In-Bulk Temperature Profile Mapping Using Fiber Bragg Grating in Fluids.

The capabilities of Fiber Bragg Grating (FBG) sensors to measure temperature variations in the bulk of liquid flows were considered. In the first step of our research project, reported in this paper, we investigated to what extent the use of thin glass fibers without encapsulation, which only minimally disturb a flow, can fulfill the requirements for robustness and measurement accuracy. Experimental tests were performed in a benchmark setup containing 24 FBG measuring positions, which were instrumented in parallel with thermocouples for validation. We suggest a special assembly procedure in which the fiber is placed under a defined tension to improve its stiffness and immobility for certain flow conditions. This approach uses a single FBG sensor as a reference that measures the strain effect in real time, allowing accurate relative temperature measurements to be made at the other FBG sensor points, taking into account an appropriate correction term. Absolute temperature readings can be obtained by installing another well-calibrated, strain-independent thermometer on the reference FBG. We demonstrated this method in two test cases: (i) a temperature gradient with stable density stratification in the liquid metal GaInSn and (ii) the heating of a water column using a local heat source. In these measurements, we succeeded in recording both spatial and temporal changes in the linear temperature distribution along the fiber. We present the corresponding results from the tests and, against this background, we discuss the capabilities and limitations of this measurement technique with respect to the detection of temperature fields in liquid flows.

Evolution of surgical treatment of metastatic spine tumors.

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

Toward more accurate documentation in neurosurgical care.

OBJECTIVE: Accurate clinical documentation is foundational to any quality improvement endeavor as it is ultimately the medical record that is measured in assessing change. Literature on high-yield interventions to improve the accuracy and completeness of clinical documentation by neurosurgical providers is limited. Therefore, the authors sought to share a single-institution experience of a two-part intervention to enhance clinical documentation by a neurosurgery inpatient service. METHODS: At an urban, level I trauma, academic teaching hospital, a two-part intervention was implemented to enhance the accuracy of clinical documentation of neurosurgery inpatients by residents and advanced practice providers (APPs). Residents and APPs were instructed on the most common neurosurgical complications or comorbidities (CCs) and major complications or comorbidities (MCCs), as defined by Medicare. Additionally, a "system-based" progress note template was changed to a "problem-based" progress note template. Prepost analysis was performed to compare the CC/MCC capture rates for the 12 months prior to the intervention with those for the 3 months after the intervention. RESULTS: The CC/MCC capture rate for the neurosurgery service line rose from 62% in the 12 months preintervention to 74% in the 3 months after intervention, representing a significant change (p = 0.00002). CONCLUSIONS: Existing clinical documentation habits by neurosurgical residents and APPs may fail to capture the extent of neurosurgical inpatients with CC/MCCs. An intervention that focuses on the most common CC/MCCs and utilizes a problem-based progress note template may lead to more accurate appraisals of neurosurgical patient acuity.

Existing clinical evidence on the use of cellular bone matrix grafts in spinal fusion: updated systematic review of the literature.

OBJECTIVE: Spinal fusion surgery is increasingly common; however, pseudarthrosis remains a common complication affecting as much as 15% of some patient populations. Currently, no clear consensus on the best bone graft materials to use exists. Recent advances have led to the development of cell-infused cellular bone matrices (CBMs), which contain living components such as mesenchymal stem cells (MSCs). Relatively few clinical outcome studies on the use of these grafts exist, although the number of such studies has increased in the last 5 years. In this study, the authors aimed to summarize and critically evaluate the existing clinical evidence on commercially available CBMs in spinal fusion and reported clinical outcomes. METHODS: The authors performed a systematic search of the MEDLINE and PubMed electronic databases for peer-reviewed, English-language original articles (1970-2020) in which the articles' authors studied the clinical outcomes of CBMs in spinal fusion. The US National Library of Medicine electronic clinical trials database (www.ClinicalTrials.gov) was also searched for relevant ongoing clinical trials. RESULTS: Twelve published studies of 6 different CBM products met inclusion criteria: 5 studies of Osteocel Plus/Osteocel (n = 354 unique patients), 3 of Trinity Evolution (n = 114), 2 of ViviGen (n = 171), 1 of map3 (n = 41), and 1 of VIA Graft (n = 75). All studies reported high radiographic fusion success rates (range 87%-100%) using these CBMs. However, this literature was overwhelmingly limited to single-center, noncomparative studies. Seven studies disclosed industry funding or conflicts of interest (COIs). There are 4 known trials of ViviGen (3 trials) and Bio4 (1 trial) that are ongoing. CONCLUSIONS: CBMs are a promising technology with the potential of improving outcome after spinal fusion. However, while the number of studies conducted in humans has tripled since 2014, there is still insufficient evidence in the literature to recommend for or against CBMs relative to cheaper alternative materials. Comparative, multicenter trials and outcome registries free from industry COIs are indicated.

Rehabilitation of hand function after spinal cord injury using a novel handgrip device: a pilot study.

BACKGROUND: Activity-based therapy (ABT) for patients with spinal cord injury (SCI), which consists of repetitive use of muscles above and below the spinal lesion, improves locomotion and arm strength. Less data has been published regarding its effects on hand function. We sought to evaluate the effects of a weekly hand-focused therapy program using a novel handgrip device on grip strength and hand function in a SCI cohort. METHODS: Patients with SCI were enrolled in a weekly program that involved activities with the MediSens (Los Angeles, CA) handgrip. These included maximum voluntary contraction (MVC) and a tracking task that required each subject to adjust his/her grip strength according to a pattern displayed on a computer screen. For the latter, performance was measured as mean absolute accuracy (MAA). The Spinal Cord Independence Measure (SCIM) was used to measure each subject's independence prior to and after therapy. RESULTS: Seventeen patients completed the program with average participation duration of 21.3 weeks. The cohort included patients with American Spinal Injury Association (ASIA) Impairment Scale (AIS) A (n = 12), AIS B (n = 1), AIS C (n = 2), and AIS D (n = 2) injuries. The average MVC for the cohort increased from 4.1 N to 21.2 N over 20 weeks, but did not reach statistical significance. The average MAA for the cohort increased from 9.01 to 21.7% at the end of the study (p = .02). The cohort's average SCIM at the end of the study was unchanged compared to baseline. CONCLUSIONS: A weekly handgrip-based ABT program is feasible and efficacious at increasing hand task performance in subjects with SCI.

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

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

Natural language processing augments comorbidity documentation in neurosurgical inpatient admissions.

OBJECTIVE: To establish whether or not a natural language processing technique could identify two common inpatient neurosurgical comorbidities using only text reports of inpatient head imaging. MATERIALS AND METHODS: A training and testing dataset of reports of 979 CT or MRI scans of the brain for patients admitted to the neurosurgery service of a single hospital in June 2021 or to the Emergency Department between July 1-8, 2021, was identified. A variety of machine learning and deep learning algorithms utilizing natural language processing were trained on the training set (84% of the total cohort) and tested on the remaining images. A subset comparison cohort (n = 76) was then assessed to compare output of the best algorithm against real-life inpatient documentation. RESULTS: For "brain compression", a random forest classifier outperformed other candidate algorithms with an accuracy of 0.81 and area under the curve of 0.90 in the testing dataset. For "brain edema", a random forest classifier again outperformed other candidate algorithms with an accuracy of 0.92 and AUC of 0.94 in the testing dataset. In the provider comparison dataset, for "brain compression," the random forest algorithm demonstrated better accuracy (0.76 vs 0.70) and sensitivity (0.73 vs 0.43) than provider documentation. For "brain edema," the algorithm again demonstrated better accuracy (0.92 vs 0.84) and AUC (0.45 vs 0.09) than provider documentation. DISCUSSION: A natural language processing-based machine learning algorithm can reliably and reproducibly identify selected common neurosurgical comorbidities from radiology reports. CONCLUSION: This result may justify the use of machine learning-based decision support to augment provider documentation.

Bacterial taxonomic and functional profiles from Bohai Sea to northern Yellow Sea.

Microbial distribution patterns are the result of a combination of biotic and abiotic factors, which are the core issues in microbial ecology research. To better understand the biogeographic pattern of bacteria in water environments from the Bohai Sea to the northern Yellow Sea, the effects of environmental factors, and spatial distance on the structure of bacterial communities in marine water were investigated using high-throughput sequencing technology based on 16S rRNA genes. The results showed that Proteobacteria, Bacteroidetes, Actinobacteri, Desulfobacterota, and Bdellovibrionota were the dominant phyla in the study area. A clear spatial pattern in the bacterial community was observed, and environmental factors, including salinity, nutrient concentration, carbon content, total phosphorus, dissolved oxygen, and seawater turbidity emerged as the central environmental factors regulating the variation in bacterial communities. In addition, the study provides direct evidence of the existence of dispersal limitation in this strongly connected marine ecological system. Therefore, these results revealed that the variation in bacterial community characteristics was attributed to environmental selection, accompanied by the regulation of stochastic diffusion. The network analysis demonstrated a nonrandom co-occurrence pattern in the microbial communities with distinct spatial distribution characteristics. It is implied that the biogeography patterns of bacterial community may also be associated with the characteristics of co-occurrence characterize among bacterial species. Furthermore, the PICRUSt analysis indicated a clear spatial distribution of functional characteristics in bacterial communities. This functional variation was significantly modulated by the environmental characteristics of seawater but uncoupled from the taxonomic characteristics of bacterial communities (e.g., diversity characteristics, community structure, and co-occurrence relationships). Together, this findings represent a significant advance in linking seawater to the mechanisms underlying bacterial biogeographic patterns and community assembly, co-occurrence patterns, and ecological functions, providing new insights for identifying the microbial ecology as well as the biogeochemical cycle in the marine environment.

Gross total resection and survival outcomes in elderly patients with spinal chordoma: a SEER-based analysis.

Objective: The association between aggressive resection and improved survival for adult spinal chordoma patients has not been well characterized in the geriatric population. Thus, the present study aimed to elucidate the relationship between gross total resection (GTR) and survival outcomes for patients across different age groups. Methods: The authors isolated all adult patients diagnosed with spinal chordoma from the 2000-2019 Surveillance, Epidemiology, and End Results database and divided patients into three surgical subgroups: no surgery, subtotal resection (STR), and GTR. Kaplan-Meier curves with a log-rank test were used to discern differences in overall survival (OS) between surgical subgroups. Univariate and multivariate analyses were used to identify prognostic factors of mortality. Results: There were 771 eligible patients: 227 (29.4%) received no surgery, 267 (34.6%) received STR, and 277 (35.9%) received GTR. Patients receiving no surgery had the lowest 5-year OS (45.2%), 10-year OS (17.6%), and mean OS (72.1 months). After stratifying patients by age, our multivariate analysis demonstrated that patients receiving GTR aged 40-59 (HR=0.26, CI=0.12-0.55, p<0.001), 60-79 (HR=0.51, CI=0.32-0.82, p=0.005), and 80-99 (HR=0.14, CI=0.05-0.37, p<0.001) had a lower risk of mortality compared to patients undergoing no surgery. The frequency of receiving GTR also decreased as a function of age (16.4% [80-99 years] vs. 43.2% [20-39 years]; p<0.001), but the frequency of receiving radiotherapy was comparable across all age groups (48.3% [80-99 years] vs. 45.5% [20-39 years]; p=0.762). Conclusion: GTR is associated with improved survival for middle-aged and elderly patients with spinal chordoma. Therefore, patients should not be excluded from aggressive resection on the basis of age alone. Rather, the decision to pursue surgery should be decided on an individual basis.

Optimizing surgical management of facet cysts of the lumbar spine: systematic review, meta-analysis, and local case series of 1251 patients.

OBJECTIVE: Lumbar facet cysts (LFCs) can cause neurological dysfunction and intractable pain. Surgery is the current standard of care for patients in whom conservative therapy fails, those with neurological deficits, and those with evidence of spinal instability. No study to date has comprehensively examined surgical outcomes comparing the multiple surgical treatment options for LFCs. Therefore, the authors aimed to perform a combined analysis of cases both in the literature and of patients at a single institution to compare the outcomes of various surgical treatment options for LFC. METHODS: The authors performed a literature review in accordance with PRISMA guidelines and meta-analysis of the PubMed, Embase, and Cochrane Library databases and reviewed all studies from database inception published until February 3, 2023. Studies that did not contain 3 or more cases, clearly specify follow-up durations longer than 6 months, or present new cases were excluded. Bias was evaluated using Cochrane Collaboration's Risk of Bias in Nonrandomised Studies-of Interventions (ROBINS-I). The authors also reviewed their own local institutional case series from 2015 to 2020. Primary outcomes were same-level cyst recurrence, same-level revision surgery, and perioperative complications. ANOVA, common and random-effects modeling, and Wald testing were used to compare treatment groups. RESULTS: A total of 1251 patients were identified from both the published literature (29 articles, n = 1143) and the authors' institution (n = 108). Patients were sorted into 5 treatment groups: open cyst resection (OCR; n = 720), tubular cyst resection (TCR; n = 166), cyst resection with arthrodesis (CRA; n = 165), endoscopic cyst resection (ECR; n = 113), and percutaneous cyst rupture (PCR; n = 87), with OCR being the analysis reference group. The PCR group had significantly lower complication rates (p = 0.004), higher recurrence rates (p < 0.001), and higher revision surgery rates (p = 0.001) compared with the OCR group. Patients receiving TCR (3.01%, p = 0.021) and CRA (0.0%, p < 0.001) had significantly lower recurrence rates compared with those undergoing OCR (6.36%). The CRA group (6.67%) also had significantly lower rates of revision surgery compared with the OCR group (11.3%, p = 0.037). CONCLUSIONS: While PCR is less invasive, it may have high rates of same-level recurrence and revision surgery. Recurrence and revision rates for modalities such as ECR were not significantly different from those of OCR. While concomitant arthrodesis is more invasive, it might lead to lower recurrence rates and lower rates of subsequent revision surgery. Given the limitations of our case series and literature review, prospective, randomized studies are needed.

Patterns in Decompression and Fusion Procedures for Patients With Lumbar Stenosis After Major Clinical Trial Results, 2016 to 2019.

Importance: Use of lumbar fusion has increased substantially over the last 2 decades. For patients with lumbar stenosis and degenerative spondylolisthesis, 2 landmark prospective randomized clinical trials (RCTs) published in the New England Journal of Medicine in 2016 did not find clear evidence in favor of decompression with fusion over decompression alone in this population. Objective: To assess the national use of decompression with fusion vs decompression alone for the surgical treatment of lumbar stenosis and degenerative spondylolisthesis from 2016 to 2019. Design, Setting, and Participants: This retrospective cohort study included 121 745 hospitalized adult patients (aged ≥18 years) undergoing 1-level decompression alone or decompression with fusion for the management of lumbar stenosis and degenerative spondylolisthesis from January 1, 2016, to December 31, 2019. All data were obtained from the National Inpatient Sample (NIS). Analyses were conducted, reviewed, or updated on June 9, 2023. Main Outcome and Measure: The primary outcome of this study was the use of decompression with fusion vs decompression alone. For the secondary outcome, multivariable logistic regression analysis was used to evaluate factors associated with the decision to perform decompression with fusion vs decompression alone. Results: Among 121 745 eligible hospitalized patients (mean age, 65.2 years [95% CI, 65.0-65.4 years]; 96 645 of 117 640 [82.2%] non-Hispanic White) with lumbar stenosis and degenerative spondylolisthesis, 21 230 (17.4%) underwent decompression alone, and 100 515 (82.6%) underwent decompression with fusion. The proportion of patients undergoing decompression alone decreased from 2016 (7625 of 23 405 [32.6%]) to 2019 (3560 of 37 215 [9.6%]), whereas the proportion of patients undergoing decompression with fusion increased over the same period (from 15 780 of 23 405 [67.4%] in 2016 to 33 655 of 37 215 [90.4%] in 2019). In univariable analysis, patients undergoing decompression alone differed significantly from those undergoing decompression with fusion with regard to age (mean, 68.6 years [95% CI, 68.2-68.9 years] vs 64.5 years [95% CI, 64.3-64.7 years]; P < .001), insurance status (eg, Medicare: 13 725 of 21 205 [64.7%] vs 53 320 of 100 420 [53.1%]; P < .001), All Patient Refined Diagnosis Related Group risk of death (eg, minor risk: 16 900 [79.6%] vs 83 730 [83.3%]; P < .001), and hospital region of the country (eg, South: 7030 [33.1%] vs 38 905 [38.7%]; Midwest: 4470 [21.1%] vs 23 360 [23.2%]; P < .001 for both comparisons). In multivariable logistic regression analysis, older age (adjusted odds ratio [AOR], 0.96 per year; 95% CI, 0.95-0.96 per year), year after 2016 (AOR, 1.76 per year; 95% CI, 1.69-1.85 per year), self-pay insurance status (AOR, 0.59; 95% CI, 0.36-0.95), medium hospital size (AOR, 0.77; 95% CI, 0.67-0.89), large hospital size (AOR, 0.76; 95% CI, 0.67-0.86), and highest median income quartile by patient residence zip code (AOR, 0.79; 95% CI, 0.70-0.89) were associated with lower odds of undergoing decompression with fusion. Conversely, hospital region in the Midwest (AOR, 1.34; 95% CI, 1.14-1.57) or South (AOR, 1.32; 95% CI, 1.14-1.54) was associated with higher odds of undergoing decompression with fusion. Decompression with fusion vs decompression alone was associated with longer length of stay (mean, 2.96 days [95% CI, 2.92-3.01 days] vs 2.55 days [95% CI, 2.49-2.62 days]; P < .001), higher total admission costs (mean, $30 288 [95% CI, $29 386-$31 189] vs $16 190 [95% CI, $15 189-$17 191]; P < .001), and higher total admission charges (mean, $121 892 [95% CI, $119 566-$124 219] vs $82 197 [95% CI, $79 745-$84 648]; P < .001). Conclusions and Relevance: In this cohort study, despite 2 prospective RCTs that demonstrated the noninferiority of decompression alone compared with decompression with fusion, use of decompression with fusion relative to decompression alone increased from 2016 to 2019. A variety of patient- and hospital-level factors were associated with surgical procedure choice. These results suggest the findings of 2 major RCTs have not yet produced changes in surgical practice patterns and deserve renewed focus.

Time of Discharge and 30-Day Re-Presentation to an Acute Care Setting After Elective Lumbar Decompression Surgery.

BACKGROUND: Evidence regarding the consequence of efforts to increase patient throughput and decrease length of stay in the context of elective spine surgery is limited. OBJECTIVE: To evaluate whether early time of discharge results in increased rates of hospital readmission or return to emergency department for patients admitted after elective, posterior, lumbar decompression surgery. METHODS: We conducted a retrospective cohort study of 779 patients admitted to hospital after undergoing elective, posterior, lumbar decompression surgery. Multiple logistic regression evaluated the relationship between time of discharge and the primary outcome of return to acute care within 30 days, while controlling for sociodemographic, procedural, and discharge characteristics. RESULTS: In multiple logistic regression, time of discharge earlier in the day was not associated with increased odds of return to acute care within 30 days (odds ratio [OR] 1.18, 95% CI 0.92-1.52, P = .19). Weekend discharge (OR 1.99, 95% CI 1.04-3.79, P = .04) increased the likelihood of return to acute care. Surgeon experience (<1 year of attending practice, OR 0.43, 95% CI 0.19-1.00, P = .05 and 2-5 years of attending practice, OR 0.50, 95% CI 0.25-1.01, P = .054), weekend discharge (OR 0.49, 95% CI 0.27-0.89, P = .02), and physical therapy evaluation (OR 0.20, 95% CI 0.12-0.33, P < .001) decreased the likelihood of discharge before noon. CONCLUSION: Time of discharge is not associated with risk of readmission or presentation to the emergency department after elective lumbar decompression. Weekend discharge is independently associated with increased risk of readmission and decreased likelihood of prenoon discharge.

Awake, Transforaminal Endoscopic Lumbar Decompression Surgery to Treat L5-S1 Adjacent Segment Disease: A Case Series.

BACKGROUND: Lumbar radiculopathy secondary to L5-S1 degenerative changes adjacent to a lumbar fusion usually requires extending the fusion to include the degenerative L5-S1 level; this revision surgery can often be a very invasive procedure. OBJECTIVE: To describe outcomes of awake, transforaminal endoscopic decompression surgery for patients presenting with lumbar radiculopathy as a result of L5-S1 degenerative disc disease below lumbar fusions. STUDY DESIGN: Retrospective chart review. METHODS: Awake, endoscopic decompression surgery was performed in 538 patients over a 5-year period from 2014 through 2019 by a single surgeon at a single institution.  The records of 18 consecutive patients who underwent transforaminal lumbar endoscopic decompression surgery to treat radiculopathy secondary to L5-S1 adjacent segment disease were retrospectively reviewed. All included patients were followed for at least 2 years after surgery. All patients were treated at L5-S1 and had fusion constructs that ended at L5. RESULTS: Thirteen men and 5 women patients ranging in age from 38 to 83 (average age of 68.9 ± 11.5) were treated for symptomatic adjacent segment disease at L5-S1 during the 5-year time period. Surgery was successful in all cases, except 2 patients (11%) at 2 years follow-up had recurrent symptomatic pathology at L5-S1 and required additional surgical treatment. The average preoperative visual analog scale (VAS) and Oswestry Disability Index (ODI) scores were 7.5(± 1.3) and 45.3 (± 12.3) respectively. The average 2-year postoperative VAS and ODI scores were 2.4 (± 1.5) and 22.5 (± 9.6) respectively, excluding the 2 patients with recurrent pathology. The average body mass index (BMI) and L5-S1 disc height in the 2-year successful group (n = 16) were 30.6 (± 7.4) and 8.7 mm (± 3.5 mm) respectively; the average BMI and L5-S1 disc height in the 2-year failure group (n = 2) were 25.8 (± 5.9) and 7.9 (± 2.6) respectively. LIMITATIONS: This was a retrospective case series. CONCLUSIONS: Endoscopic spine surgery offers patients with fusions that terminate at L5 a safe and effective option for treatment of lumbar degenerative spine disease at L5-S1 below their fusion constructs. A longer follow-up and a larger prospective study would be necessary to consider the utility of endoscopic compression versus extending the fusion construct.

Foraminal Access Strategies in Patients with Lumbar Posterolateral Fusions in Transforaminal Endoscopic Spine Surgery: Case Series and Technical Note.

BACKGROUND: The treatment of post-laminectomy lumbar radiculopathy in the setting of a large posterolateral fusion mass presents an anatomic challenge to the spine interventionalist. OBJECTIVE: To describe outcomes of awake, transforaminal endoscopic surgical treatment for patients presenting with lumbar radiculopathy after instrumented posterolateral lumbar fusions. STUDY DESIGN: Retrospective chart review. SETTING: This study took place in a single-center, academic hospital. METHODS: The records of 538 patients who underwent awake transforaminal lumbar endoscopic decompression surgery performed by a single surgeon at a single institution between 2014 and 2019 were retrospectively reviewed. Fifteen consecutive patients who required drilling through their posterolateral fusion masses to access the post-fusion foraminal stenosis were included in this study. All included patients were followed for at least one year after surgery. RESULTS: Fifteen patients (7 male and 8 female) with an average age of 68.1 years (range 38-89, standard deviation 13.4 years) underwent awake transforaminal foraminal decompression surgeries that utilized special techniques to drill through large posterolateral fusion masses to access their foraminal stenosis. One patient (7%) required repeat surgery in the postoperative period due to lack of surgical improvement. For the remaining 14 patients, at one year follow up, the preoperative visual analog scale (VAS) for leg pain and Oswestry disability index (ODI) improved from 7.0 (± 1.7) and 40.7% (± 12.9) to 1.7 (± 1.6) and 12.1% (± 11.3). There were no complications such as infection, durotomy, or neurologic injury. LIMITATIONS: Retrospective case series. CONCLUSION: Transforaminal endoscopic spine surgery offers a unique approach to post-laminectomy and post-fusion foraminal compression because it avoids scar tissue resulting from previous posterior approaches. Large posterolateral fusion masses associated with some posterior fusions can be a sizeable bony barrier to transforaminal access. The authors share their techniques and success for navigating large posterior, bony fusion masses in transforaminal post-fusion foraminal decompression.

Awake, Transforaminal Endoscopic Lumbar Spine Surgery in Octogenarians: Case Series.

BACKGROUND: Optimal approaches for treating surgical spine pathology in very geriatric patients, such as those over the age of 80, remain unclear. OBJECTIVE: To describe outcomes of awake, transforaminal endoscopic surgical treatment for patients 80 years old and older presenting with lumbar radiculopathy. STUDY DESIGN: Retrospective case review. METHODS: The records of 52 consecutive patients who underwent awake transforaminal lumbar endoscopic decompression surgery performed by a single surgeon at a single institution between 2014 and 2019 were retrospectively reviewed. All included patients were followed for at least one year after surgery. RESULTS: Transforaminal surgeries performed were discectomies (21), foraminotomies (7), redo foraminotomies post-laminectomy (5), fusion explorations (13), facet cyst resections (3), spondylolisthesis decompressions (2), and a decompression for metastatic disease (1). Seven patients (13.5%) required repeat surgery at the treated level during the one-year follow-up. For the remaining 45 patients, at one-year follow-up, preoperative visual analog scale (VAS) for leg pain and Oswestry disability index (ODI) improved from 6.9 (± 1.4) and 40.5% (± 11.5) to 1.8 (± 1.4) and 12.0% (± 10.8), respectively. The only complication of the procedure was a single durotomy (2%). LIMITATIONS: Single-center, retrospective case review with a relatively small number of cases with diverse clinical pathology. A multi-center case study with a larger number of patients with a more homogeneous case pathology would be more revealing. CONCLUSIONS: Endoscopic spine surgery offers octogenarians a safe and effective option for the treatment of lumbar degenerative spine disease and may represent a valuable treatment strategy in a growing patient population.

Instrumentation choice and early radiographic outcome following lateral lumbar interbody fusion (LLIF): Lateral instrumentation versus posterior pedicle screw fixation.

Background: Lateral lumbar interbody fusion (LLIF) is a minimally invasive fusion procedure that may be performed with or without supplemental instrumentation. However, there is a paucity of evidence on the effect of supplemental instrumentation technique on perioperative morbidity and fusion rate in LLIF. Methods: A single-institutional retrospective review of patients who underwent LLIF for lumbar spondylosis was conducted. Patients were grouped according to supplemental instrumentation technique: stand-alone LLIF, LLIF with laterally placed instrumentation, or LLIF with posterior percutaneous pedicle screw fixation (PPSF). Outcomes included fusion rates, peri-operative complication, and reoperation; estimated blood loss (EBL); surgery duration; length of stay; and length of follow-up. Results: 82 patients underwent LLIF at 114 levels. 35 patients (42.7%) received supplemental lateral instrumentation, 30 (36.6%) received supplemental PPSF, and 17 (20.7%) underwent stand-alone LLIF. More patients in the lateral instrumentation group had prior lumbar fusion at adjacent levels (23/35, 65.71%) versus stand-alone (3/17, 17.6%) or PPSF (2/30, 6.67%) groups (p = 0.003). 4/17 patients (23.5%) with stand-alone LLIF and 4/35 patients (11.42%) with lateral instrumentation underwent reoperation, versus 0/30 with PPSF (p = 0.030). There was no difference in fusion rates between groups (p = 0.717). Operation duration was longer in patients with PPSF (p < 0.005) and length of follow-up was longer for PPSF than lateral instrumentation (p = 0.001). Choice of instrumentation group was a statistically significant predictor of reoperation. Conclusions: While rates of complete radiographic fusion on imaging follow-up didn't differ, patients receiving PPSF were less likely than stand-alone or lateral instrumentation groups to require reoperation, though operative time was significantly longer. Further study of choice of supplemental instrumentation with LLIF is indicated.

Influence of Time of Discharge and Length of Stay on 30-Day Outcomes After Elective Anterior Cervical Spine Surgery.

BACKGROUND: Encouraging early time of discharge (TOD) for medical inpatients is commonplace and may potentially improve patient throughput. It is unclear, however, whether early TOD after elective spine surgery achieves this goal without a consequent increase in re-presentations to the hospital. OBJECTIVE: To evaluate whether early TOD results in increased rates of hospital readmission or return to the emergency department after elective anterior cervical spine surgery. METHODS: We analyzed 686 patients who underwent elective uncomplicated anterior cervical spine surgery at a single institution. Logistic regression was used to evaluate the relationship between sociodemographic, procedural, and discharge characteristics, and the outcomes of readmission or return to the emergency department and TOD. RESULTS: In multiple logistic regression, TOD was not associated with increased risk of readmission or return to the emergency department within 30 days of surgery. Weekend discharge (odds ratio [OR] 0.33, 95% CI 0.21-0.53), physical therapy evaluation (OR 0.44, 95% CI 0.28-0.71), and occupational therapy evaluation (OR 0.32, 95% CI 0.17-0.63) were all significantly associated with decreased odds of discharge before noon. Disadvantaged status, as measured by area of deprivation index, was associated with increased odds of readmission or re-presentation (OR 1.86, 95% CI 0.95-3.66), although this result did not achieve statistical significance. CONCLUSION: There does not appear to be an association between readmission or return to the emergency department and early TOD after elective spine surgery. Overuse of inpatient physical and occupational therapy consultations may contribute to decreased patient throughput in surgical admissions.

Socioeconomic and Psychosocial Predictors of Magnetic Resonance Imaging After Cervical and Thoracic Spine Trauma in the United States.

OBJECTIVE: Socioeconomic factors are known to influence outcomes after spinal trauma, but it is unclear how these factors affect health care utilization in acute care settings. We aimed to elucidate if sociodemographic and psychosocial factors are associated with obtaining magnetic resonance imaging (MRI), a costly imaging modality, after cervical or thoracic spine fracture. METHODS: Data from the 2012-2016 American College of Surgeons National Trauma Data Bank were used. We assessed the relationship between receipt of MRI and patient-level sociodemographic and psychosocial factors as well as hospital characteristics while correcting for injury-specific characteristics. Multiple logistic regression was performed to assess for associations between these variables and MRI after spine trauma. RESULTS: A total of 213,071 patients met the inclusion criteria, of whom 13.0% had an MRI (n = 27,757). After adjusting for confounders in multivariate regression, patients had increased odds of MRI if they were Hispanic (odds ratio [OR], 1.09; P = 0.001) or black (OR, 1.14; P < 0.001) or were diagnosed with major psychiatric disorder (OR, 1.06; P = 0.009), alcohol use disorder (OR, 1.05; P < 0.001), or substance use disorder (OR, 1.10; P < 0.001). Patients with Medicare (OR, 0.88; P < 0.001) or Medicaid (OR, 0.94; P < 0.011) were less likely to have an MRI than were those with private insurance, whereas patients treated in the Northeast (OR, 1.48; P < 0.001) or at for-profit hospitals (OR, 1.12; P < 0.001) were more likely. CONCLUSIONS: After adjusting for injury severity and spinal cord injury diagnosis, psychosocial comorbidities and for-profit hospital status were associated with higher odds of MRI, whereas public insurance was associated with lower odds. Results highlight potential biases in the provision of MRI as a costly imaging modality.

Neighborhood-Level Socioeconomic Status Predicts Extended Length of Stay After Elective Anterior Cervical Spine Surgery.

BACKGROUND: A significant portion of health care spending is driven by a small percentage of the overall population. Understanding risk factors predisposing patients to disproportionate use of health care resources is critical. Our objective was to identify risk factors leading to a prolonged length of stay (LOS) after cervical spine surgery. METHODS: A single-center cohort analysis was performed on patients who underwent elective anterior spine surgery from 2015 to 2021. Multivariate logistic regression evaluated the effects of sociodemographic factors including Area of Deprivation Index (quantifies income, education, employment, and housing quality), procedural, and discharge characteristics on postoperative LOS. Extended LOS was defined as greater than the 90th percentile in midnights for the study population (≥3 midnights). RESULTS: A total of 686 patients were included in the study, with a mean age of 57 years (range, 26-92 years), median of 1 level (1-4) fused, and median LOS of 1 midnight (interquartile range, 1-2). After adjusting for confounders, patients had increased odds of extended LOS if they were highly disadvantaged on the Area of Deprivation Index (odds ratio [OR], 2.24; 95% confidence interval [CI], 1.04-4.82; P = 0.039); had surgery on Thursday or Friday (OR, 1.94; 95% CI, 1.01-3.72; P = 0.046); had a corpectomy performed (OR, 2.81; 95% CI, 1.26-6.28; P = 0.012); or discharged not to home (OR, 8.24; 95% CI, 2.88-23.56; P < 0.001). Patients with extended LOS were more likely to present to the emergency department or be readmitted within 30 days after discharge (P = 0.024). CONCLUSIONS: After adjusting for potential cofounders, patients most disadvantaged on Area of Deprivation Index were more likely to have an extended LOS.