Ehlers-Danlos Syndrome is Associated with Increased Rates of Adjacent Segment Disease Following TLIF: A Propensity Matched Study.

BACKGROUND: Ehlers-Danlos syndrome (EDS) is a collection of connective tissue disorders which are often associated with tissue laxity and disc degeneration. However, the implications of EDS on the risk of adjacent segment disease (ASD) after transforaminal lumbar interbody fusion (TLIF) are not well described. The objective of this study is to compare the rates of ASD among patients with EDS and those without EDS. METHODS: Patients who underwent 1-3 level TLIF for degenerative disc disease between 2010-2022 were identified using the PearlDiver Mariner all-claims insurance database. Patients with all types of EDS were included. Patients undergoing surgery for tumors, trauma, or infection were excluded. 1:1 propensity matching was performed using demographic factors, medical comorbidities, and surgical factors which were significantly associated with ASD in a linear regression model. The primary outcome measure was the development of ASD. The secondary outcomes were the development of pseudoarthrosis, medical complications, and surgical complications. RESULTS: Propensity matching resulted in 2 equal groups of 85 patients who did or did not have EDS and underwent 1-3 level TLIF. Patients without EDS were less likely to experience ASD (RR 0.18, 95% CI 0.09-0.35, P < 0.001). There was no significant difference between the 2 patient groups with regards to a diagnosis of pseudoarthrosis, and there was no significant difference for all-cause medical and surgical complications between the 2 patient groups. CONCLUSIONS: After propensity matching to control for confounding variables, the findings of this study suggest that EDS may be associated with an increased risk of ASD following TLIF. Future studies are needed to corroborate these findings.

Do Obese Patients Lose Weight After Lumbar Spine Surgery: A Systematic Review and Meta-Analysis.

OBJECTIVE: Obesity is a major health care concern in the United States and is associated with high rates of postoperative complications after spine surgery. Obese patients assert that weight reduction is not possible unless spine surgery first relieves their pain and concomitant immobility. We describe the post-spine surgery effects on patient weight, with an emphasis on obesity. METHODS: PubMed, EMBASE, Scopus, Web of Science, and Cochrane databases were systematically searched according to the PRISMA guidelines. The search included indexed terms and text words from database inception to the date of the search (15 April 2022). Studies chosen for inclusion had to have data reporting on pre- and postoperative patient weight after spine surgery. Data and estimates were pooled using the Mantel-Haenszel method for random-effects meta-analysis. RESULTS: Eight articles encompassing 7 retrospective and 1 prospective cohort were identified. A random effects model analysis demonstrated that overweight and obese patients (body mass index [BMI], >25 kg/m2) had increased odds of clinically significant weight loss after lumbar spine surgery compared with non-obese patients (odds ratio, 1.63; 95% confidence interval, 1.43-1.86, P < 0.0001). There was no significant difference in the raw weight change between BMI categories (mean difference, -0.67 kg, 95% confidence interval, -4.71 to 3.37 kg, P = 0.7463). CONCLUSIONS: Compared with non-obese patients (BMI, <25 kg/m2), overweight and obese patients have higher odds of clinically significant weight loss after lumbar spine surgery. No difference in pre-operative and post-operative weight was found, although statistical power was lacking in this analysis. Randomized controlled trials and additional prospective cohorts are needed to further validate these findings.

Anterior occipital condyle screw placement through the endonasal corridor: proof of concept study with cadaveric analysis.

PURPOSE: Odontoidectomy for ventral compressive pathology may result in O-C1 and/or C1-2 instability. Same-stage endonasal C1-2 spinal fusion has been advocated to eliminate risks associated with separate-stage posterior approaches. While endonasal methods for C1 instrumentation and C1-2 trans-articular stabilization exist, no hypothetical construct for endonasal occipital instrumentation has been validated. We provide an anatomic description of anterior occipital condyle (AOC) screw endonasal placement as proof-of-concept for endonasal craniocervical stabilization. METHODS: Eight adult, injected cadaveric heads were studied for placing 16 AOC screws endonasally. Thin-cut CT was used for registration. After turning a standard inferior U-shaped nasopharyngeal flap endonasally, 4 mm × 22 mm AOC screws were placed with a 0° driver using neuronavigation. Post-placement CT scans were obtained to determine: site-of-entry, measured from the endonasal projection of the medial O-C1 joint; screw angulation in sagittal and axial planes, proximity to critical structures. RESULTS: Average site-of-entry was 6.88 mm lateral and 9.74 mm rostral to the medial O-C1 joint. Average angulation in the sagittal plane was 0.16° inferior to the palatal line. Average angulation in the axial plane was 23.97° lateral to midline. Average minimum screw distances from the jugular bulb and hypoglossal canal were 4.80 mm and 1.55 mm. CONCLUSION: Endonasal placement of AOC screws is feasible using a 0° driver. Our measurements provide useful parameters to guide optimal placement. Given proximity of hypoglossal canal and jugular bulb, neuronavigation is recommended. Biomechanical studies will ultimately be necessary to evaluate the strength of AOC screws with plate-screw constructs utilizing endonasal C1 lateral mass or C1-2 trans-articular screws as inferior fixation points.

C1 Lateral Mass Screw Placement Through Endonasal Corridor for Purpose of O-C1 Fusion: Morphometric Analysis in Cadaveric Specimens.

BACKGROUND: Odontoidectomy may pose some risks for O-C1 and/or C1-C2 instability, with previous authors reporting techniques for endonasal C1-C2 fusion. However, no technique for endonasal O-C1 fusion currently exists. We sought to describe the feasibility of endonasal anterior C1 (AC1) screw placement for endonasal O-C1 fusion. METHODS: Seven adult cadaveric heads were studied for endonasal placement of 14 C1 screws. Using thin-cut computed tomography (CT)-based "snapshot" neuronavigation assistance, 4 mm x 22 mm screws were placed in the C1 lateral mass using a 0° driver. Post-placement CT scans were obtained to determine site-of-entry measured from C1 anterior tubercle, screw angulation in axial and sagittal planes, and screw proximity to the central canal and foramen transversarium. RESULTS: Average site-of-entry was 16.57 mm lateral, 2.23 mm rostral, and 5.53 mm deep to the anterior-most portion of the C1 ring. Average axial angulation was 19.49° lateral to midline, measured at the C1 level. Average sagittal angulation was 13.22° inferior to the palatal line, measured from the hard palate to the opisthion. Bicortical purchase was achieved in 11 screws (78.6%). Partial breach of the foramen transversarium was observed in 2 screws (14.3%), violation of the O-C1 joint space in 1 (7.1%), and violation of the central canal in 0 (0%). Average minimum screw distances from the unviolated foramen transversaria and central canal were 1.97 mm and 4.04 mm. CONCLUSIONS: Navigation-assisted endonasal placement of AC1 screws is feasible. Additional studies should investigate the biomechanical stability of anterior C1 screw-plating systems, with anterior condylar screws as superior fixation point, compared to traditional posterior O-C1 fusion.

Systemic Risk Factors for Adult Spinal Deformity (ASD): A Retrospective Analysis of 48 Patients.

INTRODUCTION: Adult spinal deformity (ASD) results in significant patient morbidity and burden to quality of life. The degree to which systemic risk factors and comorbidities that contribute to ASD affect specific spinopelvic parameters is not well-documented. We determine the extent to which preoperative risk factors may contribute to spinopelvic parameters associated with ASD. METHODS: Retrospective single-center study of 48 patients with ASD. Analysis of variance (ANOVA) linear regression analysis was performed to evaluate correlation between systemic comorbidities (obesity, arterial hypertension (HTN), hyperlipidemia (HLD), cardiomyopathy, diabetes mellitus (DM), chronic obstructive pulmonary disease (COPD), and asthma) and the following radiographic parameters: pelvic incidence (PI), lumbar lordosis (LL), C7 sagittal vertical axis (C7SVA), and the T10-L2 sagittal cobb angle. RESULTS: A total of 48 patients were included with mean C7SVA of 79.6 mm (SD: 63, range: 43-254), mean LL of 32.9° (SD: 15.9, range: -14 to 78), T10-L2 sagittal cobb angle of 3° (SD: 12.7, range: -24 to 30), and PI was 49° (SD: 10.7, range: 21 to 77). Only DM correlated with sagittal imbalance with high C7SVA and PI-LL mismatch. The beta coefficient for DM and preoperative C7SVA was 0.49, t=3.16, p=0.003, preoperative PI-LL mismatch standardized beta coefficient was -0.4, t=-2.38, p=0.022, and preoperative T10-L2 sagittal cobb standard beta coefficient was -0.07, t=-0.46, p=0.645. No significant correlations were found for asthma, COPD, HTN, HLD, or cardiomyopathy. CONCLUSIONS: Diagnosis of DM was found to correlate with pathologic C7SVA and significant PI-LL mismatch associated with ASD. HTN, HLD, cardiomyopathy, obesity, and pulmonary disease did not correlate with radiographic findings of sagittal imbalance.

Restoring Segmental Spinal Alignment in Mini-Open Lateral Spinal Deformity Surgery-Determiners of Radiographic Outcome.

OBJECTIVE: Both under- and overcorrection are risk factors for junctional failure after deformity correction. This study investigates which factors determine the segmental radiographic outcome in mini-open lateral deformity surgery. METHODS: A single-center operative database was searched for patients undergoing multilevel mini-open lateral corrective surgery of degenerative spinal deformities. Preoperative and postoperative whole spine x-rays and computed tomography scans were compared for change in global and segmental alignment parameters. Linear regression analyses were performed to study the impact of surgical level, preoperative segmental sagittal Cobb angle, presence of bridging osteophytes, disc height, ankylosis of facet joints, and implantation site of the interbody device on postoperative increase in segmental lordosis, foraminal height, and foraminal width. RESULTS: A total of 49 patients were identified with a mean age of 68.7 years. At a mean, 4.2 segments were fused using a lateral approach, while the posterior stage comprised either minimally invasive surgery or open instrumentation. Upper instrumented vertebra was L2 (range T4-L3), and lower instrumented vertebra was L5 (range L4-pelvis) in most cases. Mean radiographic values pre- and postoperatively were as follows: C7 sagittal vertical axis +79.6 mm, +60 mm; lumbar lordosis 32.9°, 41.6°; pelvic tilt 21.1°, 21.8°; global coronal Cobb 16.3°, 10.8°; increase in segmental sagittal Cobb angle was significantly and inversely correlated with preoperative sagittal Cobb and positively correlated with preoperative coronal Cobb angle. No other variable showed significant correlations. Preoperative foraminal width and height showed significant and inverse correlation with change in postoperative foraminal width and height. CONCLUSION: Segmental sagittal correction is significantly influenced by preoperative loss of lordosis and coronal Cobb angle. Neither presence of osteophytes nor ankylosed facet joints, disc height, or implantation site of the interbody device had an influence on sagittal alignment goals. Only preoperative foraminal dimensions impact inversely the degree of foraminal decompression; no other factor investigated showed significant impact. CLINICAL RELEVANCE: Only preoperative lordosis and coronal Cobb angle influence sagittal correction.

Roadmap to Ventral Craniocervical Junction Through the Endonasal Corridor: Anatomic Evaluation of Inverted U-Shaped Nasopharyngeal Flap Exposure in a Cadaveric Study.

BACKGROUND: There is a paucity of data in the literature describing quantitative exposure of the ventral craniocervical junction through the endonasal corridor in a safe manner mindful of locoregional anatomy. OBJECTIVE: To quantify ventromedial exposure of O-C1 and C1-2 articular structures after turning an inverted U-shaped nasopharyngeal flap (IUNF) and to obtain measurements assessing the distance of flap margins to adjacent neurovascular structures. METHODS: In 8 cadaveric specimens, an IUNF was fashioned using a superior incision below the level of the pharyngeal tubercule of the clivus and lateral incisions in the approximate region of Rosenmuller fossae bilaterally. Measurements with calipers and/or neuronavigation software included flap dimensions, exposure of O-C1 and C1-2 articular structures, inferior reach of IUNF, and proximity of the internal carotid artery (ICA) and hypoglossal nerve to IUNF margins. RESULTS: The IUNF facilitated exposure of an average of 9 mm of the medial surfaces of the right/left O-C1 joints without transgression of the carotid arteries or hypoglossal nerves. The C1-2 articulation could not be routinely accessed. The margins of the IUNF were not in close (<5 mm) proximity to the ICA in any of the 8 specimens. In 6 of 8 specimens, the dimensions of the IUNF were in close (<5 mm) horizontal or vertical proximity to the hypoglossal foramina. CONCLUSION: The IUNF provided safe and reliable access to the medial O-C1 articulation. Given the close proximity of the exocranial hypoglossal foramen, neuronavigation assistance and neuromonitoring with attention to the superolateral IUNF margin are recommended.

Noninvasive electrical stimulation as an adjunct to fusion procedures: a systematic review and meta-analysis.

OBJECTIVE: Noninvasive electrical stimulation represents a distinct group of devices used to augment fusion rates. However, data regarding outcomes of noninvasive electrical stimulation have come from a small number of studies. The goal of this systematic review and meta-analysis was to determine outcomes of noninvasive electrical stimulation used as an adjunct to fusion procedures to improve rates of successful fusion. METHODS: PubMed, Embase, and the Cochrane Clinical Trials database were searched according to search strategy and PRISMA guidelines. Random-effects meta-analyses of fusion rates with the three main modalities of noninvasive electrical stimulation, capacitively coupled stimulation (CCS), pulsed electromagnetic fields (PEMFs), and combined magnetic fields (CMFs), were conducted using R version 4.1.0 (The R Foundation for Statistical Computing). Both retrospective studies and clinical trials were included. Animal studies were excluded. Risk-of-bias analysis was performed with the Risk of Bias 2 (RoB 2) and Risk of Bias in Nonrandomized Studies of Interventions (ROBINS-I) tools. RESULTS: Searches of PubMed, Embase, and the Cochrane Clinical Trials database identified 8 articles with 1216 participants meeting criteria from 213 initial results. There was a high overall risk of bias identified for the majority of randomized studies. No meta-analysis could be performed for CCS as only 1 study was identified. Meta-analysis of 6 studies of fusion rates in PEMF did not find any difference between treatment and control groups (OR 1.89, 95% CI 0.36-9.80, p = 0.449). Meta-analysis of 2 studies of CMF found no difference in fusion rates between control and treatment groups (OR 0.90, 95% CI 0.07-11.93, p = 0.939). Subgroup analysis of PEMF was limited given the small number of studies and patients, although significantly increased fusion rates were seen in some subgroups. CONCLUSIONS: This meta-analysis of clinical outcomes and fusion rates in noninvasive electrical stimulation compared to no stimulation did not identify any increases in fusion rates for any modality. A high degree of heterogeneity between studies was noted. Although subgroup analysis identified significant differences in fusion rates in certain groups, these findings were based on a small number of studies and further research is needed. This analysis does not support routine use of these devices to augment fusion rates, although the data are limited by a high risk of bias and a small number of available studies.

Retrograde ejaculation following anterior lumbar surgery: a systematic review and pooled analysis.

OBJECTIVE: The present systematic review and pooled analysis aims to assess the incidence and risk factors for the development of retrograde ejaculation (RE) following first-time open anterior lumbar surgery. METHODS: A systematic MEDLINE review via PubMed was performed, identifying 130 clinical papers relating to the topic. Eighteen publications were selected according to predetermined inclusion and exclusion criteria and were used to determine the incidence of RE. Only the publications that provided data on surgical risk factors present specifically in the men in the study were included in the analysis of risk factors. RESULTS: Of the 2503 men included, there were 57 reported events of RE (2.3%). Of the cases for which long-term data were provided, 45.8% had resolved by final follow-up. There was a statistically significant increased risk associated with a transperitoneal as opposed to a retroperitoneal approach (8.6% vs 3.2%), as well as with the use of recombinant human bone morphogenetic protein-2 (rhBMP-2) in anterior lumbar interbody fusion (ALIF) as opposed to ALIF with bone graft or arthroplasty in controls (5.0% vs 1.8%). However, when excluding from analysis the patients operated on prior to the FDA's 2008 warning that commented on the drug's neuroinflammatory properties, there was no significant difference in rates of RE in patients receiving rhBMP-2 versus the control group (2.4% vs 2.5%). There was no significant difference in risk based on single- versus multilevel procedure or on ALIF versus arthroplasty. CONCLUSIONS: In a pooled analysis of currently published data on men undergoing first-time open anterior lumbar surgery, this study found an overall incidence of RE of 2.3%. Nearly half of these patients recovered, reporting resolution of symptoms anywhere between 3 months and 48 months. Analysis of risk factors was limited by a paucity of published literature segregating data by sex. However, there was an increased risk associated with rhBMP-2 only when including data collected prior to the FDA warning on its detrimental properties. The authors therefore posit that the risk of RE is probably overestimated in the literature, given that the vast majority of the data available were collected prior to this warning and given the subsequent implementation of precautions when handling rhBMP-2.

Clinical Outcomes between Stand-Alone Zero-Profile Spacers and Cervical Plate with Cage Fixation for Anterior Cervical Discectomy and Fusion: A Retrospective Analysis of 166 Patients.

Stand-alone (SA) zero-profile implants are an alternative to cervical plating (CP) in anterior cervical discectomy and fusion (ACDF). In this study, we investigate differences in surgical outcomes between SA and CP in ACDF. We conducted a retrospective analysis of 166 patients with myelopathy and/or radiculopathy who had ACDF with SA or CP from Jan 2013-Dec 2016. We measured surgical outcomes including Bazaz dysphagia score at 3 months, Nurick grade at last follow-up, and length of hospital stay. 166 patients (92F/74M) were reviewed. 92 presented with radiculopathy (55%), 37 with myelopathy (22%), and 37 with myeloradiculopathy (22%). The average operative time with CP was longer than SA (194 ± 69 vs. 126 ± 46 min) (p < 0.001), as was the average length of hospital stay (2.1 ± 2 vs. 1.5 ± 1 days) (p = 0.006). At 3 months, 82 patients (49.4%) had a follow-up for dysphagia, with 3 patients reporting mild dysphagia and none reporting moderate or severe dysphagia. Nurick grade at last follow-up for the myelopathy and myeloradiculopathy cohorts improved in 63 patients (85%). Prolonged length of stay was associated with reduced odds of having an optimal outcome by 0.50 (CI = 0.35-0.85, p = 0.003). Overall, we demonstrate that there is no significant difference in neurological outcome or rates of dysphagia between SA and CP, and that both lead to overall improvement of symptoms based on Nurick grading. However, we also show that the SA group has shorter length of hospital stay and operative time compared to CP.

Ehlers-Danlos syndrome-associated craniocervical instability with cervicomedullary syndrome: Comparing outcome of craniocervical fusion with occipital bone versus occipital condyle fixation.

INTRODUCTION: Ehlers-Danlos syndrome (EDS) predisposes to craniocervical instability (CCI) with resulting cranial settling and cervicomedullary syndrome due to ligamentous laxity. This study investigates possible differences in radiographic outcomes and operative complication rate between two surgical techniques in patients with EDS and CCI undergoing craniocervical fusion (CCF): occipital bone (OB) versus occipital condyle (OC) fixation. METHODS: A retrospective search of the institutional operative database between January 07, 2017, and December 31, 2019, was conducted to identify EDS patients who underwent CCF with either OB (Group OB) or OC (Group OC) fixation. For each patient, pre- and post-operative radiographic measurements and operative complications were extracted and compared between groups (OB vs. OC): pB-C2, clivoaxial angle (CXA), tonsillar descent, C2C7 sagittal Cobb angle, C2 long axis, and operative complications. RESULTS: Of a total of 26 patients, 13 underwent OV and 13 underwent OC fixation. Eighty-five percent of the patients underwent OC underwent fusion from occiput to C2, while the remaining 15% fusion from occiput to C3. Radiographic outcome in the OC versus OB group was preoperative measurements were similar between OC and OB group: pB-C2 8.8 mm (1.5, 6-11) versus 8.3 mm (1.7, 4-9.6), P = 0.43; CXA 128.2° (5.4, 122-136) versus 131.9° (6.8,122-141), P = 0.41; tonsillar descent 6.2 mm (4.8, 0-15) versus 2.9 mm (3.4, 0-8), P = 0.05; C2 long axis 75.2° (6.7, 58-85) versus 67.2° (21.4, 1-80), P = 0.21; postoperative change of CXA + 14.4° (8.8, 0-30) versus 16.2° (12.4, -4-38), P = 0.43; change of pB-C2 - 2.6 mm (1.8, --5.3 to 0) versus - 1.2 mm (4, -4.6-8), P = 0.26; and postoperative C2C7 sagittal Cobb angle - 2.6° (19.5, -43-39) versus - 2.6° (11.4, -21-12). Operative complications were seen in 1 out of 13 patients (8%) versus 2 out of 13 patients (16%), P = 1. CONCLUSIONS: In EDS, patients with CCI undergoing CCF radiographic and clinical outcome were similar between those with OC versus OB fixation. Both techniques resulted in sufficient correction of pB-C2 and CXA measurements with a low complication rate.

Junctional kyphosis and junctional failure after multi-segmental posterior cervicothoracic fusion - A retrospective analysis of 64 patients.

INTRODUCTION: Junctional kyphosis (JK) and junctional failure (JF) are known complications after thoracolumbar spinal deformity surgery. This study aims to define the incidence and possible risk factors for JK/JF following multi-segmental cervicothoracic fusion. METHODS: This is a retrospective analysis of 64 consecutive patients undergoing cervicothoracic fusion surgery, including at least five segments. Clinical and radiographic outcome measures were analyzed. A univariate analysis was performed to determine the effect of the level of upper instrumented vertebra (UIV) and lower instrumented vertebra (LIV), fusion status, C2 sagittal vertical axis (SVA), C2-C7 lordotic angle and T1 slope angle on the occurrence of JK/JF. RESULTS: A total of 46 patients were followed up for a median of 1.1 years (range 0.3-4) with a median age of 65.5 years (range 42.2-84.5). Indication for surgery was spinal stenosis in 87%, trauma in 7%, and tumor in 6% of cases. The median number of levels fused was 7; the most frequent UIV was C2, and the most frequent LIV was T2. Solid fusion was achieved in 78% at the last follow-up. Postoperatively, the median C2 SVA was 32 mm (range - 7-75), median T1 slope angle was 33° (range 2°-57°), C2-C7 sagittal cobb angle was 4° (-29°-12°). JK developed in 4% of cases, no case of JF was observed. No statistically significant impact of bone density, level of UIV, level of LIV or postoperative sagittal parameters on the occurrence of JK/JF was observed, even though fusion status and pathologic T1 slope angle showed a trend toward significance. CONCLUSION: In this cohort of patients with mildly pathologic sagittal balance, JK was a rare event after multi-segmental fusion, observed in only 4% of cases. Neither level of UIV nor LIV had an influence on its occurrence; however, nonunion and pathologic sagittal alignment showed a nonsignificant trend.

Validating the Transformation of PROMIS-GH to EQ-5D in Adult Spine Patients.

Spinal disorders and associated interventions are costly in the United States, putting them in the limelight of economic analyses. The Patient-Reported Outcomes Measurement Information System Global Health Survey (PROMIS-GHS) requires mapping to other surveys for economic investigation. Previous studies have proposed transformations of PROMIS-GHS to EuroQol 5-Dimension (EQ-5D) health index scores. These models require validation in adult spine patients. In our study, PROMIS-GHS and EQ-5D were randomly administered to 121 adult spine patients. The actual health index scores were calculated from the EQ-5D instrument and estimated scores were calculated from the PROMIS-GHS responses with six models. Goodness-of-fit for each model was determined using the coefficient of determination (R2), mean squared error (MSE), and mean absolute error (MAE). Among the models, the model treating the eight PROMIS-GHS items as categorical variables (CATReg) was the optimal model with the highest R2 (0.59) and lowest MSE (0.02) and MAE (0.11) in our spine sample population. Subgroup analysis showed good predictions of the mean EQ-5D by gender, age groups, education levels, etc. The transformation from PROMIS-GHS to EQ-5D had a high accuracy of mean estimate on a group level, but not at the individual level.

Preoperative Risk Stratification in Spine Tumor Surgery: A Comparison of the Modified Charlson Index, Frailty Index, and ASA Score.

STUDY DESIGN: A retrospective review of prospectively collected data. OBJECTIVE: The purpose of this study is to compare and validate several preoperative scores for predicting outcomes following spine tumor resection. SUMMARY OF BACKGROUND DATA: Preoperative risk assessment for patients undergoing spinal tumor resection remains challenging. At present, few risk assessment tools have been validated in this high-risk population. METHODS: The 2008 to 2014 National Surgical Quality Improvement database was used to identify all patients undergoing surgical resection of spinal tumors, stratified as extradural, intradural extramedullary, and intramedullary based on CPT codes. American Society of Anesthesiologists (ASA) score, modified Charlson Comorbidity Index (CCI), and modified Frailty Index (mFI) were computed. A binary logistic regression model was used to explore the relationship between these variables and postoperative outcomes, including mortality, major and minor adverse events, and hospital length of stay (LOS). Other significant variables such as demographics, operative time, and tumor location were controlled for in each model. RESULTS: Two thousand one hundred seventy patients met the inclusion criteria. Higher CCI scores were independent predictors of mortality (OR = 1.24, 95% CI: 1.14-1.36, P < 0.001), major adverse events (OR = 1.07, 95% CI: 1.01-1.31, P = 0.018), minor adverse events (OR = 1.15, 95% CI: 1.10-1.20, P < 0.001), and prolonged LOS (OR = 1.14, 95% CI: 1.09-1.19, P < 0.001). Patients' mFI scores were significantly associated with mortality and LOS, but not major or minor adverse events. ASA scores were not associated with any outcome metric when controlling for other variables. CONCLUSION: The CCI demonstrated superior predictive capacity compared with mFI and ASA scores and may be valuable as a preoperative risk assessment tool for patients undergoing surgical resection of spinal tumors. The validation of assessment scores is important for preoperative risk stratification and improving outcomes in this high-risk group. LEVEL OF EVIDENCE: 3.

Cervical Cord-Canal Mismatch: A New Method for Identifying Predisposition to Spinal Cord Injury.

The risk for spinal cord injuries (SCIs) ranging from devastating traumatic injuries, compression because of degenerative pathology, and neurapraxia is increased in patients with congenital spinal stenosis. Classical diagnostic criteria include an absolute anteroposterior diameter of <12-13 mm or a Torg-Pavlov ratio of <0.80-0.82; however, these factors do not take into account the size of the spinal cord, which varies across patients, independent of canal size. Recent large magnetic resonance imaging studies of population cohorts have allowed newer methods to emerge that account for both cord and canal size by measuring a spinal cord occupation ratio (SCOR). A SCOR defined as ≥70% on midsagittal imaging or ≥80% on axial imaging appears to be an effective method of identifying cord-canal mismatch, but requires further validation. Cord-canal size mismatch predisposes patients to SCI because of 1) less space within the canal lowering the amount of degenerative changes needed for cord compression, and 2) less cerebrospinal fluid surrounding the spinal cord decreasing the ability to absorb kinetic forces directed at the spine. Patients with cord-canal mismatch have been reported to be at a substantially higher risk of traumatic SCI, and present with degenerative cervical myelopathy at a younger age than patients without cord-canal mismatch. However, neurologic outcome after SCI has occurred does not appear to be different in patients with or without a cord-canal mismatch. Recognition that canal and cord size are both factors which predispose to SCI supports that cord-canal size mismatch rather than a narrow cervical canal in isolation should be viewed as the underlying mechanism predisposing to SCI.

Exploratory study for identifying systemic biomarkers that correlate with pain response in patients with intervertebral disc disorders.

Molecular events that drive disc damage and low back pain (LBP) may precede clinical manifestation of disease onset and can cause detrimental long-term effects such as disability. Biomarkers serve as objective molecular indicators of pathological processes. The goal of this study is to identify systemic biochemical factors as predictors of response to treatment of LBP with epidural steroid injection (ESI). Since inflammation plays a pivotal role in LBP, this pilot study investigates the effect of ESI on systemic levels of 48 inflammatory biochemical factors (cytokines, chemokines, and growth factors) and examines the relationship between biochemical factor levels and pain or disability in patients with disc herniation (DH), or other diagnoses (Other Dx) leading to low back pain, which included spinal stenosis (SS) and degenerative disc disease (DDD). Study participants (n = 16) were recruited from a back pain management practice. Pain numerical rating score (NRS), Oswestry Disability Index (ODI), and blood samples were collected pre- and at 7 to 10 days post-treatment. Blood samples were assayed for inflammatory mediators using commercial multiplex assays. Mediator levels were compared pre- and post-treatment to investigate the potential correlations between clinical and biochemical outcomes. Our results indicate that a single ESI significantly decreased systemic levels of SCGF-ß and IL-2. Improvement in pain in all subjects was correlated with changes in chemokines (MCP-1, MIG), hematopoietic progenitor factors (SCGF-ß), and factors that participate in angiogenesis/fibrosis (HGF), nociception (SCF, IFN-α2), and inflammation (IL-6, IL-10, IL-18, TRAIL). Levels of biochemical mediators varied based on diagnosis of LBP, and changes in pain responses and systemic mediators from pre- to post-treatment were dependent on the diagnosis cohort. In the DH cohort, levels of IL-17 and VEGF significantly decreased post-treatment. In the Other Dx cohort, levels of IL-2Rα, IL-3, and SCGF-ß significantly decreased post-treatment. In order to determine whether mediator changes were related to pain, correlations between change in pain scores and change in mediator levels were performed. Subjects with DH demonstrated a profile signature that implicated hematopoiesis factors (SCGF-ß, GM-CSF) in pain response, while subjects with Other Dx demonstrated a biomarker profile that implicated chemokines (MCP-1, MIG) and angiogenic factors (HGF, VEGF) in pain response. Our findings provide evidence that systemic biochemical factors in patients with LBP vary by diagnosis, and pain response to treatment is associated with a unique profile of biochemical responses in each diagnosis group. Future hypothesis-based studies with larger subject cohorts are warranted to confirm the findings of this pilot exploratory study.

Rare cause of trigeminal neuralgia: Meckel's cave meningocele.

The most common etiology of classic trigeminal neuralgia is vascular compression. However, other causes must be excluded. It is very unlikely that a meningocele presents with symptomatic trigeminal neuralgia. We present a rare case of a patient presenting with left trigeminal neuralgia. Thin-slice CT and MRI showed a transclival Meckel's cave meningocele. The patient underwent endoscopic repair of the meningocele, which resulted in complete resolution of her symptoms. Meckel's cave meningocele or encephalocele should be considered among the differential diagnoses of trigeminal neuralgia. Meningocele repair should be suggested as the first treatment option in this rare situation.

Developments in intervertebral disc disease research: pathophysiology, mechanobiology, and therapeutics.

Low back pain is a leading cause of disability worldwide and the second most common cause of physician visits. There are many causes of back pain, and among them, disc herniation and intervertebral disc degeneration are the most common diagnoses and targets for intervention. Currently, clinical treatment outcomes are not strongly correlated with diagnoses, emphasizing the importance for characterizing more completely the mechanisms of degeneration and their relationships with symptoms. This review covers recent studies elucidating cellular and molecular changes associated with disc mechanobiology, as it relates to degeneration and regeneration. Specifically, we review findings on the biochemical changes in disc diseases, including cytokines, chemokines, and proteases; advancements in disc disease diagnostics using imaging modalities; updates on studies examining the response of the intervertebral disc to injury; and recent developments in repair strategies, including cell-based repair, biomaterials, and tissue engineering. Findings on the effects of the omega-6 fatty acid, linoleic acid, on nucleus pulposus tissue engineering are presented. Studies described in this review provide greater insights into the pathogenesis of disc degeneration and may define new paradigms for early or differential diagnostics of degeneration using new techniques such as systemic biomarkers. In addition, research on the mechanobiology of disease enriches the development of therapeutics for disc repair, with potential to diminish pain and disability associated with disc degeneration.