Endoscopic Lateral Lumbar Interbody Fusion: Technical Note and Case Series.

BACKGROUND: Our objective is to describe a minimally invasive endoscopic surgical technique for performing lateral lumbar interbody fusion (LLIF). LLIF is a common approach to lumbar fusion in cases of degenerative lumbar disease; however, complications associated with psoas and lumbar plexus injury sometimes arise. The endoscopic modification presented here diminishes the requirement for sustained muscle retraction, minimizing complication risk while allowing for adequate decompression in select cases. METHODS: Endoscopic LLIF (ELLIF) was performed in 3 patients from 2019 to 2021. Surgeries were performed in the lateral position under general anesthesia with neurophysiological monitoring. Discectomy, endplate preparation, and harvesting of iliac crest bone were performed through a working channel endoscope. The introduction of an interbody cage (Joimax EndoLIF) was performed over a nitinol blunt-tip wire (Joimax). No expandable blade retractors were required. RESULTS: At 2-year follow-up of these 3 patients, the mean visual analog scale (VAS) score for leg pain improved from 9.3 to 1.7, and the mean Oswestry Disability Index (ODI) score improved from 40 to 8.3. There were no complications, readmissions, or recurrence of symptoms during the 2-year follow-up period. Patients spent an average of 36 hours in the hospital postoperatively and returned to normal daily activities after an average of 48 days. CONCLUSIONS: A minimally invasive modification to the LLIF procedure is presented that offers several potential advantages due to the application of endoscopic techniques: reduced muscle retraction, smaller incision, and the opportunity to perform both indirect decompression and endoscopically visualized discectomy in the same fusion procedure. CLINICAL RELEVANCE: The proposed endoscopic lateral lumbar interbody fusion and decompression is a minimally invasive technique that may provide patients with minimal complications, quick recovery, and good functional recovery.

Disparities in Primary Spinal Osseous Malignant Bone Tumor Survival by Medicaid Status: A National Population-Based Risk Analysis.

BACKGROUND: The impact of Medicaid status on survival outcomes of patients with spinal primary malignant bone tumors (sPMBT) has not been investigated. METHODS: Using the SEER-Medicaid database, adults diagnosed between 2006 and 2013 with sPMBT including chordoma, osteosarcoma, chondrosarcoma, Ewing sarcoma, or malignant giant cell tumor (GCT) were studied. Five-year survival analysis was performed using the Kaplan-Meier method. Adjusted survival analysis was performed using Cox proportional-hazards regression controlling for age, sex, marital status, cancer stage, poverty level, vertebral versus sacral location, geography, rurality, tumor diameter, tumor grade, tumor histology, and therapy. RESULTS: A total of 572 patients with sPMBT (Medicaid: 59, non-Medicaid: 513) were identified. Medicaid patients were more likely to be younger (P < 0.001), Black (P < 0.001), live in high poverty neighborhoods (P = 0.006), have distant metastases at diagnosis (P < 0.001), and less likely to receive surgery (P = 0.006). The 5-year survival rate was 65.7% (chondrosarcoma: 70.0%, chordoma: 91.5%, Ewing sarcoma: 44.6%, GCT: 90.0%, osteosarcoma: 34.2%). Medicaid patients had significantly worse 5-year survival than non-Medicaid patients (52.0% vs. 67.2%, P = 0.02). Minority individuals on Medicaid were associated with an increased risk of cancer-specific mortality compared with White non-Medicaid patients (adjusted hazard ratio [aHR] = 2.51, [95% CI 1.18-5.35], P = 0.017). Among Medicaid patients, those who received surgery had significantly better survival than those who did not (64.5% vs. 30.6%, P = 0.001). For all patients, not receiving surgery (aHR = 1.90 [1.23-2.95], P = 0.004) and tumor diameter >50 mm (aHR=1.89 [1.10-3.25], P = 0.023) were associated with an increased risk of mortality. CONCLUSIONS: Medicaid patients may be less likely to receive surgery and suffer from poorer survival. These disparities may be especially prominent among minorities.

The epidemiology of crib-related head injuries: A ten-year nationwide analysis.

INTRODUCTION: Falls from cribs resulting in head injury are understudied and poorly characterized. The purpose of this study was to advance current understanding of the prevalence, descriptive characteristics of injury victims, and the types of crib fall-related head injuries (CFHI) using queried patient cases from the National Electronic Injury Surveillance System (NEISS) database. METHODS: Using the US Consumer Product Safety Commission's System NEISS database, we queried all CFHIs among children from over 100 emergency departments (EDs). Patient information regarding age, race, sex, location of the incident, diagnoses, ED disposition, and sequelae were analyzed. The number of CFHI from all US EDs during each year was also collected from the database. RESULTS: There were an estimated 54,799 (95% CI: 30,228-79,369) total visits to EDs for CFHIs between 2012 and 2021, with a decrease in incidence of approximately 20% during the onset of the COVID-19 pandemic (2019: 5616 cases, 2020: 4459 cases). The annual incidence of injuries showed no significant trend over the 10-year study period. An available subset of 1782 cases of head injuries from approximately 100 EDs was analyzed, and 1442 cases were included in final analysis. Injuries were sorted into three primary categories: unspecified closed head injury (e.g., closed head injury, blunt head trauma, or traumatic brain injury), concussion, or open head injury and skull fracture. Unspecified closed head injuries were the most common of all head injuries (95.4%, 1376/1442). Open head injuries (14/1442, 0.97%) and concussions 3.6% (52/1442, 3.6%) were rare. Most injuries involved children under the age of 1 (42.6%) compared to children who were 1, 2, 3, or 4-years old. About a fourth of patients had other diagnoses in addition to their primary injury including scalp/forehead hematomas, emesis, and contusions. Female patients were more likely to present with other diagnoses in addition to their primary head injury (Difference: 12.3%, 95% CI: 9.87%-15.4%, p < .0001). CONCLUSION: Despite minimum rail height requirements set by the Consumer Safety Product Commission (CPSC), head injuries associated with crib falls are prevalent in the United States. However, most injuries were minor with a vast majority of patients being released following examination and treatment.

Preoperative Predictors of Survival in Patients With Spinal Metastatic Disease.

BACKGROUND: There remains a number of factors thought to be associated with survival in spinal metastatic disease, but evidence of these associations is lacking. In this study, we examined factors associated with survival among patients undergoing surgery for spinal metastatic disease. METHODS: We retrospectively examined 104 patients who underwent surgery for spinal metastatic disease at an academic medical center. Of those patients, 33 received local preoperative radiation (PR) and 71 had no PR (NPR). Disease-related variables and surrogate markers of preoperative health were identified, including age, pathology, timing of radiation and chemotherapy, mechanical instability by spine instability neoplastic score, American Society of Anesthesiologists (ASA) classification, Karnofsky performance status (KPS), and body mass index (BMI). We performed survival analyses using a combination of univariate and multivariate Cox proportional hazards models to assess significant predictors of time to death. RESULTS: Local PR (Hazard Ratio [HR] = 1.84, P = 0.034), mechanical instability (HR = 1.11, P = 0.024), and melanoma (HR = 3.60, P = 0.010) were significant predictors of survival on multivariate analysis when controlling for confounders. PR vs NPR cohorts exhibited no statistically significant differences in preoperative age (P = 0.22), KPS (P = 0.29), BMI (P = 0.28), or ASA classification (P = 0.12). NPR patients had more reoperations for postoperative wound complications (11.3% vs 0%, P < 0.001). CONCLUSIONS: In this small sample, PR and mechanical instability were significant predictors of postoperative survival, independent of age, BMI, ASA classification, and KPS and in spite of fewer wound complications in the PR group. It is possible that PR was a surrogate of more advanced disease or poor response to systemic therapy, independently portending a worse prognosis. Future studies in larger, more diverse populations are crucial for understanding the relationship between PR and postoperative outcomes to determine the optimal timing for surgical intervention. CLINICAL RELEVANCE: These findings are clinically relevent as they provide insight into factors associated with survival in metastatic spinal disease.

Pediatric all-terrain vehicle (ATV) related head injury rates and patterns: A 10-year nationwide analysis.

INTRODUCTION: The use of all-terrain vehicles (ATVs) carries significant risk of permanent injury and death, disproportionately affecting children. These injuries commonly affect the head and are especially severe among children as they are often unhelmeted and more likely than adults to experience rollover injuries. Many studies examining patients with ATV-related injuries are single-center cohort studies, with few focusing specifically on head injuries. In the present study, we aimed to characterize the annual incidence of ATV-related head injuries between 2012 and 2021, classify and compare head injury types, and identify descriptive characteristics of ATV-related head injury victims. METHODS: Using the US Consumer Product Safety Commission's National Electronic Injury Surveillance System (NEISS) database, we queried all head injuries associated with operating or riding an ATV in children under 18 years-old from over 100 emergency departments (EDs). Patient information regarding age, race, sex, location of incident, diagnoses, and sequelae were analyzed. We also collected the estimated number of ATV-related head injuries from all US EDs using the NEISS algorithm provided by the database. RESULTS: Using the NEISS algorithm we identified 67,957 (95% CI: 43,608 - 92,305) total pediatric ATV-related head injuries between 2012 and 2021. The annual incidence of ATV-related head injury was similar throughout this study period except for a 20% increase during the COVID-19 pandemic period of 2019-2021 (2019: 6382 injuries, 2020: 6757 injuries, 2021: 7600 injuries). A subset of 1890 cases from approximately 100 EDs were then analyzed. Unspecified closed head injuries were the prevailing type of injury (38%, 900/1890), followed by concussions (27%, 510/1890). More severe injuries included intracranial hemorrhages in 91 children (3.8%, 91/1890). Injuries of all types were predominantly seen in 14-17 year-old's (780/1890, 41%) and in males (64.1%, 1211/1890). In addition, ATV-associated injuries were significantly more common in those coded as white (58.0%, 1096/1890) than any other racial group. ATV-associated accidents among children younger than 9 more commonly occurred at the home compared to accidents involving children older than 9 (57% vs. 32%, p < 0.0001). CONCLUSION: ATV-related head injuries cause a significant annual burden among children, with growing incidence in recent years. Further research may wish to explore potential benefits of helmet use and supervision of younger children in possible prevention of these accidents and their associated economic and non-economic costs.

The burden of unhelmeted motorcycle injury: A nationwide scoring-based analysis of helmet safety legislation.

INTRODUCTION: Motorcycle collisions comprise a large portion of motor vehicle injuries and fatalities with over 80,000 injuries and 5,500 fatalities per year in the United States. Unhelmeted riders have poor medical outcomes and generate billions in costs. Despite helmet use having been shown to lower the risk of neurological injury and death, helmet compliance is not universal, and legislation concerning helmet use also varies widely across the United States. METHODS: In this study, we systematically reviewed helmet-related statutes from all US jurisdictions. We evaluated the stringency of these statutes using a legislative scoring system termed the Helmet Safety Score (HSS) ranging from 0-7 points, with higher scores denoting more stringent statutes. Regression modeling was used to predict unhelmeted mortality using our safety scores. RESULTS: The mean score across all jurisdictions was 4.73. We found jurisdictions with higher HSS's generally had lower percentages of unhelmeted fatalities in terms of total fatalities as well as per 100,000 people and 100,000 registered motorcycles. In contrast, some lower-scoring jurisdictions had over 100 times more unhelmeted fatalities than higher-scoring jurisdictions. Our HSS significantly predicted unhelmeted motorcycle fatalities per 100,000 people (ß = -0.228 per 1-point increase, 95% CI: -0.288 to -0.169, p < .0001) and per 100,000 registered motorcycles (ß = -6.17 per 1-point increase, 95% CI: -8.37 to -3.98, p < .0001) in each state. Aspects of our score concerning helmet exemptions for riders and motorcycle-type vehicles independently predicted higher fatalities (p < .0001). Higher safety scores predicted lower unhelmeted fatalities. CONCLUSION: Stringent helmet laws may be an effective mechanism for decreasing unhelmeted mortality. Therefore, universal helmet laws may be one such mechanism to decrease motorcycle-related neurological injury and fatality burden. In states with existing helmet laws, elimination of exemptions for certain riders and motorcycle-type vehicles may also decrease fatalities.

Influence of socioeconomic factors on discharge disposition following traumatic cervicothoracic spinal cord injury at level I and II trauma centers in the United States.

Background: Discharge to acute rehabilitation is strongly correlated with functional recovery after traumatic injury, including spinal cord injury (SCI). However, services such as acute care rehabilitation and Skilled Nursing Facilities (SNF) are expensive. Our objective was to understand if high-cost, resource-intensive post-discharge rehabilitation or alternative care facilities are utilized at disparate rates across socioeconomic groups after SCI. Methods: We performed a cohort analysis using the National Trauma Data Bank® tabulated from 2012-2016. Eligible patients had a diagnosis of cervical or thoracic spine fracture with spinal cord injury (SCI) and were treated surgically. We evaluated associations of sociodemographic and psychosocial variables with non-home discharge (e.g., discharge to SNF, other healthcare facility, or intermediate care facility) via multivariable logistic regression while correcting for injury severity and hospital characteristics. Results: We identified 3933 eligible patients. Patients who were older, male (OR=1.29 95% Confidence Interval [1.07-1.56], p=.007), insured by Medicare (OR=1.45 [1.08-1.96], p=.015), diagnosed with a major psychiatric disorder (OR=1.40 [1.03-1.90], p=.034), had a higher Injury Severity Score (OR=5.21 [2.96-9.18], p<.001) or a lower Glasgow Coma Score (3-8 points, OR=2.78 [1.81-4.27], p<.001) had a higher chance of a non-home discharge. The only sociodemographic variable associated with lower likelihood of utilizing additional healthcare facilities following discharge was uninsured status (OR=0.47 [0.37-0.60], p<.001). Conclusions: Uninsured patients are less likely to be discharged to acute rehabilitation or alternative healthcare facilities following surgical management of SCI. High out-of-pocket costs for uninsured patients in the United States may deter utilization of these services.

Navigation-assisted resection of tumoral calcinosis of the lumbosacral spine: illustrative case.

BACKGROUND: Tumoral calcinosis is an uncommon disease resulting from dystrophic calcium phosphate crystal deposition, with only 7% of cases involving the spine, and it may diagnostically mimic neoplasms. OBSERVATIONS: In this case, a 54-year-old woman with history of systemic scleroderma presented with 10 months of progressive left lumbosacral pain. Imaging revealed an expansile, 4 × 7-cm, well-circumscribed mass in the lumbosacral spine with L5-S1 neuroforaminal compression. Because intractable pain and computed tomography (CT)-guided needle biopsy did not entirely rule out malignancy, operative management was pursued. The patient underwent L4-S2 laminectomies, left L5-S1 facetectomy, L5 and S1 pediculectomies, and en bloc resection, performed under stereotactic CT-guided intraoperative navigation. Subsequently, instrumented fusion was performed with L4 and L5 pedicle screws and S2 alar-iliac screws. Pathological examination was consistent with tumoral calcinosis, with multiple nodules of amorphous basophilic granular calcified material lined by histiocytes. There was no evidence of recurrence or neurological deficits at 5-month follow-up. LESSONS: Because spinal tumoral calcinosis may mimic neoplasms on imaging or gross intraoperative appearance, awareness of this clinical entity is essential for any spine surgeon. A review of all case reports of lumbosacral tumoral calcinosis (n = 14 from 1952 to 2016) was additionally performed. The case featured in this report presents the first known case of navigation-assisted resection of lumbosacral tumoral calcinosis.

Influence of Sociodemographic and Psychosocial Factors on Length of Stay After Surgical Management of Traumatic Spine Fracture with Spinal Cord Injury.

OBJECTIVE: Identifying patients at risk of increased health care resource utilization is a valuable opportunity to develop targeted preoperative and perioperative interventions. In the present investigation, we sought to examine patient sociodemographic factors that predict prolonged length of stay (LOS) after traumatic spine fracture. METHODS: We performed a cohort analysis using the National Trauma Data Bank tabulated during 2012-2016. Eligible patients were those who were diagnosed with cervical or thoracic spine fracture with spinal cord injury and who were treated surgically. We evaluated the effects of sociodemographic as well as psychosocial variables on LOS by negative binomial regression and adjusted for injury severity, injury mechanism, and hospital characteristics. RESULTS: We identified 3856 eligible patients with a median LOS of 9 days (interquartile range, 6-15 days). Patients in older age categories, who were male (incidence rate ratio (IRR), 1.05; 95% confidence interval [CI], 1.01-1.09), black (IRR, 1.12; CI, 1.05-1.19) or Hispanic (IRR, 1.09; CI, 1.03-1.16), insured by Medicaid (IRR, 1.24; CI, 1.17-1.31), or had a diagnosis of alcohol use disorder (IRR, 1.12; CI, 1.06-1.18) were significantly more likely to have a longer LOS. In addition, patients with severe injury on Injury Severity Score (IRR, 1.32; CI, 1.14-1.53) and lower Glasgow Coma Scale (GCS) scores (GCS score 3-8, IRR, 1.44; CI, 1.35-1.55; GCS score 9-11, IRR, 1.40; CI, 1.25-1.58) on admission had a significantly lengthier LOS. Patients admitted to a hospital in the Southern United States (IRR, 1.09; CI, 1.05-1.14) had longer LOS. CONCLUSIONS: Socioeconomic factors such as race, insurance status, and alcohol use disorder were associated with a prolonged LOS after surgical management of traumatic spine fracture with spinal cord injury.

Evolution of surgical treatment of metastatic spine tumors.

PURPOSE: The treatment of cancer has transformed over the past 40 years, with medical oncologists, radiation oncologists and surgeons working together to prolong survival times and minimize treatment related morbidity. With each advancement, the risk-benefit scale has been calibrated to provide an accurate assessment of surgical hazard. The goal of this review is to look back at how the role of surgery has evolved with each new medical advance, and to explore the role of surgeons in the future of cancer care. METHODS: A literature review was conducted, highlighting the key papers guiding surgical management of spinal metastatic lesions. CONCLUSION: The roles of surgery, medical therapy, and radiation have evolved over the past 40 years, with new advances requiring complex multidisciplinary care.

Implantation of Engineered Axon Tracts to Bridge Spinal Cord Injury Beyond the Glial Scar in Rats.

Regeneration after spinal cord injury (SCI) is limited by the presence of a glial scar and inhibitory cell signaling pathways that favor scar formation over regrowth of endogenous neurons. Tissue engineering techniques, including the use of allografted neural networks, have shown promise for nervous system repair in prior studies. Through the use of a minimally invasive injury model in rats, we describe the implantation of micro-tissue engineered neural networks (micro-TENNs) across a region of SCI, spanning the glial scar to promote axonal regeneration. Forty-three female Sprague-Dawley rats were included in this study. Micro-TENNs were preformed in vitro before implant, and comprised rat sensory dorsal root ganglion (DRG) neurons projecting long bundled axonal tracts within the lumen of a biocompatible hydrogel columnar encasement (1.2 cm long; 701 µm outer diameter × 300 µm inner diameter). Animals were injured using a 2F embolectomy catheter inflated within the epidural space. After a 2-week recovery period, micro-TENNs were stereotactically implanted across the injury. Animals were euthanized at 1 week and 1 month after implantation, and the tissue was interrogated for the survival of graft DRG neurons and outgrowth of axons. No intraoperative deaths were noted with implantation of the micro-TENNs to span the injury cavity. Graft DRG axons were found to survive at 1 week postimplant within the hydrogel encasement. Graft-derived axonal outgrowth was observed within the spinal cord up to 4.5 mm from the implant site at 1 month postinjury. Limited astroglial response was noted within the host, suggesting minimal trauma and scar formation in response to the graft. Micro-TENN sensory neurons survive and extend axons into the host spinal cord following a minimally invasive SCI in rats. This work serves as the foundation for future studies investigating the use of micro-TENNs as a living bridge to promote recovery following SCI. Impact statement As spinal cord injury pathology develops, the establishment of a glial scar puts an end to the hope of regeneration and recovery from the consequent neurological deficits. Therefore, growing attention is given to bioengineered scaffolds that can bridge the lesions bordered by this scar tissue. The utilization of longitudinally aligned preformed neural networks-referred to as micro-tissue engineered neural networks (TENNs)-presents a promising opportunity to provide a multipurpose bridging strategy that may take advantage of several potential mechanisms of host regeneration. In addition to providing physical support for regenerating spinal cord axons, micro-TENNs may serve as a functional "cable" that restores lost connections within the spinal cord.

Postoperative Sagittal Spinal Alignment Changes Following Corrective Surgery in Adult Spinal Deformity.

BACKGROUND: There is a paucity of literature covering the spinal alignment changes following adult spinal deformities (ASD) corrective surgeries. In theory, patients' posture and overall alignment may vary with postoperative pain, bracing, and other external variables requiring further radiographic follow-up. The purpose of the study is to investigate changes in sagittal alignment in the first 3 months postoperatively. METHODS: This is a retrospective case series of ASD patients who underwent deformity surgeries from October 2015 to June 2018. Patients < 40 years old, had < 6 levels fused, had acute proximal junctional kyphosis (PJK) or failure, or lacked imaging were excluded. Physiologic measures, spine alignment changes measured in whole-spine radiographs. Lumbar lordosis (LL), thoracic kyphosis (TK), and sagittal vertical axis (SVA) at immediate and 3-month postoperative time points were measured, then compared via 2-sample Student t tests. Furthermore, TK after upper thoracic to pelvis (UT-P) fusions was compared with lower thoracic to pelvis (LT-P) fusions via paired t test. RESULTS: Thirty-six patients (24 females, 67%) with a mean age of 61.5 years (range, 40-75 years) were included. Spinal alignment comparisons showed a significant increase in TK at the 3-month time point (P = 0.006). Additionally, wide variations in SVA (range, 47-144 mm) were noted, yet not statistically significant, likely due to the changes being in both positive and negative directions (P = 0.18). No significant difference was found when TK was compared in the UT-P vs LT-P groups. CONCLUSIONS: Our results suggest that as postoperative pain subsides and the body settles into its new alignment, significant changes occur in spine sagittal parameters in the subacute period following surgery. LEVEL OF EVIDENCE: 4.

Osteoradionecrosis of the Occipitocervical Junction After Radiation for Head and Neck Cancer: A Report of 8 Cases.

BACKGROUND: Osteoradionecrosis (ORN) refers to the degenerative changes seen in bone after local radiation, particularly in head and neck cancer. ORN can present as neck or facial pain and may be confused with tumor recurrence. Magnetic resonance imaging (MRI) and positron emission tomography (PET) scans are often inconclusive, requiring percutaneous biopsy to differentiate ORN from infection and recurrent disease. We reviewed the utility of preprocedural imaging in guiding the decision to biopsy in cases of ORN. CASE DESCRIPTION: Eight patients with a history of prior head and neck cancer, radiation therapy, and suspected ORN at the skull base, occipitocervical junction, and atlantoaxial spine were identified retrospectively from a single academic medical center. In 4 cases, MRI findings and PET imaging were negative for recurrence. One patient in this group underwent an aborted biopsy. Four patients had MRI concerning for infection or recurrent tumor with PET-positive lesions. Three patients in this group underwent biopsy that was negative for recurrent tumor. One patient developed an arteriovenous fistula after biopsy. The fourth patient was observed and did not demonstrate progression at 5 months. At last follow-up for all patients, there was no evidence of tumor recurrence or metastasis at the index site to indicate a misdiagnosis for recurrent tumor. CONCLUSIONS: This case series highlights that PET scanning may not be useful in predicting which patients will benefit from biopsy for ORN because no patients with PET-positive lesions had histopathologic evidence of tumor recurrence or metastasis on biopsy.

Proximal junctional kyphosis following T10-pelvis fusion presenting with neurologic compromise: case presentations and review of the literature.

Purpose: Proximal Junctional Kyphosis (PJK) is a well-documented phenomenon following spinal instrumented fusion. Myelopathy associated with proximal junctional failure (PJF) is poorly described in the literature. Adjacent segment disease, fracture above the upper instrumented vertebrae and subluxation may all cause cord compression, ambulatory dysfunction, and/or lower extremity weakness in the postoperative period.Materials and methods: We review the literature on PJK and PJF, and discusses the postoperative management of three patients who experienced myelopathy associated with PJF following T9/10 to pelvis fusion at a single institution.Results and conclusions: PJF with myelopathy must be diagnosed and surgically corrected early on so as to minimize permanent neurologic injury. Patients requiring significant sagittal deformity correction are at greater risk for PJF, and may benefit from constructs terminating in the upper thoracic spine.

Association of spinal instability due to metastatic disease with increased mortality and a proposed clinical pathway for treatment.

OBJECTIVE: Multidisciplinary treatment including medical oncology, radiation oncology, and surgical consultation is necessary to provide comprehensive therapy for patients with spinal metastases. The goal of this study was to review the use of radiation therapy and/or surgical intervention and their impact on patient outcomes. METHODS: In this retrospective series, the authors identified at their institution those patients with spinal metastases who had received radiation therapy alone or had undergone surgery with or without radiation therapy within a 6-year period. Data on patient age, chemotherapy, surgical procedure, radiation therapy, Karnofsky Performance Status (KPS), primary tumor pathology, Spinal Instability Neoplastic Score (SINS), and survival after treatment were collected from the patient electronic medical records. N - 1 chi-square testing was used for comparisons of proportions. The Student t-test was used for comparisons of means. A p value < 0.05 was considered statistically significant. A survival analysis was completed using a multivariate Cox proportional hazards model. RESULTS: Two hundred thirty patients with spinal metastases were identified, 109 of whom had undergone surgery with or without radiation therapy. Among the 104 patients for whom the surgical details were reviewed, 34 (33%) had a history of preoperative radiation to the surgical site but ultimately required surgical intervention. In this surgical group, a significantly increased frequency of death within 30 days was noted for the SINS unstable patients (23.5%) as compared to that for the SINS stable patients (2.3%; p < 0.001). The SINS was a significant predictor of time to death among surgical patients (HR 1.11, p = 0.037). Preoperative KPS was not independently associated with decreased survival (p > 0.5) on univariate analysis. One hundred twenty-six patients met the criteria for inclusion in the radiation-only analysis. Ninety-eight of these patients (78%) met the criteria for potential instability (PI) at the time of treatment, according to the SINS system. Five patients (5%) with PI in the radiation therapy group had a documented neurosurgical or orthopedic surgery consultation prior to radiation therapy. CONCLUSIONS: At the authors' institution, patients with gross mechanical instability per the SINS system had an increased rate of 30-day postoperative mortality, which remained significant when controlling for other factors. Surgical consultation for metastatic spine patients receiving radiation oncology consultation with PI is low. The authors describe an institutional pathway to encourage multidisciplinary treatment from the initial encounter in the emergency department to expedite surgical evaluation and collaboration.

Dorsal root ganglion axons facilitate and guide cortical neural outgrowth: In vitro modeling of spinal cord injury axonal regeneration.

BACKGROUND: Spinal cord injury (SCI) patients represent a heterogeneous group, with injuries ranging from partial compression to complete transection. Patients with complete injuries are unlikely to exhibit recovery and suffer from paralysis as well as the loss of bowel and bladder function. One treatment option is the formation of a bridge through a lesion site, whereby transplanted cells or biocompatible scaffolds guide the regenerating axons across the site of injury. Moreover, the viability of transplanted dorsal root ganglia (DRGs) into rat spinal cord has been previously demonstrated. OBJECTIVE: We aim to demonstrate the feasibility of using DRG axons as a bridging tool to help guide the axonal growth of cortical neurons. METHODS: Cortical neurons were isolated from embryonic rats and two aggregated populations were cultured at increasing distances in isolation and in a co-culture with DRG explants. Growth rates of the sprouting axons and connections between the two populations were observed over a period of twelve days. RESULTS: DRG explants demonstrated the ability to grow robust axonal connections that can connect two explants separated by up to 10 mm, however, CNAs could not achieve connections in distances greater than 2 mm. The co-culture of CNAs with DRG explants facilitated axonal growth between two populations of CNAs at distances they cannot otherwise traverse. CONCLUSIONS: Our findings support the use of DRG axons to facilitate the growth of cortical neurons in a process of axon-facilitated axon regeneration. We believe these results could have implications for the treatment of SCI.

A Strategy Toward Bridging a Complete Spinal Cord Lesion Using Stretch-Grown Axons.

In this study, we evaluated the ability of stretch-grown tissue-engineered nerve grafts (TENGs) to perform as a living scaffold for axonal regeneration across a severed spinal cord lesion. TENGs, consisting of stretch-grown axons spanning two populations of dorsal root ganglia neurons, have proven to be effective in bridging gaps in peripheral nerve injury. A complete transection was performed at the thoracic level in a rodent model and 5 mm of cord was completely removed. TENGs encapsulated in a collagen hydrogel were placed within the cavity and compared against a collagen only transplant. Through hematoxylin and eosin (H&E) staining and immunohistochemistry, we found that TENGs survived up to 6 weeks post-transplant, extending neuronal processes into and through host tissue early on in both the rostral and caudal direction. In several cases, TENG axons penetrated into and through glial scar tissue, appearing to overcome a common obstacle for axonal regeneration in spinal cord injuries (SCIs). H&E staining also provided evidence that animals treated with TENGs resulted in lesion sites with greater tissue infiltration and less compression than animals treated with a collagen hydrogel only, an encouraging finding given the severity of the injury model. We also observed effects the TENGs had on glial scar formation, cyst formation, and immune response at multiple time points as these are common difficulties faced in tissue engineering methods to treat or repair SCI. If able to address these universal challenges associated with SCI, TENGs may offer an alternative option in neural transplantation and may represent a viable tool in the multifaceted treatment of SCI. Impact statement In complete spinal cord injury (SCI), a significant gap forms in the injury sites replacing the neural connections and limiting the link between healthy spinal cord distal to the injury and cerebral cortex. This study aims to demonstrate the potential benefit of hydrogel collagen constructs bearing stretch-grown dorsal root ganglion axons to bridge a complete injury gap, to restore the lost connections and forming a basic infrastructure to support the regrowth of new connection. This application of stretch-grown axons in neural implants offers hope to achieve a highly modifiable and resilient bridging strategy to treat SCI.

Risk of Vertebral Artery Injury and Stroke Following Blunt and Penetrating Cervical Spine Trauma: A Retrospective Review of 729 Patients.

BACKGROUND: Cervical spine trauma (CST) may result in vertebral artery injury (VAI), increasing the risk of developing stroke. Stroke risk following CST is poorly reported. METHODS: In total, 729 patients with CST were retrospectively analyzed, including rates of VAI, age at injury, cause of injury, cardiovascular history, smoking history, substance abuse history, embolization therapy, and antiplatelet or anticoagulant therapy prior or after injury. VAIs were identified and graded following the Modified Denver Criteria for Blunt Cerebrovascular Injury using magnetic resonance angiography and computed tomography angiography. Brain scans were reviewed for stroke rates and statistically significant variations. RESULTS: Thirty-three patients suffered penetrating trauma, whereas 696 patients experienced blunt trauma. In total, 81 patients met the criteria for analysis with confirmed VAI. VAI was more common in penetrating injury group compared with blunt injury group (64% vs. 9%, P < 0.0005). However, low-grade VAI (less than grade III) was more common in blunt injury group versus penetrating group (37% vs. 14%, P < 0.05). The frequency of posterior circulation strokes did not vary significantly between groups (26.3% vs. 13.8%, P = 0.21). Cardiovascular comorbidities were significantly more common in the blunt group (50%, P = 0.0001) compared with the penetrating group (0%). CONCLUSIONS: VAI occurs with a high incidence in penetrating CST. Although stroke risk following penetrating and blunt CST did not vary significantly, they resulted in serious complications in a group of patients. Further study of this patient population is required to provide high-level, evidence-based preventions for VAI complications.

LACE+ Index as Predictor of 30-Day Readmission in Brain Tumor Population.

BACKGROUND: The LACE+ index (Length of stay, Acuity of admission, Charlson Comorbidity Index score, and Emergency department [ED] visits in the past 6 months) is a tool used to predict 30-day readmissions. We sought to examine this predictive tool in patients undergoing brain tumor surgery. METHODS: Admissions and readmissions for patients undergoing craniotomy for supratentorial neoplasm at a single multihospital academic medical center were analyzed. All brain tumor cases for which the patient was alive at 30 days after surgery were included (n = 352). Simple logistic regression analyses were used to assess the ability of the LACE+ index and subsequent single variables to accurately predict the outcome measures of 30-day readmission, reoperation, and ED visit. Analysis of the model's or variable's discrimination was determined by the receiver operating characteristic curve as represented by the C-statistic. RESULTS: The sample included admissions for craniotomy for supratentorial neoplasm (n = 352). Assessment of the LACE+ index demonstrates a 1.02× increased odds of 30-day readmission for every 1-unit increase in LACE+ score (P = 0.031, CI = 1.00-1.03). Despite this, analysis of the receiver operating characteristic curve indicates that LACE+ index has poor specificity in predicting 30-day readmission (C-statistic = 0.58). A 1-unit increase in LACE+ score also predicts a 0.98× reduction in odds of home discharge (P < 0.001, CI = 0.97-0.99, C-statistic = 0.70). But LACE+ index does not predict 30-day reoperation (P = 0.945) or 30-day ED visits (P = 0.218). CONCLUSIONS: The results of this study demonstrate that the LACE+ index is not yet suitable as a prediction model for 30-day readmission in a brain tumor population.

Intraoperative Molecular Imaging with Second Window Indocyanine Green Facilitates Confirmation of Contrast-Enhancing Tissue During Intracranial Stereotactic Needle Biopsy: A Case Series.

BACKGROUND: Stereotactic needle biopsy provides a minimally invasive option for the diagnosis of intracranial lesions but is limited by inconclusive diagnoses on frozen pathology. For rapid pathology, 5-aminovelunic acid and sodium fluorescein have previously demonstrated potential as diagnostic adjuvants. Stereotactic biopsy with near-infrared (NIR) fluorophores has not been reported. We identified 5 representative cases using NIR fluorescent dye indocyanine green (ICG) administered in a high dose, delayed manner. METHODS: Five patients underwent second window indocyanine green (SWIG)-guided stereotactic biopsy for diagnosis of suspected glioma or tumor recurrence. Up to 5 mg/kg ICG was administered approximately 24 hours prior to surgery. Biopsies were conducted in the standard fashion, targeting regions of suspected tumor using intraoperative frameless navigation. Samples were examined intraoperatively under standard visible light and for fluorescence using conventional NIR imaging platforms. Findings were correlated with frozen and final tumor pathology for all cases. RESULTS: A total of 10 biopsy specimens were obtained. Three did not fluoresce and did not demonstrate tumor on preliminary or final pathology, including a non-gadolinium-enhancing sample taken proximal to the final target. The remaining 7 fluoresced, of which 6 contained tumor and 1 contained necrosis. Fluorescence was also noted in a patient with radiation treatment effect. Overall fluorescence characteristics were highly concordant with preliminary and final diagnoses. CONCLUSIONS: SWIG provides rapid intraoperative confirmation of pathologic brain tissue by permeating neoplastic or inflammatory brain tissue via a mechanism similar to that of gadolinium enhancement. SWIG-guided stereotactic biopsy can improve surgical efficiency by enhancing confidence in acquisition of target tissue.