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Prompt surgical decompression after traumatic spinal cord injury (TSCI) may be associated with improved sensorimotor outcomes. Delays in presentation may prevent timely decompression after TSCI.To systematically review existing studies investigating delays in presentation after TSCI in low- and middle-income countries (LMICs) and high-income countries (HICs).A systematic review was conducted and studies featuring quantitative or qualitative data on prehospital delays in TSCI presentation were included. Studies lacking quantitative or qualitative data on prehospital delays in TSCI presentation, case reports or series with5 patients, review articles, or animal studies were excluded from our analysis.After exclusion criteria were applied, 24 studies were retained, most of which were retrospective. Eleven studies were from LMICs and 13 were from HICs. Patients with TSCI in LMICs were younger than those in HICs, and most patients were male in both groups. A greater proportion of patients with TSCI in studies from LMICs presented24 hours after injury (HIC average proportion, 12.0%; LMIC average proportion, 49.9%; P = 0.01). Financial barriers, lack of patient awareness and education, and prehospital transportation barriers were more often cited as reasons for delays in LMICs than in HICs, with prehospital transportation barriers cited as a reason for delay by every LMIC study included in this review.Disparities in prehospital infrastructure between HICs and LMICs subject more patients in LMICs to increased delays in presentation to care.

S2 alar-iliac (S2AI) screws provide spinopelvic fixation with the advantages of minimized dissection, easier rod contouring, and decreased symptomatic screw-head prominence. However, placement of S2AI screws may be challenging because of the anatomy of the lumbosacral junction. Augmented reality is a nascent technology that may enhance placement of S2AI screws.To report the first in-human placement of augmented reality (AR)-assisted S2 alar-iliac screws and evaluate the accuracy of screw placement.A retrospective review was performed of patients who underwent AR-assisted S2AI screw placement. All surgeries were performed by 2 neurosurgeons using an AR head-mounted display (Xvision, Augmedics). Screw accuracy was analyzed in a blinded fashion by an independent neuroradiologist using the cortical breach grading scale.Twelve patients underwent AR-assisted S2AI screw placement for a total of 23 screws. Indications for surgery included deformity, degenerative disease, and tumor. Twenty-two screws (95.6%) were accurate-defined as grade 0 or grade 1. Twenty-one screws (91.3%) were classified as grade 0, 1 screw (4.3%) was grade 1, and 1 screw (4.3%) was grade 3. All breaches were asymptomatic.AR-assisted S2AI screw placement had an overall accuracy rate of 95.6% (grade 0 and grade 1 screws) in a cohort of 12 patients and 23 screws. This compares favorably with freehand and robotic placement. 1,2 AR enables spine surgeons to both better visualize anatomy and accurately place spinal instrumentation. Future studies are warranted to research the learning curve and cost analysis of AR-assisted spine surgery.

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

Spinal deformation during surgical intervention (caused by patient positioning and/or the correction of malalignment) confounds conventional navigation due to the assumptions of rigid transformation. Moreover, the ability to accurately quantify spinal alignment in the operating room would provide an assessment of the surgical product via metrics that correlate with clinical outcomes.A method for deformable 3D-2D registration of preoperative CT to intraoperative long-length tomosynthesis images is reported for an accurate 3D evaluation of device placement in the presence of spinal deformation and automated evaluation of global spinal alignment (GSA).Long-length tomosynthesis ("Long Film," LF) images were acquired using an O-arm imaging system (Medtronic, Minneapolis USA). A deformable 3D-2D patient registration was developed using multi-scale masking (proceeding from the full-length image to local subvolumes about each vertebra) to transform vertebral labels and planning information from preoperative CT to the LF images. Automatic measurement of GSA (main thoracic kyphosis [MThK] and lumbar lordosis [LL]) was obtained using a spline fit to registered labels. The "Known-Component Registration" method for device registration was adapted to the multi-scale process for 3D device localization from orthogonal LF images. The multi-scale framework was evaluated using a deformable spine phantom in which pedicle screws were inserted, and deformations were induced over a range in LL ∼25°-80°. Further validation was carried out in a cadaver study with implanted pedicle screws and a similar range of spinal deformation. The accuracy of patient and device registration was evaluated in terms of 3D translational error and target registration error, respectively, and the accuracies of automatic GSA measurements were compared to manual annotation.Phantom studies demonstrated accurate registration via the multi-scale framework for all vertebral levels in both the neutral and deformed spine: median (interquartile range, IQR) patient registration error was 1.1 mm (0.7-1.9 mm IQR). Automatic measures of MThK and LL agreed with manual delineation within -1.1° ± 2.2° and 0.7° ± 2.0° (mean and standard deviation), respectively. Device registration error was 0.7 mm (0.4-1.0 mm IQR) at the screw tip and 0.9° (1.0°-1.5°) about the screw trajectory. Deformable 3D-2D registration significantly outperformed conventional rigid registration (p 0.05), which exhibited device registration errors of 2.1 mm (0.8-4.1 mm) and 4.1° (1.2°-9.5°). Cadaver studies verified performance under realistic conditions, demonstrating patient registration error of 1.6 mm (0.9-2.1 mm); MThK within -4.2° ± 6.8° and LL within 1.7° ± 3.5°; and device registration error of 0.8 mm (0.5-1.9 mm) and 0.7° (0.4°-1.2°) for the multi-scale deformable method, compared to 2.5 mm (1.0-7.9 mm) and 2.3° (1.6°-8.1°) for rigid registration (p 0.05).The deformable 3D-2D registration framework leverages long-length intraoperative imaging to achieve accurate patient and device registration over the extended lengths of the spine (up to 64 cm) even with strong anatomical deformation. The method offers a new means for the quantitative validation of spinal correction (intraoperative GSA measurement) and the 3D verification of device placement in comparison to preoperative images and planning data.

OBJECTIVE Augmented reality (AR) is a novel technology which, when applied to spine surgery, offers the potential for efficient, safe, and accurate placement of spinal instrumentation. The authors report the accuracy of the first 205 pedicle screws consecutively placed at their institution by using AR assistance with a unique head-mounted display (HMD) navigation system. METHODS A retrospective review was performed of the first 28 consecutive patients who underwent AR-assisted pedicle screw placement in the thoracic, lumbar, and/or sacral spine at the authors’ institution. Clinical accuracy for each pedicle screw was graded using the Gertzbein-Robbins scale by an independent neuroradiologist working in a blinded fashion. RESULTS Twenty-eight consecutive patients underwent thoracic, lumbar, or sacral pedicle screw placement with AR assistance. The median age at the time of surgery was 62.5 (IQR 13.8) years and the median body mass index was 31 (IQR 8.6) kg/m2. Indications for surgery included degenerative disease (n = 12, 43%); deformity correction (n = 12, 43%); tumor (n = 3, 11%); and trauma (n = 1, 4%). The majority of patients (n = 26, 93%) presented with low-back pain, 19 (68%) patients presented with radicular leg pain, and 10 (36%) patients had documented lower extremity weakness. A total of 205 screws were consecutively placed, with 112 (55%) placed in the lumbar spine, 67 (33%) in the thoracic spine, and 26 (13%) at S1. Screw placement accuracy was 98.5% for thoracic screws, 97.8% for lumbar/S1 screws, and 98.0% overall. CONCLUSIONS AR depicted through a unique HMD is a novel and clinically accurate technology for the navigated insertion of pedicle screws. The authors describe the first 205 AR-assisted thoracic, lumbar, and sacral pedicle screws consecutively placed at their institution with an accuracy of 98.0% as determined by a Gertzbein-Robbins grade of A or B.

OBJECTIVE International research fellows have been historically involved in academic neurosurgery in the United States (US). To date, the contribution of international research fellows has been underreported. Herein, the authors aimed to quantify the academic output of international research fellows in the Department of Neurosurgery at The Johns Hopkins University School of Medicine. METHODS Research fellows with Doctor of Medicine (MD), Doctor of Philosophy (PhD), or MD/PhD degrees from a non-US institution who worked in the Hopkins Department of Neurosurgery for at least 6 months over the past decade (2010–2020) were included in this study. Publications produced during fellowship, number of citations, and journal impact factors (IFs) were analyzed using ANOVA. A survey was sent to collect information on personal background, demographics, and academic activities. RESULTS Sixty-four international research fellows were included, with 42 (65.6%) having MD degrees, 17 (26.6%) having PhD degrees, and 5 (7.8%) having MD/PhD degrees. During an average 27.9 months of fellowship, 460 publications were produced in 136 unique journals, with 8628 citations and a cumulative journal IF of 1665.73. There was no significant difference in total number of publications, first-author publications, and total citations per person among the different degree holders. Persons holding MD/PhDs had a higher number of citations per publication per person (p = 0.027), whereas those with MDs had higher total IFs per person (p = 0.048). Among the 43 (67.2%) survey responders, 34 (79.1%) had nonimmigrant visas at the start of the fellowship, 16 (37.2%) were self-paid or funded by their country of origin, and 35 (81.4%) had mentored at least one US medical student, nonmedical graduate student, or undergraduate student. CONCLUSIONS International research fellows at the authors’ institution have contributed significantly to academic neurosurgery. Although they have faced major challenges like maintaining nonimmigrant visas, negotiating cultural/language differences, and managing self-sustainability, their scientific productivity has been substantial. Additionally, the majority of fellows have provided reciprocal mentorship to US students.

Objective To explore the relationship between spinal cord compression and hypertension through analysis of blood pressure (BP) variations in a cervical spondylotic myelopathy (CSM) cohort after surgical decompression, along with a review of the literature. Methods A single-institution retrospective review of patients with CSM who underwent cervical decompression between 2016 and 2017 was conducted. Baseline clinical and imaging characteristics, preoperative and postoperative BP readings, heart rate, functional status, and pain scores were collected. In addition, a PRISMA guidelines–based systematic review was performed. Results We identified 264 patients with CSM treated surgically; 149 (56.4%) of these had hypertension. The degree of spinal canal compromise and spinal cord compression, preoperative neurologic examination, and the presence of T2-signal hyperintensity on magnetic resonance imaging were associated with hypertension. Overall mean arterial pressure (MAP) decreased significantly at 1 and 12 months after surgery. Patients without T2-signal hyperintensity on imaging showed a MAP reduction at 12 months postoperatively, whereas those with T2-signal hyperintensity showed a transient MAP reduction at 1 month postoperatively before returning to preoperative values. At 12 months after surgery, 24 of 97 patients (24.7%) with initially uncontrolled hypertension had controlled BP values with significant reduction of MAP, systolic BP, and diastolic BP. Including the present study, 5 articles were eligible for systematic review, with all reporting a BP decrease in patients with CSM after decompression. Conclusions Analysis of our retrospective cohort and a systematic review suggest that cervical surgical decompression reduces BP in some patients with CSM. However, this improvement is less apparent in patients with preoperative spinal cord T2-signal hyperintensity.

Comparative effectiveness research has a vital role in health reform and policies. Specialty training is one of these provider-side variables, and surgeons performing the same procedure who were trained in different specialties may have different outcomes. The objective of this study was to investigate the impact of spine surgeon specialty (neurosurgery vs. orthopedic surgery) on early perioperative outcome measures of elective anterior/lateral lumbar interbody fusion (ALIF/LLIF) for degenerative disc diseases.In a retrospective, 1:1 propensity score-matched cohort study, 9070 patients were reviewed from the American College of Surgeons National Surgical Quality Improvement Program database. Propensity score matching and subgroup analysis were used.In both groups (single-level and multilevel ALIF/LLIF), patients operated on by neurosurgeons had longer operative time (188 minutes vs. 172 minutes/239 minutes vs. 221 minutes); shorter total hospital stay (71 hours vs. 90 hours/89 hours vs. 96 hours); and lower rates of return to the operating room (2.1% vs. 4.1%/2.4% vs. 4.2%), nonhome discharge (8.7% vs. 11.1%/10.1% vs. 14.9%), discharge after postoperative day 3 (22.0% vs. 30.0%/38.0% vs. 43.9%), and perioperative blood transfusion (2.1% vs. 5.1%/5.0% vs. 9.9%) (P0.05). In multilevel ALIF/LLIF, patients operated on by neurosurgeons had lower readmission rates (3.9% vs. 6.9%) (P0.05). Other outcome measures and mortality rates were similar between the single-level and multilevel ALIF/LLIF cohorts regardless of surgeon specialty.Our analysis found significant differences in early perioperative outcomes of patients undergoing ALIF/LLIF by neurosurgeons and orthopedic surgeons. These differences have significant clinical and cost implications for patients, physicians, program directors, payers, and health systems.

The objective of this study was to examine the association between electrophysiology data post-C5-palsy and referral to peripheral nerve surgeons (PNS) using a 15-year cohort of patients who underwent posterior cervical decompression. Endpoints included the associations of postoperative treatments employed with functional recovery and abnormal electrophysiology data. Of 77 included patients (median 64 yr; 68% male), 48% completely recovered. The most common treatments were physical therapy (90%), occupational therapy (34%), oral corticosteroids (18%), and PNS referral (17%). Baseline weakness did not associate with PNS referral or postoperative treatment strategy. None of the treatments predicted recovery, though patients with no [versus complete] recovery were more likely to be recommended for nerve transfers (22.2 vs 0%; p = 0.03). Abnormal electromyography data associated with PNS referral (p 0.01), nerve transfer recommendation (p 0.01), occupational therapy referral, and oral corticosteroid therapy. Abnormal findings on EMG obtained between 6-weeks and 6-months post-injury were the most strongly associated with peripheral nerve surgeon referral (p = 0.02) and nerve transfer recommendation (p 0.01). These data suggest strategies for postoperative C5 palsy management are highly heterogeneous. None of the treatments employed significantly predicted the extent of functional recovery. However, patients with abnormal electrophysiology results were most likely to receive multimodal treatment, suggesting these results may significantly alter medical management of patients with postoperative C5 palsy. Early (6-week to 6-month) electrophysiology data may help to ensure that patients likely to benefit from nerve transfer procedures are referred to a PNS within the 9-12-month time frame associated with the best recovery of function.

Augmented reality (AR) navigation refers to novel technologies that superimpose images, such as radiographs and navigation pathways, onto a view of the operative field. The development of AR navigation has focused on improving the safety and efficacy of neurosurgical and orthopedic procedures. In this review, the authors focus on 3 types of AR technology used in spine surgery: AR surgical navigation, microscope-mediated heads-up display, and AR head-mounted displays. Microscope AR and head-mounted displays offer the advantage of reducing attention shift and line-of-sight interruptions inherent in traditional navigation systems. With the U.S. Food and Drug Administration’s recent clearance of the XVision AR system (Augmedics, Arlington Heights, IL), the adoption and refinement of AR technology by spine surgeons will only accelerate.

BACKGROUND Grade V spondylolisthesis, or spondyloptosis, is a complication of high-energy trauma that is most commonly reported at the lumbosacral junction. Sacral intersegmental spondyloptosis is extremely rare. The authors present a case of spondyloptosis of S1 on S2 with a comminuted fracture of S2 and complex fractures of the L4 and L5 transverse processes, resulting in severe stenosis of the lumbosacral nerve roots. OBSERVATIONS The patient was a 70-year-old woman with a history of a fall 3 weeks prior and progressive L5 and S1 radiculopathy. Instrumentation and fusion were undertaken, extending from L3 to the pelvis because degenerative stenosis at L3–4 and L4–5 was also found. Reduction was achieved, leading to diminished pain and partial resolution of weakness. LESSONS Traumatic sacral spondyloptosis adds a degree of difficulty to reduction, fixation, and fusion. The technique presented herein achieved sagittal realignment via a distraction maneuver of S1–2 in which rods were attached to bilateral dual S2 alar-iliac screws with reduction screws placed at S1, ultimately pulling L5 and S1 up to the rod for fixation.

While bone marrow-derived mesenchymal stem cells (BMCs) have been widely used in spinal fusion procedures, adipose-derived stem cells (ASCs) offer a number of advantages as an alternative clinical cell source. This study directly compares the efficacy of ASCs and BMCs from the same donor animals to achieve successful fusion when combined with a clinical-grade bone graft substitute in a rat lumbar fusion model. ASCs and BMCs were isolated from the same Lewis donor rats and grown to passage 2 (P2). Single-level bilateral posterolateral intertransverse process lumbar fusion surgery was performed on syngeneic rats divided into three experimental groups: clinical-grade bone graft substitute alone (CBGS); CBGS + rat ASCs (rASC); and, CBGS + rat BMCs (rBMC). Eight weeks postoperatively, fusion was evaluated via microCT, manual palpation and histology. In vitro analysis of the osteogenic capacity of rBMCs and rASCs was also performed. Results indicated that the average fusion volume in the rASC group was the largest and was significantly larger than the CBGS group. Although the rASC group displayed the highest fusion rates via microCT and manual palpation, this difference was not statistically significant. Cell-seeded grafts showed more histological bone formation than cell-free grafts. P2 rASCs and rBMCs displayed similar in vitro osteogenic differentiation capacities. Overall, this study showed that, when combined with a clinical-grade bone graft substitute in a rat model, rASCs cells yielded the largest fusion masses and comparable fusion results to rBMCs. These results add to growing evidence that ASCs provide an attractive alternative to BMCs for spinal fusion procedures. This article is protected by copyright. All rights reserved.

Objective Existing data have demonstrated significant differences in morbidity and mortality measures between men and women undergoing various spinal surgeries. However, studies of lumbar fusion surgery have been limited. Thus, we investigated the effects of patient sex on 30-day perioperative outcomes after elective lumbar fusion spine surgery. Methods Patients who had undergone lumbar fusion from 2015 to 2018 were reviewed from the American College of Surgeons National Surgical Quality Improvement Program database. Propensity score matching was used to determine whether the patient's sex had influenced the 30-day perioperative complications. Results A total of 44,526 cases had met the inclusion criteria and were reviewed. Of the 44,526 patients, 13,715 had undergone posterior lumbar fusion, 21,993 had undergone posterior/transforaminal lumbar interbody fusion, and 8818 had undergone anterior/lateral lumbar interbody fusion. The women were more likely to be older, functionally dependent, and taking steroids for chronic conditions and to have a higher body mass index and lower preoperative hematocrit level. The men were more likely to be white, to smoke, and to have diabetes mellitus, hypertension, and bleeding disorders. In all cohorts, except for a higher incidence of urinary tract infection in the female patients and myocardial infarction in the male patients, no significant differences were found in morbidity and mortality between the sexes. Conclusions Several differences in demographics and baseline health status were found between men and women undergoing lumbar fusion. When attempting to control for comorbid conditions using propensity score matching, we found that sex was an independent predictor of urinary tract infection in women and myocardial infarction in men across major morbidity and mortality categories in patients undergoing lumbar fusion surgery.

En bloc spinal tumor resections are technically demanding procedures with high morbidity because of the conventionally large exposure area and aggressive resection goals. Stereotactic surgical navigation presents an opportunity to perform the smallest possible resection plan while still achieving an en bloc resection. Augmented reality (AR)–mediated spine surgery (ARMSS) via a mounted display with an integrated tracking camera is a novel FDA-approved technology for intraoperative “heads up” neuronavigation, with the proposed advantages of increased precision, workflow efficiency, and cost-effectiveness. As surgical experience and capability with this technology grow, the potential for more technically demanding surgical applications arises. Here, the authors describe the use of ARMSS for guidance in a unique osteotomy execution to achieve an en bloc wide marginal resection of an L1 chordoma through a posterior-only approach while avoiding a tumor capsule breach. A technique is described to simultaneously visualize the navigational guidance provided by the contralateral surgeon’s tracked pointer and the progress of the BoneScalpel aligned in parallel with the tracked instrument, providing maximum precision and safety. The procedure was completed by reconstruction performed with a quad-rod and cabled fibular strut allograft construct, and the patient did well postoperatively. Finally, the authors review the technical aspects of the approach, as well as the applications and limitations of this new technology.

Aortic injury is a rare, yet underreported and underestimated complication of spine surgery. Anatomical relation between the aorta and the spine changes under physiological (positional) as well as pathological (deformity) conditions, which puts the aorta at risk of injury during spine surgery. Clinical presentation of aortic injury ranges from asymptomatic perforation of the aorta to acute fatal bleeding. Although several diagnostic methods have been reported, CT-angiography remains an important diagnostic study. Several advancements in the open and the endovascular surgical management have been reported to be successfully used in the management of aortic injury following spine surgery. Management approach of malpositioned screws abutting the aorta is still controversial. Anatomical knowledge and understanding of the previously reported mechanisms of aortic injury are important to be integrated in the preoperative planning process. If the complication occurs, time-to- recognition and to-appropriate-management are important factors for predicting mortality. If unrecognized and untreated in the acutely injured patients, mortality can approach 100%.

Poor bone quality and low bone mineral density (BMD) have been previously tied to higher rates of postoperative mechanical complications in patients undergoing spinal fusion. These include higher rates of proximal junctional kyphosis, screw pullout, pseudoarthrosis, and interbody subsidence. For these reasons, accurate preoperative assessment of a patient's underlying bone quality is paramount for all elective procedures. Dual-energy X-ray absorptiometry (DXA) is currently considered to be the gold standard for assessing BMD. However, a growing body of research has suggested that in vivo assessments of BMD using DXA are inaccurate and have, at best, moderate correlations to postoperative mechanical complications. Consequently, there have been investigations into using alternative methods for assessing in vivo bone quality, including using computed tomography (CT) and magnetic resonance imaging (MRI) volumes that are commonly obtained as part of surgical evaluation. Here we review the data regarding the accuracy of DXA for the evaluation of spine bone quality and describe the alternative imaging modalities currently under investigation.

Objective Determining factors that predict a career in academic neurosurgery can help to improve neurosurgical training and faculty mentoring efforts. Although many academic career predictors have been established in the literature, no method has yet been developed to allow for individualized predictions of an academic career trajectory. The objective of the present study was to develop a Web-based calculator for predicting the probability of a career in academic neurosurgery. Methods The present study used data from neurosurgeons listed in the American Association of Neurological Surgeons database. A logistic regression model was used to predict probability of an academic career, and bootstrapping with 2000 samples was used to calculate an optimism-corrected C-statistic. P Results A total of 1818 neurosurgeons were included in our analysis. Most surgeons were male (89.7%) and employed in nonacademic positions (60.2%). Factors independently associated with an academic career were female sex, attending a residency program affiliated with a top 10 U.S. News medical school, attaining a Doctor of Philosophy (PhD) degree, attaining a Master of Science (MS) degree, higher h-index during residency, more months of protected research time during residency, and completing a clinical fellowship. Our final model had an optimism-corrected C-statistic of 0.74. This model was incorporated into a Web-based calculator ( https://neurooncsurgery.shinyapps.io/academic_calculator/ ). Conclusions The present study consolidates previous research investigating neurosurgery career predictors into a simple, open-access tool. Our work may serve to better clarify the many factors influencing trainees' likelihood of pursuing a career in academic neurosurgery.

Objective Pharmacogenomics may help personalize medicine and improve therapeutic selection. This is the first study investigating how pharmacogenomic testing may inform analgesic selection in patients with spine disease. We profile pharmacogenetic differences in pain medication–metabolizing enzymes across patients presenting at an outpatient spine clinic and provide preliminary evidence that genetic polymorphisms may help explain interpatient differences in preoperative pain refractory to conservative management. Methods Adults presenting to our outpatient spine clinic with chief symptoms of neck and/or back pain were prospectively enrolled over 9 months. Patients completed the Wong-Baker FACES and numeric pain rating scales for their chief pain symptom and provided detailed medication histories and cheek swab samples for genomic analysis. Results Thirty adults were included (mean age, 60.6 ± 15.3 years). The chief concern was neck pain in 23%, back pain in 67%, and combined neck/back pain in 10%. At enrollment, patient analgesic regimens comprised 3 ± 1 unique medications, including 1 ± 1 opioids. After genomic analysis, 14/30 patients (47%) were identified as suboptimal metabolizers of ≥1 medications in their analgesic regimen. Of these patients, 93% were suboptimal metabolizers of their prescribed opioid analgesic. Nonetheless, pain scores were similar between optimal and suboptimal metabolizer groups. Conclusions This pilot study shows that a large proportion of the spine outpatient population may use pain medications for which they are suboptimal metabolizers. Further studies should assess whether these pharmacogenomic differences indicate differences in odds of receiving therapeutic benefit from surgery or if they can be used to generate more effective postoperative analgesic regimens.

BACKGROUND Few have explored the safety and efficacy of posterior vertebral column subtraction osteotomy (PVCSO) to treat tethered cord syndrome (TCS). OBJECTIVE To evaluate surgical outcomes after PVCSO in adults with TCS caused by lipomyelomeningocele, who had undergone a previous detethering procedure(s) that ultimately failed. METHODS This is a multicenter, retrospective analysis of a prospectively collected cohort. Patients were prospectively enrolled and treated with PVCSO at 2 institutions between January 1, 2011 and December 31, 2018. Inclusion criteria were age ≥18 yr, TCS caused by lipomyelomeningocele, previous detethering surgery, and recurrent symptom progression of less than 2-yr duration. All patients undergoing surgery with a 1-yr minimum follow-up were evaluated. RESULTS A total of 20 patients (mean age: 36 yr; sex: 15F/5M) met inclusion criteria and were evaluated. At follow-up (mean: 23.3 ± 7.4 mo), symptomatic improvement/resolution was seen in 93% of patients with leg pain, 84% in back pain, 80% in sensory abnormalities, 80% in motor deficits, 55% in bowel incontinence, and 50% in urinary incontinence. Oswestry Disability Index improved from a preoperative mean of 57.7 to 36.6 at last follow-up (P

Pseudarthrosis continues to affect a nontrivial proportion of spine fusion patients. Given its ties to poorer patient outcomes and high reoperation rates, there remains great interest in interventions aimed at reducing the rates of nonunion. Recently, silicate-substituted calcium phosphate (SiCaP) bone grafts have been suggested to improve fusion rates, yet there exists no systematic review of the body of evidence for SiCaP grafts. Here, we present the first such review along with a meta-analysis of the effect of SiCaP bone grafts on fusion rates. Using the PubMed, Embase, and Web of Science databases, we queried the English-language literature for all studies examining the effect of SiCaPs on spinal fusion. Primary endpoints were: 1) radiographic fusion rate at last follow-up and 2) postoperative improvements in Visual Analog Scale (VAS) pain scores and Oswestry Disability Index (ODI) at last follow-up. Meta-analyses were performed for each endpoint using random effects. Ten articles (694 patients treated with SiCaP bone grafts) were included. Among SiCaP-treated patients, 93% achieved radiographic fusion (range: 79-100%), with comparable rates across subgroups. Meta-analysis of the three randomized controlled trials demonstrated no difference in fusion rates between SiCaP-treated patients and patients receiving grafts with recombinant human bone morphogenetic protein-2 (rhBMP-2) (OR: 1.11; p = 0.83). Patients treated with SiCaP bone grafts experienced significant improvements in VAS back pain (-3.3 points), VAS leg pain (-4.8 points), and ODI (-31.6 points) by last follow-up (p 0.001 for each). Additional high-quality research is needed to evaluate the relative cost-effectiveness of SiCaP bone grafts in spinal fusion.

Background Poor bone quality is a known risk factor for hardware failure and adjacent segment disease after lumbar fusion. One new method of analyzing bone quality is the vertebral bone quality (VBQ) score, which can be obtained from preoperative lumbar magnetic resonance imaging (MRI) scans. We decided to evaluate whether patients' VBQ scores were associated with reoperation after lumbar fusion. Methods We queried records of patients who underwent elective lumbar fusion for degenerative conditions between 2012 and 2017. Patients who required reoperations after lumbar fusions because of symptomatic hardware failure or adjacent segment disease were combined into a case group and compared with a matched control group. Results Of the 46 patients who underwent elective lumbar fusions and required reoperation, 30 met the inclusion criteria. A 2:1 control group of 60 individually age-, body mass index–, and sex-matched patients who did not require reoperation was then created. The reoperation group had significantly lower degrees of postoperative lumbar lordosis. There were no significant differences regarding other spinopelvic parameters, adjacent Pfirrmann scores, or dual energy x-ray absorptiometry (DXA) T scores. There was, however, a significant difference in VBQ scores between the groups, with the reoperation group having a higher VBQ score. Conclusions This study found that bone quality, according to the VBQ score rather than the DXA T score, is an important risk factor for reoperation after lumbar fusion surgery. Therefore, this MRI-based tool may be used to assist surgeons in preoperative planning for spine surgeries with the goal of reducing the risk of requiring reoperation.

Pseudarthrosis following spinal fusion is correlated with poorer patient outcomes and consequently is an area of continued interest within spinal research. Recently, bioactive glasses have been proposed as a means of augmenting fusion rates. Here, we present the first systematic review and meta-analysis of the existing preclinical and clinical literature on the effect of bioactive glasses on spinal fusion. Using the MEDLINE, Embase, and Web of Science databases, we queried all publications in the English-language literature examining the effect of bioactive glasses on spinal fusion. The primary endpoint was fusion rate at last follow-up and the secondary endpoint for clinical studies was the rate of deep wound infection. Random-effects meta-analyses were performed independently for the preclinical and clinical data. Twelve preclinical studies (267 animals) and 12 clinical studies (396 patients) evaluating a total of twelve unique bioactive glass formulations were included. Across clinical studies, fusion was seen in 84% treated with bioactive glass. On sub-analysis, fusion rates were similar for standalone autograft (91.6%) and bioactive glass-local autograft mixtures (89.6%). Standalone bioactive glass substrates produced inferior fusion rates relative to autograft alone (33.6% vs. 98.8%; OR 0.01, p 0.02). Rates of deep wound infection did not differ between the bioactive glass and autograft groups (3.1%). The preclinical data similarly showed comparable rates of fusion between autograft and bioactive glass-treated animals. The available data suggest that bioactive glass-autograft mixtures confer similar rates of spinal fusion relative to standalone autograft without altering the risk of deep wound infection.

Background As of May 4, 2020, the coronavirus disease 2019 (COVID-19) pandemic has affected >3.5 million people and touched every inhabited continent. Accordingly, it has stressed health systems worldwide, leading to the cancellation of elective surgical cases and discussions regarding health care resource rationing. It is expected that rationing of surgical resources will continue even after the pandemic peak and may recur with future pandemics, creating a need for a means of triaging patients for emergent and elective spine surgery. Methods Using a modified Delphi technique, a cohort of 16 fellowship-trained spine surgeons from 10 academic medical centers constructed a scoring system for the triage and prioritization of emergent and elective spine surgeries. Three separate rounds of videoconferencing and written correspondence were used to reach a final scoring system. Sixteen test cases were used to optimize the scoring system so that it could categorize cases as requiring emergent, urgent, high-priority elective, or low-priority elective scheduling. Results The devised scoring system included 8 independent components: neurologic status, underlying spine stability, presentation of a high-risk postoperative complication, patient medical comorbidities, expected hospital course, expected discharge disposition, facility resource limitations, and local disease burden. The resultant calculator was deployed as a freely available Web-based calculator ( https://jhuspine3.shinyapps.io/SpineUrgencyCalculator/ ). Conclusions We present the first quantitative urgency scoring system for the triage and prioritizing of spine surgery cases in resource-limited settings. We believe that our scoring system, although not all encompassing, has potential value as a guide for triaging spine surgical cases during the COVID pandemic and post-COVID period.

OBJECTIVEPostoperative C5 palsy affects 7%–12% of patients who undergo posterior cervical decompression for degenerative cervical spine pathologies. Minimal evidence exists regarding the natural history of expected recovery and variables that affect palsy recovery. The authors investigated pre- and postoperative variables that predict recovery and recovery time among patients with postoperative C5 palsy.METHODSThe authors included patients who underwent posterior cervical decompression at a tertiary referral center between 2004 and 2018 and who experienced postoperative C5 palsy. All patients had preoperative MR images and full records, including operative note, postoperative course, and clinical presentation. Kaplan-Meier survival analysis was used to evaluate both times to complete recovery and to new neurological baseline—defined by deltoid strength on manual motor testing of the affected side—as a function of clinical symptoms, surgical maneuvers, and the severity of postoperative deficits.RESULTSSeventy-seven patients were included, with an average age of 64 years. The mean follow-up period was 17.7 months. The mean postoperative C5 strength was grade 2.7/5, and the mean time to first motor examination with documented C5 palsy was 3.5 days. Sixteen patients (21%) had bilateral deficits, and 9 (12%) had new-onset biceps weakness; 36% of patients had undergone C4–5 foraminotomy of the affected root, and 17% had presented with radicular pain in the dermatome of the affected root. On univariable analysis, patients’ reporting of numbness or tingling (p = 0.02) and a baseline deficit (p < 0.001) were the only predictors of time to recovery. Patients with grade 4+/5 weakness had significantly shorter times to recovery than patients with grade 4/5 weakness (p = 0.001) or ≤ grade 3/5 weakness (p < 0.001). There was no difference between those with grade 4/5 weakness and those with ≤ grade 3/5 weakness. Patients with postoperative strength < grade 3/5 had a < 50% chance of achieving complete recovery.CONCLUSIONSThe timing and odds of recovery following C5 palsy were best predicted by the magnitude of the postoperative deficit. The use of C4–5 foraminotomy did not predict the time to or likelihood of recovery.

Of the more than 30,000 posterior cervical spine fusions performed annually, 7%-12% will be complicated by postoperative C5 palsy, a condition characterized by new-onset deltoid weakness with or without C5 dermatomal findings and biceps weakness. Posterior translation of the cervical spinal cord has been proposed as a risk factor for this complication.To evaluate if C5 palsy can be predicted by spinal cord float back.Retrospective cohort.Patients ≥18 years of age undergoing posterior cervical decompression between 2002 and 2017 for degenerative cervical spine pathologies.Occurrence of C5 palsy as evaluated by manual motor testing (MMT).We recorded baseline neurological status, operative notes, details of postoperative course, and both pre- and postoperative magnetic resonance imaging images. Float back was defined by the change in the distance between the spinal cord and posterior face of the C4/5 annulus from preoperative to postoperative imaging. C5 palsy was defined by new-onset deltoid weakness on MMT.We identified 242 patients with a mean age of 62.4 years and mean follow-up of 27.9 months. Forty-two (17.4%) experienced postoperative C5 palsy. On univariable analysis, significant predictors of postoperative C5 palsy were mean C4/5 foraminal diameter (2.8 vs. 3.2 mm; p.001), anterior projection of the C5 superior articular process (4.12 vs. 3.70 mm; p=.04), cord float back (0.35 vs. 0.28 cm; p=.02), undergoing laminectomy of the C5 (p=.02) or C4 and C5 levels (p=.02), and undergoing instrumented fusion extending one level above and below the C4/5 level. Foraminotomy of the C4/5 level was not predictive of postoperative palsy. On multivariable analysis mean C4/5 foraminal diameter (odds ratio=0.38 per mm; p.01) predicted C5 palsy; cord float back at the C4/5 level was not predictive of C5 palsy.Spinal cord float back was not an independent predictor of C5 palsy on multivariable analysis. Only smaller foraminal diameter was independently predictive of postoperative C5 palsy. This suggests that chronic preoperative compression of the C5 roots, not postdecompression float back may be the biggest contributor to the etiology of postoperative C5 palsy.

OBJECTIVENonunion is a common complication of spinal fusion surgeries. Electrical stimulation technologies (ESTs)—namely, direct current stimulation (DCS), capacitive coupling stimulation (CCS), and inductive coupling stimulation (ICS)—have been suggested to improve fusion rates. However, the evidence to support their use is based solely on small trials. Here, the authors report the results of meta-analyses of the preclinical and clinical data from the literature to provide estimates of the overall effect of these therapies at large and in subgroups.METHODSA systematic review of the English-language literature was performed using PubMed, Embase, and Web of Science databases. The query of these databases was designed to include all preclinical and clinical studies examining ESTs for spinal fusion. The primary endpoint was the fusion rate at the last follow-up. Meta-analyses were performed using a Freeman-Tukey double arcsine transformation followed by random-effects modeling.RESULTSA total of 33 articles (17 preclinical, 16 clinical) were identified, of which 11 preclinical studies (257 animals) and 13 clinical studies (2144 patients) were included in the meta-analysis. Among preclinical studies, the mean fusion rates were higher among EST-treated animals (OR 4.79, p < 0.001). Clinical studies similarly showed ESTs to increase fusion rates (OR 2.26, p < 0.001). Of EST modalities, only DCS improved fusion rates in both preclinical (OR 5.64, p < 0.001) and clinical (OR 2.13, p = 0.03) populations; ICS improved fusion in clinical studies only (OR 2.45, p = 0.014). CCS was not effective at increasing fusion, although only one clinical study was identified. A subanalysis of the clinical studies found that ESTs increased fusion rates in the following populations: patients with difficult-to-fuse spines, those who smoke, and those who underwent multilevel fusions.CONCLUSIONSThe authors found that electrical stimulation devices may produce clinically significant increases in arthrodesis rates among patients undergoing spinal fusion. They also found that the pro-arthrodesis effects seen in preclinical studies are also found in clinical populations, suggesting that findings in animal studies are translatable. Additional research is needed to analyze the cost-effectiveness of these devices.

The objective of the study was to determine home program matching percentage (staying in a program affiliated with one's medical school) for each neurosurgical residency program in the United States. Secondarily, it was to elucidate both program-level and resident characteristics associated with home program matching.Demographic and bibliometric characteristics were collected for 1572 residents in U.S.-based and Accreditation Council for Graduate Medical Education-accredited neurosurgery programs over the 2014-2020 match period using publicly available websites. Program characteristics were collected, including number of clinical faculty, top 20 Doximity research ranking, top 10 Doximity reputation ranking, top 10 U.S. News department ranking, affiliation with a U.S. News top 10 medical school, and geographic region. Programs were ranked according to home program matching percentage, and associations were statistically evaluated.The average home program matching percentage per residency was 18.6%. NewYork-Presbyterian/Columbia retained the largest percentage of its own medical students with a home program matching percentage of 57.14%. From the resident frame of reference, only a higher preresidency H-index (3.7 ± 4.0 vs. 3.2 ± 3.7, P = 0.033) was significantly associated with home program matching. From a program perspective, program size (standardized β = 0.234, P = 0.006), Doximity research (standardized β = 0.206, P = 0.031), Doximity reputation (standardized β = 0.196, P = 0.040), and U.S. News program rankings (standardized β = 0.200, P = 0.036) were all significantly associated with home program matching. Overall home program matching percentage remained relatively constant over the 2014-2020 time period.The results of this study delineate home program matching patterns on a program-by-program level for U.S. neurosurgical residency programs.

OBJECTIVE The authors aimed to characterize which US medical schools have the most female neurosurgery residents and to identify potential associations between medical school characteristics and successful recruitment of women pursuing a neurosurgery career. METHODS The authors evaluated a total of 1572 residents in US neurosurgery programs accredited by the Accreditation Council for Graduate Medical Education as of February 2021, representing match cohorts from 2014 to 2020. The authors extracted US medical school characteristics and ranked schools based on the percentages of women graduates entering neurosurgery. They additionally studied yearly trends of the percentage of women constituting incoming neurosurgery resident cohorts as well as associations between female recruitment percentage and medical school characteristics using univariable and stepwise multivariable linear regression (including significant univariable factors). RESULTS The cohort consisted of 1255 male and 317 (20%) female residents. Yearly trends indicated a significant drop in incoming female residents in 2016, followed by significant increases in 2017 and 2019. On multivariable analysis, the following factors were associated with a higher average percentage of female graduates entering neurosurgery: total affiliated neurosurgery clinical faculty (β = 0.006, 95% CI 0.001–0.011, p = 0.01), allopathic versus osteopathic schools (β = 0.231, 95% CI 0.053–0.409, p = 0.01), and top 10 U.S. News & World Report ranking (β = 0.380, 95% CI 0.129–0.589, p < 0.01). When the number of female clinical faculty was added to the model, the variable was not statistically significant. Multivariable bibliometric analyses indicated a higher mean preresidency H-index for men, with an even greater gender difference identified in the 2021 H-index. CONCLUSIONS This study characterizes which medical schools are most successful at recruiting female students who constituted the total neurosurgery resident workforce of the 2020–2021 academic year. The overall number of clinical neurosurgery faculty rather than faculty gender was independently associated with female recruitment. Gender differences in research productivity persisted with control for confounders and increased between preresidency and 2021 time points. Such understanding of factors that influence the recruitment of women can help improve female representation in neurosurgery residency training moving forward.

Awake spine surgery is growing in popularity, and may facilitate earlier postoperative recovery, reduced cost, and fewer complications than spine surgery conducted under general anesthesia (GA). However, trends in the adoption of awake (ie, non-GA) spine surgery have not been previously studied.To investigate temporal trends in non-GA spine surgery utilization and outcomes in the United States.A retrospective observational study.Patients undergoing cervical or lumbar decompression or/and fusion from the American College of Surgeons National Surgical Quality Improvement Program database records dated 2005-2019.The primary outcome was the adoption trends of awake cervical and lumbar spine operations from 2005 to 2019. The secondary outcomes included the outcomes trends of 30-day complications, readmission rates, and length of stay in cervical and lumbar spine operations from 2005 to 2019.Patients were stratified into two groups: GA and non-GA (regional, epidural, spinal, monitored anesthesia care/intravenous sedation). Pearson chi-square or Fisher exact test and independent-sample t test were used to compare demographics between groups. Jonckheere-Terpstra test was used to determine whether trends and outcomes of non-GA operations from 2005 to 2019 were statistically significant. No non-GA spine operations were reported in the database from 2005 to 2006.We included 301,521 patients who underwent cervical or lumbar spine operations from 2005 to 2019. GA was used in 294,903 (97.8%) operations; 6,618 (2.2%) operations were non-GA. Patients in the non-GA cohort were more likely to be younger (50.1 vs 57.2 years; p.001), less likely to have American Society of Anesthesiologists classification ≥3 (39.7% vs 48.3%; p.001), and to have lower BMI (27.8 vs 31.5 kg/mOur trends analysis revealed increasing utilization and improved outcomes of non-GA spine surgery from 2005 to 2019; however, the proportion of non-GA spine operations remains small. Future research should investigate the barriers to adoption of non-GA spine surgery.

BACKGROUND Intracranial deposits of fat droplets are an unusual presentation of a spinal dermoid cyst after spontaneous rupture and are even more uncommon after trauma. Here, the authors present a case with this rare clinical presentation, along with a systematic review of the literature to guide decision making in these patients. OBSERVATIONS A 54-year-old woman with Lynch syndrome presented with severe headache and sacrococcygeal pain after a traumatic fall. Computed tomography of the head revealed multifocal intraventricular and intracisternal fat deposits, which were confirmed by magnetic resonance imaging (MRI) of the neuroaxis; in addition, a ruptured multiloculated cyst was identified within the sacral canal with proteinaceous/hemorrhagic debris, most consistent with a sacral dermoid cyst with rupture into the cerebrospinal fluid (CSF) space. An unruptured sacral cyst was later noted on numerous previous MRI scans. In our systematic review, we identified 20 similar cases, most of which favored surgical treatment. LESSONS Rupture of an intraspinal dermoid cyst must be considered when intracranial fat deposits are found in the context of cauda equina syndrome, meningism, or hydrocephalus. Complete tumor removal with close postoperative follow-up is recommended to decrease the risk of complications. CSF diversion must be prioritized if life-threatening hydrocephalus is present.

Low oxygen (O(2)) diffusion into large tissue engineered scaffolds hinders the therapeutic efficacy of transplanted cells. To overcome this, we previously studied hollow, hyperbarically-loaded microtanks (μtanks) to serve as O(2) reservoirs. To adapt these for bone regeneration, we fabricated biodegradable μtanks from polyvinyl alcohol and poly(lactic-co-glycolic acid) and embedded them to form 3D-printed, porous poly-ε-caprolactone (PCL)-μtank scaffolds. PCL-μtank scaffolds were loaded with pure O(2) at 300 – 500 psi. When placed at atmospheric pressures, the scaffolds released O(2) over a period of up to 8 hours. We confirmed the inhibitory effects of hypoxia on the osteogenic differentiation of human adipose-derived stem cells (hASCs and we validated that μtank-mediated transient hyperoxia had no toxic impacts on hASCs, possibly due to upregulation of endogenous antioxidant regulator genes. We assessed bone regeneration in vivo by implanting O(2)-loaded, hASC-seeded, PCL-μtank scaffolds into murine calvarial defects (4 mm diameters × 0.6 mm height) and subcutaneously (4 mm diameter × 8 mm height). In both cases we observed increased deposition of extracellular matrix in the O(2) delivery group along with greater osteopontin coverages and higher mineral deposition. This study provides evidence that even short-term O(2) delivery from PCL-μtank scaffolds may enhance hASC-mediated bone tissue regeneration.

Porous Magnesium (Mg) is a promising biodegradable scaffold for treating critical-size bone defects, and as an essential element for human metabolism, Mg has shown sufficient biocompatibility. Its elastic moduli and yield strengths are closer to those of cortical bone than common, inert metallic implants, effectively reducing stress concentrations around host tissue as well as stress shielding. More importantly, Mg can degrade and be absorbed in the human body in a safe and controlled manner, thereby reducing the need for second surgeries to remove implants. The development of porous Mg scaffolds via conventional selective laser melting techniques has been limited due to Mg’s low boiling point, high vapor pressures, high reactivity, and non-ideal microstructures in additively manufactured parts. Here we present an exciting alternative to conventional additive techniques: 3D weaving with Mg wires that have controlled chemistries and microstructures. The weaving process offers high throughput manufacturing as well as porous architectures that can be optimized for stiffness and porosity with topology optimization. Once woven, we dip-coat the weaves with polylactic acid to enhance their strength and corrosion resistance. Following fabrication, we characterize their mechanical properties, corrosion behavior, and cell compatibility in vitro, and we use an intramuscular implantation model to evaluate their in vivo corrosion behavior and tissue response.

Vascularization is critical for skull development, maintenance, and healing. Yet, there remains a significant knowledge gap in the relationship of blood vessels to cranial skeletal progenitors during these processes. Here, we introduce a quantitative 3D imaging platform to enable the visualization and analysis of high-resolution data sets (>100 GB) throughout the entire murine calvarium. Using this technique, we provide single-cell resolution 3D maps of vessel phenotypes and skeletal progenitors in the frontoparietal cranial bones. Through these high-resolution data sets, we demonstrate that CD31hiEmcnhi vessels are spatially correlated with both Osterix+ and Gli1+ skeletal progenitors during postnatal growth, healing, and stimulated remodeling, and are concentrated at transcortical canals and osteogenic fronts. Interestingly, we find that this relationship is weakened in mice with a conditional knockout of PDGF-BB in TRAP+ osteoclasts, suggesting a potential role for osteoclasts in maintaining the native cranial microvascular environment. Our findings provide a foundational framework for understanding how blood vessels and skeletal progenitors spatially interact in cranial bone, and will enable more targeted studies into the mechanisms of skull disease pathologies and treatments. Additionally, our technique can be readily adapted to study numerous cell types and investigate other elusive phenomena in cranial bone biology., Vascularization is critical for cranial bone growth, maintenance, and healing, but it remains unknown how blood vessels are spatially distributed in the calvarium, and how they interact with skeletal progenitors during these processes. Here, the authors apply a quantitative light-sheet imaging platform to visualize and analyze the relationship between blood vessels and skeletal progenitors throughout the murine calvarium.

Text message-based interventions have been demonstrated to be a valuable monitoring tool across various conditions. Here, we aimed to describe our early experience using a newly developed text message-based platform designed to track symptoms in spine surgery patients.We used the Informed Mindset Medical (IMM) platform to automatically send text messages with secure and encrypted hyperlinks to enrolled patients. Patient symptoms were monitored using well-standardized functional assessments. Limited patient data and responses were stored on a Health Insurance Portability and Accountability Act-compliant SQL cloud-based server database.In 3 months, 101 patients scheduled for elective spine surgery accepted participation in our pilot study. Overall, 71.2% of the enrolled patients responded to at least 1 preoperative baseline questionnaire. The response rates were similar across attendings, questionnaire bundles (cervical vs. thoracolumbar), genders, and age groups. The overall preoperative IMM pain scores were found to correlate positively with the preoperative electronic medical record pain rates. Similarly, the overall preoperative IMM and electronic medical record pain scores correlated positively with the IMM-collected Neck Disability Index/Oswestry Disability Index scores. From an initial 71.2%, the response rate decreased to 54.9% for the 6-week follow-up questionnaires.Our preliminary findings support the reliability of this text message-based strategy to monitor symptoms in spine surgery patients. Further studies are warranted to explore strategies to increase the response rate and expand this platform's clinical and research applicability.

Thoracic meningoceles and dural ectasia are less commonly recognized manifestations of neurofibromatosis 1 (NF1). Rarely, large thoracic meningoceles may become compressive and lead to respiratory compromise secondary to lung compression. Surgical goals aim to increase lung aeration through decreasing the size of the meningocele through shunting, excision or repair of the meningocele, and varying degrees of dural tube reconstruction. There is no agreement on the best approach for large, symptomatic meningoceles. Here, we discuss the case of a 41-year-old woman with NF1 who presented with dyspnea and enlargement of a large, 19 cm thoracic meningocele. A multidisciplinary team of thoracic, plastic, and neurological surgery participated in the operation to excise the meningocele and reconstruct the dural tube without the need for subsequent shunting of spinal fluid. We also systematically review the literature on thoracic meningoceles in NF1 to understand the optimal treatment of this pathology.

Purpose To characterize the 3D imaging performance and radiation dose for a prototype slot-beam configuration on an intraoperative O-arm™ Surgical Imaging System (Medtronic Inc., Littleton MA) and identify potential improvements in soft-tissue image quality for surgical interventions. Methods A slot collimator was integrated with the O-arm™ system for slot-beam axial CT. The collimator can be automatically actuated to provide 1.2° slot-beam longitudinal collimation. Cone-beam and slot-beam configurations were investigated with and without an antiscatter grid (12:1 grid ratio, 60 lines/cm). Dose, scatter, image noise, and soft-tissue contrast resolution were evaluated in quantitative phantoms for head and body configurations over a range of exposure levels (beam energy and mAs), with reconstruction performed via filtered-backprojection. Qualitative imaging performance across various anatomical sites and imaging tasks was assessed with anthropomorphic head, abdomen, and pelvis phantoms. Results The dose for a slot-beam scan varied from 0.02-0.06 mGy/mAs for head protocols to 0.01-0.03 mGy/mAs for body protocols, yielding dose reduction by ∼1/5 to 1/3 compared to cone-beam, owing to beam collimation and reduced x-ray scatter. The slot-beam provided a ∼6-7× reduction in scatter-to-primary ratio (SPR) compared to the cone-beam, yielding SPR ∼20%-80% for head and body without the grid and ∼7%-30% with the grid. Compared to cone-beam scans at equivalent dose, slot-beam images exhibited a ∼2.5× increase in soft-tissue CNR for both grid and gridless configurations. For slot-beam scans, a further ∼10-30% improvement in CNR was achieved when the grid was removed. Slot-beam imaging could benefit certain interventional scenarios in which improved visualization of soft tissues is required within a fairly narrow longitudinal region of interest (7 mm in ) - e.g., checking the completeness of tumor resection, preservation of adjacent anatomy, or detection of complications (e.g., hemorrhage). While preserving existing capabilities for fluoroscopy and cone-beam CT, slot-beam scanning could enhance the utility of intraoperative imaging and provide a useful mode for safety and validation checks in image-guided surgery. Conclusions The 3D imaging performance and dose of a prototype slot-beam CT configuration on the O-arm™ system was investigated. Substantial improvements in soft-tissue image quality and reduction in radiation dose are evident with the slot-beam configuration due to reduced x-ray scatter. This article is protected by copyright. All rights reserved.

BACKGROUND Intradural spinal cord cysts are uncommon and generally benign. It can be difficult to determine whether the cyst is intramedullary or extramedullary on preoperative imaging, and the location of the cyst may be determined intraoperatively. This patient presented with intractable back pain associated with imbalance and was found to have a cystic lesion of the ventriculus terminalis (VT). OBSERVATIONS The patient was found to have a cystic lesion of the VT that was intramedullary rather than extramedullary, as initially expected based on preoperative imaging. LESSONS VT is a rare cystic expansion of the conus medullaris that can appear extramedullary on preoperative imaging. Intraoperatively, this lesion was found to be intramedullary and was successfully treated with fenestration.

BACKGROUND Local, intrawound use of antibiotic powder, such as vancomycin and tobramycin, in spinal fusion surgery has become an increasingly common prophylactic measure in an attempt to reduce rates of postsurgical infection. However, the effects of localized antibiotic delivery on fusion remain unclear. The objective of this study was to examine the in vivo effects of intraoperative local delivery of 2 antibiotics commonly used in bone-grafting surgery on spinal fusion outcomes in a rat model. METHODS Single-level (L4-L5), bilateral posterolateral intertransverse process lumbar fusion surgery was performed on 60 female Lewis rats (6 to 8 weeks of age) using syngeneic iliac crest allograft mixed with clinical bone-graft substitute and varying concentrations of antibiotics (n = 12 each): (1) control without any antibiotics, (2) low-dose vancomycin (14.3 mg/kg), (3) high-dose vancomycin (71.5 mg/kg), (4) low-dose tobramycin (28.6 mg/kg), and (5) high-dose tobramycin (143 mg/kg). Eight weeks postoperatively, fusion was evaluated via micro-computed tomography (µCT), manual palpation, and histological analysis, with blinding to treatment group. In the µCT analysis, fusion-mass volumes were measured for each rat. Each spine specimen (L4-L5) was rated (manual palpation score) on a scale of 2 to 0 (2 = fused, 1 = partially fused, and 0 = non-fused). RESULTS The mean fusion-mass volume on µCT (mm) was as follows: control, 29.3 ± 6.2; low-dose vancomycin, 26.3 ± 8.9; high-dose vancomycin, 18.8 ± 7.9; low-dose tobramycin, 32.7 ± 9.0; and high-dose tobramycin, 43.8 ± 11.9 (control versus high-dose vancomycin, p < 0.05; and control versus high-dose tobramycin, p < 0.05). The mean manual palpation score for each group was as follows: control, 1.46 ± 0.58; low-dose vancomycin, 0.86 ± 0.87; high-dose vancomycin, 0.68 ± 0.62; low-dose tobramycin, 1.25 ± 0.71; and high-dose tobramycin, 1.32 ± 0.72 (control versus high-dose vancomycin, p < 0.05). The histological analyses demonstrated a similar trend with regard to spinal fusion volume. CONCLUSIONS Intraoperative local application of vancomycin, particularly at a supraphysiological dosage, may have detrimental effects on fusion-mass formation. No inhibitory effect of tobramycin on fusion-mass formation was observed. CLINICAL RELEVANCE When spine surgeons decide to use intraoperative intrawound antibiotics in spinal fusion surgery, they should weigh the reduction in surgical site infection against a possible inhibitory effect on fusion.

OBJECTIVEAugmented reality (AR) is a novel technology that has the potential to increase the technical feasibility, accuracy, and safety of conventional manual and robotic computer-navigated pedicle insertion methods. Visual data are directly projected to the operator’s retina and overlaid onto the surgical field, thereby removing the requirement to shift attention to a remote display. The objective of this study was to assess the comparative accuracy of AR-assisted pedicle screw insertion in comparison to conventional pedicle screw insertion methods.METHODSFive cadaveric male torsos were instrumented bilaterally from T6 to L5 for a total of 120 inserted pedicle screws. Postprocedural CT scans were obtained, and screw insertion accuracy was graded by 2 independent neuroradiologists using both the Gertzbein scale (GS) and a combination of that scale and the Heary classification, referred to in this paper as the Heary-Gertzbein scale (HGS). Non-inferiority analysis was performed, comparing the accuracy to freehand, manual computer-navigated, and robotics-assisted computer-navigated insertion accuracy rates reported in the literature. User experience analysis was conducted via a user experience questionnaire filled out by operators after the procedures.RESULTSThe overall screw placement accuracy achieved with the AR system was 96.7% based on the HGS and 94.6% based on the GS. Insertion accuracy was non-inferior to accuracy reported for manual computer-navigated pedicle insertion based on both the GS and the HGS scores. When compared to accuracy reported for robotics-assisted computer-navigated insertion, accuracy achieved with the AR system was found to be non-inferior when assessed with the GS, but superior when assessed with the HGS. Last, accuracy results achieved with the AR system were found to be superior to results obtained with freehand insertion based on both the HGS and the GS scores. Accuracy results were not found to be inferior in any comparison. User experience analysis yielded “excellent” usability classification.CONCLUSIONSAR-assisted pedicle screw insertion is a technically feasible and accurate insertion method.