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Retrospective cohort study.The aim was to investigate the accuracy of pedicle screw placement by freehand technique and to compare revision surgery rates among three different imaging verification pathways.Studies comparing different imaging modalities in freehand screw placement surgery are limited.A single-institution retrospective chart review identified adult patients who underwent freehand pedicle screw placement in the thoracic, lumbar or sacral levels. Patients were stratified into three cohorts based on the intraoperative imaging modality used to assess the accuracy of screw position: intraoperative X-rays (cohort 1); intraoperative O-arm (cohort 2); or intraoperative computed tomography (CT)-scan (cohort 3). Postoperative CT scans were performed on all patients in cohorts 1 and 2. Postoperative CT scan was not required in cohort 3. Screw accuracy was assessed using the Gertzbein-Robbins grading system.A total of 9179 pedicle screws were placed in the thoracic or lumbosacral spine in 1311 patients. 210 (2.3%) screws were identified as Gertzbein-Robbins grades C-E on intraoperative/postoperative CT scan, 137 thoracic screws, and 73 lumbar screws ( P0.001). Four hundred and nine patients underwent placement of 2754 screws followed by intraoperative X-ray (cohort 1); 793 patients underwent placement of 5587 screws followed by intraoperative O-arm (cohort 2); and 109 patients underwent placement of 838 screws followed by intraoperative CT scan (cohort 3). Postoperative CT scans identified 65 (2.4%) and 127 (2.3%) malpositioned screws in cohorts 1 and 2, respectively. Eleven screws (0.12%) were significantly malpositioned and required a second operation for screw revision. Nine patients (0.69%) required revision operations: eight of these patients were from cohort 1 and one patient was from cohort 2.When compared to intraoperative X-ray, intraoperative O-arm verification decreased the revision surgery rate for malpositioned screws from 0.37% to 0.02%. In addition, our analysis suggests that the use of intraoperative O-arm can obviate the need for postoperative CT scans.

Intramedullary spinal cord tumors (IMSCTs) are rare tumors associated with significant morbidity and mortality. Surgical resection is often indicated for symptomatic lesions but may result in new neurological deficits and decrease quality of life. Identifying predictors of these adverse outcomes may help target interventions designed to reduce their occurrence. Nonetheless, most prior studies have employed population-level datasets with limited granularity.To determine independent predictors of nonroutine discharge, prolonged length of stay (LOS), and 30 day readmission and reoperation, and to deploy these results as a web-based calculator.Retrospective cohort study PATIENT SAMPLE: A total of 235 patients who underwent resection of IMSCTs at a single comprehensive cancer center.Nonroutine discharge, prolonged LOS, 30 day readmission, and 30 day reoperation METHODS: Patients who underwent surgery from June 2002 to May 2020 at a single tertiary center were included. Data was collected on patient demographics, clinical presentation, tumor histology, surgical procedures, and 30 day readmission and reoperation. Functional status was assessed using the Modified McCormick Scale (MMS) and queried preoperative neurological symptoms included weakness, urinary and bowel dysfunction, numbness, and back and radicular pain. Variables significant on univariable analysis at the α≤0.15 level were entered into a stepwise multivariable logistic regression model.Of 235 included cases, 131 (56%) experienced a nonhome discharge and 68 (29%) experienced a prolonged LOS. Of 178 patients with ≥ 30 days of follow-up, 17 (9.6%) were readmitted within 30 days and 13 (7.4%) underwent reoperation. Wound dehiscence (29%) was the most common reason for readmission. Nonhome discharge was independently predicted by older age (OR=1.03/year; p.01), thoracic location of the tumor (OR=2.36; p=.01), presenting with bowel dysfunction (OR=4.09; p=.03), and longer incision length (OR=1.44 per level; p=.03). Independent predictors of prolonged LOS included presenting with urinary incontinence (OR=2.65; p=.05) or a higher preoperative white blood cell count (OR=1.08 per 10We found that neurological presentation, patient demographics, and incision length were important predictors of adverse perioperative outcomes in patients with IMSCTs. The calculators can be used by clinicians for risk stratification, preoperative counseling, and targeted interventions.

OBJECTIVE Treatment of primary spinal infection includes medical management with or without surgical intervention. The objective of this study was to identify risk factors for the eventual need for surgery in patients with primary spinal infection on initial presentation. METHODS From January 2010 to July 2019, 275 patients presented with primary spinal infection. Demographic, infectious, imaging, laboratory, treatment, and outcome data were retrospectively reviewed and collected. Thirty-three patients were excluded due to insufficient follow-up (≤ 90 days) or death prior to surgery. RESULTS The mean age of the 242 patients was 58.8 ± 13.6 years. The majority of the patients were male (n = 130, 53.7%), White (n = 150, 62.0%), and never smokers (n = 132, 54.5%). Fifty-four patients (22.3%) were intravenous drug users. One hundred fifty-four patients (63.6%) ultimately required surgery while 88 (36.4%) never needed surgery during the duration of follow-up. There was no significant difference in age, gender, race, BMI, or comorbidities between the surgery and no-surgery groups. On univariate analysis, the presence of an epidural abscess (55.7% in the no-surgery group vs 82.5% in the surgery group, p < 0.0001), the median spinal levels involved (2 [interquartile range (IQR) 2–3] in the no-surgery group vs 3 [IQR 2–5] in the surgery group, p < 0.0001), and active bacteremia (20.5% in the no-surgery vs 35.1% in the surgery group, p = 0.02) were significantly different. The cultured organism and initial laboratory values (erythrocyte sedimentation rate, C-reactive protein, white blood cell count, creatinine, and albumin) were not significantly different between the groups. On multivariable analysis, the final model included epidural abscess, cervical or thoracic spine involvement, and number of involved levels. After adjusting for other variables, epidural abscess (odds ratio [OR] 3.04, 95% confidence interval [CI] 1.64–5.63), cervical or thoracic spine involvement (OR 2.03, 95% CI 1.15–3.61), and increasing number of involved levels (OR 1.16, 95% CI 1.01–1.35) were associated with greater odds of surgery. Fifty-two surgical patients (33.8%) underwent decompression alone while 102 (66.2%) underwent decompression with fusion. Of those who underwent decompression alone, 2 (3.8%) of 52 required subsequent fusion due to kyphosis. No patient required hardware removal due to persistent infection. CONCLUSIONS At time of initial presentation of primary spinal infection, the presence of epidural abscess, cervical or thoracic spine involvement, as well as an increasing number of involved spinal levels were potential risk factors for the eventual need for surgery in this study. Additional studies are needed to assess for risk factors for surgery and antibiotic treatment failure.

Von Hippel-Lindau (VHL) disease is a tumor predisposition syndrome caused by mutations in the VHL gene that presents with visceral neoplasms and growths, including clear cell renal cell carcinoma, and central nervous system manifestations, such as hemangioblastomas of the brain and spine. The pathophysiology involves dysregulation of oxygen sensing caused by the inability to degrade HIFα, leading to the overactivation of hypoxic pathways. Hemangioblastomas are the most common tumors in patients with VHL and cause significant morbidity. Until recently, there were no systemic therapies available for patients that could effectively reduce the size of these lesions. Belzutifan, the first approved HIF-2α inhibitor, has demonstrated benefit in VHL-associated tumors, with a 30% response rate in hemangioblastomas and ~30%–50% reduction in their sizes over the course of treatment. Anemia is the most prominent adverse effect, affecting 76%–90% of participants and sometimes requiring dose reduction or transfusion. Other significant adverse events include hypoxia and fatigue. Overall, belzutifan is well tolerated; however, long-term data on dosing regimens, safety, and fertility are not yet available. Belzutifan holds promise for the treatment of neurological manifestations of VHL and its utility may influence the clinical management paradigms for this patient population.

Study design This was a cross-sectional study. Objective The objective of this study is to report the impact of COVID-19 on spine surgery fellow education and readiness for practice. Summary of background data COVID-19 has emerged as one of the most devastating global health crises of our time. To minimize transmission risk and to ensure availability of health resources, many hospitals have cancelled elective surgeries. There may be unintended consequences of this decision on the education and preparedness of current surgical trainees. Materials and methods A multidimensional survey was created and distributed to all current AO Spine fellows and fellowship directors across the United States and Canada. Results Forty-five spine surgery fellows and 25 fellowship directors completed the survey. 62.2% of fellows reported >50% decrease in overall case volume since cancellation of elective surgeries. Mean hours worked per week decreased by 56.2%. Fellows reported completing a mean of 188.4±64.8 cases before the COVID-19 crisis and 84.1% expect at least an 11%-25% reduction in case volume compared with previous spine fellows. In all, 95.5% of fellows did not expect COVID-19 to impact their ability to complete fellowship. Only 2 directors were concerned about their fellows successfully completing fellowship; however, 32% of directors reported hearing concerns regarding preparedness from their fellows and 25% of fellows were concerned about job opportunities. Conclusions COVID-19 has universally impacted work hours and case volume for spine surgery fellows set to complete fellowship in the middle of 2020. Nevertheless, spine surgery fellows generally feel ready to enter practice and are supported by the confidence of their fellowship directors. The survey highlights a number of opportunities for improvement and innovation in the future training of spine surgeons. Level of evidence Level III.

Spine surgery has evolved from the advent of imaging and navigation guidance, particularly with the rise of robotic surgical assistance. Navigation guidance has demonstrated potential for increased accuracy of transpedicular screw placement and resecting primary and metastatic spinal tumors. Robotic surgery is widely accepted in other surgical fields because laparoscopic techniques applied to robots can increase operator dexterity and improve visualization. Robotic assistance with spinal tumors has enjoyed rising interest owing to the potential for safe and minimally traumatic resection. We discuss available robots used for navigation-guided transpedicular screw placement and state-of-the-art robotic techniques for spinal or paraspinal tumor resection.

OBJECTIVE Intramedullary spinal cord tumors (IMSCTs) are rare neoplasms whose treatment is often technically challenging. Given the low volume seen at most centers, perioperative outcomes have been reported infrequently. Here, the authors present the largest single-institution series of IMSCTs, focusing on the clinical presentation, histological makeup, perioperative outcomes, and long-term survival of surgically treated patients. METHODS A cohort of patients operated on for primary IMSCTs at a comprehensive cancer center between June 2002 and May 2020 was retrospectively identified. Data on patient demographics, tumor histology, neuraxial location, baseline neurological status, functional deficits, and operative characteristics were collected. Perioperative outcomes of interest included length of stay, postoperative complications, readmission, reoperation, and discharge disposition. Data were compared across tumor histologies using the Kruskal-Wallis H test, chi-square test, and Fisher exact test. Pairwise comparisons were conducted using Tukey’s honest significant difference test, chi-square test, and Fisher exact test. Long-term survival was assessed across tumor categories and histological subtype using the log-rank test. RESULTS Three hundred two patients were included in the study (mean age 34.9 ± 19 years, 77% white, 57% male). The most common tumors were ependymomas (47%), astrocytomas (31%), and hemangioblastomas (11%). Ependymomas and hemangioblastomas disproportionately localized to the cervical cord (54% and 59%, respectively), whereas astrocytomas were distributed almost equally between the cervical cord (36%) and thoracic cord (38%). Clinical presentation, extent of functional dependence, and postoperative 30-day outcomes were largely independent of underlying tumor pathology, although tumors of the thoracic cord had worse American Spinal Injury Association (ASIA) grades than cervical tumors. Rates of gross-total resection were lower for astrocytomas than for ependymomas (54% vs 84%, p < 0.01) and hemangioblastomas (54% vs 100%, p < 0.01). Additionally, 30-day readmission rates were significantly higher for astrocytomas than ependymomas (14% vs 6%, p = 0.02). Overall survival was significantly affected by the underlying pathology, with astrocytomas having poorer associated prognoses (40% at 15 years) than ependymomas (81%) and hemangioblastomas (66%; p < 0.01) and patients with high-grade ependymomas and astrocytomas having poorer long-term survival than those with low-grade lesions (p < 0.01). CONCLUSIONS The neuraxial location of IMSCTs, extent of resection, and postoperative survival differed significantly across tumor pathologies. However, perioperative outcomes did not vary significantly across tumor cohorts, suggesting that operative details, rather than pathology, may have a stronger influence on the short-term clinical course, whereas pathology appears to have a stronger impact on long-term survival.

Spinal oncology has had many advancements often necessitating serial imaging for post-surgical treatment planning and close follow up. Traditional spinal instrumentation introduces artifact into MRI and CT imaging, which can reduce the efficacy of follow up imaging and treatment. Newly created carbon-fiber instrumentation can offer many advantages compared to traditional instrumentation while typically maintaining biomechanical stability. The utility of this new instrumentation continues to evolve as more surgeons utilize these materials, which can improve patient outcomes. We illustrate the utility of this new hardware technology through various patient examples., Carbon fiber, Oncology, Radiation, Reconstruction.

Intramedullary spinal cord tumors (IMSCTs) are rare neoplasms that have limited treatment options and are associated with high rates of morbidity and mortality. To better understand the genetic basis of these tumors we performed whole exome sequencing on 45 tumors and matched germline DNA, including twenty-nine spinal cord ependymomas and sixteen astrocytomas. Though recurrent somatic mutations in IMSCTs were rare, we identified NF2 mutations in 15.7% of tumors (ependymoma, N = 7; astrocytoma, N = 1), RP1 mutations in 5.9% of tumors (ependymoma, N = 3), and ESX1 mutations in 5.9% of tumors (ependymoma, N = 3). We further identified copy number amplifications in CTU1 in 25% of myxopapillary ependymomas. Given the paucity of somatic driver mutations, we further performed whole-genome sequencing of 12 tumors (ependymoma, N = 9; astrocytoma, N = 3). Overall, we observed that IMSCTs with intracranial histologic counterparts (e.g. glioblastoma) did not harbor the canonical mutations associated with their intracranial counterparts. Our findings suggest that the origin of IMSCTs may be distinct from tumors arising within other compartments of the central nervous system and provides the framework to begin more biologically based therapeutic strategies.

Background Spinal chordomas, a subtype of primary spinal column malignancies (PSCM), are rare tumors with poor prognosis, and we have limited understanding of the molecular drivers of neoplasia. Methods Study design was a retrospective review of prospectively collected data with cross-sectional survival. Archived paraffin embedded pathologic specimens were collected for 133 patients from 6 centers within Europe and North America between 1987 and 2012. Tumor DNA was extracted and the human telomerase reverse transcriptase (hTERT) promoter was sequenced. The hTERT mutational status was correlated with overall survival (OS) and time to first local recurrence. Results Ninety-two chordomas, 26 chondrosarcomas, 7 osteosarcomas, 3 Ewing’s sarcomas, and 5 other malignant spinal tumors were analyzed. Median OS following surgery was 5.8 years (95% CI: 4.6 to 6.9) and median time to first local recurrence was 3.9 years (95% CI: 2.5 to 6.7). Eight chordomas, 2 chondrosarcomas, 1 Ewing’s sarcoma, and 1 other malignant spinal tumor harbored either a C228T or C250T mutation in the hTERT promoter. In the overall cohort, all patients with hTERT mutation were alive at 10 years postoperative with a median OS of 5.1 years (95% CI: 4.5 to 6.6) (P = 0.03). hTERT promoter mutation was observed in 8.7% of spinal chordomas, and 100% of chordoma patients harboring the mutation were alive at 10 years postoperative compared with 67% patients without the mutation (P = 0.05). Conclusions We report for the first time that hTERT promoter mutations C228T and C250T are present in approximately 8.7% of spinal chordomas. The presence of hTERT mutations conferred a survival benefit and could potentially be a valuable positive prognostic molecular marker in spinal chordomas.

Metastatic spinal tumors commonly arise from primary breast cancer. We assessed outcomes and identified associated variables for patients who underwent surgical management for spinal metastases of breast cancer.We retrospectively reviewed patients surgically treated for spinal metastases of breast cancer. Neurologic and functional outcomes were analyzed via Frankel scale and Karnofksy Performance Status (KPS) scores, respectively. Variables associated with Frankel and KPS scores after surgery were identified. Multivariable analysis was used to assess predictors for postoperative survival.Forty-nine patients were identified. There was no significant difference in Frankel scores postoperatively and at last follow-up. KPS scores (P = 0.002) significantly improved at last follow-up. Preoperative non-ambulation and postprocedural complications were associated with non-ambulation postoperatively. Postprocedural complications and disease-free interval (DFI)lt; 24 andlt; 60 months were associated with functional impairment at last follow-up. Current smoking status at the time of surgery (P = 0.021) and triple negative (negative immunohistochemistry for estrogen receptor, progesterone receptor, and HER2) breast cancer (P = 0.038) were significantly associated with shortened postoperative survival.When indicated, surgery for spinal metastases of breast cancer leads to preservation of neurologic status and long-term functional improvement. Preoperative ambulatory status and postprocedural complications were associated with ambulatory status after surgery, while postprocedural complications and shortened DFI were associated with functional status after surgery.Current smoking status at the time of surgery and triple negative breast cancer are negative predictors for postoperative survival after metastatic breast cancer to the spine.

Background Chordomas are the most common primary spinal column malignancy in the United States. The aim of this study was to determine whether chordomas may be detected by evaluating mutations in circulating tumor DNA (ctDNA). Methods Thirty-two patients with a biopsy-confirmed diagnosis of chordoma had blood drawn pre-operatively and/or at follow-up appointments. Mutations in the primary tumor were identified by whole exome sequencing and liquid biopsy by ddPCR and/or RACE-Seq was used to detect one or more of these mutations in plasma ctDNA at concurrent or later time points. Results At the time of initial blood draw, 87.1% of patients were ctDNA positive (P Conclusions Detection of ctDNA mutations may allow for the detection and monitoring of disease progression for chordomas.

Sacral tumors present several unique surgical challenges due to their intimate relationship with critical retroperitoneal, vascular, and neurologic structures as well as the biomechanical implications of sacrectomy. Consequently, clear treatment goals must be established prior to surgery based on the natural history, location, and extent of the tumor in addition to patient factors, morbidity, and acceptable functional outcomes. Several important questions that must be addressed pre-operatively include the following: Is the lesion best treated with surgery, chemotherapy, radiation, or a multimodal approach? Is the goal of surgery palliative or curative? Can the surgery be performed with acceptable functional outcomes? We begin this chapter with a brief overview of common and clinically important primary sacral tumors with an emphasis on distinguishing surgical lesions from those better treated with combinatorial or other therapeutic modalities.

OBJECTIVEResection of metastatic spine tumors can improve patients’ quality of life by addressing pain or neurological compromise. However, resections are often complicated by wound dehiscence, infection, instrumentation failures, and the need for reoperation. Moreover, when reoperations are needed, the most common indication is surgical site infection and wound breakdown. In turn, wound reoperations increase morbidity as well as the length and cost of hospitalization. The aim of this study was to examine perioperative risk factors associated with increased rate of wound reoperations after metastatic spine tumor resection.METHODSA retrospective study of patients at a single institution who underwent metastatic spine tumor resection between 2003 and 2013 was conducted. Factors with a p value < 0.200 in a univariate analysis were included in the multivariate model.RESULTSA total of 159 patients were included in this study. Karnofsky Performance Scale score > 70, smoking status, hypertension, thromboembolic events, hyperlipidemia, increasing number of vertebral levels, and posterior approach were included in the multivariate analysis. Thromboembolic events (95% CI 1.19–48.5, p = 0.032) and number of levels involved were independently associated with increased wound reoperation rates in the multivariate model. For each additional spinal level involved, the risk for wound reoperations increased by 21% (95% CI 1.03–1.43, p = 0.018).CONCLUSIONSAlthough wound complications and subsequent reoperations are potential risks for all patients with metastatic spine tumor, due to adjuvant radiotherapy and other medical comorbidities, this study identified patients with thromboembolic events or those requiring a larger incision as being at the highest risk. Measures intended to decrease the occurrence of perioperative venous thromboembolism and to improve wound care, especially for long incisions, may decrease wound-related revision surgeries in this vulnerable group of patients.

Background Robotic-assisted techniques have been implemented in the surgical treatment of tumors in the pelvis, abdomen, and thorax. In pelvic tumors, robotic-assisted techniques evade the need for sizable surgical exposure, but make stimulation of the nerves of the sacral plexus very difficult. Objective To describe how laparoscopic robotic-assisted surgery can couple with tools such as the nerve stimulator to aid in the resection of presacral masses emanating from the neural elements and potentially improve neurological outcome by preventing inadvertent injury to involved nerves. Methods A patient with a large presacral ganglioneuroma underwent resection using the DaVinci system (Intuitive Surgical, Sunnyvale, California) for robotic assistance. A nerve stimulator was coupled to the bipolar cautery instrument of the DaVinci robot to define the presence of functional nerves in the surroundings of the tumor. Results By coupling a nerve stimulator to the bipolar cautery instrument of the DaVinci robot (Intuitive Surgical), it was possible to identify important neural structures in close proximity to the tumor. After identifying functional nerves, the surgeon was able to preserve them and preserve neurological function avoiding motor dysfunction. Conclusion The use of a nerve stimulator coupled to the bipolar cautery instrument of the DaVinci robot (Intuitive Surgical) during laparoscopic, robotic-assisted surgery for resection of presacral masses is safe and feasible. In addition to the preoperative evaluation, intraoperative monitoring and stimulation of nerves in close proximity to the tumor and also exiting through neural foramina involved by the tumor allowed the surgeon to understand the anatomy and preserve neurological function while obtaining optimal surgical resection.

Background Surgical treatment of severe cervicothoracic kyphotic deformity may require the use of 3-column osteotomies such as the pedicle subtraction osteotomy and vertebral column resection (VCR), or VCR with anterior longitudinal ligament resection. Such procedures are extensive and are associated with high intra- and perioperative morbidity, in part, due to the need for risky reduction maneuvers. Objective To describe a novel technique utilizing a laterally placed articulating hinge to facilitate kyphotic deformity correction of the cervicothoracic spine. Methods A patient with severe chin-on-chest deformity of the cervicothoracic spine presented for evaluation and a 2-stage VCR with anterior longitudinal ligament resection was planned. To reduce the risk of intraoperative neurological injury and for increased control during reduction maneuvers, lateral instrumentation was placed through the chest wall resection above and below the level of VCR, which was adjoined with an articulating hinge rod apparatus. Results Satisfactory reduction of the kyphosis was achieved utilizing the hinge rod apparatus for controlled deformity correction. The patient remained neurologically intact following this procedure with improvement in their spinal alignment. Conclusion We present a novel technique utilizing a lateral hinge rod apparatus for efficient, controlled correction of severe kyphotic deformity.

BACKGROUND AND PURPOSE: The early diagnosis of spinal vascular malformations suffers from the nonspecificity of their clinical and radiologic presentations. Spinal angiography requires a methodical approach to offer a high diagnostic yield. The prospect of false-negative studies is particularly distressing when addressing conditions with a narrow therapeutic window. The purpose of this study was to identify factors leading to missed findings or inadequate studies in patients with spinal vascular malformations. MATERIALS AND METHODS: The clinical records, laboratory findings, and imaging features of 18 patients with spinal arteriovenous fistulas and at least 1 prior angiogram read as normal were reviewed. The clinical status was evaluated before and after treatment by using the Aminoff-Logue Disability Scale. RESULTS: Eighteen patients with 19 lesions underwent a total of 30 negative spinal angiograms. The lesions included 9 epidural arteriovenous fistulas, 8 dural arteriovenous fistulas, and 2 perimedullary arteriovenous fistulas. Seventeen patients underwent endovascular (11) or surgical (6) treatment, with a delay ranging between 1 week and 32 months; the Aminoff-Logue score improved in 13 (76.5%). The following factors were identified as the causes of the inadequate results: 1) lesion angiographically documented but not identified (55.6%); 2) region of interest not documented (29.6%); or 3) level investigated but injection technically inadequate (14.8%). CONCLUSIONS: All the angiograms falsely reported as normal were caused by correctible, operator-dependent factors. The nonrecognition of documented lesions was the most common cause of error. The potential for false-negative studies should be reduced by the adoption of rigorous technical and training standards and by second opinion reviews.

Systematic review.We conducted a systematic review of the literature to answer the following questions regarding the use of steroid therapy in metastatic spinal cord compression (MSCC): 1. In cases of MSCC, what is the effect of steroid administration before definitive radiotherapy or surgery on ambulatory status, bowel and bladder function and survival? 2. What steroid dosing regimens are associated with the best outcomes concerning neurological symptoms and complication prevention in cases of MSCC?Currently, there is significant variation in the initial bolus dose, daily maintenance dose and duration of treatment when steroids are used as a bridge to definitive therapy for MSCC.A literature search following PRISMA guidelines was conducted in June 2016, using Medline via Ovid SP, Medline via PubMed, Embase, Biosis Previews and the Cochrane Library. Search terms used in each database varied slightly to optimize results. All generic steroid formulations were included along with spinal cord compression or myelopathy combined with metastatic or malignant tumors. Papers discussing acute traumatic causes of spinal cord compression were excluded, as were papers discussing cord compression from nonmetastatic tumors or epidural lipomatosis. Subjects were limited to adult humans undergoing definitive treatment with radiotherapy or surgery.Of the 309 papers retrieved, 66 full text studies were reviewed and 6 papers were found to address the stated questions.There is a paucity of high quality literature evaluating the use of steroids in MSCC. On the basis of the evidence available an initial 10 mg intravenous bolus of dexamethasone followed by 16 mg PO QD has been associated with fewer complications compared with 100 mg bolus and 96 mg QD. Weaning of steroids should occur rapidly after definitive treatment. Risk of gastric bleeding or perforation can be managed with the routine use of proton-pump inhibitors.Level IIIa.

OBJECTIVE The aim of this study was to investigate the incidence of spinal tuberculosis (TB) in the US between 2002 and 2011. METHODS The Nationwide Inpatient Sample database from 2002 to 2011 was used to identify patients with a discharge diagnosis of TB and spinal TB. Demographic and hospital data were obtained for all admissions, and included age, sex, race, comorbid conditions, insurance status, hospital location, hospital teaching status, and hospital region. The incidence rate of spinal TB adjusted for population growth was calculated after application of discharge weights. RESULTS A total of 75,858 patients with a diagnosis of TB were identified, of whom 2789 had a diagnosis of spinal TB (3.7%); this represents an average of 278.9 cases per year between 2002 and 2011. The incidence of spinal TB decreased significantly—from 0.07 cases per 100,000 persons in 2002 to 0.05 cases per 100,000 in 2011 (p < 0.001), corresponding to 1 case per 2 million persons in the latter year. The median age for patients with spinal TB was 51 years, and 61% were male; 11.6% were patients with diabetes, 11.4% reported recent weight loss, and 8.1% presented with paralysis. There were 619 patients who underwent spinal surgery for TB, with the most common location being the thoracolumbar spine (61.9% of cases); 50% of patients had instrumentation of 3 or more spinal segments. CONCLUSIONS During the examined 10-year period, the incidence of spinal TB was found to significantly decrease over time in the US, reaching a rate of 1 case per 2 million persons in 2011. However, the absolute reduction was relatively small, suggesting that although it is uncommon, spinal TB remains a public health concern and most commonly affects male patients approximately 50 years of age. Approximately 20% of patients with spinal TB underwent surgery, most commonly in the thoracolumbar spine.

Spinal screw placement is a challenging task due to small bone corridors and high risk of neurological or vascular complications, benefiting from precision guidance/navigation and quality assurance (QA). Implicit to both guidance and QA is the definition of a surgical plan-i.e. the desired trajectories and device selection for target vertebrae-conventionally requiring time-consuming manual annotations by a skilled surgeon. We propose automation of such planning by deriving the pedicle trajectory and device selection from a patient's preoperative CT or MRI. An atlas of vertebrae surfaces was created to provide the underlying basis for automatic planning-in this work, comprising 40 exemplary vertebrae at three levels of the spine (T7, T8, and L3). The atlas was enriched with ideal trajectory annotations for 60 pedicles in total. To define trajectories for a given patient, sparse deformation fields from the atlas surfaces to the input (CT or MR image) are applied on the annotated trajectories. Mean value coordinates are used to interpolate dense deformation fields. The pose of a straight trajectory is optimized by image-based registration to an accumulated volume of the deformed annotations. For evaluation, input deformation fields were created using coherent point drift (CPD) to perform a leave-one-out analysis over the atlas surfaces. CPD registration demonstrated surface error of 0.89 ± 0.10 mm (median ± interquartile range) for T7/T8 and 1.29 ± 0.15 mm for L3. At the pedicle center, registered trajectories deviated from the expert reference by 0.56 ± 0.63 mm (T7/T8) and 1.12 ± 0.67 mm (L3). The predicted maximum screw diameter differed by 0.45 ± 0.62 mm (T7/T8), and 1.26 ± 1.19 mm (L3). The automated planning method avoided screw collisions in all cases and demonstrated close agreement overall with expert reference plans, offering a potentially valuable tool in support of surgical guidance and QA.

Retrospective comparative study.To compare clinical and radiographic outcomes between the S2-alar-iliac (S2AI) and the iliac screw (IS) techniques in the adult population and clarify the clinical strength of S2AI screws.S2AI screws have been described as an alternative method for lumbosacropelvic fixation in place of ISs. The S2AI technique has several advantages with lower prominence, increased ability to directly connect to proximal instrumentation, less extensive dissection of tissue, and enhanced biomechanical strength over the IS technique. However, the clinical significance of these advantages remains unclear.A single-center retrospective review of patients who underwent lumbosacropelvic fixation yielded 25 IS group patients and 65 S2AI group patients. Baseline demographic information, postoperative complications, pain and functional outcomes, and screw-related outcomes were collected.The S2AI group had lower rates of reoperation (8.8% vs. 48.0%, P 0.001), surgical site infection (SSI) (1.5% vs. 44.0%, P 0.001), wound dehiscence (1.5% vs. 36.0%, P 0.001), and symptomatic screw prominence (0.0% vs. 12.0%, P = 0.02) than the IS group, whereas rates of L5-S1 pseudarthrosis, proximal junctional failure, and sacroiliac joint pain were similar in both groups. Statistically significant pain relief and functional recovery were achieved in both groups without any significant intergroup differences. On multivariate analyses, age [odds ratio (OR) = 0.91, P = 0.004] and S2AI instrumentation (OR = 0.08, P 0.001) were protective of reoperation, whereas diabetes mellitus (OR = 10.9, P = 0.03) and preoperative diagnosis of tumor (OR = 12.3, P = 0.04) were associated with SSI, and S2AI instrumentation (OR = 0.09, P 0.001) was protective of SSI.The use of the S2AI technique over the IS technique was an independent predictor of preventing reoperation and SSI, while achieving similar clinical and functional outcomes.4.

Objective The primary objective of this study is to examine the effects smoking status on rhBMP-2 supplementation in spinal fusion constructs. Methods Patient records were reviewed retrospectively for a consecutive set of patients who underwent first-time posterolateral, instrumented fusion of the lumbar spine for degenerative spinal disease. All operations included arthrodesis supplementation with rhBMP-2. All patients were followed for at least 2 years. The primary endpoint of this study was reoperation for pseudarthrosis, instrumentation failure, or adjacent segment disease. After a rigorous sensitivity analysis, the measure of association was calculated with a multivariable logistic regression controlling for smoking, age, and number of spinal levels fused. Results Of the 110 patients in the study population, 82 (74.6%) were nonsmokers and 28 (25.5%) were smokers. Among perioperative predictors, smokers were younger in age (53.9 ± 9.6 vs. 61.1 ± 13.1 years; P = 0.008) and had shorter length of inpatient hospital stay (4.1 ± 1.8 vs. 5.3 ± 3.0; P = 0.039). After a mean follow-up of 59 months, the 32% incidence of reoperation for pseudarthrosis, instrumentation failure, or adjacent segment among smokers was statistically significantly higher than the 13.4% incidence in nonsmokers ( P = 0.027). Following multivariable logistic regression, the odds of reoperation among smokers was 4.75-fold higher than for nonsmokers ( P = 0.009; 95% confidence interval, 1.48–15.24). Conclusions While rhBMP-2 supplements arthrodesis of instrumented lumbar fusion constructs, smoking status ascertains the strongest predictor of reoperation for pseudarthrosis, instrumentation failure, and adjacent segment.

OBJECTIVEMyelopathy selectively involving the lower extremities can occur secondary to spondylotic changes, tumor, vascular malformations, or thoracolumbar cord ischemia. Vascular causes of myelopathy are rarely described. An uncommon etiology within this category is diaphragmatic crus syndrome, in which compression of an intersegmental artery supplying the cord leads to myelopathy. The authors present the operative technique for treating this syndrome, describing their experience with 3 patients treated for acute-onset lower-extremity myelopathy secondary to hypoperfusion of the anterior spinal artery.METHODSAll patients had compression of a lumbar intersegmental artery supplying the cord; the compression was caused by the diaphragmatic crus. Compression of the intersegmental artery was probably producing the patients’ symptoms by decreasing blood flow through the artery of Adamkiewicz, causing lumbosacral ischemia.RESULTSAll patients underwent surgery to transect the offending diaphragmatic crus. Each patient experienced substantial symptom improvement, and 2 patients made a full neurological recovery before discharge.CONCLUSIONSDiaphragmatic crus syndrome is a rare or under-recognized cause of ischemic myelopathy. Patients present with episodic acute-on-chronic lower-extremity paraparesis, gait instability, and numbness. Angiography confirms compression of an intersegmental artery that gives rise to a dominant radiculomedullary artery. Transecting the offending diaphragmatic crus can produce complete resolution of neurological symptoms.

Study design This is a retrospective study. Objective To report the safety profile of S2-alar-iliac (S2AI) in patients over 60, comparing S2AI screws with iliac screws (ISs). Summary of background data The surgical management involving the lumbosacropelvic spine remains a challenge due to high mechanical demand and risk of pseudarthrosis. Previous articles showed lower rates of complications in patients receiving S2AI screws than ISs; however, none of them have focused on patients aged over 60 who may harbor significant comorbidities and thus require more meticulous perioperative management, given these invasive and lengthy procedures. Materials and methods Retrospective review of clinical records from 2010 to 2015 identified 60 patients undergoing lumbosacropelvic fixation (17 patients with ISs and 43 patients with S2AI screws) who satisfied the following criteria: (1) patients aged over 60 years old and (2) patients with >1-year follow-up periods. Rates of complications such as unplanned reoperation and cardiorespiratory complications were collected and statistically analyzed. Results Baseline characteristics such as age, sex, and comorbidities were similar in both groups. The S2AI group had lower rates of reoperation (18.6% vs. 47.4%; P=0.02), surgical site infection (2.3% vs. 29.4%; P=0.006), wound dehiscence (2.3% vs. 29.4%; P=0.006), and postoperative anemia (7.0% vs. 29.4%; P=0.03) and had lower total volume of estimated blood loss (EBL) (mL) (1846.4 vs. 2721.2; P=0.02) and transfused red blood cell units (7.2 vs. 4.7; P=0.04) than the IS group, while rates of L5-S1 pseudarthrosis and other cardiorespiratory complications were similar in both groups. In multivariate analysis, operative time, body mass index, and use of S2AI screws over ISs were independent predictors of EBL. Conclusions Use of S2AI screws over ISs in patients aged over 60 was associated with lower rates of reoperation, surgical site infection, wound dehiscence, and lower volume of EBL and red blood cell transfusion and is a viable surgical option.

Accurate intraoperative localization of target anatomy and adjacent nervous and vascular tissue is essential to safe, effective surgery, and multimodality deformable registration can be used to identify such anatomy by fusing preoperative CT or MR images with intraoperative images. A deformable image registration method has been developed to estimate viscoelastic diffeomorphisms between preoperative MR and intraoperative CT using modality-independent neighborhood descriptors (MIND) and a Huber metric for robust registration. The method, called MIND Demons, optimizes a constrained symmetric energy functional incorporating priors on smoothness, geodesics, and invertibility by alternating between Gauss-Newton optimization and Tikhonov regularization in a multiresolution scheme. Registration performance was evaluated for the MIND Demons method with a symmetric energy formulation in comparison to an asymmetric form, and sensitivity to anisotropic MR voxel-size was analyzed in phantom experiments emulating image-guided spine-surgery in comparison to a free-form deformation (FFD) method using local mutual information (LMI). Performance was validated in a clinical study involving 15 patients undergoing intervention of the cervical, thoracic, and lumbar spine. The target registration error (TRE) for the symmetric MIND Demons formulation (1.3 ± 0.8 mm (median ± interquartile)) outperformed the asymmetric form (3.6 ± 4.4 mm). The method demonstrated fairly minor sensitivity to anisotropic MR voxel size, with median TRE ranging 1.3-2.9 mm for MR slice thickness ranging 0.9-9.9 mm, compared to TRE = 3.2-4.1 mm for LMI FFD over the same range. Evaluation in clinical data demonstrated sub-voxel TRE (

Study design Systematic review and expert consensus. Objective To address the following two questions: (A) Is there a difference in outcomes after spino-pelvic reconstruction of total sacrectomy defects compared with no reconstruction? (B) What constitutes best surgical technique for soft tissue and bony reconstruction after total sacrectomy? Summary of background data The management of the soft tissue and bony defect after total sacrectomy for primary sacral tumors remains a challenge due to the complex anatomical relationships and biomechanical requirements. The scarcity of evidence-based literature in this specialized field makes it difficult for the treating surgeon to make an informed choice. Methods A systematic literature review was performed (1950-2015), followed by a meeting of an international expert panel. Medline, Embase, and CINAHL databases and Cochrane Libraries were searched. Using the GRADE guidelines, the panel of experts formulated recommendations based on the available evidence. Results Three hundred fifty-three studies were identified. Of these, 17 studies were included and were case series. Seven were evaluated as high quality of evidence and nine were of low quality. There were a total of 116 participants. Three studies included patients (n = 24) with no spino-pelvic reconstruction. One study included patients (n = 3) with vascularized bone reconstruction. Twelve studies included patients (n = 80) with no soft tissue reconstruction, three studies described patients with a local flap (n = 20), and four studies with patients having regional flap reconstruction (n = 16). Patients with or without spino-pelvic reconstruction had similar outcomes with regards to walking; however, most patients in the nonreconstructed group had some ilio-lumbar ligamentous stability preserved. The wound dehiscence and return to theater rates were higher in patients with no soft tissue reconstruction. Conclusion We recommend spino-pelvic reconstruction be undertaken with soft tissue reconstruction after total sacrectomy. Level of evidence N/A.

Background In sacropelvic fixation, the iliac screw technique offers biomechanically strong constructs, but its disadvantages include screw prominence, wound dehiscence, and postoperative pain secondary to the high profile nature. To overcome this drawback, S2-alar-iliac (S2AI) screws were developed as an alternative technique for sacropelvic fixation. This study aimed to compare the S2AI screw technique with the iliac screw technique in terms of postoperative symptomatic screw prominence. Methods A retrospective review of the records of sacropelvic fusion procedures performed at a single institution between October 2010 and January 2015 identified 32 patients with 72 iliac screws and 68 patients with 148 S2AI screws, and clinical and radiographic data were collected. If a patient had wound dehiscence and/or tenderness in the buttock immediately overlying a pelvic screw head postoperatively, it was defined as symptomatic screw prominence. The minimal distance from screw head to skin (MDSS) on postoperative computed tomography scans was measured for each patient to clarify the relationship between symptomatic screw prominence and MDSS. Results Mean follow-up period was 22.0 months. There was significantly more symptomatic pelvic screw prominence in the iliac screw group (11.1% vs. 1.4%, P = 0.002). MDSS ≤23 mm was the strongest predictor of symptomatic pelvic screw prominence, which yielded sensitivity of 100%, specificity of 94.1%, positive predictive value of 47.6%, and negative predictive value of 100%. Conclusions The use of the S2AI screw technique resulted in a reduced rate of symptomatic screw prominence. MDSS ≤23 mm was the strongest predictor of symptomatic screw prominence.

Background Even though virtually all patients with Ewing sarcoma achieve a radiographic complete response, up to 30% of patients who present with localized disease and up to 90% of those who present with metastases experience a metastatic disease recurrence, highlighting the inability to identify patients with residual disease at the end of therapy. Up to 95% of Ewing sarcomas carry a driving EWS-ETS translocation that has an intronic breakpoint that is specific to each tumor, and the authors developed a system to quantitatively detect the specific breakpoint DNA fragment in patient plasma. Methods The authors used a long-range multiplex polymerase chain reaction (PCR) technique to identify tumor-specific EWS-ETS breakpoints in Ewing sarcoma cell lines, patient-derived xenografts, and patient tumors, and this sequence was used to design tumor-specific primer sets to detect plasma tumor DNA (ptDNA) by droplet digital PCR in xenograft-bearing mice and patients. Results Tumor-specific breakpoint DNA fragments were detected in the plasma of xenograft-bearing mice, and the signal correlated with tumor burden during primary tumor growth, after surgical resection, and at the time of metastatic disease recurrence. Furthermore, the authors were able to detect the specific breakpoint in plasma DNA obtained from 3 patients with Ewing sarcoma and in 2 patients the authors were able to detect ptDNA when there was radiographically undetectable disease present. Conclusions The use of droplet digital PCR to detect tumor-specific EWS-ETS fusion gene breakpoint ptDNA fragments can be developed into a highly personalized biomarker of disease recurrence that can be optimized in animal studies for ultimate use in patients. Cancer 2016;122:3015-3023. © 2016 American Cancer Society.

To report outcomes after total en bloc spondylectomy (TES) for primary aggressive/malignant tumors of the lumbar spine. We performed a retrospective review of 23 neurosurgical patients operated between 2004 and 2014. Outcomes included perioperative complication rates and reoperation rates for instrumentation failure. The relationship between patient/operative parameters and complication development/instrumentation failure was investigated. There were 15 men (65.2 %) and eight women (24.8 %), with a median of 47 years. The most common tumor was chordoma in 11 patients (47.8 %), followed by sarcoma in four (17.4 %), and giant cell tumor in three (13.0 %). All patients but one underwent a two-staged operation; median total estimated blood loss was 3200 mL and median total operative time was 18.5 h. Fifteen patients developed at least one perioperative complication (65.2 %), with the most common being wound infection and ileus (26.1 % each). There was one case of intraoperative iliac vein injury (4.4 %). Instrumentation failure occurred in 9 patients (39.1 %) at a median time of 23 months after index spondylectomy. Following logistic regression, there were no factors associated with complication development. On the other hand, postoperative radiation was significantly associated with instrumentation failure (OR 7.49; 95 % CI, 1.02–54.9). Local recurrence and 5-year survival was 8.7 and 84.4 %, respectively. Median follow-up time was 50 months. Although favorable oncological outcomes after en bloc resection of spinal tumors may be achieved in terms of recurrence and survival, TES in the lumbar spine remains a challenging procedure. Future investigation into complication avoidance and reconstruction techniques is encouraged.

Background Anterior cervical discectomy and fusion (ACDF) is a commonly performed procedure. Cerebrospinal fluid (CSF) leaks, although uncommon, may occur and can be a potentially serious complication. Little is known regarding the fusion rate after durotomy in ACDF. This study sought to investigate the clinical outcomes and fusion rates of patients with CSF leak after ACDF. Methods In this single-institution retrospective review, 14 patients who experienced CSF leak after ACDF between 1995 and September 2014 were identified. Results The median follow-up was 13.1 months. The diagnoses included spondylosis/degenerative disc disease ( n = 10), disc herniation with radiculopathy ( n = 3), and kyphotic deformity ( n = 1). Of ACDFs, 7 were 1-level, 5 were 2-level, and 2 were 3-level procedures. The posterior longitudinal ligament was intentionally opened in all cases, and the microscope was used in 9 cases. Durotomy was discovered intraoperatively in all cases and was generally repaired with a combination of fibrin glue and synthetic dural replacement. Lumbar drainage was used in 5 patients, and 3 patients reported orthostatic headaches, which resolved within 1 month. Two patients reported hoarseness, and 8 patients reported dysphagia; all cases were transient. Follow-up imaging for fusion assessment was available for 12 patients, and a 100% fusion rate was achieved with no postoperative infections. Conclusions ACDFs with CSF leak had a 100% fusion rate in this series, with generally excellent clinical outcomes, although it is difficult to conclude definitively that there is no effect on fusion rates because of the small sample size. However, given the relative rarity of this complication, this study provides important data in the clinical literature regarding outcomes after CSF leak in ACDFs.

In image-guided spine surgery, robust three-dimensional to two-dimensional (3D-2D) registration of preoperative computed tomography (CT) and intraoperative radiographs can be challenged by the image content mismatch associated with the presence of surgical instrumentation and implants as well as soft-tissue resection or deformation. This work investigates image similarity metrics in 3D-2D registration offering improved robustness against mismatch, thereby improving performance and reducing or eliminating the need for manual masking. The performance of four gradient-based image similarity metrics (gradient information (GI), gradient correlation (GC), gradient information with linear scaling (GS), and gradient orientation (GO)) with a multi-start optimization strategy was evaluated in an institutional review board-approved retrospective clinical study using 51 preoperative CT images and 115 intraoperative mobile radiographs. Registrations were tested with and without polygonal masks as a function of the number of multistarts employed during optimization. Registration accuracy was evaluated in terms of the projection distance error (PDE) and assessment of failure modes (PDE 30 mm) that could impede reliable vertebral level localization. With manual polygonal masking and 200 multistarts, the GC and GO metrics exhibited robust performance with 0% gross failures and median PDE6.4 mm (±4.4 mm interquartile range (IQR)) and a median runtime of 84 s (plus upwards of 1-2 min for manual masking). Excluding manual polygonal masks and decreasing the number of multistarts to 50 caused the GC-based registration to fail at a rate of14%; however, GO maintained robustness with a 0% gross failure rate. Overall, the GI, GC, and GS metrics were susceptible to registration errors associated with content mismatch, but GO provided robust registration (median PDE = 5.5 mm, 2.6 mm IQR) without manual masking and with an improved runtime (29.3 s). The GO metric improved the registration accuracy and robustness in the presence of strong image content mismatch. This capability could offer valuable assistance and decision support in spine level localization in a manner consistent with clinical workflow.

Objective The objective of this study is to analyze time to surgery as both a continuous and discrete variable to determine its association with outcomes in cauda equina syndrome (CES). Methods Patients at a single center whose medical record allowed precise calculation of time to surgery were included. CES was defined as at least four of the following: bladder dysfunction, saddle anesthesia, lower extremity weakness, lower extremity sensory disturbance, bowel dysfunction, or acute lower back or leg pain. Time to surgery was analyzed as a continuous variable using logistic and ordered logistic regression, and as a discrete variable by comparing patients treated before and after set thresholds. Results Forty-five patients were identified. Analysis of time as a continuous variable did not reveal any significant association with outcomes. A parsimonious model with adjustment for age, sex, race, acute onset of CES, saddle anesthesia, motor deficit, and bowel dysfunction at presentation was used to analyze the continuous influence of time to surgery on bladder dysfunction and an aggregate outcome of symptoms. Neither time to surgery nor any of the covariates were significantly associated with either outcome. Discrete analysis of outcomes across thresholds of 12, 24, 36, 48, 60, and 72 hours did not reveal prognostic time points. Conclusion In this single-center CES series, time to surgery did not have a convincing continuous or discrete relationship with outcome. Future prospective studies are needed to determine the best timing for surgery in patients with CES.

Pseudarthrosis occurs after approximately 2-20% of anterior cervical discectomy and fusion (ACDF) procedures; it is unclear if posterior or anterior revision should be pursued. In this study, we retrospectively evaluate the outcomes in 22 patients with pseudarthrosis following ACDF and revision via posterior cervical fusion (PCF). Baseline demographics, preoperative symptoms, operative data, time to fusion failure, symptoms of pseudarthrosis, and revision method were assessed. Fusion outcome and clinical outcome were determined at last follow-up (LFU). Thirteen females (59%) and 9 (41%) males experienced pseudarthrosis at a median of 11 (range: 3-151)months after ACDF. Median age at index surgery was 51 (range: 33-67)years. All patients with pseudarthrosis presented with progressive neck pain, with median visual analog scale (VAS) score of 8 (range: 0-10), and/or myeloradiculopathy. Patients with pseudarthrosis12 months compared to12 months after index surgery were older (p=0.013), had more frequent preoperative neurological deficits (p=0.064), and lower baseline VAS scores (p=0.006). Fusion was successful after PCF in all patients, with median time to fusion of 10 (range: 2-14)months. Eighteen patients fused both anteriorly and posteriorly, two patients fused anteriorly only, and two patients fused posteriorly only. Median VAS neck score at LFU significantly improved from the time of pseudarthrosis (p=0.012). While uncommon, pseudarthrosis may occur after ACDF. All patients achieved successful fusion after subsequent posterior cervical fusion, with 91% fusing a previous anterior pseudarthrosis after posterior stabilization. Neck pain significantly improved by LFU in the majority of patients in this study.