Bone Quality as Measured by Hounsfield Units More Accurately Predicts Proximal Junctional Kyphosis than Vertebral Bone Quality Following Long-Segment Thoracolumbar Fusion.

OBJECTIVE: To compare the prognostic power of Hounsfield units (HU) and Vertebral Bone Quality (VBQ) score for predicting proximal junctional kyphosis (PJK) following long-segment thoracolumbar fusion to the upper thoracic spine (T1-T6). METHODS: Vertebral bone quality around the upper instrumented vertebrae (UIV) was measured using HU on preoperative CT and VBQ on preoperative MRI. Spinopelvic parameters were also categorized according to the Scoliosis Research Society-Schwab classification. Univariable analysis to identify predictors of the occurrence of PJK and survival analyses with Kaplan-Meier method and Cox regression were performed to identify predictors of time to PJK (defined as ≥10° change in Cobb angle of UIV+2 and UIV). Sensitivity analyses showed thresholds of HU < 164 and VBQ > 2.7 to be most predictive for PJK. RESULTS: Seventy-six patients (mean age 66.0 ± 7.0 years; 27.6% male) were identified, of whom 15 suffered PJK. Significant predictors of PJK were high postoperative pelvic tilt (P = 0.038), high postoperative T1-pelvic angle (P = 0.041), and high postoperative PI-LL mismatch (P = 0.028). On survival analyses, bone quality, as assessed by the average HU of the UIV and UIV+1 was the only significant predictor of time to PJK (odds ratio [OR] 3.053; 95% CI 1.032-9.032; P = 0.044). VBQ measured using the UIV, UIV+1, UIV+2, and UIV-1 vertebrae approached, but did not reach significance (OR 2.913; 95% CI 0.797-10.646; P = 0.106). CONCLUSIONS: In larger cohorts, VBQ may prove to be a significant predictor of PJK following long-segment thoracolumbar fusion. However, Hounsfield units on CT have greater predictive power, suggesting preoperative workup for long-segment thoracolumbar fusion benefits from computed tomography versus magnetic resonance imaging alone to identify those at increased risk of PJK.

Clinical presentation, role of surgery and prognosis in spinal astrocytoma: Cohort study.

Spinal astrocytoma is a rare neoplasm with discouraging prognosis, which accounts for 6-8 % of total intramedullary spinal tumors. As this is a rare entity, details of the clinical and molecular features have not been fully unraveled. We evaluated the radiologic findings, perioperative clinical presentation, histopathological features and treatment response in a single institution series of 37 consecutive cases of spinal astrocytomas (WHO grades 1 to 4). We identified 8, 16, 8, and 5 patients with grade 1, 2, 3, and 4 lesions, respectively, from 1988 to 2017. Peak ages were youngest in grade 1, followed in order by grades 4, 3 and 2. Whereas all cases of grade 1 and 4 enhanced with contrast, less than half of the cases of grade 2 tumors enhanced (44 %). Grade 3 tumors had a higher rate of multiplicity at presentation (50 %). A concomitant brain lesion at presentation was present in 14 % and 43 % of grade 2 and 3 lesions, respectively. Progression-free and overall survival were worse in grades 3 and 4 compared to grade 2 lesions but no significant difference was observed between grade 3 and 4. Many patients (16-of-36) experienced new neurological deficits postoperatively regardless of grade. Most patients (88 %) required postoperative rehabilitation, and 61 % were not discharged to home. Discharge destination closely correlated with age (p = 0.002). These clinical findings may be useful in understanding the clinical phenotype and improving the management of this rare disease.

What Factors Predict the Development of Neurologic Deficits Following Resection of Intramedullary Spinal Cord Tumors: A Multi-Center Study.

BACKGROUND: Intramedullary spinal cord tumors are challenging to resect, and their postoperative neurological outcomes are often difficult to predict, with few studies assessing this outcome. METHODS: We reviewed the medical records of all patients surgically treated for Intramedullary spinal cord tumors at our multisite tertiary care institution (Mayo Clinic Arizona, Mayo Clinic Florida, Mayo Clinic Rochester) between June 2002 and May 2020. Variables that were significant in the univariate analyses were included in a multivariate logistic regression. "MissForest" operating on the Random Forest algorithm, was used for data imputation, and K-prototype was used for data clustering. Heatmaps were added to show correlations between postoperative neurological deficit and all other included variables. Shapley Additive exPlanations were implemented to understand each feature's importance. RESULTS: Our query resulted in 315 patients, with 160 meeting the inclusion criteria. There were 53 patients with astrocytoma, 66 with ependymoma, and 41 with hemangioblastoma. The mean age (standard deviation) was 42.3 (17.5), and 48.1% of patients were women (n = 77/160). Multivariate analysis revealed that pathologic grade >3 (OR = 1.55; CI = [0.67, 3.58], P = 0.046 predicted a new neurological deficit. Random Forest algorithm (supervised machine learning) found age, use of neuromonitoring, histology of the tumor, performing a midline myelotomy, and tumor location to be the most important predictors of new postoperative neurological deficits. CONCLUSIONS: Tumor grade/histology, age, use of neuromonitoring, and myelotomy type appeared to be most predictive of postoperative neurological deficits. These results can be used to better inform patients of perioperative risk.

Comparison of Hounsfield units and vertebral bone quality score for the prediction of time to pathologic fracture in mobile spine metastases treated with radiotherapy.

OBJECTIVE: Spine metastases are commonly treated with radiotherapy for local tumor control; pathologic fracture is a potential complication of spinal radiotherapy. Both Hounsfield units (HUs) on CT and vertebral bone quality (VBQ) on MRI have been argued to predict stability as measured by odds of pathologic fracture, although it is unclear if there is a difference in the predictive power between the two methodologies. The objective of the present study was to examine whether one methodology is a better predictor of pathologic fracture following radiotherapy for mobile spine metastases. METHODS: Patients who underwent radiotherapy (conventional external-beam radiation therapy, stereotactic body radiation therapy, or intensity-modulated radiation therapy) for mobile spine (C1-L5) metastases at a tertiary care center were retrospectively identified. Details regarding underlying pathology, patient demographics, and tumor morphology were collected. Vertebral involvement was assessed using the Weinstein-Boriani-Biagini (WBB) system. Bone quality of the non-tumor-involved bone was assessed on both pretreatment CT and MRI. Univariable analyses were conducted to identify independent predictors of fracture, and Kaplan-Meier analyses were used to identify significant predictors of time to pathologic fracture. Stepwise Cox regression analysis was used to determine independent predictors of time to fracture. RESULTS: One hundred patients were included (mean age 62.7 ± 11.9 years; 61% male), of whom 35 experienced postradiotherapy pathologic fractures. The most common histologies were lung (22%), prostate (21%), breast (14%), and renal cell (13%). On univariable analysis, the mean HUs of the vertebrae adjacent to the fractured vertebra were significantly lower among those experiencing fracture; VBQ was not significantly associated with fracture odds. Survival analysis showed that average HUs ≤ 132, nonprostate pathology, involvement of ≥ 3 vertebral body segments on the WBB system, Spine Instability Neoplastic Score (SINS) ≥ 7, and the presence of axial pain all predicted increased odds of fracture (all p < 0.001). Cox regression found that HUs ≤ 132 (OR 2.533, 95% CI 1.257-5.103; p = 0.009), ≥ 3 WBB vertebral body segments involved (OR 2.376, 95% CI 1.132-4.987; p = 0.022), and axial pain (OR 2.036, 95% CI 0.916-4.526; p = 0.081) predicted increased fracture odds, while prostate pathology predicted decreased odds (OR 0.076, 95% CI 0.009-0.613; p = 0.016). Sensitivity analysis suggested that an HU threshold of ≤ 132 and a SINS of ≥ 7 identified patients at increased risk of fracture. CONCLUSIONS: The present results suggest that bone density surrogates as measured on CT, but not MRI, can be used to predict the risk of pathologic fracture following radiotherapy for mobile spine metastases. More extensive vertebral body involvement and the presence of mechanical axial pain additionally predict increased fracture odds.

Bone but not Bone: Systemic Calcinosis Presenting as Lumbar Facet Pseudohypertrophy with Neurogenic Claudication.

Systemic sclerosis affects 14-21 per million persons annually and can present with calcinosis-deposition in the skin and subcutaneous tissues. In rare circumstances, paraspinal depositions are also seen, which can cause neural element compression requiring surgical intervention. Here we present the case of a 61-year-old woman with systemic sclerosis on goal-directed therapy who presented with neurogenic pseudoclaudication and imaging suggesting severe joint hypertrophy. The case illustrates that calcinosis in scleroderma can cause facet joint pseudohypertrophy that is difficult to distinguish from true hypertrophy on imaging. Such pseudohypertrophy is often refractory to medical therapy, necessitating surgical intervention. Last, owing to the fluid nature of the calcinotic fluid, decompression is often easier than would be expected based on preoperative imaging alone.

Risk factors for sacral fracture following en bloc chordoma resection.

OBJECTIVE: The purpose of this study was to analyze risk factors for sacral fracture following noninstrumented partial sacral amputation for en bloc chordoma resection. METHODS: A multicenter retrospective chart review identified patients who underwent noninstrumented partial sacral amputation for en bloc chordoma resection with pre- and postoperative imaging. Hounsfield units (HU) were measured in the S1 level. Sacral amputation level nomenclature was based on the highest sacral level with bone removed (e.g., S1 foramen amputation at the S1-2 vestigial disc is an S2 sacral amputation). Variables collected included basic demographics, patient comorbidities, surgical approach, preoperative radiographic details, neoadjuvant and adjuvant radiation therapy, and postoperative sacral fracture data. RESULTS: A total of 101 patients (60 men, 41 women) were included; they had an average age of 69 years, BMI of 29 kg/m2, and follow-up of 60 months. The sacral amputation level was S1 (2%), S2 (37%), S3 (44%), S4 (9%), and S5 (9%). Patients had a posterior-only approach (77%) or a combined anterior-posterior approach (23%), with 10 patients (10%) having partial sacroiliac (SI) joint resection. Twenty-seven patients (27%) suffered a postoperative sacral fracture, all occurring between 1 and 7 months after the index surgery. Multivariable logistic regression analysis demonstrated S1 or S2 sacral amputation level (p = 0.001), combined anterior-posterior approach (p = 0.0064), and low superior S1 HU (p = 0.027) to be independent predictors of sacral fracture. The fracture rate for patients with superior S1 HU < 225, 225-300, and > 300 was 38%, 15%, and 9%, respectively. An optimal superior S1 HU cutoff of 300 was found to maximize sensitivity (89%) and specificity (42%) in predicting postamputation sacral fracture. In addition, the fracture rate for patients who underwent partial SI joint resection was 100%. CONCLUSIONS: Patients with S1 or S2 partial sacral amputations, a combined anterior-posterior surgical approach, low superior S1 HU, and partial SI joint resection are at higher risk for postoperative sacral fracture following en bloc chordoma resection and should be considered for spinopelvic instrumentation at the index procedure.

Impact of tumor-associated syrinx on outcomes following resection of primary ependymomas of the spinal cord.

PURPOSE: To interrogate the association of tumor-associated syrinxes with postoperative neurological and oncological outcomes in patients surgically treated for WHO grade 2 spinal ependymomas. METHODS: Adults treated for primary spinal intramedullary ependymomas between 2000 and 2020 were identified and data were gathered on preoperative neurological exam, radiographic characteristics, operative details, and postoperative neurological outcome. Neurological status was graded on the modified McCormick Scale (MMS). Neurological worsening immediately postoperatively and at last follow-up were defined by ≥ 1 MMS grade deterioration. Decision-tree analyses were also performed to identify independent predictors of new neurological deficits. RESULTS: Seventy patients were identified; mean age 45.4 ± 12.7; 60% male. Forty-eight patients (68.6%) had tumor-associated syrinxes, were more common among males (68.8%) and cervical lesions (68.8 vs. 31.8%; P = 0.005). Postoperatively patients with syrinxes had better MMS (P = 0.035) and were less likely to require a gait aid (39.6 vs. 81.8; P = 0.002). This latter difference persisted to last follow-up (22.9 vs. 59.1%; P = 0.006). On decision-tree analysis the strongest predictors of long-term neurological worsening were advanced age (≥ 63 years) and worse baseline neurological function. Worsened neurological status in the immediate postoperative period was best predicted by thoracic localization, the presence of a hemosiderin cap, and longer craniocaudal extension. CONCLUSION: For spinal ependymomas, tumor-associated syrinxes may portend decreased risk for immediate postoperative neurologic deficits but do not predict long-term neurological outcomes (MMS) or odds of successful gross total resection. Thoracic localization appears to best predict new immediate postoperative deficits, and worse baseline neurological function and advanced age best predict long-term deficits.

Surgical management of sacral schwannomas: a 21-year mayo clinic experience and comparative literature analysis.

INTRODUCTION: Sacral and presacral schwannomas are rare, accounting for a minority of spinal schwannomas. We present our institution's experience surgically treating spinal schwannomas and compare it to the literature. METHODS: Data were collected for 27 patients treated surgically for sacral or presacral schwannoma between 1997 and 2018 at all Mayo Clinic locations and 93 patients in the literature. Kaplan-Meier disease-free survival analysis was conducted. Unpaired two-sample t tests and Fisher's exact tests assessed statistical significance between groups. RESULTS: Our patients and those in the literature experienced a similar age at diagnosis (49.9 y/o. vs 43.4 y/o., respectively). Most of our patients (59.3%) reported full recovery from symptoms, while a minority reported partial recovery (33.3%) and no recovery (11.1%). A smaller percentage in the literature experienced full recovery (31.9%) and partial recovery (29.8%) but also no recovery (1.1%). Our patients experienced fewer complications (14.8% versus 25.5%). Disease-free survival curves for all patients showed no significant variation in progression by extent of resection of schwannoma (log-rank P = 0.26). No lesion progression was associated with full or partial symptom improvement (p = 0.044), and female patients were more likely to undergo resection via a posterior approach (p = 0.042). CONCLUSION: Outcomes of patients with sacral or presacral schwannomas vary based on patient demographics, tumor characteristics, symptoms, and surgical treatment. Among the range of symptoms experienced by these patients, the most common is pain. Prognosis improves and overall survival is high when the surgical approach towards sacral schwannomas is prepared and executed appropriately.

Prognostic Factors Independently Associated With Improved Progression-Free Survival After Surgical Resection in Patients With Spinal Cord Astrocytomas: An Institutional Case Series.

BACKGROUND: Spinal astrocytomas are rare tumors in which the extent of resection and adjuvant therapy remain controversial. A number of new molecular markers are used, but their utility in spinal cord tumors remains unclear. OBJECTIVE: To determine prognostic indicators of progression-free survival (PFS) in patients with spinal astrocytomas. METHODS: A retrospective chart review identified all patients managed at a single institution for spinal cord astrocytomas between 1999 and 2019. Data collected included baseline demographics, presenting signs and symptoms, tumor size, operative outcomes, and adjuvant treatment. Pathological data including histopathological grade, proliferative index, and molecular profile were collected. Duration of follow-up, presence of tumor progression, and status at last follow-up were documented. Univariate and multivariate analyses were performed to determine predictors of PFS. RESULTS: Seventy-five patients were included in our study with an average age of 42 ± 17 yr. The thoracic spine was the most commonly involved spinal segment (50 patients), and most patients had grade I or grade II tumors (50 patients). On univariate analysis, gross total resection (GTR), lower tumor grade, and low Ki-67 index were associated with lower tumor progression (P-values .01, .04, and .00013, respectively). On multivariate Cox regression analysis, GTR, adjuvant chemotherapy and radiation, and low Ki-67 index were independent predictors of PFS (P-values .009, .011, and .031, respectively). CONCLUSION: In spinal astrocytomas, GTR, adjuvant therapy, and low Ki-67 are independently associated with improved PFS. These data may help guide management of these tumors and provide important prognosticating information.

Myxopapillary ependymomas; proximity to the conus and its effect on presentation and outcomes.

BACKGROUND: Myxopapillary ependymomas (MPE) are intradural spinal tumors with a predilection to the filum terminale. Damage to conus medullaris during surgery can result in sphincteric and sexual dysfunction. The purpose of this study is to determine how myxopapillary ependymoma proximity to the conus impacts patient presentation, extent of resection, and clinical outcomes. METHODS: Fifty-one patients who underwent surgical resection of pathologically confirmed myxopapillary ependymoma with at least 1 year of follow-up were included in the study. We collected initial presenting symptoms, distance of the tumor from the conus, extent of resection, and postoperative clinical outcomes including bladder dysfunction. RESULTS: Average age was 38 years (range 7-75 years) with a male to female ratio of 1.43:1. Patients most commonly presented with pain symptoms (88%), and 12 patients (23.5%) had urologic symptoms on presentation. The mean tumor distance from the tip of the conus was 1.60 cm (10 cm above to 21 cm below the tip of the conus). Patients with tumors in contact with the conus had a significantly higher rate of preoperative urinary symptoms and were more likely (32% vs. 14%) to suffer postoperative urinary sphincteric disturbances. Tumors with direct invasion of the conus medullaris were more likely to require intralesional resection and fail to achieve a gross total resection (GTR). CONCLUSION: Patients with MPE in close proximity to the conus were more likely to suffer from long-term morbidity related to urologic issues following surgical resection. Adjuvant radiotherapy may be a viable option for patients who fail to achieve GTR.

Impact of Opioid Prescribing Guidelines on Postoperative Opioid Prescriptions Following Elective Spine Surgery: Results From an Institutional Quality Improvement Initiative.

BACKGROUND: With a dramatic rise in prescription opioid use, it is imperative to review postsurgical prescribing patterns given their contributions to the opioid epidemic. OBJECTIVE: To evaluate the impact of departmental postoperative prescribing guidelines on opioid prescriptions following elective spine surgery. METHODS: Patients undergoing elective cervical or lumbar spine surgery between 2017 and 2018 were identified. Procedure-specific opioid prescribing guidelines to limit postoperative prescribing following neurosurgical procedures were developed in 2017 and implemented in January 2018. Preguideline data were available from July to December 2017, and postguideline data from July to December 2018. Discharge prescriptions in morphine milliequivalents (MMEs), the proportion of patients (i) discharged with an opioid prescription, (ii) needing refills within 30 d, (iii) with guideline compliant prescriptions were compared in the 2 groups. Multivariable (MV) analyses were performed to assess the impact of guideline implementation on refill prescriptions within 30 d. RESULTS: A total of 1193 patients were identified (cervical: 308; lumbar: 885) with 569 (47.7%) patients from the preguideline period. Following guideline implementation, fewer patients were discharged with a postoperative opioid prescription (92.5% vs 81.7%, P < .001) and median postoperative opioid prescription decreased significantly (300 MMEs vs 225 MMEs, P < .001). The 30-d refill prescription rate was not significantly different between preguideline and postguideline cohorts (pre: 24.4% vs post: 20.2%, P = .079). MV analyses did not demonstrate any impact of guideline implementation on need for 30-d refill prescriptions for both cervical (odds ratio [OR] = 0.68, confidence interval [CI] = 0.37-1.26, P = .22) and lumbar cohorts (OR = 0.95, CI = 0.66-1.36, P = .78). CONCLUSION: Provider-aimed interventions such as implementation of procedure-specific prescribing guidelines can significantly reduce postoperative opioid prescriptions following spine surgery without increasing the need for refill prescriptions for pain control.

Variations in Postoperative Opioid Prescription Practices and Impact on Refill Prescriptions Following Lumbar Spine Surgery.

OBJECTIVE: Understanding postsurgical prescribing patterns and their impact on persistent opioid use is important for establishing reasonable opioid prescribing protocols. We aimed to determine national variation in postoperative opioid prescription practices following elective lumbar spine surgery and their impact on short-term refill prescriptions. METHODS: The OptumLabs Data Warehouse was queried from 2016 to 2017 for adults undergoing anterior lumbar fusion, posterior lumbar fusion, circumferential lumbar fusion, and lumbar decompression/discectomy for degenerative spine disease. Discharge opioid prescription fills were obtained and converted to morphine milligram equivalents (MMEs). Age- and sex-adjusted MMEs and frequency of discharge prescriptions >200 MMEs were determined for each U.S. census division and procedure type. RESULTS: The study included 43,572 patients with 37,894 postdischarge opioid prescription fills. There was wide variation in mean filled MMEs across all census divisions (anterior lumbar fusion: 774-1147 MMEs; posterior lumbar fusion: 717-1280 MMEs; circumferential lumbar fusion: 817-1271 MMEs; lumbar decompression/discectomy: 619-787 MMEs). A significant proportion of cases were found to have filled discharge prescriptions >200 MMEs (posterior lumbar fusion: 78.6%-95%; anterior lumbar fusion: 87.5%-95.6%; circumferential lumbar fusion: 81.4%-96.5%; lumbar decompression/discectomy: 80.5%-91%). Multivariable logistic regression showed that female sex and inpatient surgery were associated with a top-quartile discharge prescription and a short-term second opioid prescription fill, while the opposite was noted for elderly and opioid-naïve patients (all P ≤ 0.05). Prescriptions with long-acting opioids were associated with higher odds of a second opioid prescription fill (reference: nontramadol short-acting opioid). CONCLUSIONS: In analysis of filled opioid prescriptions, we observed a significant proportion of prescriptions >200 MMEs and wide regional variation in postdischarge opioid prescribing patterns following elective lumbar spine surgery.

Clinical characteristics and management differences for grade II and III spinal meningiomas.

PURPOSE: The majority of spinal meningiomas are grade I tumors, as defined by World Health Organization (WHO) classification making atypical (grade II) or anaplastic (grade III) tumors extremely rare lesions to encounter in clinical practice. Here, we present our institutional experience of management of grade II and III spinal meningiomas. METHODS: Following IRB approval, we queried all available institutional electronic medical records for patients undergoing surgical resection of pathology-proven spinal meningiomas, with further review of patients with grade II and III. Variables of interest included age, sex, histological type, tumor size, symptoms at baseline, treatment characteristics, symptom resolution at the last follow-up, recurrence, NF-2 status, concurrent intracranial meningioma, and mortality. Kaplan Meier curves were constructed to study time to progression/recurrence. RESULTS: A total of 188 patients undergoing surgical resection of spinal meningioma between 1988 and 2018 were identified. Among those, 172 (91.5%) patients had grade I meningioma and 16 (8.5%) patients had high grade meningiomas [grade II (15) and III (1)]. Over a median (IQR) follow-up of 8.0 years (5.1-13.0), mortality and recurrence rates were 18.8% (n = 3) and 47.1% (n = 8), respectively. In univariate analysis, adjuvant radiotherapy and thoracic segment involvement were associated with lower rates of recurrence while male sex was associated with a higher rate of recurrence. CONCLUSIONS: Results showed variations in clinical outcomes for patients with high grade spinal meningiomas, especially the recurrence. Adjuvant radiotherapy and thoracic segment involvement was associated with lower rates of recurrence while recurrence ocurred at a higher rate in males.

Expanded neuromuscular morbidity in Hodgkin lymphoma after radiotherapy.

Our study aims to quantitate neuromuscular morbidity from radiotherapy in Hodgkin lymphoma including: (i) frequency and (ii) time of onsets for neurological localizations; (iii) degree of disabilities and (iv) number of clinical visits compared to cardiopulmonary Hodgkin lymphoma-radiation complications. Medical records from Mayo Health systems were retrieved; identifying neuromuscular radiation treated Hodgkin lymphoma-complications from 1 January 1994 to 31 December 2016. Of an estimated 4100 post-radiotherapy Hodgkin lymphoma patients, 4.6% (189) were identified with complications. Mean latency to physician visit for symptoms was 23.7 years (range: 1-50). Most commonly identified complications included: head drop 10% (19) with or without myopathy, myopathy 39% (73), plexopathy 29% (54), myelopathy 27% (51) and polyradiculopathy 13% (24). Other findings included benign and malignant nerve sheath tumours 5% (9), phrenic and long thoracic mononeuropathies 7% (14) and compressive spinal meningioma 2% (4). Patients frequently had multiple coexisting complications (single = 76% [144], double = 17% [33], triple = 4% [8], quadruple = 2% [4]). Cardiac 28% (53) and pulmonary 15% (29) complications were also seen in these patients. History of Hodgkin lymphoma was initially overlooked by neurologists (14.3%, 48/336 clinical notes). Hospital and outpatient visits for complications were frequent: neuromuscular 19% (77/411) versus cardiopulmonary 30% (125/411). Testing was largely exclusionary, except when imaging identified secondary malignancy. Modified Rankin score at diagnosis varied: 0-1 (55.8%), 2-3 (5.8%) and 4-5 (38.3%). Neuromuscular complications among post-radiation Hodgkin lymphoma are diverse, occurring in ∼1 of 20 having markedly delayed onsets often eluding diagnosis. Frequent care visits and major morbidity are common. Survivorship recommendations should recognize the diverse neurological complications.

Making the Most of Systematic Reviews and Meta-analyses in Spine Surgery: A Primer for the Practicing Spine Surgeon.

STUDY DESIGN: Review. OBJECTIVE: To provide practicing spine surgeons a primer with key insights for reading, interpreting, and clinically integrating systematic reviews and meta-analyses. SUMMARY OF BACKGROUND DATA: Evidence-based medicine (EBM) refers to a family of standardized techniques for critical appraisal of clinical research. Within the contemporary spine literature, EBM is most commonly encountered in the form of systematic reviews and meta-analyses. Although these analytic techniques are potentially useful when appropriately applied to well-formulated questions with adequate primary data in the literature, the rapid and somewhat indiscriminate increase in volume of systematic reviews and meta-analyses published may be associated with an overall dilution in their quality, as well as misperceptions regarding the applicability of particular EBM studies to spine surgery in general. METHODS: The collective experience of spine specialists with vested interests in advancing EBM and its utility was summarized into a primer. RESULTS: We emphasize components that are pertinent methodologically (search strategy, study number, meta-analysis, bias, and certainty), and pertinent clinically (outcomes) to interpreting, and clinically integrating systematic reviews and meta-analyses into spine surgery practice. CONCLUSIONS: Armed with these insights into these five perspectives, we anticipate that practicing spine surgeons will be better equipped to interpret systematic reviews and meta-analyses in a fashion that will meaningfully impact their patient care. LEVEL OF EVIDENCE: 2.

Spontaneous Regression of a Symptomatic Intramedullary Spinal Cord Lesion.

Intramedullary spinal cord tumors and cavernous malformations are rare lesions that can lead to progressive neurologic deficits, impaired quality of life, and even death. Early diagnosis and surgical resection of spinal cord tumors and cavernous malformations are often quoted as essential to optimizing a patient's functional outcome. Unfortunately, these are high-risk operations, with many patients having worse neurological deficits after surgery - sometimes permanent. We present a case of a patient with a cervical intramedullary spinal cord lesion that almost completely resolved spontaneously at short-term follow-up and remained stable at longe-term follow up. Conservative management with careful observation and sequential imaging should be considered in patients with intramedullary spinal cord lesions presenting with acute onset, stable symptoms, especially if the lesion has a hemorrhagic component.

Radiotherapy in addition to surgical resection may not improve overall survival in WHO grade II spinal ependymomas.

OBJECTIVES: Spinal ependymomas are rare intramedullary neoplasms. The paucity of cases limits the ability to conduct large prospective studies. Current guidelines recommend maximal safe resection followed by adjuvant radiotherapy (RT) in cases of grade II spinal ependymomas with subtotal resections (STR) and all grade III spinal ependymomas. Herein we assess the impact of RT on survival in grades II and III spinal ependymomas. PATIENTS AND METHODS: The National Cancer Database was queried for adult patients with WHO grades II or III spinal ependymomas diagnosed between 2004 and 2014 who underwent resection or biopsy. Kaplan-Meier and multivariable Cox regression models were used to determine the impact of radiotherapy on survival. RESULTS: A total of 1058 patients met inclusion criteria. Most patients (85.9 %) received a biopsy/STR versus gross total resection (GTR, 14.1 %). Radiotherapy was preferentially performed in those with residual tumor (p = 0.001). We found a 10-fold increased hazard of death in grade III versus grade II tumors (HR: 10.33; 95 % CI: 5.01-21.3; p < 0.001). Age positively correlated with worsened survival (HR: 1.04; 95 % CI: 1.02-1.10; p < 0.001). Adjuvant RT did not reduce the hazard of death for the cohort overall (HR: 1.08; 95 % CI: 0.55-2.10; p = 0.810) or among those with grade II tumors (HR: 0.90; 95 % CI: 0.38-2.10; p = 0.810). We found no additional survival benefit of GTR compared to biopsy/STR (HR: 0.52; 95 % CI: 0.19-1.50; p = 0.217). CONCLUSION: While RT may improve progression-free survival, it may not impact overall survival in surgically resected grade II and III spinal ependymomas. Future studies should evaluate the impact of RT on local recurrence and symptomatic improvement.