Accuracy of endobronchial ultrasound (EBUS) in the staging of lung cancer - A comparison of staging EBUS with postoperative pathological nodal staging.

BACKGROUND: Endobronchial ultrasound-guided transbronchial fine-needle aspiration (EBUS-TBNA) has replaced mediastinoscopy as the preferred investigation for evaluating mediastinum in staging lung cancer. There is little evidence of mediastinal staging by EBUS-TBNA from India. OBJECTIVES: To study endobronchial ultrasound's diagnostic accuracy in staging lung cancer. METHODOLOGY: We retrospectively analysed patients operated on for lung cancer where EBUS was performed preoperatively for mediastinal staging. We compared the histological findings obtained from different mediastinal lymph nodes (LNs) by EBUS-TBNA with the pathology of the same LNs obtained after surgical dissection as the reference standard. RESULTS: Seventy-six patients underwent curative surgery for lung cancer. The diagnostic accuracy, sensitivity, specificity, positive predictive value and negative predictive value of EBUS-TBNA in predicting mediastinal metastasis were 93.9%, 40%, 99%, 80% and 94.6%, respectively. Of the 115 LNs sampled, EBUS-TBNA was false negative in six nodes, resulting in an up-staging of six patients. CONCLUSIONS: EBUS-TBNA has a high diagnostic accuracy for lung cancer staging.

Oncogene-driven non-small cell lung cancers in patients with a history of smoking lack smoking-induced mutations.

Non-small cell lung cancers (NSCLCs) in non-smokers are mostly driven by mutations in the oncogenes EGFR, ERBB2, and MET and fusions involving ALK and RET. In addition to occurring in non-smokers, alterations in these "non-smoking-related oncogenes" (NSROs) also occur in smokers. To better understand the clonal architecture and genomic landscape of NSRO-driven tumors in smokers compared to typical-smoking NSCLCs, we investigated genomic and transcriptomic alterations in 173 tumor sectors from 48 NSCLC patients. NSRO-driven NSCLCs in smokers and non-smokers had similar genomic landscapes. Surprisingly, even in patients with prominent smoking histories, the mutational signature caused by tobacco smoking was essentially absent in NSRO-driven NSCLCs, which was confirmed in two large NSCLC datasets from other geographic regions. However, NSRO-driven NSCLCs in smokers had higher transcriptomic activities related to regulation of the cell cycle. These findings suggest that, while the genomic landscape is similar between NSRO-driven NSCLC in smokers and non-smokers, smoking still affects the tumor phenotype independently of genomic alterations.

Valorization of waste engine oil to mono- and di-rhamnolipid in a sustainable approach to circular bioeconomy.

This study aims to valorize waste engine oil (WEO) for synthesizing economically viable biosurfactants (rhamnolipids) to strengthen the circular bioeconomy concept. It specifically focuses on investigating the influence of key bioprocess parameters, viz. agitation and aeration rates, on enhancing rhamnolipid yield in a fed-batch fermentation mode. The methodology involves conducting experiments in a stirred tank bioreactor (3 L) using Pseudomonas aeruginosa gi |KP 163922| as the test organism. Central composite design and response surface methodology (CCD-RSM) are employed to design the experiments and analyze the effects of agitation and aeration rates on various parameters, including dry cell biomass (DCBM), surface tension, tensoactivity, and rhamnolipid yield. It is also essential to determine the mechanistic pathway of biosurfactant production followed by the strain using complex hydrophobic substrates such as WEO. The study reveals that optimal agitation and aeration rates of 200 rpm and 1 Lpm result in the highest biosurfactant yield of 29.76 g/L with minimal surface tension (28 mN/m). Biosurfactant characterization using FTIR, 1H NMR, and UPLC-MS/MS confirm the presence of dominant molecular ion peaks m/z 543.9 and 675.1. This suggests that the biosurfactant is a mixture of mono- and di-rhamnolipids (RhaC10C10, RhaRhaC10C12:1, RhaRhaC12:1C10). The findings present a sustainable approach for biosurfactant production in a fed-batch bioreactor. This research opens the possibility of exploring the use of pilot or large-scale bioreactors for biosurfactant production in future investigations.

Postoperative Herpes Viral Infections in Neurosurgery - An Experience and Arguments for and against the Plausible Hypotheses.

BACKGROUND: The literature contains several reports of herpes recrudescence after neurosurgery. We analyze our experience by vindicating or refuting the existing plausible hypotheses. MATERIAL AND METHODS: This is a retrospective review of all neurosurgical cases that developed postoperative herpes infection between January 2016 and June 2020. RESULTS: Six patients developed herpes infection after vestibular schwannoma (VS) surgery. Other neurosurgical cases did not develop herpes infection. There were five females and one male, with a mean age of 44.1 years. Four out of six patients developed delayed facial palsy (DFP) and did not improve after antiviral treatment. Postoperative herpes infections were 0.2% among all operated patients, 3.07% among all cerebellopontine (CP) angle surgeries, and 5.6% among VS surgeries. CONCLUSIONS: To date, none of the plausible hypotheses satisfactorily addresses all aspects of viral recrudescence. The etiology may be multi-factorial, and in all cases of unexplained clinical deterioration, herpes infection needs consideration in the differential diagnosis.

Development of a Novel Risk Stratification Score to Predict 30-Day Mortality in Cervical Trauma Patients: CLAAD Score.

STUDY DESIGN: Case control. OBJECTIVE: Traumatic cervical spine injuries are associated with a substantial risk of mortality. The aim of this study is to develop a novel mortality prediction model for patients with cervical trauma who require operative treatment. SUMMARY OF BACKGROUND DATA: Patients with cervical spine trauma have a high risk of postoperative complications and mortality. There are few reliable systems that can accurately predict mortality after surgery for cervical spine trauma, and those that do exist are typically not specific to cervical trauma. MATERIALS AND METHODS: The National Surgical Quality Improvement Program (NSQIP) database was used to identify patients undergoing surgery for cervical spine trauma. Univariate analyses were performed to identify variables associated with mortality. Variables that were found to be significant in the univariate models were compiled into a multivariable model. The final model was compared with the American Society of Anesthesiologists (ASA), a modified Charlson comorbidity index (mCCI), and the 5-factor modified frailty index (mFI-5) in respect to predicting 30-day mortality after cervical trauma. The score was then externally validated using the Nationwide Inpatient Sample (NIS) database. RESULTS: Fifty-five (6.7%) of 822 patients did not survive 30 days after surgery. The final multivariable logistic regression model consisted of the following variables: circumferential fusion "C." long "L" fusion (more than 4 levels), anemia "A," age over 60 "A," and dialysis "D." The risk of mortality increased with increasing CLAAD score, with mortality rates of 0.9%, 3.1%, 7.4%, 22.7%, and 14.3% for scores of 0, 1, 2, 3, and 4, respectively. The CLAAD model had an AUC of 0.73 for predicting mortality after cervical trauma. CONCLUSIONS: The CLAAD score is a simple and effective system that can help identify patients at risk of increased mortality within 30 days of cervical trauma. LEVEL OF EVIDENCE: Level III.

The Evidence for the Use of Osteobiologics in Hybrid Constructs (Anterior Cervical Discectomy and Fusion and Total Disc Replacement) in Multilevel Cervical Degenerative Disc Disease: A Systematic Review.

STUDY DESIGN: Systematic review. OBJECTIVE: Examine the clinical evidence for the use of osteobiologics in hybrid surgery (combined anterior cervical discectomy and fusion (ACDF) and total disc replacement (TDR)) in patients with multilevel cervical degenerative disc disease (DDD). METHODS: PubMed and Embase were searched between January 2000 and August 2020. Clinical studies investigating 18-80 year old patients with multilevel cervical DDD who underwent hybrid surgery with or without the use of osteobiologics were considered eligible. Two reviewers independently screened and assessed the identified articles. The methodological index for non-randomized studies (MINORS) tool and the risk of bias (RoB 2.0) assessment tool were used to assess risk of bias. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) was used to evaluate quality of evidence across studies per outcome. RESULTS: Eleven studies were included. A decrease in cervical range of motion was observed in most studies for both the hybrid surgery and the control groups consisting of stand-alone ACDF or TDR. Fusion rates of 70-100% were reported in both the hybrid surgery and control groups consisting of stand-alone ACDF. The hybrid surgery group performed better or comparable to the control group in terms of adjacent segment degeneration. Studies reported an improvement in visual analogue scale for pain and neck disability index values after surgery compared to preoperative scores for both treatment groups. The included studies had moderate methodological quality. CONCLUSIONS: There is insufficient evidence for assessing the use of osteobiologics in multilevel hybrid surgery and additional high quality and controlled research is deemed essential.

AO Spine Guideline for the Use of Osteobiologics (AOGO) in Anterior Cervical Discectomy and Fusion for Spinal Degenerative Cases.

STUDY DESIGN: Guideline. OBJECTIVES: To develop an international guideline (AOGO) about the use of osteobiologics in anterior cervical discectomy and fusion (ACDF) for treating degenerative spine conditions. METHODS: The guideline development process was guided by AO Spine Knowledge Forum Degenerative (KF Degen) and followed the Guideline International Network McMaster Guideline Development Checklist. The process involved 73 participants with expertise in degenerative spine diseases and surgery from 22 countries. Fifteen systematic reviews were conducted addressing respective key topics and evidence was collected. The methodologist compiled the evidence into GRADE Evidence-to-Decision frameworks. Guideline panel members judged the outcomes and other criteria and made the final recommendations through consensus. RESULTS: Five conditional recommendations were created. A conditional recommendation is about the use of allograft, autograft or a cage with an osteobiologic in primary ACDF surgery. Other conditional recommendations are about the use of osteobiologic for single- or multi-level ACDF, and for hybrid construct surgery. It is suggested that surgeons use other osteobiologics rather than human bone morphogenetic protein-2 (BMP-2) in common clinical situations. Surgeons are recommended to choose 1 graft over another or 1 osteobiologic over another primarily based on clinical situation, and the costs and availability of the materials. CONCLUSION: This AOGO guideline is the first to provide recommendations for the use of osteobiologics in ACDF. Despite the comprehensive searches for evidence, there were few studies completed with small sample sizes and primarily as case series with inherent risks of bias. Therefore, high-quality clinical evidence is demanded to improve the guideline.

Detection of circulating tumor DNA with ultradeep sequencing of plasma cell-free DNA for monitoring minimal residual disease and early detection of recurrence in early-stage lung cancer.

BACKGROUND: In early-stage non-small cell lung cancer (NSCLC), recurrence is frequently observed. Circulating tumor DNA (ctDNA) has emerged as a noninvasive tool to risk stratify patients for recurrence after curative intent therapy. This study aimed to risk stratify patients with early-stage NSCLC via a personalized, tumor-informed multiplex polymerase chain reaction (mPCR) next-generation sequencing assay. METHODS: This retrospective cohort study included patients with stage I-III NSCLC. Recruited patients received standard-of-care management (surgical resection with or without adjuvant chemotherapy, followed by surveillance). Whole-exome sequencing of NSCLC resected tissue and matched germline DNA was used to design patient-specific mPCR assays (Signatera, Natera, Inc) to track up to 16 single-nucleotide variants in plasma samples. RESULTS: The overall cohort with analyzed plasma samples consisted of 57 patients. Stage distribution was 68% for stage I and 16% each for stages II and III. Presurgery (i.e., at baseline), ctDNA was detected in 15 of 57 patients (26%). ctDNA detection presurgery was significantly associated with shorter recurrence-free survival (RFS; hazard ratio [HR], 3.54; 95% confidence interval [CI], 1.00-12.62; p = .009). In the postsurgery setting, ctDNA was detected in seven patients, of whom 100% experienced radiological recurrence. ctDNA positivity preceded radiological findings by a median lead time of 2.8 months (range, 0-12.9 months). Longitudinally, ctDNA detection at any time point was associated with shorter RFS (HR, 16.1; 95% CI, 1.63-158.9; p < .0001). CONCLUSIONS: ctDNA detection before surgical resection was strongly associated with a high risk of relapse in early-stage NSCLC in a large unique Asian cohort. Prospective studies are needed to assess the clinical utility of ctDNA status in this setting.

A case of metastatic lymphoepithelial carcinoma of parotid gland identified on 68gallium DOTA-[Tyr3] octreotate PET CT.

The authors present the case of a 59-year-old lady diagnosed with lymphoepithelial carcinoma (LEC) of the left parotid gland. The primary tumour was identified using contrast-enhanced CT, and diagnosis was confirmed via fine needle aspiration cytology and immunohistochemistry. Staging using fluorine-18 fluorodeoxyglucose PET CT revealed regional nodal metastases, while no distant metastasis was evident. Following radical radiotherapy, a favourable locoregional response was observed on MRI, yet the patient's plasma Epstein-Barr virus load continued to rise. Given her primary tumour's somatostatin receptor type 2 (SSTR2) positivity, gallium-68 DOTA-[Tyr3] octreotate PET CT (68Ga-DOTATATE PET CT) was performed, revealing multiple distant metastases with DOTATATE avidity. Despite attempts at palliative chemotherapy and immunotherapy, disease progression led to the decision for the best supportive care. The unique presentation of metastatic LEC on 68Ga-DOTATATE PET CT suggests a potential role for SSTR2-targeted imaging in diagnosis and management.

Medicare Advantage Is Associated with Lower Utilization of Total Joint Arthroplasty.

BACKGROUND: Medicare Advantage (MA) insurers use managed care techniques to review the utilization of medical services and control costs. It is unclear if MA enrollees have a lower utilization of elective surgical procedures such as inpatient hip and knee total joint arthroplasty (TJA), which have traditionally been covered by traditional Medicare (TM) without restrictions. METHODS: We conducted a cross-sectional study using a 20% sample of 2018 TM claims and MA encounter records for 5,300,188 TM enrollees and 1,970,032 MA enrollees who were 65 to 85 years of age. We calculated unadjusted and adjusted differences (controlling for beneficiary and market characteristics) in the incidence of TJA for MA compared with TM, and by MA plan type. Finally, we calculated differences in the time to contact with an orthopaedic surgeon and time to the surgical procedure among enrollees with an osteoarthritis diagnosis. RESULTS: After controlling for observable characteristics, there was a 15.6% lower incidence of TJA in MA enrollees compared with TM enrollees (p < 0.001). Compared with TM enrollees, health maintenance organization (HMO) enrollees were 28.1% less likely to undergo TJA, controlling for observable characteristics (p < 0.001). From the initial diagnosis, the time to contact with an orthopaedic surgeon and the time to the surgical procedure were also lower among TM enrollees compared with MA enrollees. At 2 years after an osteoarthritis diagnosis, 10.4% of TM enrollees, 7.9% of preferred provider organization (PPO) enrollees, and 5.7% of HMO enrollees had undergone inpatient TJA. CONCLUSIONS: MA coverage was associated with a lower utilization of elective, inpatient hip and knee TJA. MA was also associated with a longer time to orthopaedic surgeon evaluation and surgical procedure. LEVEL OF EVIDENCE: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Measuring Value in Spine Care Using the PROMIS-Preference Scoring System.

BACKGROUND: A transition to value-based care requires a thorough understanding of the costs and impacts of various interventions on patients' overall health utility. The Patient-Reported Outcomes Measurement Information System (PROMIS) has gained popularity and is frequently used to assess physical, mental, and social health domains in clinical and research settings. To assess health utility, the PROMIS-Preference (PROPr) score, a societal preference-based measure, has been proposed to produce a single estimate of health utility. We determined the psychometric properties (validity and responsiveness) of the PROPr score as a health state utility measure in patients undergoing spine surgery. We hypothesized that PROPr score would be lower in the presence of comorbid conditions and lower socioeconomic status and in those with more severe pain-related disability and would be responsive to changes in health status following spine surgery. METHODS: In this prospective cohort study, 904 adults presented for cervical (n = 359) and/or lumbar (n = 622) conditions, and 624 underwent surgery, from August 2019 through January 2022. To assess concurrent validity, we correlated the PROPr score with Neck Disability Index (NDI)/Oswestry Disability Index (ODI) values. To assess known-groups validity, we regressed the PROPr score on participant age, sex, pain-related disability, and social determinants of health. To assess responsiveness, we used an anchor-based approach, evaluating change from preoperatively to 6 and 12 months postoperatively anchored by the Patient Global Impression of Change. A p level of <0.05 was considered significant. RESULTS: The median overall preoperative PROPr score was 0.20 (interquartile range [IQR], 0.10 to 0.32; range, -0.02 to 0.95). The PROPr score was associated with higher educational attainment (p = 0.01), higher household income (p < 0.001), and a greater number of comorbid conditions (p = 0.04). The median PROPr score decreased (worse health utility) with greater disability (NDI, 0.44 [none] to 0.09 [severe/complete], p < 0.001; ODI, 0.57 [none] to 0.08 [severe/complete], p < 0.001). The change in the median PROPr score differed in participants who rated their postoperative health as improved (0.17) compared with little or no change (0.04; p < 0.001) or worse (-0.06; p = 0.025) at 6 months and in those who rated their health as improved (0.15) compared with little or no change (0.02; p < 0.001) or worse (-0.05; p = 0.043) at 12 months. CONCLUSIONS: The PROPr score is a valid and responsive preference-based assessment of health utility for patients undergoing spine surgery. It can be calculated from PROMIS outcome data. LEVEL OF EVIDENCE: Prognostic Level II . See Instructions for Authors for a complete description of levels of evidence.

Elevated preoperative blood pressure and its relationship to intraoperative mean arterial pressure and blood loss in posterior spinal fusion for adolescent idiopathic scoliosis.

PURPOSE: The relationship between preoperative blood pressure (BP) and intraoperative mean arterial pressure (MAP) and estimated blood loss (EBL) in pediatric spine surgery is currently unknown. The objectives of this study were to determine if elevated preoperative BP is associated with elevated intraoperative MAP, EBL, and percentage estimated blood volume (EBV) lost, and to determine if intraoperative MAP is associated with percentage of EBV lost during posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS). METHODS: This is a retrospective cohort analysis of 209 patients undergoing PSF for AIS between 2016 and 2019 by a single surgeon. Data extracted included demographic characteristics, preoperative systolic and diastolic BP, continuous intraoperative MAP measured by arterial line, EBL, radiographic, and surgical characteristics. Time points of interest for MAP included incision and exposure. Elevated BP was defined as > 1 standard deviation above the mean BP of patients included in the study, and elevated MAP was defined as > 65 mmHg. RESULTS: Elevated preoperative systolic BP was associated with elevated MAP at incision (p = 0.002). Patients with elevated preoperative diastolic BP had significantly higher MAP at exposure and throughout the procedure (p = 0.04). MAP > 65 at incision was associated with a 5% increase in EBV lost (p < 0.001). CONCLUSIONS: Patients with elevated preoperative BP parameters have increased MAPs at incision, exposure, and throughout surgery. Elevated MAP at incision is associated with an increased percentage of EBV lost in a small number of patients undergoing PSF for AIS.

Inflation-adjusted medicare physician reimbursement for adult spinal deformity surgery substantially declined from 2002 to 2020.

PURPOSE: Physician fees for orthopaedic surgeons by the Centers for Medicare and Medicaid Services (CMS) are increasingly scrutinized. The present retrospective review aims to assess whether adult spinal deformity (ASD) surgeries are properly valued for Medicare reimbursement. METHODS: Current Procedural Terminology (CPT) codes related to posterior fusion of spinal deformity of ≤ 6, 7-12, and ≥ 13 vertebral levels, as well as additional arthrodesis and osteotomy levels, were assessed for (1) Compound annual growth rate (CAGR) from 2002 to 2020, calculated using physician fee data from the CMS Physician Fee Schedule Look-Up Tool; and (2) work relative value units (RVUs) per operative minute, using data from the National Surgical Quality Improvement Program. RESULTS: From 2002 to 2020, all CPT codes for ASD surgery had negative inflation-adjusted CAGRs (range, - 18.49% to - 27.66%). Mean physician fees for spinal fusion declined by 26.02% (CAGR, - 1.66%) in ≤ 6-level fusion, 27.91% (CAGR, - 1.80%) in 7- to 12-level fusion, and 28.25% (CAGR, - 1.83%) ≥ 13-level fusion. Fees for both 7-12 (P < 0.00001) and ≥ 13 levels (P < 0.00001) declined more than those for fusion of ≤ 6 vertebral levels. RVU per minute was lower for 7- to 12-level and ≥ 13-level (P < 0.00001 for both) ASD surgeries than for ≤ 6-level. CONCLUSIONS: Reimbursement for ASD surgery declined overall. CAGR for fusions of ≥ 7 levels were lower than those for fusions of ≤ 6 levels. For 2012-2018, ≥ 7-level fusions had lower RVU per minute than ≤ 6-level fusions. Revaluation of Medicare reimbursement for longer-level ASD surgeries may be warranted. LEVEL OF EVIDENCE: III.

Using a Modern Linked Research Database to Examine Gender Disparities in Orthopaedic Grant Funding from 2010 to 2022.

BACKGROUND: Gender disparities in research grant funding persist in many disciplines. With use of the Dimensions database, we sought to examine the extent of gender disparities in U.S. orthopaedic grant funding from 2010 onward. Our aim was to provide insights into the extent of gender disparities in the field of orthopaedic research and to highlight the potential need for future action to address these disparities. METHODS: Using orthopaedic-related search terms, we queried all U.S. grants awarded for orthopaedic research from 2010 to 2022. A total of 22,326 results were then manually screened to exclude those without a direct focus on orthopaedic research. The amounts received per principal investigator were reported in U.S. dollars and adjusted for inflation. Author gender was predicted with use of the Genderize.io algorithm application programming interface. The iCite Relative Citation Ratio (RCR) was utilized to assess the impact of the publications linked to each grant. RESULTS: A total of 1,723 grants were included. Men principal investigators received significantly higher median funding per grant in 2011, 2012, and 2013; however, this trend reversed with women receiving nonsignificantly higher funding in 2015, 2017, 2018, 2021, and 2022. In 2020, women received significantly higher median funding per grant than men ($166,234 versus $121,384; p = 0.04). Throughout the 13-year period, men principal investigators accounted for approximately 71% of grants, with a very weak increasing trend in the percent of grants attributed to women (R 2 = 0.16; p < 0.001). Grants with men principal investigators resulted in more publications than those with women principal investigators (mean publications, 11.1 versus 6.6; p = 0.001). Publications resulting from grants awarded to men had a significantly higher mean RCR than those resulting from grants awarded to women (2.42 versus 2.09; p = 0.04). CONCLUSIONS: There was no significant difference in the median amounts of funding per grant awarded to men and to women in 7 of the past 8 years, despite significantly greater funding per grant having been awarded to men from 2011 to 2013. Men principal investigators accounted for the majority of grants received during the study period, although this proportion was lower than the proportion of men among orthopaedic surgeons in 2022. This study could inform initiatives aimed at promoting equity in grant funding for orthopaedic research.

Predicting Mortality Following Odontoid Fracture Fixation in Elderly Patients: CAADS-16 Score.

STUDY DESIGN: Retrospective Review of a National Database. INTRODUCTION: By utilizing a national database, this study aims to quantify the predictors of 30-day mortality after odontoid fixation and guide appropriate management for patients in whom the choice between operative and non-operative management is unclear. METHODS: The American College of Surgeons National Surgical Quality Improvement Database was queried using Current Procedural Terminology (CPT) codes and International Classification of Disease (ICD) codes to identify patients 60 or older who underwent surgical fixation of an odontoid fracture from 2005 to 2020. Risk factors for mortality significant in univariate and subsequent multivariate analysis were used to develop a scoring system to predict post-operative mortality. RESULTS: 608 patients were identified. Patients were split into a non-mortality 30 days post-op group, and into a mortality 30 days post-op group. The following risk factors were included in the scoring system: functional dependency, disseminated cancer, albumin less than 3.5, WBC count greater than 16 k, anterior surgical approach, and pre-op SIRS. Using a cutoff value of 2, the CAAD-16 score had a sensitivity and specificity of 82% and 81%, respectively. The ASA score, cutoff at 4, showed a sensitivity and specificity of 64% and 75% respectively. CONCLUSIONS: This sample of 294 patients represents one of the largest samples of odontoid fracture fixation patients available in the literature and comes from a nationally representative database. We structure relevant risk factors into the CAADS-16 score, which has the potential to be a clinically relevant tool to prevent short-term postoperative mortality.

Gender diversity at spine surgery academic conferences: a 15-year investigation.

BACKGROUND CONTEXT: Enhancing gender diversity at academic conferences is critical for advancing women's representation and career trajectories in spine surgery. PURPOSE: To discover trends in women's representation at major spine conferences over a 15-year period. STUDY DESIGN/SETTING: Conference records from the 2007-2021 annual meetings of the Congress of Neurological Surgeons, North American Spine Society, and Scoliosis Research Society (SRS). PATIENT SAMPLE: Authors of spine-related presentations. OUTCOME MEASURES: Authorship by gender. METHODS: Retrospective bibliometric analysis with univariate and multivariate modeling to identify trends and predictors of gender diversity. RESULTS: Among 8,948 presentations, 750 (8.4%) had female first authors and 618 (6.9%) had female senior authors. There was no change in rates of female first authorship (p=.41) or senior authorship (p=.88) over time. The strongest predictors of female first authorship were having a female senior author (OR 7.32, p<.001), and delivering presentations at SRS (OR 1.95, p=.001). Factors negatively associated with female first authorship included poster format (OR 0.82, p=.039) and conference location in the United States/Canada (OR 0.76, p=.045). Similar trends were encountered for senior authorship. Productivity per senior author was similar between genders (p=.160); whereas a gender gap in productivity per first author during 2007 to 2011 (p=.020) equalized by 2017 to 2021 (p=.300). Among the 10 most productive authors of each gender, male authors delivered more presentations, but all authors shared similar format, content, and location. CONCLUSIONS: Women's representation in spine-related presentations did not increase at three major conferences over a 15-year period. Our findings regarding the positive effects of female mentorship, and international or virtual venues merit further investigation to address the gender gap. The upstream pipeline of recruiting women into academic spine surgery also needs to be addressed.

Prior Fragility Fractures are Associated With Higher Risk of Bone Health-Related Complications Within 8-Years Following Lumbar Fusion.

STUDY DESIGN: Retrospective study. OBJECTIVE: To determine the 8-year risk of revision lumbar fusion, pseudoarthrosis, mechanical failure, fragility fracture, and vertebral compression fracture in patients with a prior fragility fracture compared to those without. SUMMARY OF BACKGROUND DATA: Osteoporosis is a known modifiable risk factor for revision following lumbar fusion due to inadequate fixation. Patients with prior fragility fractures have been shown to have increased bone health-related complications following various orthopedic surgeries, however there is a paucity of literature that identifies these complications in patients undergoing lumbar fusion. METHODS: Patients aged 50 years and older who underwent elective lumbar fusion were identified in a large national database and stratified based on whether they sustained a fragility fracture within 3 years prior to fusion. These patients were propensity-score matched to a control based on age, gender, and Charlson Comorbidity Index (CCI) using a 1:1 ratio. Kaplan-Meier and Cox Proportional Hazards analyses were used to observe the cumulative incidences and risk of complications within 8-years of index surgery. RESULTS: After matching, 8,805 patients were included in both cohorts. Patients who sustained a prior fragility fracture had a higher risk of revision (Hazard Ratio [HR]: 1.46; 95% Confidence Interval [CI]: 1.26-1.69; P<0.001), pseudoarthrosis (HR: 1.31; 95% CI: 1.17-1.48; P<0.001), mechanical failure (HR: 2.08; 95% CI: 1.78-2.45; P<0.001), secondary fragility fracture (HR: 6.36; 95% CI: 5.86-6.90; P<0.001), and vertebral compression fracture (HR: 7.47; 95% CI: 7.68-8.21; P<0.001) when compared to the control cohort. CONCLUSION: Patients who sustain a fragility fracture prior to lumbar fusion have an increased risk of revision, pseudoarthrosis, and mechanical failure within 8 years. Surgeons should be aware of this high-risk patient population and consider bone health screening and treatment to reduce these preventable complications.

Trends in usage of navigation and robotic assistance in elective spine surgeries: a study of 105,212 cases from 2007 to 2015.

OBJECTIVE: Identify trends of navigation and robotic-assisted elective spine surgeries. METHODS: Elective spine surgery patients between 2007 and 2015 in the Nationwide Inpatient Sample (NIS) were isolated by ICD-9 codes for Navigation [Nav] or Robotic [Rob]-Assisted surgery. Basic demographics and surgical variables were identified via chi-squared and t tests. Each system was analyzed from 2007 to 2015 for trends in usage. RESULTS: Included 3,759,751 patients: 100,488 Nav; 4724 Rob. Nav were younger (56.7 vs 62.7 years), had lower comorbidity index (1.8 vs 6.2, all p < 0.05), more decompressions (79.5 vs 42.6%) and more fusions (60.3 vs 52.6%) than Rob. From 2007 to 2015, incidence of complication increased for Nav (from 5.8 to 21.7%) and Rob (from 3.3 to 18.4%) as well as 2-3 level fusions (from 50.4 to 52.5%) and (from 1.3 to 3.2%); respectively. Invasiveness increased for both (Rob: from 1.7 to 2.2; Nav: from 3.7 to 4.6). Posterior approaches (from 27.4 to 41.3%), osteotomies (from 4 to 7%), and fusions (from 40.9 to 54.2%) increased in Rob. Anterior approach for Rob decreased from 14.9 to 14.4%. Nav increased posterior (from 51.5% to 63.9%) and anterior approaches (from 16.4 to 19.2%) with an increase in osteotomies (from 2.1 to 2.7%) and decreased decompressions (from 73.6 to 63.2%). CONCLUSIONS: From 2007 to 2015, robotic and navigation systems have been performed on increasingly invasive spine procedures. Robotic systems have shifted from anterior to posterior approaches, whereas navigation computer-assisted procedures have decreased in rates of usage for decompression procedures.

Rhamnolipid production by Pseudomonas aeruginosa (SSL-4) on waste engine oil (WEO): Taguchi optimization, soil remediation, and phytotoxicity investigation.

ABSTRACTEnvironmental concerns and rising biosurfactant demand emphasize the need for this study. The objective is to maximize rhamnolipid-biosurfactant production by Pseudomonas aeruginosa (SSL-4) utilizing waste engine oil (WEO) as the sole substrate for use in soil bioremediation and commercial production. Using an L16 Taguchi orthogonal array, a signal-to-noise ratio, and an analysis of variance (ANOVA), the effects of environmental (pH, incubation temperature) and dietary parameters (carbon source concentration, carbon/nitrogen (C/N) and carbon/phosphorus (C/P) ratio) are examined. Variations of the following parameters were made within a carefully selected range: incubation temperature of 25-40℃, pH range of 5-11, WEO concentration of 1-7% (v/v), and C/N and C/P ratios of 10-40. Response variables in this batch study include surface tension reduction (mN/m), dry cell biomass (DCBM) (g/L), and rhamnolipids yield based on substrate consumption, YP/S (g/g). Rhamnolipid was synthesized under optimal conditions, providing a yield of 21.42 g/g. The oil recovery of 74.05 ± 1.481% was achieved from oil-contaminated soil at a CMC of ∼70 mg/L. FTIR, 1H NMR, and UPLC-MS techniques were utilized for the characterization of rhamnolipids, and AAS for determining heavy metals concentration in WEO and residual waste engine oil (RWEO). The Germination Index (GI) of ∼82.55% indicated no phytotoxicity associated with synthesized rhamnolipid.