Abdominal Arterial Translation in Lower Lumbar Spine Level Due to Positional Change: A Clinical Survey Using Intraoperative Computed Tomography.

Background: Abdominal vascular injury, a fatal complication of lumbar disc surgery, should concern spine surgeons. This study aimed to compare the position of the abdominal arteries in the supine and prone positions and the factors involved. Thirty patients who underwent lumbar surgery by posterior approach were included. Methods: All patients underwent computed tomography (CT) preoperatively in the supine position and intraoperatively in the prone position. In the CT axial image, at the L4, L4/5 disc, L5, and L5/S1 disc level, we measured the shortest distance between the abdominal arteries and the vertebral body (SDA: shortest distance to the aorta), and the amount of abdominal arterial translation, defined as "SDA on intraoperative CT" minus "SDA on preoperative CT". Additionally, the preoperative CT axial images were evaluated for the presence of aortic calcification. Results: No significant difference in SDA values based on patients' positions was observed at each level. In males, the supine position brought the abdominal artery significantly closer to the spine at the left side of the L5/S level (p = 0.037), and, in cases of calcification of the abdominal artery, the abdominal artery was found to be closer to the spine at the left side of the L4/5 level (p = 0.026). Conclusions: It is important to confirm preoperative images correctly to prevent great vessel injuries in lumbar spine surgery using a posterior approach.

Association between preoperative neutrophil-lymphocyte ratio, uric acid, and postoperative delirium in elderly patients undergoing degenerative spine surgery.

PURPOSE: There are few reports regarding the association between the neutrophil-lymphocyte ratio (NLR), uric acid, and the development of postoperative delirium (POD) in patients who are undergoing spine surgeries. We investigated the associations between the NLR, uric acid as a natural antioxidant, and POD in elderly patients undergoing degenerative spine surgery. PATIENTS AND METHODS: This was a single-center, observational, and retrospective study conducted in Japan. We enrolled 410 patients who underwent degenerative spine surgery. POD was diagnosed after the surgeries by psychiatrists, based on the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V). We performed a multivariable logistic regression analysis to clarify whether the NLR and uric acid values were associated with the development of POD in the patients. RESULTS: 129 of the 410 patients were excluded from the analysis. Of the 281 patients (137 females, 144 males), 32 patients (11.4%) were diagnosed with POD. The multivariable logistic regression analysis revealed that the preoperative uric acid level (adjusted odds ratio [aOR]: 0.67, 95% confidence interval [CI]: 0.49-0.90, p = 0.008) and age (aOR: 1.09, 95% CI: 1.02-1.16, p = 0.008) were significantly associated with POD. The preoperative NLR (aOR: 0.82, 95% CI: 0.60-1.13, p = 0.227) and antihyperuricemic medication (aOR: 0.97, 95% CI: 0.24-3.82, p = 0.959) were not significantly associated with POD. CONCLUSION: Our results demonstrated that in elderly patients undergoing degenerative spine surgery, the preoperative NLR was not significantly associated with POD, but a lower preoperative uric acid value was an independent risk factor for developing POD. Uric acid could have a neuroprotective impact on POD in patients with degenerative spine diseases.

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.

Impact of Preoperative Motor Status for the Positive Predictive Value of Transcranial Motor-Evoked Potentials Alerts in Thoracic Spine Surgery: A Prospective Multicenter Study by the Monitoring Committee of the Japanese Society for Spine Surgery and Related Research.

STUDY DESIGN: Prospective multicenter study. OBJECTIVE: To investigate the validity of transcranial motor-evoked potentials (Tc-MEP) in thoracic spine surgery and evaluate the impact of specific factors associated with positive predictive value (PPV). METHODS: One thousand hundred and fifty-six cases of thoracic spine surgeries were examined by comparing patient backgrounds, disease type, preoperative motor status, and Tc-MEP alert timing. Tc-MEP alerts were defined as an amplitude decrease of more than 70% from the baseline waveform. Factors were compared according to preoperative motor status and the result of Tc-MEP alerts. Factors that showed significant differences were identified by univariate and multivariate analysis. RESULTS: Overall sensitivity was 91.9% and specificity was 88.4%. The PPV was significantly higher in the preoperative motor deficits group than in the preoperative no-motor deficits group for both high-risk (60.3% vs 38.3%) and non-high-risk surgery groups (35.1% vs 12.8%). In multivariate logistic analysis, the significant factors associated with true positive were surgical maneuvers related to ossification of the posterior longitudinal ligament (odds ratio = 11.88; 95% CI: 3.17-44.55), resection of intradural intramedullary spinal cord tumor (odds ratio = 8.83; 95% CI: 2.89-27), preoperative motor deficit (odds ratio = 3.46; 95% CI: 1.64-7.3) and resection of intradural extramedullary spinal cord tumor (odds ratio = 3.0; 95% CI: 1.16-7.8). The significant factor associated with false positive was non-attributable alerts (odds ratio = .28; 95% CI: .09-.85). CONCLUSION: Surgeons are strongly encouraged to use Tc-MEP in patients with preoperative motor deficits, regardless of whether they are undergoing high-risk spine surgery or not. Knowledge of PPV characteristics will greatly assist in effective Tc-MEP enforcement and minimize neurological complications with appropriate interventions.

A delayed diagnostic case with complaints of severe lower back pain and sciatic nerve symptoms caused by osteoid osteoma of the sacrum: A case report.

BACKGROUND: Osteoid sacral osteomas are rare. Patients present with severe lower back pain and, rarely, sciatic nerve symptoms. CASE PRESENTATION: Herein, we report a patient with delayed diagnosis with complaints of severe lower back pain and sciatic nerve symptoms compressed by a sacral osteoid osteoma. En bloc tumor resection was performed using computed tomography (CT)-based navigation. Complete resolution of symptoms was achieved immediately after surgery. CONCLUSION: Even if a patient with an osteoid osteoma has sciatic symptoms, spinal surgeons should recognize a subgroup of patients with unexpected spinal or pelvic tumors compressing the nerve root.

Association of cervical atherosclerosis on Doppler ultrasonography and postoperative delirium in patients undergoing spinal surgery: a single-center, retrospective, observational study.

PURPOSE: This study aimed to evaluate the association between cervical atherosclerosis on Doppler ultrasonography and postoperative delirium (POD) in patients undergoing spinal surgery. METHODS: In this retrospective observational study using prospectively collected data, 295 consecutive patients aged > 50 years underwent spine surgery at a single institution between March 2015 and February 2021. Cervical atherosclerosis was defined as the intima-media thickness (IMT) of the common carotid artery (CCA) being ≥ 1.1 mm on pulsed-wave Doppler ultrasonography. Univariate and multivariate logistic regression analyses were performed with the prevalence of postoperative delirium as a dependent variable. Age, sex, body mass index, medical history, American Society of Anesthesiologists Physical Status (ASA-PS), CHADS2 score (an assessment score for stroke), instrumentation, duration of surgery, blood loss, and cervical arteriosclerosis were the independent variables. RESULTS: Twenty-seven patients of 295 (9.2%) developed delirium postoperatively. Forty-one (13.9%) of the 295 patients had cervical atherosclerosis. Their univariate analyses showed that age (P = 0.001), hypertension (P = 0.016), cancer (P = 0.046), antiplatelet agent use (P < 0.001), ASA-PS ≥ 3 (P < 0.001), CHADS2 score (P < 0.001), cervical atherosclerosis (P = 0.008), and right CCA-IMT (P = 0.007) were significantly associated with POD. However, multivariate logistic regression analyses showed older age (odds ratio [OR], 1.109; 95% confidence interval [CI] 1.035-1.188; P = 0.03) and antiplatelet agent use (OR, 3.472; 95% CI 1.221-9.870; P = 0.020) to be significantly associated with POD. CONCLUSIONS: There was a significant association between POD and the prevalence of cervical atherosclerosis using the univariate logistic regression analysis. Furthermore, multivariate logistic regression analyses showed that older age and antiplatelet agent use were independently associated with POD.

Preoperative Symptom Duration Influences Neurological Recovery and Patient-Reported Outcome Measures After Surgical Treatment of Cervical Ossification of the Posterior Longitudinal Ligament.

STUDY DESIGN: A prospective multicenter study. OBJECTIVE: To investigate the effect of preoperative symptom duration on neurological recovery for the treatment of cervical ossification of the posterior longitudinal ligament (OPLL). SUMMARY OF BACKGROUND DATA: The optimal timing to perform surgery in the setting of cervical OPLL remains unknown. It is important to know the influence of symptom duration on postoperative outcomes to facilitate discussions regarding the timing of surgery. PATIENTS AND METHODS: The study included 395 patients (291 men and 104 women; mean age, 63.7 ± 11.4 yr): 204 were treated with laminoplasty, 90 with posterior decompression and fusion, 85 with anterior decompression and fusion, and 16 with other procedures. The Japanese Orthopedic Association (JOA) score and patient-reported outcomes of the JOA Cervical Myelopathy Evaluation Questionnaire were used to assess clinical outcomes preoperatively and 2 years after surgery. Logistic regression analysis was used to identify factors associated with the achievement of minimum clinically important difference (MCID) after surgery. RESULTS: The recovery rate was significantly lower in the group with symptom duration of ≥5 years compared with the groups with durations of <0.5 years, 0.5 to 1 year, and 1 to 2 years. Improvement of JOA Cervical Myelopathy Evaluation Questionnaire in the upper extremity function score ( P < 0.001), lower extremity function ( P = 0.039), quality of life ( P = 0.053), and bladder function ( P = 0.034) were all decreased when the symptom duration exceeded 2 years. Duration of symptoms ( P = 0.001), age ( P < 0.001), and body mass index ( P < 0.001) were significantly associated with the achievement of MCID. The cutoff value we established for symptom duration was 23 months (area under the curve, 0.616; sensitivity, 67.4%; specificity, 53.5%). CONCLUSIONS: Symptom duration had a significant impact on neurological recovery and patient-reported outcome measures in this series of patients undergoing surgery for cervical OPLL. Patients with symptom duration exceeding 23 months may be at greater risk of failing to achieve MCID after surgery. LEVEL OF EVIDENCE: 3.

Factors Associated With Loss of Cervical Lordosis After Laminoplasty for Patients With Cervical Ossification of the Posterior Longitudinal Ligament: Data From a Prospective Multicenter Study.

STUDY DESIGN: A prospective multicenter study. OBJECTIVE: The objective of this study was to investigate the incidence of loss of cervical lordosis after laminoplasty for cervical ossification of the posterior longitudinal ligament (OPLL). We also sought to determine associated risk factors and the relationship with patient-reported outcomes. SUMMARY OF BACKGROUND DATA: Loss of cervical lordosis is a sequelae often observed after laminoplasty, which may adversely impact surgical outcomes. Cervical kyphosis, especially in OPLL, is associated with reoperation, but risk factors and relationship to postoperative outcomes remain understudied at this time. MATERIALS AND METHODS: This study was conducted by the Japanese Multicenter Research Organization for Ossification of the Spinal Ligament. We included 165 patients who underwent laminoplasty and completed Japanese Orthopaedic Association (JOA) score or Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaires (JOACMEQ), as well as Visual Analog Scales (VAS) for pain, with imaging. The participants were divided into two groups: those with loss of cervical lordosis of >10° or 20° after surgery and those without loss of cervical lordosis. A paired t test was applied to evaluate the association between changes in cervical spinal angles, range of motion, and cervical JOA and VAS scores before and at 2 years postoperatively. Mann-Whitney U test was used for JOACMEQ. RESULTS: Postoperative loss of cervical lordosis >10° and >20° was observed in 32 (19.4%) and 7 (4.2%), respectively. JOA, JOACMEQ, and VAS scores were not significantly different between those with, and without, loss of cervical lordosis. Preoperative small extension range of motion (eROM) was significantly associated with postoperative loss of cervical lordosis, and the cutoff values of eROM were 7.4° [area under the curve (AUC): 0.76] and 8.2° (AUC: 0.92) for loss of cervical lordosis >10° and >20°, respectively. A large occupation ratio of OPLL was also associated with loss of cervical lordosis, with a cutoff value of 39.9% (AUC: 0.94). Laminoplasty resulted in functional improvement in most patient-reported outcomes; however, neck pain and bladder function tended to become worse postoperatively in cases with postoperative loss of cervical lordosis >20°. CONCLUSIONS: JOA, JOACMEQ, and VAS scores were not significantly different between those with, and without, loss of cervical lordosis. Preoperative small eROM and large OPLL may represent factors associated with loss of cervical lordosis after laminoplasty in patients with OPLL.

Comparison of the Anti-Inflammatory Effects of Mouse Adipose- and Bone-Marrow-Derived Multilineage-Differentiating Stress-Enduring Cells in Acute-Phase Spinal Cord Injury.

Abstract Spinal cord injury (SCI) is a serious neurological disorder, with the consequent disabilities conferred by this disorder typically persisting for life. Multilineage-differentiating stress-enduring (Muse) cells are endogenous stem cells that can be collected from various tissues as well as from mesenchymal stem cells (MSCs); additionally, these Muse cells are currently being used in clinical trials. The anti-inflammatory effect of stem cell transplantation prevents secondary injuries of SCI; however, its effect on Muse cells remains unclear. In this study, we aimed to compare the anti-inflammatory effects of adipose (AD)- and bone marrow (BM)-Muse cells that were isolated from mice (6-week-old C57BL/6J) following intralesional administration during the acute phase of SCI. Flow cytometry was used to isolate Muse cells from AD and BM MSCs. The percentage of Muse cells was 3.9 and 2.7% for AD and BM MSCs, respectively. To examine cell viability, Muse cells were incubated under H2O2-induced oxidative stress conditions. Overall, AD-Muse cells exhibited higher viability than BM-Muse cells (p = 0.032). In enzyme-linked immunosorbent assay analysis, AD-Muse cells displayed greater secretion of brain-derived neurotrophic factor (BDNF; p = 0.008), vascular endothelial growth factor (p = 0.032), and hepatocyte growth factor (p = 0.016). DNA microarray analysis revealed higher expression of Bdnf, neurotrophin-3 (Ntf3), nerve growth factor (Ngf), pleiotrophin (Ptn), and midkine (Mdk) in AD-Muse cells than in BM-Muse cells. To assess their anti-inflammatory effects in vitro, Muse cells and macrophages were co-cultured, and the levels of cytokines (tumor necrosis factor [TNF] α and interleukin [IL] 10) were measured in the medium. Consequently, we found that TNFα levels were lower in AD-Muse cells than in BM-Muse cells (p = 0.009), and IL10 levels were higher in AD-Muse cells than in BM-Muse cells (p = 0.008). Further, we induced moderate injuries via contusion of the spinal cord at the T10 level; Muse cells were transplanted intralesionally 7 days post-SCI. The number of surviving cells, alongside the number of CD86+ (M1 inflammatory effect), and CD206+ (M2 anti-inflammatory effect) macrophages in the spinal cord were measured 7 days post-transplantation. The number of surviving AD-Muse cells was higher than the number of surviving BM-Muse cells (ratio of AD-Muse/BM-Muse = 2.5, p > 0.05). The M1/M2 ratio in the AD-Muse cell-group (0.37) was lower than that in the control (phosphate-buffered saline) group (3.60, p = 0.008). The lesion area in the AD-Muse cell group was smaller than that in the BM-non-Muse (p = 0.049) and control groups (p = 0.012). As AD-Muse cells conferred a higher cell survival and neurotrophic factor secretion ability in vitro, AD-Muse cells demonstrated reduced inflammation after SCI. Overall, intralesional AD-Muse cell therapy is a potential therapeutic candidate that is expected to exhibit anti-inflammatory effects following acute SCI.

Intraperitoneal Administration of Etizolam Improves Locomotor Function in Mice After Spinal Cord Injury.

Neuroinflammation occurs in the acute phase of spinal cord injury (SCI) and inhibits neural regeneration. In mouse models, etizolam (ETZ) is a strong anxiolytic with unclear effects on SCI. This study investigated the effects of short-term administration of ETZ on neuroinflammation and behavior in mice after SCI. We administrated an ETZ (0.5 mg/kg) daily intraperitoneal injection from the day after SCI for 7 days. Mice were randomly divided into three groups (sham group: only laminectomy, saline group, and ETZ group). Inflammatory cytokine concentrations in the injured spinal cord epicenter were measured using an enzyme-linked immunosorbent assay on day 7 after SCI to evaluate spinal cord inflammation in the acute phase. Behavior analysis was performed the day before surgery and on days 7, 14, 28, and 42 after surgery. The behavioral analysis included anxiety-like behavior using the open field test, locomotor function using the Basso Mouse Scale, and sensory function using the mechanical and heat test. Inflammatory cytokine concentrations were significantly lower in the ETZ group than in the saline group in the acute phase after spinal surgery. After SCI, anxiety-like behaviors and sensory functions were comparable between the ETZ and saline groups. ETZ administration reduced neuroinflammation in the spinal cord and improved locomotor function. Gamma-amino butyric acid type A receptor stimulants may be effective therapeutic agents for patients with SCI.

Role of Transcranial Motor Evoked Potential Monitoring During Traumatic Spinal Injury Surgery: A Prospective Multicenter Study of the Monitoring Committee of the Japanese Society for Spine Surgery and Related Research.

STUDY DESIGN: A prospective multicenter observational cohort study. OBJECTIVE: This study aimed to investigate the role of transcranial motor evoked potential (TcMEP) monitoring during traumatic spinal injury surgery, the timing of TcMEP alerts, and intervention strategies to avoid intraoperative neurological complications. SUMMARY OF BACKGROUND DATA: Intraoperative neuromonitoring, including TcMEP monitoring, is commonly used in high-risk spinal surgery to predict intraoperative spinal cord injury; however, little information is available on its use in traumatic spinal injury surgery. METHODS: The TcMEP monitoring data of 350 consecutive patients who underwent traumatic spinal injury surgery (mean age, 69.3 y) between 2017 and 2021 were prospectively reviewed. In this study, a TcMEP amplitude reduction ≥70% was established as a TcMEP alert. A rescue case was defined as a case with the recovery of TcMEP amplitudes after certain procedures and without postoperative neurological complications. RESULTS: Among the 350 patients who underwent traumatic spinal injury surgery (TcMEP derivation rate 94%), TcMEP monitoring revealed seven true-positive (TP) (2.0%), three rescues (0.9%; rescue rate 30%), 31 false-positive, one false-negative, and 287 true-negative cases, resulting in 88% sensitivity, 90% specificity, 18% positive predictive value, and 99% negative predictive value. The TP rate in patients with preoperative motor deficits was 2.9%, which was higher than that in patients without preoperative motor deficits (1.1%). The most common timing of TcMEP alerts was during decompression (40%). During decompression, suspension of surgery with intravenous steroid injection was ineffective (rescue rate, 0%), and additional decompression was effective. CONCLUSION: Given the low prevalence of neurological complications (2.3%) and the low positive predictive value (18.4%), single usage of TcMEP monitoring during traumatic spinal injury surgery is not recommended. Further efforts should be made to reduce FP alert rates through better interpretation of multimodal Intraoperative neuromonitorings and the incorporation of anesthesiology to improve the positive predictive value. LEVEL OF EVIDENCE: 3.

Comparison of Surgical Outcomes of Anterior and Posterior Fusion Surgeries for K-line (-) Cervical Ossification of the Posterior Longitudinal Ligament: A Prospective Multicenter Study.

STUDY DESIGN: A prospective multicenter study. OBJECTIVE: The objective of this study is to compare the surgical outcomes of anterior and posterior fusion surgeries in patients with K-line (-) cervical ossification of the posterior longitudinal ligament (OPLL). SUMMARY OF BACKGROUND DATA: Although laminoplasty is effective for patients with K-line (+) OPLL, fusion surgery is recommended for those with K-line (-) OPLL. However, whether the anterior or posterior approach is preferable for this pathology has not been effectively determined. MATERIALS AND METHODS: A total of 478 patients with myelopathy due to cervical OPLL from 28 institutions were prospectively registered from 2014 to 2017 and followed up for two years. Of the 478 patients, 45 and 46 with K-line (-) underwent anterior and posterior fusion surgeries, respectively. After adjusting for confounders in baseline characteristics using a propensity score-matched analysis, 54 patients in both the anterior and posterior groups (27 patients each) were evaluated. Clinical outcomes were assessed using the cervical Japanese Orthopaedic Association and the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire. RESULTS: Both approaches showed comparable neurological and functional recovery. The cervical range of motion was significantly restricted in the posterior group because of the large number of fused vertebrae compared with the anterior group. The incidence of surgical complications was comparable between the cohorts, but the posterior group demonstrated a higher frequency of segmental motor paralysis, whereas the anterior group more frequently reported postoperative dysphagia. CONCLUSIONS: Clinical improvement was comparable between anterior and posterior fusion surgeries for patients with K-line (-) OPLL. The ideal surgical approach should be informed based on the balance between the surgeon's technical preference and the risk of complications.

Current Trends in Intraoperative Spinal Cord Monitoring: A Survey Analysis among Japanese Expert Spine Surgeons.

Introduction: Although intraoperative spinal neuromonitoring (IONM) is recommended for spine surgeries, there are no guidelines regarding its use in Japan, and its usage is mainly based on the surgeon's preferences. Therefore, this study aimed to provide an overview of the current trends in IONM usage in Japan. Methods: In this web-based survey, expert spine surgeons belonging to the Japanese Society for Spine Surgery and Related Research were asked to respond to a questionnaire regarding IONM management. The questionnaire covered various aspects of IONM usage, including the preferred modality, operation of IONM, details regarding muscle-evoked potential after electrical stimulation of the brain (Br(E)-MsEP), and need for consistent use of IONM in major spine surgeries. Results: Responses were received from 134 of 186 expert spine surgeons (response rate, 72%). Of these, 124 respondents used IONM routinely. Medical staff rarely performed IONM without a medical doctor. Br(E)-MsEP was predominantly used for IONM. One-third of the respondents reported complications, such as bite injuries caused by Br(E)-MsEP. Interestingly, two-thirds of the respondents did not plan responses to alarm points. Intramedullary spinal cord tumor, scoliosis (idiopathic, congenital, or neuromuscular in pediatric), and thoracic ossification of the posterior longitudinal ligament were representative diseases that require IONM. Conclusions: IONM has become an essential tool in Japan, and Br(E)-MsEP is a predominant modality for IONM at present. Although we investigated spine surgeries for which consistent use of IONM is supported, a cost-benefit analysis may be required.

Residual Neuropathic Pain in Postoperative Patients With Cervical Ossification of Posterior Longitudinal Ligament.

STUDY DESIGN: A prospective multi-institutional observational study. OBJECTIVE: To investigate and identify risk factors for residual neuropathic pain after surgery in patients with cervical ossification of posterior longitudinal ligament (c-OPLL). SUMMARY OF BACKGROUND DATA: Patients with c-OPLL often require surgery for numbness and paralysis of the extremities; however, postoperative neuropathic pain can considerably deteriorate their quality of life. METHODS: Out of 479 patients identified from multicenter c-OPLL registries between 2014 and 2017, 292 patients who could be followed up for 2 years postoperatively were reviewed, after excluding patients with nervous system comorbidities. Demographic details; medical history; radiographic factors including the K-line, spinal canal occupancy rate of OPLL, cervical kyphosis angle, and presence of spinal cord myelomalacia; preoperative Japanese Orthopaedic Association (JOA) score; surgical procedure (fusion or decompression surgery); postoperative neurological deterioration; and the visual analogue scale for pain and numbness in the upper extremities (U/E) or trunk/lower extremities (L/E) at baseline and at 2 years postoperatively were assessed. Patients were grouped into residual and non-residual groups based on a postoperative visual analogue scale ≥40 mm. Risk factors for residual neuropathic pain were evaluated by multiple logistic regression analysis. RESULTS: The prevalence of U/E and L/E residual pain in postoperative c-OPLL patients was 51.7% and 40.4%, respectively. The U/E residual group had a poor preoperative JOA score and longer illness duration, and fusion surgery was more common in the residual group than in non-residual group. The L/E residual group was older with a poorer preoperative JOA score. On multivariate analysis, risk factors for U/E residual pain were long illness duration and poor preoperative JOA score, whereas those for L/E residual pain were age and poor preoperative JOA score. CONCLUSIONS: The risk factors for residual spinal neuropathic pain after c-OPLL surgery were age, long duration of illness, and poor preoperative JOA score. LEVEL OF EVIDENCE: IV.

Deep learning-based prediction model for postoperative complications of cervical posterior longitudinal ligament ossification.

PURPOSE: Postoperative complication prediction helps surgeons to inform and manage patient expectations. Deep learning, a model that finds patterns in large samples of data, outperform traditional statistical methods in making predictions. This study aimed to create a deep learning-based model (DLM) to predict postoperative complications in patients with cervical ossification of the posterior longitudinal ligament (OPLL). METHODS: This prospective multicenter study was conducted by the 28 institutions, and 478 patients were included in the analysis. Deep learning was used to create two predictive models of the overall postoperative complications and neurological complications, one of the major complications. These models were constructed by learning the patient's preoperative background, clinical symptoms, surgical procedures, and imaging findings. These logistic regression models were also created, and these accuracies were compared with those of the DLM. RESULTS: Overall complications were observed in 127 cases (26.6%). The accuracy of the DLM was 74.6 ± 3.7% for predicting the overall occurrence of complications, which was comparable to that of the logistic regression (74.1%). Neurological complications were observed in 48 cases (10.0%), and the accuracy of the DLM was 91.7 ± 3.5%, which was higher than that of the logistic regression (90.1%). CONCLUSION: A new algorithm using deep learning was able to predict complications after cervical OPLL surgery. This model was well calibrated, with prediction accuracy comparable to that of regression models. The accuracy remained high even for predicting only neurological complications, for which the case number is limited compared to conventional statistical methods.

Diseases and comorbidities associated with early-onset scoliosis: a retrospective multicenter analysis.

PURPOSE: To determine the frequencies of various diseases associated with all types of early-onset scoliosis, both idiopathic and nonidiopathic. METHODS: Retrospective collection of patients within a 21-year interval. Children under 10 years old presenting with scoliosis were included. Medical records were used to collect: identifier, date of birth, sex, diagnosis, follow-up, curve pattern, comorbidities, initial and final cobb angle. Different patient variables were tabulated with associated comorbidities for comparison. RESULTS: The cohort contained 469 patients, with 227(48.4%) males and 242(51.6%) females. Total comorbidities equaled 1051, where 190 were unique. Only 124(26.4%) patients had an isolated diagnosis of early-onset scoliosis, 79(16.8%) had a single comorbidity, and 266(56.7%) had multiple comorbidities. "Global developmental delay" was most commonly observed, 198(42.2%) times. The central nervous system was involved more often than other organ systems, seen in 394(54.4%) instances. Males had more comorbidities than females. Idiopathic patients had the least number of comorbidities, while neuromuscular patients had the most. Idiopathic types had more musculoskeletal conditions, while congenital types had more cardiovascular diseases. Curve sides did not affect distributions. Cases which progressed had more comorbidities, especially in the respiratory, digestive, and cardiovascular systems. Diseases that could affect either extremity or side, were more likely to be bilateral. CONCLUSIONS: Early-onset scoliosis patients may present with complex comorbidities in multiple organ systems. The most commonly observed disease entities were: global developmental delay, developmental dysplasia of the hip, and epilepsy. Clinicians should be aware of the common associations, in order to screen for and begin appropriate investigations, referrals, and treatments in affected cases. LEVEL OF EVIDENCE: Level III.

Association between Preoperative Urine Culture and Urinary Tract Infection after Spinal Surgery.

STUDY DESIGN: This is a retrospective study. PURPOSE: This study assessed risk factors accounting for urinary tract infections (UTIs) to determine whether preoperative asymptomatic UTI (aUTI) could be used to predict UTIs in patients after spinal surgery. OVERVIEW OF LITERATURE: UTI is a spinal surgery complication that increases the incidence of surgical site infections. However, the risk factors for UTIs after spinal surgery remain unclear. METHODS: This study included 509 (mean age, 54.5 years; 239 males and 270 females) patients who underwent posterior spine surgery at the department of the current study. First, clean catch urine was collected, after which a urine culture was performed for all patients before surgery. Preoperative detection of the aUTI (>105 colony-forming units/mL) rate was then determined. Subsequently, risk factors for postoperative UTI were evaluated using logistic regression analysis with the following as independent variables: age, sex, obesity, diabetes, spinal cord tumor, the preoperative Japanese Orthopedic Association (JOA) score, JOA-bladder function, preoperative urine culture positivity, aUTI, preoperative Escherichia coli detection, the postoperative catheter placement period, instrumentation, number of surgical levels, surgery duration, and blood loss. RESULTS: The preoperative aUTI and postoperative UTI incidences were 8.1% and 4.1%, respectively. Furthermore, multivariate logistic analysis showed that the risk factor for postoperative UTI was preoperative aUTI (odds ratio, 4.234; 95% confidence interval, 1.532-11.702; p=0.005). CONCLUSIONS: Preoperative aUTI is a risk factor for UTI in patients after spinal surgery.

Efficacy of D-Wave Monitoring Combined With the Transcranial Motor-Evoked Potentials in High-Risk Spinal Surgery: A Retrospective Multicenter Study of the Monitoring Committee of the Japanese Society for Spine Surgery and Related Research.

STUDY DESIGN: Retrospective multicenter cohort study. OBJECTIVES: We aimed to clarify the efficacy of multimodal intraoperative neuromonitoring (IONM), especially in transcranial electrical stimulation of motor-evoked potentials (TES-MEPs) with spinal cord-evoked potentials after transcranial stimulation of the brain (D-wave) in the detection of reversible spinal cord injury in high-risk spinal surgery. METHODS: We reviewed 1310 patients who underwent TES-MEPs during spinal surgery at 14 spine centers. We compared the monitoring results of TES-MEPs with D-wave vs TES-MEPs without D-wave in high-risk spinal surgery. RESULTS: There were 40 cases that used TES-MEPs with D-wave and 1270 cases that used TES-MEPs without D-wave. Before patients were matched, there were significant differences between groups in terms of sex and spinal disease category. Although there was no significant difference in the rescue rate between TES-MEPs with D-wave (2.0%) and TES-MEPs (2.5%), the false-positivity rate was significantly lower (0%) in the TES-MEPs-with-D-wave group. Using a one-to-one propensity score-matched analysis, 40 pairs of patients from the two groups were selected. Baseline characteristics did not significantly differ between the matched groups. In the score-matched analysis, one case (2.5%) in both groups was a case of rescue (P = 1), five (12.5%) cases in the TES-MEPs group were false positives, and there were no false positives in the TES-MEPs-with-D-wave group (P = .02). CONCLUSIONS: TES-MEPs with D-wave in high-risk spine surgeries did not affect rescue case rates. However, it helped reduce the false-positivity rate.

Efficacy of Transcranial Motor Evoked Potential Monitoring During Intra- and Extramedullary Spinal Cord Tumor Surgery: A Prospective Multicenter Study of the Monitoring Committee of the Japanese Society for Spine Surgery and Related Research.

STUDY DESIGN: Multicenter prospective study. OBJECTIVES: Although intramedullary spinal cord tumor (IMSCT) and extramedullary SCT (EMSCT) surgeries carry high risk of intraoperative motor deficits (MDs), the benefits of transcranial motor evoked potential (TcMEP) monitoring are well-accepted; however, comparisons have not yet been conducted. This study aimed to clarify the efficacy of TcMEP monitoring during IMSCT and EMSCT resection surgeries. METHODS: We prospectively reviewed TcMEP monitoring data of 81 consecutive IMSCT and 347 EMSCT patients. We compared the efficacy of interventions based on TcMEP alerts in the IMSCT and EMSCT groups. We defined our alert point as a TcMEP amplitude reduction of ≥70% from baseline. RESULTS: In the IMSCT group, TcMEP monitoring revealed 20 true-positive (25%), 8 rescue (10%; rescue rate 29%), 10 false-positive, a false-negative, and 41 true-negative patients, resulting in a sensitivity of 95% and a specificity of 80%. In the EMSCT group, TcMEP monitoring revealed 20 true-positive (6%), 24 rescue (7%; rescue rate 55%), 29 false-positive, 2 false-negative, and 263 true-negative patients, resulting in a sensitivity of 91% and specificity of 90%. The most common TcMEP alert timing was during tumor resection (96% vs. 91%), and suspension surgeries with or without intravenous steroid administration were performed as intervention techniques. CONCLUSIONS: Postoperative MD rates in IMSCT and EMSCT surgeries using TcMEP monitoring were 25% and 6%, and rescue rates were 29% and 55%. We believe that the usage of TcMEP monitoring and appropriate intervention techniques during SCT surgeries might have predicted and prevented the occurrence of intraoperative MDs.