Elder, Benjamin D.

Study Design. Retrospective cohort study. Objective. The present study is the first to assess the impact of paraspinal sarcopenia on patient-reported outcome measures (PROMs) following posterior cervical decompression and fusion (PCDF). Summary of Background Data. While the impact of sarcopenia on PROMs following lumbar spine surgery is well-established, the impact of sarcopenia on PROMs following PCDF has not been investigated. Materials and Methods. We performed a retrospective review of patients undergoing PCDF from C2 to T2 at a single institution between the years 2017 and 2020. Two independent reviewers who were blinded to the clinical outcome scores utilized axial cuts of T2-weighted magnetic resonance imaging sequences to assess fatty infiltration of the bilateral multifidus muscles at the C5–C6 level and classify patients according to the Fuchs Modification of the Goutalier grading system. PROMs were then compared between subgroups. Results. We identified 99 patients for inclusion in this study, including 28 patients with mild sarcopenia, 45 patients with moderate sarcopenia, and 26 patients with severe sarcopenia. There was no difference in any preoperative PROM between the subgroups. Mean postoperative Neck Disability Index scores were lower in the mild and moderate sarcopenia subgroups (12.8 and 13.4, respectively) than in the severe sarcopenia subgroup (21.0, P <0.001). A higher percentage of patients with severe multifidus sarcopenia reported postoperative worsening of their Neck Disability Index (10 patients, 38.5%; P =0.003), Visual Analog Scale Neck scores (7 patients, 26.9%; P =0.02), Patient-Reported Outcome Measurement Information System Physical Component Scores (10 patients, 38.5%; P =0.02), and Patient-Reported Outcome Measurement Information System Mental Component Scores (14 patients, 53.8%; P =0.02). Conclusion. Patients with more severe paraspinal sarcopenia demonstrate less improvement in neck disability and physical function postoperatively and are substantially more likely to report worsening PROMs postoperatively. Level of Evidence. 3.

OBJECTIVE Patients with ankylosing spinal disorders (ASDs), including ankylosing spondylitis (AS) and diffuse idiopathic skeletal hyperostosis (DISH), have been shown to experience significantly increased rates of postoperative complications. Despite this, very few risk stratification tools have been validated for this population. As such, the purpose of this study was to identify predictors of adverse events and mortality in ASD patients undergoing surgery for 3-column fractures. METHODS All adult patients with a documented history of AS or DISH who underwent surgery for a traumatic 3-column fracture between 2000 and 2020 were identified. Perioperative variables, including comorbidities, time to diagnosis, and number of fused segments, were collected. Three instruments, including the Charlson Comorbidity Index (CCI), modified frailty index (mFI), and Injury Severity Score (ISS), were computed for each patient. The primary outcomes of interest included 1-year mortality, as well as postoperative complications. RESULTS A total of 108 patients were included, with a mean ± SD age of 73 ± 11 years. Of these, 41 (38%) experienced at least 1 postoperative complication and 22 (20.4%) died within 12 months after surgery. When the authors controlled for potential known confounders, the CCI score was significantly associated with postoperative adverse events (OR 1.20, 95% CI 1.00–1.42, p = 0.045) and trended toward significance for mortality (OR 1.19, 95% CI 0.97–1.45, p = 0.098). In contrast, mFI score and ISS were not significantly predictive of either outcome. CONCLUSIONS Complications in spine trauma patients with ASD may be driven by comorbidity burden rather than operative or injury-related factors. The CCI may be a valuable tool for the evaluation of this unique population.

OBJECTIVE The aim of this study was to analyze risk factors and avoidance techniques for proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) in the upper thoracic spine with an emphasis on bone mineral density (BMD) as estimated by Hounsfield units (HU). METHODS A retrospective chart review identified patients at least 50 years of age who underwent instrumented fusion extending from the pelvis to an upper instrumented vertebra (UIV) between T1 and T6 and had a preoperative CT, pre- and postoperative radiographs, and a minimum follow-up of 12 months. HU were measured in the UIV, the vertebral body cephalad to the UIV (UIV+1), and the L3 and L4 vertebral bodies. Numerous perioperative variables were collected, including basic demographics, smoking and steroid use, preoperative osteoporosis treatment, multiple frailty indices, use of a proximal junctional tether, UIV soft landing, preoperative dual-energy x-ray absorptiometry, spinopelvic parameters, UIV screw tip distance to the superior endplate, UIV pedicle screw/pedicle diameter ratio, lumbar lordosis distribution, and postoperative spinopelvic parameters compared with age-adjusted normal values. RESULTS Eighty-one patients were included in the study (21 men and 60 women) with a mean (SD) age of 66 years (6.9 years), BMI of 29 (5.5), and follow-up of 38 months (25 months). Spinal fusion constructs at the time of surgery extended from the pelvis to a UIV of T1 (5%), T2 (15%), T3 (25%), T4 (33%), T5 (21%), and T6 (1%). Twenty-seven patients (33%) developed PJK and/or PJF; 21 (26%) had PJK and 15 (19%) had PJF. Variables associated with PJK/PJF with p < 0.05 were included in the multivariable analysis, including HU at the UIV/UIV+1, HU at L3/L4, DXA femoral neck T-score, UIV screw tip distance to the superior endplate, UIV pedicle screw/pedicle diameter ratio, and postoperative lumbar lordosis distribution. Multivariable analysis (area under the curve = 0.77) demonstrated HU at the UIV/UIV+1 to be the only independent predictor of PJK and PJF with an OR of 0.96 (p = 0.005). Patients with < 147 HU (n = 27), 147–195 HU (n = 27), and > 195 HU (n = 27) at the UIV/UIV+1 had PJK/PJF rates of 59%, 33%, and 7%, respectively. CONCLUSIONS In patients with upper thoracic–to-pelvis spinal reconstruction, lower HU at the UIV and UIV+1 were independently associated with PJK and PJF, with an optimal cutoff of 159 HU that maximizes sensitivity and specificity.

Study Design Systematic Review and Meta-analysis Objective The purpose of this study is to synthesize recommendations for perioperative medical management of RA patients and quantify outcomes after spine surgery when compared to patients without RA. Methods A search of available literature on patients with RA and spine surgery was performed. Studies were included if they provided a direct comparison of outcomes between patients undergoing spine surgery with or without RA diagnosis. Meta-analysis was performed on operative time, estimated blood loss, hospital length of stay, overall complications, implant-related complications, reoperation, infection, pseudarthrosis, and adjacent segment disease. Results Included in the analysis were 9 studies with 703 patients with RA undergoing spine surgery and 2569 patients without RA. In RA patients compared to non-RA patients undergoing spine surgery, the relative risk of infection was 2.29 times higher (P = .036), overall complications 1.61 times higher (P < .0001), implant-related complications 3.93 times higher (P = .009), and risk of reoperation 2.45 times higher (P < .0001). Hospital length of stay was 4.6 days longer in RA patients (P < .0001). Conclusions Treatment of spinal pathology in patients with RA carries an increased risk of infection and implant-related complications. Spine-specific guidelines for perioperative management of antirheumatic medication deserve further exploration. All RA patients should be perioperatively co-managed by a rheumatologist. This review helps identify risk profiles in RA specific to spine surgery and may guide future studies seeking to medically optimize RA patients perioperatively.

Although hypothermia has shown to protect against ischemic and traumatic neuronal death, its potential role in neurologic recovery following traumatic spinal cord injury (TSCI) remains incompletely understood. Herein, we systematically review the safety and efficacy of hypothermia therapy for TSCI. The English medical literature was reviewed using PRISMA guidelines to identify preclinical and clinical studies examining the safety and efficacy of hypothermia following TSCI. Fifty-seven articles met full-text review criteria, of which twenty-eight were included. The main outcomes of interest were neurological recovery and postoperative complications. Among the 24 preclinical studies, both systemic and local hypothermia significantly improved neurologic recovery. In aggregate, the 4 clinical studies enrolled 60 patients for treatment, with 35 receiving systemic hypothermia and 25 local hypothermia. The most frequent complications were respiratory in nature. No patients suffered neurologic deterioration because of hypothermia treatment. Rates of American Spinal Injury Association (AIS) grade conversion after systemic hypothermia (35.5%) were higher when compared to multiple SCI database control studies (26.1%). However, no statistical conclusions could be drawn regarding the efficacy of hypothermia in humans. These limited clinical trials show promise and suggest therapeutic hypothermia to be safe in TSCI patients, though its effect on neurological recovery remains unclear. The preclinical literature supports the efficacy of hypothermia after TSCI. Further clinical trials are warranted to conclusively determine the effects of hypothermia on neurological recovery as well as the ideal means of administration necessary for achieving efficacy in TSCI.

Study Design: This was a multicenter retrospective cohort study. Objective: The purpose of this study was to compare the surgical and radiographic outcomes of patients undergoing posterior cervical fusion (PCF) with constructs extending from C2 to T2 to patients with constructs extending from C3 to T1. Summary of Background Data: Limited evidence exists regarding the appropriate level of proximal and distal extension of PCF constructs. Methods: A multicenter retrospective cohort study of patients who underwent PCF between 2012 and 2020 was performed. Surgical and radiographic outcomes were compared between those who had C3–T1 or C2–T2 constructs. Results: A total of 155 patients were included in the study (C2–T2: 106 patients, C3–T1: 49 patients). There were no significant differences in demographics or preoperative symptoms between cohorts. Fusion rates were significantly higher in the C2–T2 (93%) than the C3–T1 (80%, P=0.040) cohort. When comparing the C2–T2 to the C3–T1 cohort, the C3–T1 cohort had a significantly greater rate of proximal junctional failure (2% vs. 10%, P=0.006), distal junctional failure (1% vs. 20%, P<0.001) and distal screw loosening (4% vs. 15%, P=0.02). Although ∆C2–C7 sagittal vertical axis increased significantly in both cohorts (C2–T2: 6.2 mm, P=0.04; C3–T1: 8.4 mm, P<0.001), correction did not significantly differ between groups (P=0.32). The C3–T1 cohort had a significantly greater increase in ∆C2 slope (8.0 vs. 3.1 degrees, P=0.03) and ∆C0–C2 Cobb angle (6.4 vs. 1.2 degrees, P=0.04). Conclusion: In patients undergoing PCF, a C2–T2 construct demonstrated lower rates of pseudarthrosis, distal junctional failure, proximal junctional failure, and compensatory upper cervical hyperextension compared with a C3–T1 construct.

Abstract The complex and dynamic system of fluid flow through the perivascular and interstitial spaces of the CNS has new-found implications for neurological diseases. CSF movement throughout the CNS parenchyma is more dynamic than could be explained via passive diffusion mechanisms alone. Indeed, a semistructured glial-lymphatic (glymphatic) system of astrocyte-supported extracellular perivascular channels serves to directionally channel extracellular fluid, clearing metabolites and peptides to optimize neurological function. Clinical studies of the glymphatic network have to date proven challenging, with most data gleaned from rodent models and post-mortem investigations. However, increasing evidence suggests that disordered glymphatic function contributes to the pathophysiology of CNS ageing, neurodegenerative disease and CNS injuries, as well as normal pressure hydrocephalus. Unlocking such pathophysiology could provide important avenues towards novel therapeutics. We here provide a multidisciplinary overview of glymphatics and critically review accumulating evidence regarding its structure, function and hypothesized relevance to neurological disease. We highlight emerging technologies of relevance to the longitudinal evaluation of glymphatic function in health and disease. Finally, we discuss the translational opportunities and challenges of studying glymphatic science.

Transdiscal screw fixation through the Boachie screw technique at the lumbosacral junction is a well-accepted procedure in the treatment of high-grade spondylolisthesis. This technique allows for partial reduction of the spondylolisthesis, decompression of the neural elements, and reliable posterior lumbosacral fixation. When performed properly, this procedure produces reliable results and high rates of arthrodesis with relief of preoperative neurological symptoms.

Study Design Retrospective cohort study Objective Substantial variability in both the measurement and classification of subsidence limits the strength of conclusions that can be drawn from previous studies. The purpose of this study was to precisely characterize patterns of cervical cage subsidence utilizing computed tomography (CT) scans, determine risk factors for cervical cage subsidence, and investigate the impact of subsidence on pseudarthrosis rates. Methods We performed a retrospective review of patients who underwent one- to three-levels of anterior cervical discectomy and fusion (ACDF) utilizing titanium interbodies with anterior plating between the years 2018 and 2020. Subsidence measurements were performed by two independent reviewers on CT scans obtained 6 months postoperatively. Subsidence was then classified as mild if subsidence into the inferior and superior endplate were both ≤2 mm, moderate if the worst subsidence into the inferior or superior endplate was between 2 to 4 mm, or severe if the worst subsidence into the inferior or superior endplate was ≥4 mm. Results A total of 51 patients (100 levels) were included in this study. A total of 48 levels demonstrated mild subsidence (≤2 mm), 38 demonstrated moderate subsidence (2-4 mm), and 14 demonstrated severe subsidence (≥4 mm). Risk factors for severe subsidence included male gender, multilevel constructs, greater mean vertebral height loss, increased cage height, lower Taillard index, and lower screw tip to vertebral body height ratio. Severe subsidence was not associated with an increased rate of pseudarthrosis. Conclusion Following ACDF with titanium cervical cages, subsidence is an anticipated postoperative occurrence and is not associated with an increased risk of pseudarthrosis.