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R. John Hurlbert, Neil R. Crawford, Won Gyu Choi and Curtis A. Dickman

Object. The purpose of this study was to compare cable techniques used in occipitocervical fixation with two types of screw fixation. The authors hypothesized that screw fixation would provide superior immobilization compared with cable methods.

Methods. Ten cadaveric specimens were prepared for biomechanical analyses by using standard techniques. Angular and linear displacement data were recorded from the occiput to C-6 with infrared optical sensors after conditioning runs. Specimens underwent retesting after fatiguing. Six methods of fixation were analyzed: Steinmann pin with and without C-1 incorporation; Cotrel-Dubousett horseshoe with and without C-1 incorporation; Mayfield loop with C1–2 transarticular screw fixation; and a custom-designed occipitocervical transarticular screw-plate system. Sublaminar techniques were extended to include C-3 in the fusion construct, whereas transarticular techniques incorporated the occiput, C-1, and C-2 only.

All methods of fixation provided significant immobilization in all specimens compared with the nonconstrained destabilized state. Despite incorporation of an additional vertebral segment, sublaminar techniques performed worse as a function of applied load than screw fixation techniques. Following fatiguing, these differences were more pronounced. The sublaminar techniques failed most prominently in flexion—extension and in axial rotation. On gross inspection, increased angular displacement associated with loosening of the sublaminar cables was observed.

Conclusion. Occipitocervical fixation can be performed using a variety of techniques; all bestow significant immobilization compared with the destabilized spine. All methods tested in this study were susceptible to fatigue and loss of reduction and were weakest in resisting vertical settling. Screw fixation of the occiput—C2 reduces the number of vertebral segments that are necessary to incorporate into the fusion construct while providing superior immobilization and resistance to fatigue and vertical settling compared with sublaminar methods.

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Samer K. Elbabaa, Murat Gokden, John R. Crawford, Santosh Kesari and Ali G. Saad

Object

Radiation-associated meningiomas (RAMs) arise after treatment with radiation to the cranium and are recognized as clinically separate from sporadic meningiomas. Compared with their sporadic counterparts, RAMs are often aggressive or malignant, likely to be multiple, and have a high recurrence rate. However, limited information exists about the clinical, pathological, and cytogenetic features of RAMs in pediatric patients. The authors report the findings in 9 children with meningiomas following therapeutic radiation to the cranium. In addition, they performed a critical review of the English language literature on pediatric RAMs.

Methods

Medical files were searched for patients who demonstrated meningiomas after a history of radiation to the brain. Only those patients in whom a meningioma occurred before the age of 18 years were included in this study. Clinical and demographic data along with the MIB-1 labeling index and cytogenetic studies were evaluated.

Results

The patients consisted of 5 males and 4 females with a median age of 5 years (range 2–10 years) at radiation therapy. The latency period was a median of 10 years after radiation therapy (range 6–13 years). The MIB-1 labeling index was a median of 6.6% (range 4%–10%). Five patients (55.6%) displayed multiple meningiomas at the first presentation. Histological types included clear cell meningioma in 1 patient, fibroblastic meningioma in 2, chordoid meningioma in 2, meningothelial meningioma in 7 (atypical in 2 cases), xanthomatous meningioma in 1, and chordoid meningioma in 1. Cytogenetic studies showed that the loss of 22q12.2 was the most common abnormality (3 patients), followed by complex cytogenetic abnormalities (2 patients) and rearrangements between chromosomes 1 and 12 (1 patient) and a 1p deletion (1 patient).

Conclusions

In contrast to RAMs occurring in adults, those in pediatric patients show an increased incidence of multiplicity on first presentation and unusual histological variants, some of which are described here for the first time. There was no difference in the MIB-1 labeling index in children with RAMs as compared with that in children with non-RAMs.

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Brandon C. Gabel, Joel Martin, John R. Crawford and Michael Levy

OBJECTIVE

The object of this study is to address what factors may necessitate the need for intensive care monitoring after elective uncomplicated craniotomy in pediatric patients who are initially managed in a non–intensive care unit setting postoperatively.

METHODS

A retrospective chart review was undertaken for all patients who underwent elective craniotomy for brain tumor between April of 2007 and April of 2012 and who were directly admitted to the floor postoperatively. Factors such as age, tumor type, craniotomy location, neurological comorbidities, reason for transfer to intensive care unit (ICU) level of care (if applicable), time between admittance to floor and transfer to ICU level of care, and reason for transfer to ICU level of care were assessed.

RESULTS

Adjusted logistic regression found 2 significant positive predictors of postoperative transfer to the ICU after initial admission to the floor: primitive neuroectodermal tumor pathology (OR 44.10, 95% CI 1.24–1572.16, p = 0.04), and repeat craniotomy during the same hospitalization (OR 13.97, 95% CI 1.21–160.66, p = 0.03). Conversely, 1 negative factor was found: low-grade glioma pathology (OR 0.05, 95% CI 0.00–0.87, p = 0.04).

CONCLUSIONS

Select pediatric patients may not require ICU level of care after elective uncomplicated pediatric craniotomy. Additional studies are needed to adequately address which patients would benefit from initial ICU admittance following elective craniotomies for brain tumors.

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Mladen Djurasovic, Steven D. Glassman, John R. Dimar II, Charles H. Crawford III, Kelly R. Bratcher and Leah Y. Carreon

Object

Clinical studies use both disease-specific and generic health outcomes measures. Disease-specific measures focus on health domains most relevant to the clinical population, while generic measures assess overall health-related quality of life. There is little information about which domains of the Oswestry Disability Index (ODI) are most important in determining improvement in overall health-related quality of life, as measured by the 36-Item Short Form Health Survey (SF-36), after lumbar spinal fusion. The objective of the study is to determine which clinical elements assessed by the ODI most influence improvement of overall health-related quality of life.

Methods

A single tertiary spine center database was used to identify patients undergoing lumbar fusion for standard degenerative indications. Patients with complete preoperative and 2-year outcomes measures were included. Pearson correlation was used to assess the relationship between improvement in each item of the ODI with improvement in the SF-36 physical component summary (PCS) score, as well as achievement of the SF-36 PCS minimum clinically important difference (MCID). Multivariate regression modeling was used to examine which items of the ODI best predicted achievement for the SF-36 PCS MCID. The effect size and standardized response mean were calculated for each of the items of the ODI.

Results

A total of 1104 patients met inclusion criteria (674 female and 430 male patients). The mean age at surgery was 57 years. All items of the ODI showed significant correlations with the change in SF-36 PCS score and achievement of MCID for the SF-36 PCS, but only pain intensity, walking, and social life had r values > 0.4 reflecting moderate correlation. These 3 variables were also the dimensions that were independent predictors of the SF-36 PCS, and they were the only dimensions that had effect sizes and standardized response means that were moderate to large.

Conclusions

Of the health dimensions measured by the ODI, pain intensity, walking, and social life best predicted improvement in overall health-related quality of life, as measured using the SF-36 PCS.

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Mladen Djurasovic, Katlyn E. McGraw, Kelly Bratcher, Charles H. Crawford III, John R. Dimar II, Rolando M. Puno, Steven D. Glassman, R. Kirk Owens II and Leah Y. Carreon

OBJECTIVE

The goal of this study was to determine efficacy and cost-effectiveness of Cell Saver in 2- and 3-level lumbar decompression and fusion.

METHODS

Patients seen at a tertiary care spine center who were undergoing a posterior 2- or 3-level lumbar decompression and fusion were randomized to have Cell Saver used during their surgery (CS group, n = 48) or not used (No Cell Saver [NCS] group, n = 47). Data regarding preoperative and postoperative hemoglobin and hematocrit, estimated blood loss, volume of Cell Saver blood reinfused, number of units and volume of allogeneic blood transfused intraoperatively and postoperatively, complications, and costs were collected. Costs associated with Cell Saver use were calculated based on units of allogeneic blood transfusions averted.

RESULTS

Demographics and surgical parameters were similar in both groups. The mean estimated blood loss was similar in both groups: 612 ml in the CS group and 742 ml in the NCS group. There were 53 U of allogeneic blood transfused in 29 patients in the NCS group at a total blood product cost of $67,688; and 38 U of allogeneic blood transfused in 16 patients in the CS group at a total blood cost of $113,162, resulting in a cost of $3031 per allogeneic blood transfusion averted using Cell Saver.

CONCLUSIONS

Cell Saver use produced lower rates of allogeneic transfusion but was found to be more expensive than using only allogeneic blood for 2- and 3-level lumbar degenerative fusions. This increased cost may be reasonable to patients who perceive that the risks associated with allogeneic transfusions are unacceptable.

CLASSIFICATION OF EVIDENCE Type of question: therapeutic; study design: randomized controlled trial; evidence: class III.

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Yoko T. Udaka, Lanipua A. Yeh-Nayre, Chiazo S. Amene, Scott R. VandenBerg, Michael L. Levy and John R. Crawford

Object

Pediatric low-grade glioma (LGG) is the most common brain tumor of childhood. Except for the known association of gross-total resection and improved survival rates, relatively little is known about the clinical and radiographic predictors of recurrent disease and the optimal frequency of surveillance MRI. The authors sought to determine the clinical and radiographic features associated with recurrent or progressive disease in a single-institutional series of children diagnosed with primary CNS LGG.

Methods

The authors performed a retrospective analysis of data obtained in 102 consecutive patients diagnosed at Rady Children's Hospital–San Diego between 1994 and 2010 with a biopsy-proven LGG exclusive of a diagnosis of neurofibromatosis. Tumor location, patient age, sex, and symptomatology were correlated with tumor progression or recurrence. Magnetic resonance imaging characteristics and neuroimaging surveillance frequency were analyzed in those children with progressive or recurrent disease.

Results

Forty-six of 102 children diagnosed with an LGG had evidence of recurrent or progressive disease between 2 months and 11 years (mean 27.3 months) after diagnosis. In the larger group of 102 children, gross-total resection was associated with improved progression-free survival (p = 0.012). The location of tumor (p = 0.26), age at diagnosis (p = 0.69), duration of symptoms (p = 0.72), histological subtype (p = 0.74), sex (p = 0.53), or specific chemotherapeutic treatment regimen (p = 0.24) was not associated with tumor progression or recurrence. Sixty-four percent of children with recurrent or progressive disease were asymptomatic, and recurrence was diagnosed by surveillance MRI alone. All children less than 2 years of age in whom the tumor was diagnosed were asymptomatic at the time of progression (p = 0.04). Thirteen percent (6 of 46) of the children had disease recurrence 5 years after initial diagnosis; all of them had undergone an initial subtotal resection. Tumor progression was associated with either homogeneous or patchy T1-weighted post–Gd administration MRI enhancement in 94% of the cases (p = 0.0001).

Conclusions

Children diagnosed with recurrent LGG may be asymptomatic at the time of recurrence. The authors' findings support the need for routine neuroimaging in a subset of children with LGGs, even when gross-total resection has been achieved, up to 5 years postdiagnosis. The authors found that T1-weighted MR images obtained before and after Gd administration alone may be sufficient to diagnose LGG recurrence and may represent an effective strategy worthy of further validation in a larger multiinstitutional cohort.

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Robert C. Rennert, Danielle M. Levy, Jillian Plonsker, Jeffrey A. Steinberg, Rick A. Friedman, John R. Crawford and Michael L. Levy

Pediatric cerebellopontine angle (CPA) meningiomas are extremely rare and are usually treated with a retrosigmoid surgical approach or radiation. The authors present the use of a middle fossa approach for the treatment of a symptomatic CPA meningioma in a 22-month-old female. The patient initially presented at 17 months with isolated progressive, long-standing right-sided facial weakness. MRI demonstrated a 5.0 × 5.0–mm right CPA lesion just superior to the cisternal segment of cranial nerve (CN) VII, which demonstrated growth on interval imaging. At 22 months of age she underwent a successful middle fossa craniotomy, including wide exposure of the porus acusticus, allowing for a gross-total resection with preservation of CNs VII and VIII. Pathological analysis revealed a WHO grade I meningioma. The patient remained neurologically stable on follow-up. The middle fossa approach can be used to safely access the CPA in properly selected pediatric patients.

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Leah Y. Carreon, Mladen Djurasovic, John R. Dimar II, R. Kirk Owens II, Charles H. Crawford III, Rolando M. Puno, Kelly R. Bratcher, Katlyn E. McGraw and Steven D. Glassman

OBJECTIVE

Studies have shown that anxious or depressed patients may have poorer outcomes after lumbar fusion. These conclusions were drawn from questionnaires specifically designed to measure anxiety and depression. The objective of this study is to determine if responses to the EQ-5D anxiety/depression domain or the items used to calculate the 36-Item Short-Form Health Survey (SF-36) Mental Component Summary (MCS) can predict outcomes after lumbar fusion surgery.

METHODS

Patients enrolled in the National Neurosurgery Quality and Outcomes Database from a single center with 1-year follow-up were identified. The outcomes collected include the Oswestry Disability Index (ODI), EQ-5D, SF-36, and the back- and leg-pain numeric rating scales (range 0–10). Linear regression modeling was performed to predict the 1-year ODI scores using the EQ-5D anxiety/depression domain and the 14 items used to calculate SF-36 MCS.

RESULTS

Complete data were available for 312 (88%) of 353 eligible patients. The mean patient age was 58.5 years, 175 (56%) patients were women, and 52 patients were smokers. After controlling for other factors, the item in the SF-36 that asks “Have you felt downhearted and depressed?” is the strongest predictor of the 1-year ODI score (r2 = 0.191; p = 0.000) and 1-year EQ-5D score (r2 = 0.205; p = 0.000). Neither the EQ-5D anxiety/depression domain nor the diagnoses of anxiety or depression were predictors of 1-year outcomes.

CONCLUSIONS

Patient responses to SF-36 item “Have you felt downhearted and depressed?” account for 20% of the variability of the 1-year ODI and EQ-5D scores and can be used by clinicians to screen for anxiety or depression in patients prior to lumbar fusion surgery. Clinicians may offer psychological support to these patients preoperatively in order to improve treatment outcomes.

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Yoji Ogura, Jeffrey L. Gum, Portia Steele, Charles H. Crawford III, Mladen Djurasovic, R. Kirk Owens II, Joseph L. Laratta, Morgan Brown, Christy Daniels, John R. Dimar II, Steven D. Glassman and Leah Y. Carreon

OBJECTIVE

Unexpected nonhome discharge causes additional costs in the current reimbursement models, especially to the payor. Nonhome discharge is also related to longer length of hospital stay and therefore higher healthcare costs to society. With increasing demand for spine surgery, it is important to minimize costs by streamlining discharges and reducing length of hospital stay. Identifying factors associated with nonhome discharge can be useful for early intervention for discharge planning. The authors aimed to identify the drivers of nonhome discharge in patients undergoing 1- or 2-level instrumented lumbar fusion.

METHODS

The electronic medical records from a single-center hospital administrative database were analyzed for consecutive patients who underwent 1- to 2-level instrumented lumbar fusion for degenerative lumbar conditions during the period from 2016 to 2018. Discharge disposition was determined as home or nonhome. A logistic regression analysis was used to determine associations between nonhome discharge and age, sex, body mass index (BMI), race, American Society of Anesthesiologists grade, smoking status, marital status, insurance type, residence in an underserved zip code, and operative factors.

RESULTS

A total of 1502 patients were included. The majority (81%) were discharged home. Factors associated with a nonhome discharge were older age, higher BMI, living in an underserved zip code, not being married, being on government insurance, and having more levels fused. Patients discharged to a nonhome facility had longer lengths of hospital stay (5.6 vs 3.0 days, p < 0.001) and significantly increased hospital costs ($21,204 vs $17,518, p < 0.001).

CONCLUSIONS

Increased age, greater BMI, residence in an underserved zip code, not being married, and government insurance are drivers for discharge to a nonhome facility after a 1- to 2-level instrumented lumbar fusion. Early identification and intervention for these patients, even before admission, may decrease the length of hospital stay and medical costs.