Multimodal Deep Learning-based Radiomics Approach for Predicting Surgical Outcomes in Patients with Cervical Ossification of the Posterior Longitudinal Ligament.

STUDY DESIGN: A retrospective analysis. OBJECTIVE: This research sought to develop a predictive model for surgical outcomes in patients with cervical ossification of the posterior longitudinal ligament (OPLL) using deep learning and machine learning (ML) techniques. SUMMARY OF BACKGROUND DATA: Determining surgical outcomes assists surgeons in communicating prognosis to patients and setting their expectations. Deep learning and ML are computational models that identify patterns from large datasets and make predictions. METHODS: Of the 482 patients, 288 patients were included in the analysis. A minimal clinically important difference (MCID) was defined as gain in Japanese Orthopaedic Association (JOA) score of 2.5 points or more. The predictive model for MCID achievement at 1 year post-surgery was constructed using patient background, clinical symptoms, and preoperative imaging features (x-ray, CT, MRI) analyzed via LightGBM and deep learning with RadImagenet. RESULTS: The median preoperative JOA score was 11.0 (IQR: 9.0-12.0), which significantly improved to 14.0 (IQR: 12.0-15.0) at 1 year after surgery (P < 0.001, Wilcoxon signed-rank test). The average improvement rate of the JOA score was 44.7%, and 60.1% of patients achieved the MCID. Our model exhibited an area under the receiver operating characteristic curve of 0.81 and the accuracy of 71.9% in predicting MCID at 1 year. Preoperative JOA score and certain preoperative imaging features were identified as the most significant factors in the predictive models. CONCLUSION: A predictive ML and deep learning model for surgical outcomes in OPLL patients is feasible, suggesting promising applications in spinal surgery. LEVEL OF EVIDENCE: 4.

Emergency Patient Triage Improvement through a Retrieval-Augmented Generation Enhanced Large-Scale Language Model.

OBJECTIVES: Emergency medical triage is crucial for prioritizing patient care in emergency situations, yet its effectiveness can vary significantly based on the experience and training of the personnel involved. This study aims to evaluate the efficacy of integrating Retrieval Augmented Generation (RAG) with Large Language Models (LLMs), specifically OpenAI's GPT models, to standardize triage procedures and reduce variability in emergency care. METHODS: We created 100 simulated triage scenarios based on modified cases from the Japanese National Examination for Emergency Medical Technicians. These scenarios were processed by the RAG-enhanced LLMs, and the models were given patient vital signs, symptoms, and observations from emergency medical services (EMS) teams as inputs. The primary outcome was the accuracy of triage classifications, which was used to compare the performance of the RAG-enhanced LLMs with that of emergency medical technicians and emergency physicians. Secondary outcomes included the rates of under-triage and over-triage. RESULTS: The Generative Pre-trained Transformer 3.5 (GPT-3.5) with RAG model achieved a correct triage rate of 70%, significantly outperforming Emergency Medical Technicians (EMTs) with 35% and 38% correct rates, and emergency physicians with 50% and 47% correct rates (p < 0.05). Additionally, this model demonstrated a substantial reduction in under-triage rates to 8%, compared with 33% for GPT-3.5 without RAG, and 39% for GPT-4 without RAG. CONCLUSIONS: The integration of RAG with LLMs shows promise in improving the accuracy and consistency of medical assessments in emergency settings. Further validation in diverse medical settings with broader datasets is necessary to confirm the effectiveness and adaptability of these technologies in live environments.

Conversion of T2-Weighted Magnetic Resonance Images of Cervical Spine Trauma to Short T1 Inversion Recovery (STIR) Images by Generative Adversarial Network.

INTRODUCTION: The short T1 inversion recovery (STIR) sequence is advantageous for visualizing ligamentous injuries, but the STIR sequence may be missing in some cases. The purpose of this study was to generate synthetic STIR images from MRI T2-weighted images (T2WI) of patients with cervical spine trauma using a generative adversarial network (GAN).  Methods: A total of 969 pairs of T2WI and STIR images were extracted from 79 patients with cervical spine trauma. The synthetic model was trained 100 times, and the performance of the model was evaluated with five-fold cross-validation.  Results: As for quantitative validation, the structural similarity score was 0.519±0.1 and the peak signal-to-noise ratio score was 19.37±1.9 dB. As for qualitative validation, the incorporation of synthetic STIR images generated by a GAN alongside T2WI substantially enhances sensitivity in the detection of interspinous ligament injuries, outperforming assessments reliant solely on T2WI. CONCLUSION: The GAN model can generate synthetic STIRs from T2 images of cervical spine trauma using image-to-image conversion techniques. The use of a combination of synthetic STIR images generated by a GAN and T2WI improves sensitivity in detecting interspinous ligament injuries compared to assessments that use only T2WI.

A Novel Evaluation for Vertebral Artery Course Using 3D Magnetic Resonance Imaging with Computed Tomography -like Bone Contrast and Magnetic Resonance Angiography: A Proof of Concept Study.

OBJECTIVE: Vertebral artery (VA) injury poses a significant risk in cervical spine surgery, necessitating accurate preoperative assessment. This study aims to introduce and validate a novel approach that combines the Fast field echo that resembles a computed tomography using restricted echo spacing (FRACTURE) sequence with Time of Flight (TOF) Magnetic Resonance Angiography (MRA) for comprehensive evaluation of VA courses in the cervical spine. MATERIALS AND METHODS: A total of eight healthy volunteers and two patients participated in this study. The FRACTURE sequence provided high-resolution bone images of the cervical spine, while TOF MRA offered non-invasive vascular imaging. Fusion images were created by merging FRACTURE and MRA modalities to simultaneously visualize cervical spine structures and VA courses. Board-certified orthopedic spine surgeons independently evaluated images to assess the visibility of anatomical characteristics of the VA course by Likert-scale. RESULTS: The FRACTURE-MRA fusion images effectively depicted the extraosseous course of the VA at the craniovertebral junction, the intraosseous course of the VA at the craniovertebral junction, the VA entrance level to the transverse foramen, and the side-to-side asymmetry of bilateral VAs. Additionally, clinical cases demonstrated the utility of the proposed technique in identifying anomalies and guiding surgical interventions. CONCLUSIONS: The integration of the FRACTURE sequence and TOF MRA presents a promising methodology for the precise evaluation of VA courses in the cervical spine. This approach improves preoperative planning for cervical spine surgery with detailed anatomy and is a valuable alternative to conventional methods without contrast agents.

Bone union-promoting effect of romosozumab in an ovariectomized rat posterolateral lumbar fusion model.

Spinal fixation surgery has been increasingly performed in patients with osteoporosis. Romosozumab, a drug that was introduced in Japan recently, is known to possibly promote bone healing. However, few studies have reported the therapeutic effects of romosozumab in clinical practice in Japan. Therefore, here, we investigated the effects of romosozumab dosage on bone fusion promotion using an ovariectomized rat spinal fusion model. Eight-week-old female Sprague-Dawley rats were matched by body weight and divided into three groups: 1.0 romosozumab (R) group (Evenity®, 25 mg/kg), 1/10R group (Evenity®, 2.5 mg/kg), and control (C) group (saline). Subcutaneous injections were administered twice a week for 8 weeks postoperatively. Computed tomography scans were performed every 2 weeks from the time of surgery till 8 weeks postoperatively. The mean fusion rates in terms of volume were significantly higher in the R groups [1/10R, 1.0R] than in the C group from 4 weeks postoperatively. The rate of increase was significantly higher in the 1.0R group from 4 weeks postoperatively and in the 1/10R group from 6 weeks postoperatively, than in the C group. The proportion of trabecular bone area was approximately 1.5 times higher in the R groups than in the C group. No significant differences were observed between the R groups. Our results suggest that romosozumab stimulates bone growth at the graft site, and similar effects were achieved at 1/10 of the standard dosage.

Impact of malnutrition on mortality and neurological recovery of older patients with spinal cord injury.

This retrospective cohort study established malnutrition's impact on mortality and neurological recovery of older patients with cervical spinal cord injury (SCI). It included patients aged ≥ 65 years with traumatic cervical SCI treated conservatively or surgically. The Geriatric Nutritional Risk Index was calculated to assess nutritional-related risk. Overall, 789 patients (mean follow-up: 20.1 months) were examined and 47 had major nutritional-related risks on admission. One-year mortality rate, median survival time, neurological recovery, and activities of daily living (ADL) at 1 year post-injury were compared between patients with major nutrition-related risk and matched controls selected using 1:2 propensity score matching to adjust for age, pre-traumatic neurological impairment, and activity. In the Kaplan-Meier analysis, the median survival times were 44.9 and 76.5 months for patients with major nutrition-related risk and matched controls, respectively (p = 0.015). Matched controls had more individuals with a neurological improvement of American Spinal Injury Association Impairment Scale ≥ 1 grade (p = 0.039) and independence in ADL at 1 year post-injury than patients with major nutrition-related risk (p < 0.05). In conclusion, 6% of older patients with cervical SCI had major nutrition-related risks; they showed a significantly higher 1 year mortality rate, shorter survival time, poorer neurological improvement, and lower ADL at 1 year post-injury than matched controls.

Neurological recovery rate and predictive factors of incomplete AIS grade C spinal cord injury in the older aged population.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To define the prognosis and predictive factors for neurological improvement in older patients with incomplete spinal cord injury (SCI) of American Spinal Injury Association Impairment Scale grade C (AIS-C). SETTINGS: Multi-institutions in Japan. METHODS: We included patients aged ≥65 years with traumatic SCI of AIS-C who were treated conservatively or surgically with >3 follow-up months. To identify factors related to neurological improvement, patients were divided into three groups according to their neurological status at the final follow-up, with univariate among-group comparisons of demographics, radiographic, and therapeutic factors. Significant variables were included in the multivariate logistic regression analysis. RESULTS: Overall, 296 older patients with SCI of AIS-C on admission were identified (average age: 75.2 years, average follow-up: 18.7 months). Among them, 190 (64.2%) patients improved to AIS-D and 21 (7.1%) patients improved to AIS-E at final follow-up. There were significant among-group differences in age (p = 0.026), body mass index (p = 0.007), status of pre-traumatic activities of daily living (ADL) (p = 0.037), and serum albumin concentrations (p = 0.011). Logistic regression analysis showed no significant differences in variables in the stratified group of patients who improved to AIS-D. Meanwhile, serum albumin was a significant variable in patients who improved to AIS-E (p = 0.026; OR: 6.20, pre-traumatic ADL was omitted due to data skewness). CONCLUSIONS: Most older patients with incomplete AIS-C SCI demonstrated at least 1 grade of neurological improvement. However, <10% of patients achieved complete recovery. Key predictors of complete recovery were high serum albumin levels on admission and independent pre-traumatic ADL. SPONSORSHIP: No funding was received for this study.

Machine Learning and Deep Learning in Spinal Injury: A Narrative Review of Algorithms in Diagnosis and Prognosis.

Spinal injuries, including cervical and thoracolumbar fractures, continue to be a major public health concern. Recent advancements in machine learning and deep learning technologies offer exciting prospects for improving both diagnostic and prognostic approaches in spinal injury care. This narrative review systematically explores the practical utility of these computational methods, with a focus on their application in imaging techniques such as computed tomography (CT) and magnetic resonance imaging (MRI), as well as in structured clinical data. Of the 39 studies included, 34 were focused on diagnostic applications, chiefly using deep learning to carry out tasks like vertebral fracture identification, differentiation between benign and malignant fractures, and AO fracture classification. The remaining five were prognostic, using machine learning to analyze parameters for predicting outcomes such as vertebral collapse and future fracture risk. This review highlights the potential benefit of machine learning and deep learning in spinal injury care, especially their roles in enhancing diagnostic capabilities, detailed fracture characterization, risk assessments, and individualized treatment planning.

Posterior Decompression and Fusion for Cervical Spondylodiscitis due to Osteoradionecrosis after Head-and-Neck Cancer Radiotherapy: Two Case Reports.

Introduction: Cervical spondylodiscitis due to osteoradionecrosis (ORN) after head-and-neck cancer radiotherapy is a severe complication. However, there are few reports on the surgical treatment of this condition. Case Report: We report two cases of cervical spondylodiscitis due to ORN, which were successfully treated with posterior decompression and fusion. The first case was in a 73-year-old male patient with spondylodiscitis at C3-C5, due to ORN. A posterior fusion of the spine (C2-T1) was performed, and a biopsy was conducted at a site separate from the incision for fusion. The second case was in a 76-year-old female patient with spondylodiscitis due to C4-C7 ORN. Cervical posterior decompression and fusion (C2-Th2) were performed, and decompression (C5-6) was conducted through an incision separate from that for the fusion.An anterior approach was avoided in both cases because of radiation-induced tissue changes. For these two patients with cervical spondylodiscitis due to ORN, surgery resulted in an improvement of infection and neurological deficits by posterior spinal fusion, isolation from decompression or biopsy of the infected area, and antibiotic treatment. Conclusion: Posterior decompression and fusion are effective for spondylodiscitis in the cervical spine after head-and-neck radiotherapy, treating both infection and neurological deficits. Spinal fusion that avoids the level of the infected vertebral body and decompression from separate skin incision sites may prevent the spread of infection. An anterior approach should be avoided because the risk of esophageal perforation and posterior pharyngeal wall defects is high.

Early Versus Delayed Surgery for Elderly Traumatic Cervical Spinal Injury: A Nationwide Multicenter Study in Japan.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVES: The effectiveness of early surgery for cervical spinal injury (CSI) has been demonstrated. However, whether early surgery improves outcomes in the elderly remains unclear. This study investigated whether early surgery for CSI in elderly affects complication rates and neurological outcomes. METHODS: This retrospective multicenter study included 462 patients. We included patients with traumatic acute cervical spinal cord injury aged ≥65 years who were treated surgically, whereas patients with American Spinal Injury Association (ASIA) Impairment Scale E, those with unknown operative procedures, and those waiting for surgery for >1 month were excluded. The minimum follow-up period was 6 months. Sixty-five patients (early group, 14.1%) underwent surgical treatment within 24 hours, whereas the remaining 397 patients (85.9%) underwent surgery on a standby basis (delayed group). The propensity score-matched cohorts of 63 cases were compared. RESULTS: Patients in the early group were significantly younger, had significantly more subaxial dislocations (and fractures), tetraplegia, significantly lower ASIA motor scores, and ambulatory abilities 6 months after injury. However, no significant differences in the rate of complications, ambulatory abilities, or ASIA Impairment Scale scores 6 months after injury were observed between the matched cohorts. At 6 months after injury, 61% of the patients in the early group (25% unsupported and 36% supported) and 53% of the patients in the delayed group (34% unsupported and 19% supported) were ambulatory. CONCLUSIONS: Early surgery is possible for CSI in elderly patients as the matched cohort reveals no significant difference in complication rates and neurological or ambulatory recovery between the early and delayed surgery groups.

Quantitative evaluation of the lumbar ligamentum flavum using MRI T2-mapping: Efficacy of its clinical application in patients with lumbar spinal stenosis.

OBEJECTIVE: To perform a magnetic resonance imaging T2-mapping of the ligamentum flavum in healthy individuals and patients with lumbar spinal stenosis scheduled for surgery and compare the T2 relaxation times. SUBJECTS AND METHODS: The T2 relaxation time of the ligamentum flavum was compared among 3 groups, healthy young individuals (H group (age< 50)), healthy middle-aged and older individuals (H group (age≥50)), and patients with lumbar spinal stenosis (L group). Additionally, the thickness of the ligament was measured in the axial image plane, and the occupied area ratio of each fiber was measured by staining the surgically obtained ligament, and each was correlated with the T2 relaxation time. We also evaluated the adhesion of the ligamentum flavum with the dura mater during the surgery. RESULTS: The T2 relaxation times were significantly prolonged in H group (age ≥50) and L group (P < 0.001) compared to H group (age<50). The relationship between collagen fiber and T2 relaxation times was significantly positive (r = 0.720, P < 0.001). Moreover, the relaxation times were significantly prolonged in those with adhesion of the ligamentum flavum with the dura mater (P < 0.05). The cut-off for the relaxation time was 50 ms (sensitivity: 62.50%, false positive rate: 10.8%). CONCLUSION: Healthy middle-aged and older individuals and patients with lumbar spinal stenosis and adhesion of the ligamentum flavum with the dura mater have prolonged T2 relaxation times. Hence, the adhesion between the ligamentum flavum and dura mater should be considered in cases with a relaxation time ≥50 ms.

Influence of the timing of surgery for cervical spinal cord injury without bone injury in the elderly: A retrospective multicenter study.

BACKGROUND: Although previous studies have demonstrated the advantages of early surgery for traumatic spinal cord injury (SCI), the appropriate surgical timing for cervical SCIs (CSCIs) without bone injury remains controversial. Here, we investigated the influence of relatively early surgery within 48 h of injury on the neurological recovery of elderly patients with CSCI and no bone injury. METHODS: In this retrospective multicenter study, we reviewed data from 159 consecutive patients aged ≥65 years with CSCI without bone injury who underwent surgery in participating centers between 2010 and 2020. Patients were followed up for at least 6 months following CSCI. We divided patients into relatively early (≤48 h after CSCI, n = 24) and late surgery (>48 h after CSCI, n = 135) groups, and baseline characteristics and neurological outcomes were compared between them. Multivariate analysis was performed to identify factors associated with neurological recovery. RESULTS: The relatively early surgery group demonstrated a lower prevalence of cardiac disease, poorer baseline American Spinal Injury Association (ASIA) impairment scale grade, and lower baseline ASIA motor score (AMS) than those of the late surgery group (P < 0.030, P < 0.001, and P < 0.001, respectively). Although the AMS was lower in the relatively early surgery group at 6 months following injury (P = 0.001), greater improvement in this score from baseline to 6-months post injury was observed (P = 0.010). Multiple linear regression analysis revealed that relatively early surgery did not affect postoperative improvement in AMS, rather, lower baseline AMS was associated with better AMS improvement (P < 0.001). Delirium (P = 0.006), pneumonia (P = 0.030), and diabetes mellitus (P = 0.039) negatively influenced postoperative improvement. CONCLUSIONS: Although further validation by future studies is required, relatively early surgery did not show a positive influence on neurological recovery after CSCI without bone injury in the elderly.

A nationwide multicenter study of the cost effectiveness of five leading drugs for pharmacological management of cervicobrachial symptoms.

BACKGROUND: Cervicobrachial pain frequently affects the quality of life (QOL) of the general public and has a significant economic impact on the health care systems of various countries. There are a number of treatment options for this disease, including widely-used drug therapy, but the effectiveness of each option is indeterminate, and there have been no published cost-effectiveness analysis studies so far. This prospective observational study aimed to examine the cost-effectiveness of drug treatment for cervicobrachial symptoms. METHODS: A 6-month medication regimen for each of five frequently-prescribed drugs for cervicobrachial symptoms was administered to 322 patients at 24 centers in Japan. Outcome measures, including of the EuroQol Group 5D, Short Form-8, and Visual Analog Scale (VAS), were investigated at baseline and every month thereafter. Incremental cost-effectiveness ratios (ICERs) of the drug cost to quality-adjusted life years (QALYs) were calculated. A stratified analysis of patient characteristics was also performed to identify baseline factors potentially affecting cost-effectiveness. RESULTS: The ICER of entire drug treatment for cervicobrachial symptoms was 7,491,640 yen. Compared with the reference willingness-to-pay, the ICER was assumed to not be cost-effective. A certain number of QALYs were gained during the first 3 months after the treatment intervention, but almost no QALYs were gained during the following 3 months. Stratified analysis showed that cost-effectiveness was extremely low for patients with high baseline VAS and high QOL. CONCLUSIONS: The available medications for cervicobrachial symptoms did not have excellent cost-effectiveness. Although a certain number of QALYs were gained during the first 3 months after medication, no QALYs were gained in the latter half of the study period, suggesting that it is not advisable to continue the medication needlessly. LEVEL OF EVIDENCE: II, prospective cohort study.

Hangman's Fracture in Geriatric Population: A Nationwide Multicenter Study in Japan.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVES: To investigate the treatments of the geriatric population with hangman's fractures using a multicenter database under the Japan Association of Spine Surgeons with Ambition (JASA). METHODS: The multicenter database included data from 1512 patients. We employed the Levine and Edwards classification for categorizing hangman's fractures. The study incorporated epidemiological data, including the prevalence of hangman's fractures, patient age, and follow-up duration. Bony fusion rates and length of hospitalization were recorded for Type I and Type II fractures, and the degree of neurological impairment was assessed. RESULTS: Hangman's fractures represented 62 cases, accounting for 7.4% of all cervical spine injuries. The patients had an average age of 76.6 ± 6.5 years, and the mean duration of follow-up was 21.5 ± 23.6 months. The study found that the bony fusion rate for hangman's fractures in the geriatric population was 88.9%. Surgical treatment was associated with a shorter hospitalization period for Type II fractures compared to conservative treatment. Thirteen cases of hangman's fractures in the geriatric population, accounting for 21%, were complicated by spinal cord injury. CONCLUSIONS: This is the largest study to date on hangman's fractures in geriatric population ≥65 years. Type I and Type II fractures, according to the Levine and Edwards classification, had a bony fusion rate of up to 90%. In patients with Type II fractures, surgical treatment led to a shorter initial hospital stay. Geriatric patients are at risk of spinal cord injury due to hangman's fractures.

Machine Learning Web Application for Predicting Functional Outcomes in Patients With Traumatic Spinal Cord Injury Following Inpatient Rehabilitation.

Accurately predicting functional outcomes in patients with spinal cord injury (SCI) helps clinicians set realistic functional recovery goals and improve the home environment after discharge. The present study aimed to develop and validate machine learning (ML) models to predict functional outcomes in patients with SCI and deploy the models within a web application. The study included data from the Japan Association of Rehabilitation Database from January 1, 1991, to December 31, 2015. Patients with SCI who were admitted to an SCI center or transferred to a participating post-acute rehabilitation hospital after receiving acute treatment were enrolled in this database. The primary outcome was functional ambulation at discharge from the rehabilitation hospital. The secondary outcome was the total motor Functional Independence Measure (FIM) score at discharge. We used binary classification models to predict whether functional ambulation was achieved, as well as regression models to predict total motor FIM scores at discharge. In the training dataset (70% random sample) using demographic characteristics and neurological and functional status as predictors, we built prediction performance matrices of multiple ML models and selected the best one for each outcome. We validated each model's predictive performance in the test dataset (the remaining 30%). Among the 4181 patients, 3827 were included in the prediction model for the total motor FIM score. The mean (standard deviation [SD]) age was 50.4 (18.7) years, and 3211 (83.9%) patients were male. There were 3122 patients included in the prediction model for functional ambulation. The CatBoost Classifier and regressor models showed the best performances in the training dataset. On the test dataset, the CatBoost Classifier had an area under the receiver operating characteristic curve of 0.8572 and an accuracy of 0.7769 for predicting functional ambulation. Likewise, the CatBoost Regressor performed well, with an R2 of 0.7859, a mean absolute error of 9.2957, and a root mean square error of 13.4846 for predicting the total motor FIM score. The final models were deployed in a web application to provide functional predictions. The application can be found at http://3.138.174.54:8501. In conclusion, our prediction models developed using ML successfully predicted functional outcomes in patients with SCI and were deployed in an open-access web application.

A Case of Partial Resection of an Intradural Extramedullary Tuberculoma Resulting in Improvement of Lower Limb Paralysis.

Intradural extramedullary tuberculomas are a rare manifestation of tuberculosis that can lead to neurological deficits. We present a case of a 26-year-old male from Myanmar with lower limb weakness and gait disturbance, who was diagnosed with tuberculosis and found to have an intradural extramedullary lesion in the thoracic spine. Prompt surgical intervention was performed to address the lesion located at the T2-4 level. Although complete resection was hindered by strong adhesion, significant improvement in lower limb paralysis was achieved. The elasticity loss of the dura mater posed a challenge in suturing, necessitating duraplasty with a synthetic graft material. This case report emphasizes the potential significance of surgical intervention, including partial excision, in the management of intradural extramedullary tuberculomas. Surgical treatment can play a crucial role in improving neurological outcomes in patients with intradural extramedullary tuberculomas, even in challenging scenarios.

Postoperative Recovery of Gait Function at Early Phase Is Delayed in Patients with Spinal Tumors with Impairment of the Joint Position Sense in the Big Toe: A Retrospective Cohort Study.

Introduction: We investigated the effect of preoperative joint position sense in the big toe on the postoperative recovery of gait function after spinal tumor surgery. Methods: Seventy-three patients with spinal tumors who underwent surgery at our hospital between 2014 and 2019 and could be followed for at least 6 months after surgery were included. The patients were divided into the cervical spinal (41 cases) and thoracic spinal (32 cases) groups according to the localization of the tumor. These groups were further classified into an Impaired group (cervical spinal, 34 cases; thoracic spinal, 19 cases) and an Intact group (cervical spinal, 7 cases; thoracic spinal, 13 cases) according to the presence or absence of preoperative joint position sense in the big toe. The amount of change in ambulatory function from the preoperative period to 3 and 6 months postoperatively was compared between the Impaired and Intact groups within each tumor localization category. Results: Impaired preoperative joint position sense in the big toe in patients undergoing thoracic spinal tumor surgery delayed the recovery of gait function in the early postoperative period. Conclusions: In patients with thoracic spinal tumor surgery, the absence of preoperative joint position sense in the big toe delayed the recovery of postoperative gait function.

The influence of COVID-19 epidemic on the number of orthopaedic surgeries in Japan.

BACKGROUND: There is limited data on the impact of COVID-19 epidemic on the number of orthopaedic surgeries in Japan. METHODS: We conducted a nationwide hospital survey asking for the monthly number of orthopaedic surgeries performed at each facility from January 2019 to June 2021. Those facilities that had performed at least 100 surgeries in 2019 were included for analyses. The facilities were further grouped by prefecture and by hospital characteristics. A brief health economic evaluation was also performed. Risk ratios were compared using univariate analyses with P < 0.05 considered statistically significant. RESULTS: Questionnaire was sent to 1988 hospitals with 1671 hospitals (84%) responding. The survey data indicated a total number of orthopaedic surgeries decreased in 2020 compared to 2019 (1,061,541 vs 1,119,955 P < 0.01), and also for the first six months of 2021 compared to the same period in 2019 (530,388 vs 550,378 P < 0.01). In 2020, over 50% of all facilities in nearly all of the prefectures saw a decline in surgical procedures. The risk of incurring more than a 25% decease in the number of surgeries was significantly higher in 2020 for class I designated medical institutions compared to those that were not designated for any types of infectious diseases among the institutions with a tertiary emergency medical center in 2020 (crude risk ratio 2.9: 95% CI 1.2-7.4, p = 0.02) and in 2021 (crude risk ratio 4.7: 95% CI 1 0.9-12.1, p < 0.01). The estimated total nationwide decrease of revenue were in the range of approximately ¥29.2 to ¥116.8 billion per year for orthopaedic surgeries alone. CONCLUSION: There was a statistically significant decrease in the number of orthopaedic surgeries in Japan. The magnitude of the decline varied by prefectures and hospital characteristics, with the greater impact imposed on medical institutions with higher classification functions. The estimated immediate health economic impact was sizable.

Combined effect of DBM, PRP, and bone marrow fluid on bone union in a rat posterolateral fusion model.

Platelet-rich plasma (PRP) promotes bone union through osteoinduction. We investigated whether adding demineralized bone matrix (DBM), derived naturally from biomaterial and with various growth factors, for osteoconductivity and bone marrow fluid for osteogenesis results in different bone unions. Eight-week-old male Sprague-Dawley rats were divided into four groups of five based on transplantation material: sham control (C group); DBM alone (D group); DBM + PRP (DP group); and DBM + PRP + bone marrow fluid (DPB group). After posterolateral fusion at L3-5, postoperative weekly CT imaging determined average number of bone union in facet joints (4 joints × 5 animals = 20 joints) and bone formation. Pathological evaluation and bone strength were assessed using 3-point bending two weeks postoperatively. Facet joint bone union at four weeks postoperatively was 4/20 (20%, DP group) and 8/20 (40%, DPB group) joints. Six weeks postoperatively, it was 7/20 (35%, D group), 12/20 (60%, DP group), and 16/20 (80%, DPB group). Eight weeks postoperatively, it was 13/20 (65%, D group), 17/20 (85%, DP group), and 20/20 (100%, DPB group), suggesting that DPB > DP > D > C. Bone formation and bone strength showed a similar DPB > DP > D > C group trend. Adding PRP and bone marrow fluid to DBM promotes bone union and strength.

Posterior Decompression and Fixation for Thoracic Spine Ossification: A 10-Year Follow-Up Study.

Ossification of the posterior longitudinal ligament of the thoracic spine (T-OPLL) causes symptoms including leg and back pain, and motor and sensory deficits. This study retrospectively reviewed 32 patients who initially underwent posterior decompression with instrumented fusion (PDF) for T-OPLL between 2001 and 2012, with 20 qualifying for the final analysis after applying exclusion criteria. Exclusions included unknown preoperative neurological findings, follow-up less than 10 years, or prior spinal surgeries at other levels. Outcomes were assessed using the Japanese Orthopedic Association (JOA) score, recovery rate, and kyphotic angle. The average preoperative JOA score of 3.6 improved to 7.4 at 1 year post-surgery and remained at 7.4 at 10 years, with a recovery rate of 52%. The kyphotic angle at T4-12 increased from 26 degrees preoperatively to 29 degrees postoperatively and to 37 degrees at 10 years. At the fused levels, the angle remained at 26 degrees immediately post-operation and increased to 32 degrees at 10 years. Forty percent of patients required additional surgery, primarily for conditions related to cervical OPLL, such as myelopathy, or lumbar OPLL, such as radiculopathy, or cauda equina syndrome. In conclusion, PDF effectively reduces T-OPLL symptoms over the long term, but the high rate of additional surgeries calls for careful patient follow-up.