognostic information to patients and manage their expectations. ML is a mathematical model that finds patterns from a large sample of data and makes predictions outperforming traditional statistical methods. METHODS: Of 478 patients, 397 and 370 patients had complete follow-up information at 1 and 2 years, respectively, and were included in the analysis. A minimal clinically important difference (MCID) was defined as an acquired Japanese Orthopedic Association (JOA) score of ≥2.5 points, after which a ML model that predicts whether MCID can be achieved 1 and 2 years after surgery was created. Patient background, clinical symptoms, and imaging findings were used as variables for analysis. The ML model was created using LightGBM, XGBoost, random forest, and logistic regression, after which the accuracy and area under the receiver-operating characteristic curve (AUC) were calculated. RESULTS: The mean JOA score was 10.3 preoperatively, 13.4 at 1 year after surgery, and 13.5 at 2 years after surgery. XGBoost showed the highest AUC (0.72) and high accuracy (67.8) for predicting MCID at 1 year, whereas random forest had the highest AUC (0.75) and accuracy (69.6) for predicting MCID at 2 years. Among the included features, total preoperative JOA score, duration of symptoms, body weight, sensory function of the lower extremity sub-score of the JOA, and age were identified as having the most significance in most of ML models. CONCLUSION: Constructing a prognostic ML model for surgical outcomes in patients with OPLL is feasible, suggesting the potential application of ML for predictive models of spinal surgery.Level of Evidence: 4.

STUDY DESIGN: Retrospective study of magnetic resonance imaging (MRI). OBJECTIVES: To assess the ability of a convolutional neural network (CNN) model to differentiate osteoporotic vertebral fractures (OVFs) and malignant vertebral compression fractures (MVFs) using short-TI inversion recovery (STIR) and T1-weighted images (T1WI) and to compare it to the performance of three spine surgeons. SUMMARY OF BACKGROUND DATA: Differentiating between OVFs and MVFs is crucial for appropriate clinical staging and treatment planning. However, an accurate diagnosis is sometimes difficult. Recently, CNN modeling-an artificial intelligence technique-has gained popularity in the radiology field. METHODS: We enrolled 50 patients with OVFs and 47 patients with MVFs who underwent thoracolumbar MRI. Sagittal STIR images and sagittal T1WI were used to train and validate the CNN models. To assess the performance of the CNN, the receiver operating characteristic (ROC) curve was plotted and the area under the curve (AUC) was calculated. We also compared the accuracy, sensitivity, and specificity of the diagnosis made by the CNN and three spine surgeons. RESULTS: The AUC of ROC curves of the CNN based on STIR images and T1WI were 0.967 and 0.984, respectively. The CNN model based on STIR images showed a performance of 93.8% accuracy, 92.5% sensitivity, and 94.9% specificity. On the other hand, the CNN model based on T1WI showed a performance of 96.4% accuracy, 98.1% sensitivity, and 94.9% specificity. The accuracy and specificity of the CNN using both STIR and T1WI were statistically equal to or better than that of three spine surgeons. There were no significant differences in sensitivity based on both STIR images and T1WI between the CNN and spine surgeons. CONCLUSIONS: We successfully differentiated OVFs and MVFs based on MRI with high accuracy using the CNN model, which was statistically equal or superior to that of the spine surgeons.Level of Evidence: 4.

Background: Mayfield skull clamps are widely used and indispensable in current neurosurgery. Complications such as skull fractures or intracranial hematoma from using a Mayfield skull clamp have largely been reported in the pediatric population, are likely related to the relative thinness of the skull, such as in patients with hydrocephalus, and are extremely rare in adults. Here, we report a case of skull fracture and epidural hematoma caused by a Mayfield skull clamp used for posterior decompression surgery in an adult patient with chronic hemodialysis. Case presentation: A 67-year-old Asian male patient with a history of dialysis-dependent chronic renal failure over 36 years suffered from severe cervical myelopathy. Neurological examination and radiographic images revealed cervical spondylotic myelopathy due to dialysis-related spondyloarthropathy. Laminoplasty was planned on patient consent. A Mayfield skull clamp was applied with the patient supine. Torque was applied to the screws with gentle care, but there was no resistance and it was not easy to reach the standard 60 lb (267 N) to 80 lb (356 N). Because a skull fracture was suspected, we canceled the surgery. Emergency head computed tomography showed depressed skull fractures underlying the single-pin sites with an associated epidural hematoma. The fractures and epidural hematoma were treated conservatively, and spontaneous resolution of the hematoma was confirmed. Cervical laminoplasty was performed successfully using a mask-type head holder on the subsequent day. Conclusions: As a precaution for fractures and epidural hematoma in neurosurgical patients with bone fragility or a thin skull, use of a mask-type fixing device or halo ring is recommended.