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STUDY DESIGN.: A retrospective data analysis. OBJECTIVE.: To report a comprehensive assessment of preoperative prophylactic inferior vena cava (IVC) filter placement in spine surgery. SUMMARY OF BACKGROUND DATA.: Venous thromboembolism (VTE) is a serious complication after major spinal reconstructive surgery in adults. Specifically, pulmonary embolism (PE) can result in significant morbidity and mortality, and it has been reported in up to 13% of patients. Prophylactic IVC filter placement was initiated for all 'high-risk' spinal surgery patients after a pilot study demonstrated decreased VTE-related morbidity and mortality. METHODS.: After institutional review board approval, the medical records of all patients receiving an IVC filter at a single institution from 2000 to 2007 were reviewed. Age, sex, surgical approach, postoperative deep vein thrombosis (DVT), postoperative superficial thrombus, presence of pulmonary or paradoxical embolus, mortality, and IVC filter complications were all evaluated. Indications for IVC filter placement included history of DVT or PE, malignancy, hypercoagulability, prolonged immobilization, staged procedures of longer than 5 segment levels, combined anterior-posterior approaches, iliocaval manipulation during exposure, and anesthetic time of more than 8 hours. Descriptive statistics were used for the analysis of patient characteristics. Nonparametric frequency statistics (odds ratios [OR], [chi]) were used for analysis of main outcomes. RESULTS.: A total of 219 patients (150 women, 69 men) with a mean age of 58.8 (range, 17-86) years, were analyzed. There were 2 complications from IVC filter placement (66 Greenfield filters; 157 retrievable filters). The incidence of lower extremity DVT was 18.7% (41/219) in 36 patients. PE incidence was 3.7% (8/219 patients), and the paradoxical embolus rate was 0.5% (1 patient). Prophylactic IVC filter use reduced the odds of developing a pulmonary embolus (OR = 3.7, P < 0.05) compared with population controls. Patients receiving Greenfield filters had significantly higher VTE incidence than those receiving retrievable filters (OR = 2.8, P = 0.008). Anesthesia duration of more than 8 hours significantly increases VTE incidence (P = 0.029). No statistical significance (P < 0.05) was noted with combined anterior-posterior approach (118 patients) versus posterior-only approach (101 patients) and the incidence of DVT (24/118, 20.3% for former; 17/101, 16.8% for latter). There were a total of 14 deaths; none related to PE or paradoxical embolism during an 8-year period. Mean and median follow-up was 2.8 and 2.4 years, respectively, with 126 achieving 2 or more years of follow-up. CONCLUSION.: VTE-related morbidity and mortality have heightened the awareness within the spine community to the perioperative management of patients undergoing major spinal reconstruction. Prophylactic IVC filter placement significantly lowers VTE-related events, including PE development, than population controls. [ABSTRACT FROM AUTHOR]

Background and Objectives: Cervical disk arthroplasty (CDA) offers the advantage of motion preservation in the treatment of focal cervical pathology. At present, implant sizing is performed using subjective tactile feedback and imaging of trial cages. This study aims to construct interpretable machine learning (IML) models to accurately predict postoperative range of motion (ROM) and identify the optimal implant sizes that maximize ROM in patients undergoing CDA., Methods: Adult patients who underwent CDA for single-level disease from 2012 to 2020 were identified. Patient demographics, comorbidities, and outcomes were collected, including symptoms, examination findings, subsidence, and reoperation. Affected disk height, healthy rostral disk height, and implant height were collected at sequential time points. Linear regression and IML models, including bagged regression tree, bagged multivariate adaptive regression spline, and k-nearest neighbors, were used to predict ROM change. Model performance was assessed by calculating the root mean square error (RMSE) between predicted and actual changes in ROM in the validation cohort. Variable importance was assessed using RMSE loss. Area under the curve analyses were performed to identify the ideal implant size cutoffs in predicting improved ROM., Results: Forty-seven patients were included. The average RMSE between predicted and actual ROM was 7.6° (range: 5.8-10.1) in the k-nearest neighbors model, 7.8° (range: 6.5-10.0) in the bagged regression tree model, 7.8° (range: 6.2-10.0) in the bagged multivariate adaptive regression spline model, and 15.8° (range: 14.3-17.5°) in a linear regression model. In the highest-performing IML model, graft size was the most important predictor with RMSE loss of 6.2, followed by age (RMSE loss = 5.9) and preoperative caudal disk height (RMSE loss = 5.8). Implant size at 110% of the normal adjacent disk height was the optimal cutoff associated with improved ROM., Conclusion: IML models can reliably predict change in ROM after CDA within an average of 7.6 degrees of error. Implants sized comparably with the healthy adjacent disk may maximize ROM., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

Background: Preoperative anemia is known to be associated with perioperative complications in many surgical interventions. Here, we examine the effects of preoperative anemia on peri-operative complications and postoperative outcomes in pediatric patients undergoing spinal fusion., Methods: Retrospective analysis was conducted using the American College of Surgeons Pediatric National Surgery Quality Improvement Program Database between 2012-2020. Current Procedural Terminology codes 22800, 22,802, 22,804, 22,840, 22,842, 22,843, and 22,844 were included to represent all primary spinal fusion procedures performed. Patients without preoperative hematocrit (HCT) levels were excluded. Classification of anemia was determined via age- and sex-adjusted HCT levels. Patient demographics, preoperative comorbidities and risk factors, and 30-day postoperative outcomes were compared between the 2 cohorts using univariate analysis. Multivariate logistic regressions were performed to determine if anemia severity was independently associated with worse postoperative outcomes., Results: A total of 30,243 pediatric patients were included in this study, with 26,621 not having preoperative anemia and 3622 having preoperative anemia. Pediatric patients with anemia have increased length of stay (LOS) (6.7 ± 9.6 vs. 5 ± 6, P < 0.001), 30-day unplanned reoperation rate (4% vs. 2.8%, P < 0.001), and total blood transfused (489.9 ± 497.8 vs. 423.4 ± 452.6, P < 0.001). Multivariate analysis supported anemia and degree of its severity as an independent predictor of increased length of stay (LOS), reoperation rate, and postoperative complications., Conclusions: Preoperative anemia leads to worse outcomes in pediatric spinal fusion procedures. Utilizing HCT recordings could be factored into the equation for optimal patient selection and prevention of post-operative complications., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background : Pedicle subtraction osteotomy (PSO) is a powerful tool for sagittal plane correction in patients with rigid adult spinal deformity (ASD); however, it is associated with high intraoperative blood loss and the increased risk of durotomy. The objective of the present study was to identify intraoperative techniques and baseline patient factors capable of predicting intraoperative durotomy. Methods : A tri-institutional database was retrospectively queried for all patients who underwent PSO for ASD. Data on baseline comorbidities, surgical history, surgeon characteristics and intraoperative maneuvers were gathered. PSO aggressiveness was defined as conventional (Schwab 3 PSO) or an extended PSO (Schwab type 4). The primary outcome of the study was the occurrence of durotomy intraoperatively. Univariable analyses were performed with Mann-Whitney U tests, Chi-squared analyses, and Fisher's exact tests. Statistical significance was defined by p < 0.05. Results : One hundred and sixteen patients were identified (mean age 61.9 ± 12.6 yr; 44.8% male), of whom 51 (44.0%) experienced intraoperative durotomy. There were no significant differences in baseline comorbidities between those who did and did not experience durotomy, with the exception that baseline weight and body mass index were higher in patients who did not suffer durotomy. Prior surgery (OR 2.73; 95% CI [1.13, 6.58]; p = 0.03) and, more specifically, prior decompression at the PSO level (OR 4.23; 95% CI [1.92, 9.34]; p < 0.001) was predictive of durotomy. A comparison of surgeon training showed no statistically significant difference in durotomy rate between fellowship and non-fellowship trained surgeons, or between orthopedic surgeons and neurosurgeons. The PSO level, PSO aggressiveness, the presence of stenosis at the PSO level, nor the surgical instrument used predicted the odds of durotomy occurrence. Those experiencing durotomy had similar hospitalization durations, rates of reoperation and rates of nonroutine discharge. Conclusions : In this large multisite series, a history of prior decompression at the PSO level was associated with a four-fold increase in intraoperative durotomy risk. Notably the use of extended (versus) standard PSO, surgical technique, nor baseline patient characteristics predicted durotomy. Durotomies occurred in 44% of patients and may prolong operative times. Additional prospective investigations are merited.

Introduction: Radiotherapy is considered standard of care for adjuvant peri-operative treatment of many spinal tumors, including those with instrumented fusion. Unfortunately, radiation treatment has been linked to increased risk of pseudoarthrosis. Newer focused radiotherapy strategies with enhanced conformality could offer improved fusion rates for these patients, but this has not been confirmed., Methods: We performed a retrospective analysis of patients at three tertiary care academic institutions with primary and secondary spinal malignancies that underwent resection, instrumented fusion, and peri-operative radiotherapy. Two board certified neuro-radiologists used the Lenke fusion score to grade fusion status at 6 and 12-months after surgery. Secondary outcomes included clinical pseudoarthrosis, wound complications, the effect of radiation timing and radiobiological dose delivered, the use of photons versus protons, tumor type, tumor location, and use of autograft on fusion outcomes., Results: After review of 1252 spinal tumor patients, there were 60 patients with at least 6 months follow-up that were included in our analyses. Twenty-five of these patients received focused radiotherapy, 20 patients received conventional radiotherapy, and 15 patients were treated with protons. There was no significant difference between the groups for covariates such as smoking status, obesity, diabetes, intraoperative use of autograft, and use of peri-operative chemotherapy. There was a significantly higher rate of fusion for patients treated with focused radiotherapy compared to those treated with conventional radiotherapy at 6-months (64.0% versus 30.0%, Odds ratio: 4.15, p = 0.036) and 12-months (80.0% versus 42.1%, OR: 5.50, p = 0.022). There was a significantly higher rate of clinical pseudoarthrosis in the conventional radiotherapy cohort compared to patients in the focused radiotherapy cohort (19.1% versus 0%, p = 0.037). There was no difference in fusion outcomes for any of the secondary outcomes except for use of autograft. The use of intra-operative autograft was associated with an improved fusion at 12-months (66.7% versus 37.5%, OR: 3.33, p = 0.043)., Conclusion: Focused radiotherapy may be associated with an improved rate of fusion and clinical pseudoarthrosis when compared to conventional radiation delivery strategies in patients with spinal tumors. Use of autograft at the time of surgery may be associated with improved 12-month fusion rates. Further large-scale prospective and randomized controlled studies are needed to better stratify the effects of radiation delivery modality in these patients., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Metal hypersensitivity is a rare complication after spinal implant placement but is related to significant clinical challenges including implant failure and poor wound healing. The incidence is likely underreported secondary to challenges with diagnosis and retreatment options., Case Description: We present the case of a 41-year-old woman with metal hypersensitivity 6 years status post anterior lumbar interbody fusion after a previously failed revision procedure who presented with low back pain and abdominal pain with food intolerance. Diagnostics revealed presacral fluid collection, which was negative for infection. A detailed workup ruled out other possible differential diagnoses and confirmed hypersensitivity to nickel. Intraoperatively, the interbody was loose but difficult to remove secondary to scar tissue. Ultimately, it was successfully replaced with a polyetheretherketone interbody, which did not contain nickel., Conclusions: Metal hypersensitivity is likely an underreported complication in spine literature that is associated with poor outcomes. Further research to create evidence-based guidelines on diagnosis and retreatment options will facilitate diagnosis, reduce time to revision surgery, and ultimately decrease patient suffering., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Malignant large artery stroke is associated with high mortality of 70% to 80% with best medical management. Decompressive craniectomy (DC) is a highly effective tool in reducing mortality. Convincing evidence has accumulated from several randomized trials, in addition to multiple retrospective studies, that demonstrate not only survival benefit but also improved functional outcome with DC in appropriately selected patients. This article explores in detail the evidence for DC, nuances regarding patient selection, and applicability of DC for supratentorial intracerebral hemorrhage and posterior fossa ischemic and hemorrhagic stroke., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Study Design: Prospective, cross-sectional study., Objective: The aim of the study was to determine which radiographic parameters drive patient-reported outcomes (PROs) in primary presentation adult symptomatic lumbar scoliosis (ASLS)., Summary of Background Data: Previous literature suggests correlations between PROs and sagittal plane deformity (sagittal vertical axis [SVA], pelvic incidence-lumbar lordosis [PI-LL] mismatch, pelvic tilt [PT]). Prior work included revision and primary adult spinal deformity patients. The present study addresses only primary presentation ASLS., Methods: Prospective baseline data were analyzed on 286 patients enrolled in an NIH RO1 clinical trial by nine centers from 2010 to 2014., Inclusion Criteria: 40 to 80 years old, lumbar Cobb (LC) 30° or higher and Scoliosis Research Society-23 score 4.0 or less in Pain, Function or Self-Image domains, or Oswestry Disability Index (ODI) 20 or higher. Patients were primary presentation (no prior spinal deformity surgery) and had complete baseline data: standing coronal/sagittal 36" radiographs and PROs (ODI, Scoliosis Research Society-23, Short Form-12). Correlation coefficients were calculated to evaluate relations between radiographic parameters and PROs for the study population and a subset of patients with ODI 40 or higher. Analysis of variance was used to identify differences in PROs for radiographic modifier groups., Results: Mean age was 60.3 years. Mean spinopelvic parameters were: LL = -39.2°; SVA = 3.1 cm; sacral slope = 32.5°; PT = 23.9°; PI-LL mismatch = 16.8°. Only weak correlations (0.2-0.4) were identified between population sacral slope, SVA and SVA modifiers, and SRS function. SVA and SVA modifiers were weakly associated with ODI. Although there were more correlations in subset analysis of high-symptom patients, all were weak. Analysis of variance identified significant differences in ODI reported by SVA modifier groups., Conclusion: In primary presentation patients with ASLS and a subset of "high-symptom" patients (ODI ≥ 40), only weak associations between baseline PROs and radiographic parameters were identified. For this patient population, these results suggest regional radiographic parameters (LC, LL, PT, PI-LL mismatch) are not drivers of PROs and cannot be used to extrapolate effect on patient-perceived pathology., Level of Evidence: 2.

Objective: To evaluate spinal implant density and proximal junctional kyphosis (PJK) in adult spinal deformity (ASD)., Methods: Consecutive patients with ASD receiving ≥5 level fusions were retrospectively analyzed between 2007 and 2010., Inclusion Criteria: ASD, elective fusions, minimum 2-year follow-up., Exclusion Criteria: age <18 years, neuromuscular or congenital scoliosis, cervical or cervicothoracic fusions, nonelective conditions (infection, tumor, trauma). Instrumented fusions were classified by the Scoliosis Research Society-Schwab ASD classification. Statistical analysis consisted of descriptives (measures of central tendency, dispersion, frequencies), independent Student t tests, χ 2 , analysis of variance, and logistic regression to determine association of implant density [(number of screws + number of hooks)/surgical levels of fusion] and PJK. Mean and median follow-up was 2.8 and 2.7 years, respectively., Results: Eighty-three patients (17 male, 66 female) with a mean age of 59.7 years (standard deviation, 10.3) were analyzed. Mean body mass index (BMI) was 29.5 kg/m 2 (range, 18-56 kg/m 2 ) with mean preoperative Oswestry Disability Index of 48.67 (range, 6-86) and mean preoperative sagittal vertical axis of 8.42. The mean levels fused were 9.95 where 54 surgeries had interbody fusion. PJK prevalence was 21.7%, and pseudoarthrosis was 19.3%. Mean postoperative Oswestry Disability Index was 27.4 (range, 0-74). Independent Student t tests showed that PJK was not significant for age, gender, BMI, rod type, mean postoperative sagittal vertical axis, or Scoliosis Research Society-Schwab ASD classification; but iliac fixation approached significance (P = 0.077). Implant density and postoperative lumbar lordosis (LL) were predictors for PJK (P = 0.018 and 0.045, respectively). Controlling for age, BMI, and gender, postoperative LL (not implant density) continued to show significance in multivariate logistic regression model., Conclusions: PJK, although influenced by a multitude of factors, may be statistically related to implant density and LL., (Copyright © 2016. Published by Elsevier Inc.)

Objective: To report the cranial center of mass (CCOM) progression in surgically treated patients for adult spinal deformity (ASD). The C7 plumb line/sagittal vertical axis (SVA) has important relationships with patient-reported outcomes; however, this has not yet been defined for CCOM., Methods: Patients with consecutive ASD who were undergoing surgery greater than 5 levels of fusion between 2007 and 2012 and had radiographic, clinical, and outcomes data spanning ≥2 years were analyzed, retrospectively. Radiographic parameters were obtained preoperatively and at 6 weeks, 1 year, and 2 years postoperatively. Statistical analysis included descriptives (measures of central tendency, dispersion, frequencies), independent Student t tests, χ(2) square, Pearson correlation, and Kaplan-Meyer curve., Results: Fifty-eight patients (10 male, 48 female) with a mean age of 60.5 years (range, 27-81 years) were reviewed. The mean preoperative SVA was 7.40 cm (SD = 5.51; 37/58 [63.8%] malalignment), and mean CCOM was 10.0 cm (SD = 6.58; 47/58 [81%] malalignment). Six-week postoperative SVA and CCOM was -0.17 cm (SD = 3.3) and 2.5 cm (SD = 4.11), respectively. SVA malalignment was 12.7% and CCOM malalignment was 38.2% at 6 weeks postop. Six week (absolute), 6-week change, and patient number at 6 weeks who were CCOM malaligned was significant compared with SVA (P = 0.003, P < 0.001, P < 0.001, respectively). SRS appearance worsened as preoperative SVA and CCOM increased (P < 0.05), and 2-year SRS appearance and mental health was worsened as 2-year SVA and CCOM increased (P < 0.05). SVA malalignment was 8 and 10 at 1 and 2 years, respectively, and CCOM malalignment was 24 and 32, respectively. Kaplan-Meier curve demonstrates persistent malalignment of CCOM at 6 weeks if not corrected., Conclusion: CCOM alignment restoration is an important parameter in ASD, and malalignment is consistent over time., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Study Design: A retrospective review., Objective: The aim of this study was to establish clinically relevant readmission rates that permit accurate comparisons, improve risk-stratification, and direct efforts to minimize readmissions., Summary of Background Data: The 30-day hospital readmission rate is a quality of care measure that is now being used to compare hospitals in a publicly available manner., Methods: Records from 1187 consecutive spinal surgeries at Northwestern Memorial Hospital in 2010 were retrospectively reviewed and data were collected that described the patient, surgical procedure, hospital course, complications, and readmissions. The primary outcome of interest was readmission to the hospital within 30 days. Potential risk factors were examined for association with the outcome first via bivariate analysis, with significant predictors further examined by a multivariable model. Identified readmissions were independently reviewed by attending spinal neurosurgeons not involved with the cases to determine whether the readmissions were procedure related or procedure unrelated with respect to accepted criteria., Results: The overall readmission rate was 6.1%. Of these readmissions, 37.5% were deemed procedure related upon attending review, leading to a procedure-related readmission rate of 2.3%. Upon multivariate analysis, only 3 variables were found to be significant predictors of readmission: 2 or more patient comorbidities [odds ratio (OR) 3.72, 95% confidence interval (95% CI) 1.62-8.56], an admission to the ICU (OR 2.68, 95% CI 1.45-4.95), and each additional spinal level involved (OR 1.11, 95% CI 1.02-1.21)., Conclusions: Our study suggests that predictors for all-cause 30-day readmission following spinal procedures include number of spinal levels performed during the surgery, number of patient comorbidities present at the time of surgery, and whether the admission required an ICU stay. Future work should focus on developing best practices to modify medical risk factors and comorbidities that have the potential to decrease 30-day readmission rates., Level of Evidence: 3.

Objective: Venous thromboembolism (VTE) is an important complication after spine surgery with an incidence of 31%. To our knowledge, no study has reported a time-dependent examination of factors influencing VTE. We report factors influencing first and multiple VTE events and perform a time-dependent analysis., Methods: A retrospective analysis was performed of consecutive, "high-risk" patients receiving multilevel spinal fusion and an inferior vena cava (IVC) filter during the period 2000-2008. Descriptive statistics and frequencies were examined. Student t tests and logistic regression analysis identified confounders influencing development of acute VTE. Kaplan-Meier survival and Cox proportional hazard model evaluated time-dependent risk factors. Multivariate linear regression model analyzed multiple acute VTE events., Results: There were 218 patients (149 women and 69 men) with an average age of 59.2 years (range, 18-86 years) who had 252 hospitalizations with an average stay of 20.3 days (SD = 15.6). There were 72 VTE events, with mean time to VTE of 15 days (SD = 18.1). Logistic regression identified factors influencing development of acute VTE, including sex (P = 0.04, OR = 0.243), VTE history (P = 0.001, OR = 8.0), IVC filter type (P = 0.050, OR = 15.6), chemoprophylaxis (P = 0.013, OR = 0.82), and hospital stay (P < 0.001, OR = 0.16). Kaplan-Meier curve revealed VTE history increased the rate of VTE development (P = 0.003). Cox proportional hazard model demonstrated IVC filter type (P = 0.003, hazard ratio = 5.042) and VTE history (P = 0.001, hazard ratio = 4.187) were significant for first VTE events. Linear regression analysis identified factors influencing development of multiple VTE events during a hospitalization, including VTE history (P < 0.01), chemoprophylaxis (P = 0.003), IVC filter type (P = 0.015), and hospital stay (P < 0.001). Mean and median follow-up were 3.3 years and 2.8 years, respectively., Conclusions: Sex, VTE history, IVC filter type, chemoprophylaxis, and hospital stay influenced development of VTE. Time to VTE correlated with DVT history and IVC filter type, whereas VTE history and hospital stay influenced multiple VTE events., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Patients who undergo craniotomy for brain neoplasms have a high risk of developing venous thromboembolism (VTE), including deep vein thromboses (DVT) and pulmonary emboli (PE). The reasons for this correlation are not fully understood. This retrospective, single-center review aimed to determine the risk factors for VTE in patients who underwent neurosurgical resection of brain tumors at Northwestern University from 1999 to 2010. Our cohort included 1148 patients, 158 (13.7%) of whom were diagnosed with DVT and 38 (3.3%) of whom were diagnosed with PE. A variety of clinical factors were studied to determine predictors of VTE, including sex, ethnicity, medical co-morbidities, surgical positioning, length of hospital stay, tumor location, and tumor histology. Use of post-operative anticoagulants and hemorrhagic complications were also investigated. A prior history of VTE was found to be highly predictive of post-operative DVT (odds ratio [OR]=7.6, p=0.01), as was the patient's sex (OR=14.2, p<0.001), ethnicity (OR=0.5, p=0.04), post-operative intensive care unit days (OR=0.2, p=0.003), and tumor histology (OR=-0.16, p=0.01). Contrary to reports in the literature, the data collected did not indicate that the administration of post-operative medical prophylaxis for VTE was significant in preventing their formation (OR=-0.14, p=0.76). Hemorrhagic complications were low (2.2%) and resultant neurologic deficit was lower still (0.7%). The study indicates that patients with high-grade primary brain tumors and metastatic lesions should receive aggressive preventative measures in the post-operative period., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Introduction: Oligodendrogliomatosis is a rarely reported entity in literature associated with poor prognosis in terms of length and quality of life. In this paper, we describe oligodendrogliomatosis in a 15-year-old male who initially presented with altered mental status due to diabetic ketoacidosis., Clinical Presentation: He was refractory to temozolomide initially but demonstrated disease regression with radiotherapy (XRT). More recently, he has had disease recurrence, which was stabilized with temozolomide therapy for a period of time., Conclusion: Contrary to most reports in literature, our patient has had excellent quality of life since his initial diagnosis and continues to carry good prognosis. In addition to oligodendrogliomatosis, our patient also developed multiple intracranial cavernomas secondary to radiation therapy, which have remained stable and asymptomatic.

Patients with high-grade glioma are at elevated risk of venous thromboembolism (VTE). The relationship between VTE and survival in glioma patients remains unclear, as does the optimal protocol for chemoprophylaxis. The purpose of this study was to assessthe incidence of and risk factors associated with VTE in patients with high-grade glioma, and the correlation between VTE and survival in this population. Furthermore, we sought to define a protocol for perioperative DVT prophylaxis. This was a retrospective review of patients who underwent craniotomy for resection of high-grade glioma (WHO grade III or IV) at Northwestern University between 1999 and 2010. A total of 336 patients met inclusion criteria. 53 patients developed postoperative VTE (15.7 %). Median survival was 12.0 months and was not significantly different between VTE(+) and VTE(-) patients. Demographics and surgical factors were not significantly correlated with VTE development. Prior history of VTE was highly predictive of postoperative VTE (OR 7.1, p < .01), as was seizure (OR 2.4, p = .005). Increased duration of postoperative ICU stay was also a risk factor for VTE (p = .025). 25 patients in our study received prophylactic anticoagulation(pAC) with either heparin or enoxaparin. Early initiation of pAC was associated with decreased incidence of VTE (p = .042). There were no hemorrhagic complications in patients receiving pAC. VTE is a common complication in high-grade glioma patients. Early initiation of anticoagulation is safe and may decrease the risk of VTE. We recommend initiation of chemoprophylaxis on postoperative day 1 in patients without contraindication.

Study Design: Observational cohort study., Objective: To determine the accuracy of the Revised Cardiac Risk Index (RCRI) in predicting major adverse cardiac events in patients undergoing spine fusion surgery of 3 levels or more., Summary of Background Data: Preoperative cardiac testing is extensively guided by the RCRI, which was developed and validated in thoracic, abdominal, and orthopedic surgical patients. Because multilevel spine fusion surgery is often associated with major transfusion, we hypothesize that the RCRI may not accurately characterize the risk of cardiovascular morbidity in these patients., Methods: After institutional review board approval, perioperative data were collected from 547 patients who underwent 3 or more levels of spinal fusion with instrumentation. Postoperative cardiac morbidity was defined as any combination of the following: arrhythmia requiring medical treatment, myocardial infarction (either by electrocardiographic changes or troponin elevation), or the occurrence of demand ischemia. The surgical complexity was categorized as anterior surgery only, posterior cervical and/or thoracic fusion, posterior lumbar fusion, or any surgery that included transpedicular osteotomies. Logistic regression analysis was performed to determine RCRI performance., Results: The RCRI performed no better than chance (area under the curve = 0.54) in identifying the 49 patients (9%) who experienced cardiac morbidity., Conclusion: The RCRI did not predict cardiac morbidity in our patients undergoing major spine fusion surgery, despite being extensively validated in low-risk noncardiac surgical patients. Preoperative testing and optimization decisions, previously based on the RCRI, may need to be revised to include more frequent functional cardiac imaging and more aggressive implementation of pharmacologic modalities that may mitigate cardiac morbidity, similar to the preoperative evaluation for major vascular surgery., Level of Evidence: 3.

Renin-angiotensin system (RAS) inhibition by angiotensin-converting enzyme inhibitors (ACEI)/angiotensin receptor blockers (ARB) has been shown to reduce cardiovascular mortality and non-fatal myocardial infarction (MI) in high-risk surgical patients. However, their effect in spinal surgery has not been explored. Our objective was to determine the effect of RAS inhibitors on postoperative troponin elevation in spinal fusions, and to examine their correlation with hospital stay. We retrospectively analyzed 208 consecutive patients receiving spinal fusions ⩾5 levels between 2007-2010 with a mean follow-up of 1.7 years. Inclusion criteria were age ⩾18 years, elective fusions for kyphoscoliosis, and semi-elective fusions for tumor or infection. Exclusion criteria were trauma and follow-up <1 year. Descriptives, frequencies, and logistic and linear regression were used to analyze troponin elevation (⩾0.04 ng/mL), peak troponin level, and hospital stay. The results featured 208 patients with a mean body mass index (BMI) 28.5 kg/m(2) who underwent 345 spinal fusions. ACEI/ARB were withheld the day prior to surgery in 121 patients with 11 patients noteworthy for intra-operative electrocardiogram changes, 126 patients with troponin elevation, and 14 MI identified prior to discharge. Multivariate logistic regression identified BMI (p=0.04), estimated blood loss (p=0.015), and preoperative ACEI/ARB (p=0.015, odds ratio=2.7) as significant independent predictors for postoperative troponin elevation. Multivariate linear regression showed preoperative Oswestry Disability Index (p=0.002), unplanned return to operating room (p=0.007), pneumonia prior to hospital discharge (p<0.01), and preoperative ACEI/ARB to be associated with hospital stay. In patients with spinal fusions ⩾5 levels, ACEI/ARB are independently associated with postoperative troponin elevation and increased hospital stay., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Background: Obesity is a dominant public health concern and risk factor for disability, with few studies examining its impact in spinal surgery. Patients with a higher body mass index (BMI) have lower functional status, increased pain, and worse physical condition than those with ideal weight., Objective: To determine associations between BMI categories on adverse patient outcomes after long-segment spinal fusions., Methods: Consecutive, open, elective fusions (interbody and/or posterolateral arthrodesis) of more than 5 levels from 2007 to 2010 were retrospectively analyzed with follow-up of more than 1 year. Bivariate analyses examined outcome variables based on BMI categories. Linear regression analysis evaluated BMI, hospital stay, and complications at 1 and 2 years, controlling for confounders. Mean and median follow-up lengths were 2.1 and 2.0 years, respectively., Results: A total of 189 surgeries on 112 patients, with a mean age of 59.5 years and a mean BMI of 29.8 kg/m, were analyzed. Morbidly obese patients had longer hospitalizations, worse Oswestry Disability Index (ODI), and more complications at 1 and 2 years than ideal weight patients. Multivariate linear regression modeling revealed sex, cardiac medications, cerebrospinal fluid leak, and BMI category of ideal vs nonideal influenced hospitalization length. Multivariate analysis showed BMI greater than 30 kg/m, preoperative ODI, and pedicle subtraction osteotomy influenced all complications at 1 year. Mean complications at 2 years for the morbidly obese were 3 times more than those underweight and 8 times more than those with ideal weight. Controlling for age, sex, and length of stay, obese and morbidly obese patients had more complications at 2 years; morbidly obese patients had a worse 2-year ODI., Conclusion: BMI is an independent predictor of hospitalization length and all complications at 1 and 2 years in patients receiving long-segment fusions.

Arterial dissections of head and neck arteries were first identified pathologically in the 1950s, but not until the 1970s and the 1980s did they begin to be widely recognized as a clinical entity. Carotid and vertebral artery dissections account for only 2% of all ischemic strokes, but they account for approximately 20% of thromboembolic strokes in patients younger than 45 years. The cause of supra-aortic dissections can be either spontaneous or traumatic. This article addresses spontaneous cervical and cerebral artery dissections., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Study Design: Prospective radiographical analysis of cranial center of mass (CCOM), C2, and C7 plumb lines in young and elderly asymptomatic individuals., Objective: To establish a normal range for craniosagittal balance for both young and elderly asymptomatic individuals., Summary of Background Data: Global sagittal balance must account for the position of the head in relation to the spine and pelvis. The C7 plumb line defines thoracolumbar sagittal balance and has been shown to have significant impact on patient outcomes. However, the C7 plumb line fails to take into consideration the position of the head in relation to the pelvis., Methods: A total of 100 asymptomatic 20- to 40-year-old patients and 100 asymptomatic 60- to 80-year-old patients were enrolled. Standing plain radiographs of 14 × 36 in were obtained. CCOM, C2, and C7 plumb lines were drawn and measured from the superoposterior endplate of S1., Results: A total of 78 asymptomatic 20- to 40-year-old patients and 62 asymptomatic 60- to 80-year-old patients had adequate radiographs. The mean plumb line values in the 20- to 40-year-old patients and 60- to 80-year-old patients, respectively, were as follows; CCOM 9.0 mm (SD, 31.5 mm) and 41.2 mm (SD, 35.7 mm); C2 -2.7 mm (SD, 32.7 mm) and 32.1 mm (SD, 33.6 mm); and C7 -16.4 mm (SD, 31.5 mm) and 10.6 mm (SD, 27.8 mm). One-way analysis of variance and Student t tests confirmed that these mean plumb line values were significantly different between young and elderly patients (P < 0.001). The change at each level over time was highly correlated with the other levels (r > 0.97; P < 0.001) as did the degree of change between groups (r > 0.90, P < 0.001)., Conclusion: Spinopelvic alignment in conjunction with CCOM has increased our understanding of spinal balance by including the head and may better represent true global spinal balance. CCOM is an easily measured parameter by using the nasion-inion technique.

Myeloid sarcoma (MS) is an extra-osseous, solid collection of myeloblasts. It is associated with myeloid leukemias, and rarely affects the spine. The most common clinical presentation of MS in spine patients is some form of pain related to compression of neural elements. Given that MS is rare, and its imaging characteristics are similar to other more common diagnoses, it is frequently missed on initial presentation. We present a 28-year-old female, in her fifth year of remission from AML, with low back pain and right lumbar radiculopathy. Initially, the leading diagnosis was schwannoma in preference to neurofibroma; however, intra-operative pathology and subsequent bone marrow biopsy revealed the tumor to be MS. This report highlights the difficulties of diagnosis of MS in patients in remission from acute myeloid leukemia. Thus, in patients with a history of leukemia, MS should be considered in the differential diagnosis of any epidural or nerve root tumor. Timely diagnosis and treatment are key to optimal outcomes., (Published by Elsevier Ltd.)

Study Design: Retrospective study of a consecutive series of patients treated for proximal junctional kyphosis (PJK) of the upper thoracic and cervicothoracic spine., Objective: To discuss corrective techniques for the management of symptomatic kyphosis at the junction of fused and mobile segments of the upper thoracic and cervicothoracic spine in patients who complain of pain, neurological deficit, ambulatory difficulty, and/or social isolation., Summary of Background Data: PJK is an unfortunately common, but important, complication seen in long instrumented fusions to the upper thoracic and cervicothoracic spine. Although often asymptomatic, its incidence and prevalence warrant a discussion on treatment options for symptomatic patients., Methods: After the institutional review board confirmed approval, we retrospectively analyzed patients who received treatment of PJK from 2003 to 2009. Segmental instrumentation and intraoperative neurophysiological monitoring were used in all patients. Data acquisition was performed by reviewing electronic medical records and radiographs. Inclusion criteria were patients who underwent surgical correction of PJK of the cervicothoracic and upper thoracic spine and had more than 2-year follow-up. Preoperative lumbar lordosis, preoperative thoracic kyphosis, pre- and postoperative sagittal balance, and sagittal proximal junctional Cobb angle were obtained. All corrective procedures were performed in 2 stages, each patient receiving cervical traction between cases., Results: Inclusion criteria were met in 7 patients (5 women and 2 men), with mean age of 55 years (range, 18-80 years). Six patients received multilevel Smith-Petersen osteotomies, with 2 patients receiving rib osteotomies, and 1 patient received a vertebral column resection. The mean preoperative and postoperative proximal junctional Cobb angles were 45° (range, 14°-89.7°) and 14° (range, 3.0°-38.0°), respectively. The mean degree of correction was 31° (range, 11°-79.2°). All patients had maintained or improved sagittal balance. No patient sustained a temporary or permanent neurological deficit after correction related to surgery. All patients had 2-year follow-up, and there were no mortalities., Conclusion: For a selected cohort of patients who develop PJK of the upper thoracic and cervicothoracic spine, osteotomies, cervical traction, and intraoperative manual reduction provide a significant improvement of proximal junctional Cobb angles. To our knowledge, this is the first study to address treatment for symptomatic patients with this condition.

Object: As the population continues to age, relatively older geriatric patients will present more frequently with complex spinal deformities that may require surgical intervention. To the authors' knowledge, no study has analyzed factors predictive of complications after major spinal deformity surgery in the very elderly (75 years and older). The authors' objective was to determine the rate of minor and major complications and predictive factors in patients 75 years of age and older who underwent major spinal deformity surgery requiring a minimum 5-level arthrodesis procedure., Methods: Twenty-one patients who were 75 years of age or older and underwent thoracic and/or lumbar fixation and arthrodesis across 5 or more levels for spinal deformity were analyzed retrospectively. The medical and surgical records were reviewed in detail. Age, diagnosis, comorbidities, operative data, hospital data, major and minor complications, and deaths were recorded. Factors predictive of perioperative complications were identified by logistic regression analysis., Results: The mean patient age was 77 years old (range 75-83 years). There were 14 women and 7 men. The mean follow-up was 41.2 months (range 24-81 months). Fifteen patients (71%) had at least 1 comorbidity. A mean of 10.5 levels were fused (range 5-15 levels). Thirteen patients (62%) had at least 1 perioperative complication, and 8 (38%) had at least one major complication for a total of 17 complications. There were no perioperative deaths. Increasing age was predictive of any perioperative complication (p = 0.03). However, major complications were not predicted by age or comorbidities as a whole. In a subset analysis of comorbidities, only hypertension was predictive of a major complication (OR 10, 95% CI 1.3-78; p = 0.02). Long-term postoperative complications occurred in 11 patients (52%), and revision fusion surgery was necessary in 3 (14%)., Conclusions: Patients 75 years and older undergoing major spinal deformity surgery have an overall perioperative complication rate of 62%, with older age increasing the likelihood of a complication, and a long-term postoperative complication rate of 52%. Patients in this age group with a history of hypertension are 10 times more likely to incur a major perioperative complication. However, the mortality risk for these patients is not increased.

The management of thoracic ossification of the posterior longitudinal ligament has been studied by many spinal surgeons. Indications for operative intervention include progressive radiculopathy, myelopathy, and neurological deterioration. The ideal surgery for decompression remains highly debatable as various methods of surgical treatment of ossification of the posterior longitudinal ligament have been devised. Although numerous modifications to the 3 main approaches have been identified (anterior, posterior, or lateral), the indication for each depends on the nature of compression, the morphology of the lesion, the level of the compression, the structural alignment of the spine, and the neurological status of the patient. The authors discuss treatment techniques for thoracic ossification of the posterior longitudinal ligament, cite case examples from a single institution, and review the literature.

Object: Ossification of the posterior longitudinal ligament (OPLL) is a complex multifactorial disease process combining both metabolic and biomechanical factors. The role for surgical intervention and choice of anterior or posterior approach is controversial. The object of this study was to review the literature and present a single-institution experience with surgical intervention for OPLL., Methods: The authors performed a retrospective review of their institutional experience with surgical intervention for cervical OPLL. They also reviewed the English-language literature regarding the epidemiology, pathophysiology, natural history, and surgical intervention for OPLL., Results: Review of the literature suggests an improved benefit for anterior decompression and stabilization or posterior decompression and stabilization compared with posterior decompression via laminectomy or laminoplasty. Both anterior and posterior approaches are safe and effective means of decompression of cervical stenosis in the setting of OPLL., Conclusions: Anterior cervical decompression and reconstruction is a safe and appropriate treatment for cervical spondylitic myelopathy in the setting of OPLL. For patients with maintained cervical lordosis, posterior cervical decompression and stabilization is advocated. The use of laminectomy or laminoplasty is indicated in patients with preserved cervical lordosis and less than 60% of the spinal canal occupied by calcified ligament in a "hill-shaped" contour.

In this report the authors describe a unique case of spinal clear cell meningioma in a 13-year-old girl. Clear cell meningiomas (CCMs) are not uncommon. To the authors' knowledge, 14 cases of pediatric CCM occurring in the spinal canal have been reported. Factors lending resistance to meningioma initiation and invasion are analyzed. This 13-year-old girl presented with pain radiating down her left leg. Admission MR imaging showed an inhomogeneous enhancing intradural-extramedullary mass at the L4-5 level. Resection revealed a CCM, and radiotherapy was subsequently administered. Postoperatively there has been no recurrence in > 2 years. In this paper the authors report a case of CCM and provide a comprehensive literature review on this disease. Current recommendations for its management are still debatable, especially in the pediatric population, and the authors propose an algorithm for its treatment and surveillance.