Pupillary autonomic dysfunction in patients with ANCA-associated vasculitis.

OBJECTIVE: To assess autonomic function by infrared dynamic pupillometry in patients with ANCA-vasculitis (AAV) in correlation to autonomic symptoms, disease specific clinical parameters and cardiovascular reflex tests. METHODS: Patients with AAV and healthy controls underwent pupillometry at rest and after sympathetic stimulation (cold pressor test). Three parasympathetic parameters (amplitude, relative amplitude, maximum constriction velocity) and one sympathetic parameter (late dilatation velocity) were assessed. Results were correlated with clinical parameters, symptoms of autonomic dysfunction (COMPASS31 questionnaire), heart rate variability during deep breathing test and blood pressure response to pain. RESULTS: 23 patients and 18 age-matched controls were enrolled. Patients had a smaller amplitude (1.44 vs. 1.70 mm; p = 0.009) and a slower constriction velocity (4.15 vs. 4.71 mm/s; p = 0.028) at baseline and after sympathetic stimulation (1.47 vs. 1.81 mm, p = 0.001; 4.38 vs. 5.19 mm/s, p = 0.006, respectively). Relative amplitude was significantly smaller in patients after sympathetic stimulation (28.6 vs. 32.5%; p = 0.043), but not at baseline. There was no difference in sympathetic pupillary response between the groups. In patients, parasympathetic pupil response was correlated negatively with age and positively with parasympathetic cardiac response. After adjusting for age, no significant correlation was observed with clinical parameters. However, there was a trend towards a negative correlation with disease duration, vasculitis damage index and CRP. CONCLUSION: Patients with AAV exhibit parasympathetic pupillary autonomic dysfunction. Although correlations were weak and not significant, pupillary autonomic dysfunction is rather linked to chronic damage than to active inflammation or symptoms of autonomic dysfunction.

Assessment of autonomic function in a cohort of patients with ANCA-associated vasculitis.

OBJECTIVE: To assess symptoms and objective parameters of autonomic dysfunction (AD) in patients with ANCA-associated vasculitides. METHODS: Symptoms and objective parameters of AD were assessed in patients with ANCA-associated vasculitis and in age-matched healthy controls. Autonomic symptoms were explored by COMPASS31, a validated questionnaire addressing symptoms of six autonomic domains (orthostatic, vasomotor, secretomotor, gastrointestinal, pupillomotor, and bladder dysfunction). Objective autonomic parameters consisted of expiratory/inspiratory (E/I) ratio during the deep breathing test (DBT), blood pressure response to cold pressor test (CPT), and skin conductance changes during mental arithmetic. RESULTS: 27 patients and 27 healthy controls have been enrolled. 27 patients and 27 controls completed COMPASS31. 21 patients and 18 controls underwent objective autonomic testing. Vasculitis patients had significantly higher COMPASS31 total scores than controls (median 10.4 vs 3.0; p = 0.005). In the sub-domain analysis, significant differences were seen in the vasomotor and the bladder domain (p = 0.004; p < 0.001, respectively). No correlation was found between COMPASS31 score and disease duration, number of affected organs, or Birmingham vasculitis activity score (BVAS). There was no significant difference in any of the objective autonomic parameters between patients and controls. In a subgroup analysis, no difference in objective autonomic parameters was found between patients with active disease (n = 12) and patients in remission (n = 7). CONCLUSION: Patients with ANCA-associated vasculitides commonly have symptoms of autonomic dysfunction that are independent of disease duration and disease severity. However, at least in this single-centre observation, there was no evidence of impaired autonomic regulation in three autonomic function tests in vasculitis patients.

[Sporadic Cerebral Amyloid Angiopathy: An Overview with Clinical Cases]. / Die sporadische zerebrale Amyloidangiopathie - eine aktuelle Übersicht mit klinischen Fallbeispielen.

Sporadic cerebral amyloid angiopathy (CAA) is a cerebral small vessel disease in the elderly. Neuropathologically, it is characterized by deposition of amyloid-ß (Aß) in the wall of small to medium-sized arteries, capillaries and venules of the cerebral cortex and leptomeninges. Over the last years it was recognized as an important cause of spontaneous intracerebral hemorrhage and cognitive deficits in the elderly. The clinical and radiological manifestations are diverse ranging from acute onset focal neurological deficits due to intracerebral lobar hemorrhage to subacute progressive cognitive impairment due to Aß-mediated inflammation confluent subcortical edema. The wide clinico-radiological spectrum of CAA is a major challenge for the neurologist and stroke physician. This review provides a structured and detailed look at recent developments in CAA, and is illustrated with case studies.

Treatment of chronic migraine with transcutaneous stimulation of the auricular branch of the vagal nerve (auricular t-VNS): a randomized, monocentric clinical trial.

BACKGROUND: Aim of the study was assessment of efficacy and safety of transcutaneous stimulation of the auricular branch of the vagal nerve (t-VNS) in the treatment of chronic migraine. METHODS: A monocentric, randomized, controlled, double-blind study was conducted. After one month of baseline, chronic migraine patients were randomized to receive 25 Hz or 1 Hz stimulation of the sensory vagal area at the left ear by a handhold battery driven stimulator for 4 h/day during 3 months. Headache days per 28 days were compared between baseline and the last month of treatment and the number of days with acute medication was recorded The Headache Impact Test (HIT-6) and the Migraine Disability Assessment (MIDAS) questionnaires were used to assess headache-related disability. RESULTS: Of 46 randomized patients, 40 finished the study (per protocol). In the per protocol analysis, patients in the 1 Hz group had a significantly larger reduction in headache days per 28 days than patients in the 25 Hz group (-7.0 ± 4.6 vs. -3.3 ± 5.4 days, p = 0.035). 29.4 % of the patients in the 1 Hz group had a ≥50 % reduction in headache days vs. 13.3 % in the 25 Hz group. HIT-6 and MIDAS scores were significantly improved in both groups, without group differences. There were no serious treatment-related adverse events. CONCLUSION: Treatment of chronic migraine by t-VNS at 1 Hz was safe and effective. The mean reduction of headache days after 12 weeks of treatment exceeded that reported for other nerve stimulating procedures.

[Cognitive Function in Patients Before and After Micro-neurosurgical Resection of Frontal Brain Tumors]. / Kognitive Funktion bei Patienten vor und nach mikrochirurgischer Resektion von frontalen Hirntumoren.

Patients with lesions of the prefrontal cortex as a result of frontal brain tumors (intra- and extra-axial) can show impairments of executive functions 1 2 3 4. Although there are a large number of psychological tests, the detection of impairments of relevant everyday executive functions in these patients is still extremely difficult. In 30 patients with lesions of the prefrontal cortex, the executive functions were tested with the Behavioral Assessment of Dysexecutive Syndrome (BADS) and 21 patients were also followed up postoperatively. Additionally, if possible, the Wisconsin Card Sorting Test (WCST), a widely used executive function test, and the Wechsler Adult Intelligence Scale (WAIS) for general cognitive performance were conducted. Pre- and postoperatively, a total of 16 patients were followed up with all three tests. The aim was to investigate the neuropsychological assessment pre- and postoperatively, to evaluate it in terms of deficits and changes in performance and to ensure that no new relevant everyday cognitive deficits arose. Preoperatively, only one patient, who could not be tested post-surgery, showed a reduced overall profile value in the BADS.  In all tested patients, there was no evidence of deterioration of cognitive status 8 - 12 weeks postoperatively. Further investigations using fMRI should be used to clarify whether the results obtained should be interpreted as neuroplastic adaptations of prefrontal cognitive functions or as a failure to detect deficits due to a lack of sensitivity of the tests used.

Variability in expenses related to spine oncology care: comparison of payer-negotiated rates at National Cancer Institute-Designated Cancer Centers.

BACKGROUND: As of 2021, the Centers for Medicare and Medicaid Services (CMS) requires all hospitals to publish their commercially negotiated prices. To our knowledge, price variation of spine oncology diagnosis and treatments has not been previously investigated. PURPOSE: The aim of this study is to characterize the availability and variation of prices for spinal oncology services among National Cancer Institute-Designated Cancer Centers (NCI-DCC). STUDY DESIGN: Cross-sectional analysis. METHODS: Cancer centers were identified; those that did not provide patient care or participate in Medicare's Inpatient Prospective System were excluded. A cross-sectional analysis was conducted to gather commercially negotiated prices by searching online for "[center name] price transparency OR machine-readable file OR chargemaster." Data obtained was queried using 44 current procedural terminology (CPT) codes for imaging, procedures, and surgeries relevant to spine oncology. Comparison of prices was achieved by normalizing the median price for each service at each center to the estimated 2022 Medicare reimbursement for the center's Medicare Administrator Contractor. The ratios between the lowest and highest median commercial negotiated price within a center and across all centers were defined as "within-center ratio" and "across-center ratio" respectively. RESULTS: In total, 49 centers disclosed commercial payer-negotiated rates. Mean rate (±SD) for cervical corpectomy was $9,134 (±$10,034), thoracic laminectomy for neoplasm excision was $5,382 (±$5502), superficial bone biopsy was $1,853 (±$1,717), and single-photon emission computerized tomography (SPECT) was $813 (±$232). Within-center ratios ranged from 5.0 (SPECT scan) to 17.8 (radiofrequency bone ablation). Across-center ratios (for codes with > 10 centers reporting) ranged from 9.0 (corpectomy, thoracic, lateral extra-cavitary) to 418.7 (anterior approach cervical corpectomy). CONCLUSIONS: Price transparency for spinal oncology remains elusive despite recent CMS regulatory oversight, with marked heterogeneity in the quality of published rates complicating patients' ability to "shop" for care. Additionally, there continues to be significant variation in commercial rates for spine oncology diagnosis and treatment. CLINICAL SIGNIFICANCE: Despite regulation by CMS, prices for spinal oncology services are not uniformly available to patients and vary between NCI-DCC. The findings of this manuscript present potential barriers for patients to compare and obtain affordable care.

Sagittal Alignment in the Degenerative Lumbar Spine: Surgical Planning.

➤ Sagittal alignment of the spine has gained attention in the field of spinal deformity surgery for decades. However, emerging data support the importance of restoring segmental lumbar lordosis and lumbar spinal shape according to the pelvic morphology when surgically addressing degenerative lumbar pathologies such as degenerative disc disease and spondylolisthesis.➤ The distribution of caudal lordosis (L4-S1) and cranial lordosis (L1-L4) as a percentage of global lordosis varies by pelvic incidence (PI), with cephalad lordosis increasing its contribution to total lordosis as PI increases.➤ Spinal fusion may lead to iatrogenic deformity if performed without attention to lordosis magnitude and location in the lumbar spine.➤ A solid foundation of knowledge with regard to optimal spinal sagittal alignment is beneficial when performing lumbar spinal surgery, and thoughtful planning and execution of lumbar fusions with a focus on alignment may improve patient outcomes.

Plastic Surgery Closure of Complex Spinal Wounds.

Wound breakdown and infection are common complications after complex spine surgery and may occur in up to 40% of high-risk patients. These are challenging scenarios which can result in a prolonged hospital stay, revision surgery, and elevated costs. Reconstructive specialists can do prophylactic closures for high-risk groups to potentially reduce the risk of developing a wound complication. These plastic surgery techniques often involve multilayered closure, with the addition of local muscle and/or fasciocutaneous flaps. The goal of this study was to review the literature for risks associated with wound complications, identification of high-risk patients, and the advantages of using plastic surgery techniques. In addition, we elaborate on the multilayered and flap closure technique for complex spine surgery which is done at our institution.

Three-Column Osteotomy for Frail Versus Nonfrail Patients with Adult Spinal Deformity: Assessment of Medical and Surgical Complications, Revision Surgery Rates, and Cost.

BACKGROUND: Three-column osteotomy (3-CO) is a powerful tool for spinal deformity correction but has been associated with substantial risk and surgical invasiveness. It is incompletely understood how frailty might affect patients undergoing 3-CO. METHODS: The PearlDiver database was used to examine spinal deformity patients with a diagnosis of frailty who had undergone 3-CO. Frail and nonfrail patients were matched, and the revision surgery rates, complications, and hospitalization costs were calculated. Logistic regression was used to account for possible confounding variables. Of the 2871 included patients, 1460 had had frailty and 1411 had had no frailty. RESULTS: The frail patients were older, had had more comorbidities (P < 0.001), and were more likely to have undergone posterior interbody fusion (P < 0.05), without differences in the anterior interbody fusion rates. No differences were found in the reoperation rates for ≤5 years. At 30 days, the frail patients were more likely to have experienced acute kidney injury (P = 0.018), bowel/bladder dysfunction (P = 0.014), cardiac complications (P = 0.006), and pneumonia (P = 0.039). At 2 years, the frail patients were also more likely to have experienced bowel/bladder dysfunction (P = 0.028), cardiac complications (P < 0.001), deep vein thrombosis (P = 0.027), and sepsis (P = 0.033). The cost for the procedures was also higher for the frail patients than for the nonfrail patients ($24,544.79 vs. $21,565.63; P = 0.043). CONCLUSIONS: We found that frail patients undergoing 3-CO were more likely to experience certain medical complications and had had higher associated costs but similar reoperation rates compared with nonfrail patients. Careful patient selection and surgical strategy modification might alter the risks of medical and surgical complications after 3-CO for frail patients.

Robotic Spine Surgery in Rhode Island.

Surgical robots were first proposed in the 1960s with subsequent development and clinical implementation in the 1980s and 1990s. Recent advances in technology have led to widespread utilization of robots in many surgical subspecialties. In spine surgery, robots are primarily utilized for pedicle screw placement, with several studies highlighting the potential benefits of improved accuracy and reduction in radiation exposure. Once streamlined, robotic spine surgery (RSS) can provide financial renumeration through potential cost savings and marketing benefits, and in the future will likely aid in more complex surgeries. In Rhode Island, this technology has been implemented and has the potential to deliver optimized outcomes for patients. Robotic spine surgery is not a substitute for a skilled spine surgeon however, and careful diagnosis, care planning, and surgical execution are still mandatory to deliver the best possible patient outcomes. In this review, we chronicle the history of RSS, outline currently available RSS platforms, describe the efficacy, risks, and complications of RSS procedures, and explain the current and future utilization of RSS in Rhode Island.

Does fusion length matter? Total hip arthroplasty dislocation after extension of lumbosacral fusion: a case report.

CASE: Hip-spine syndrome is a complex challenge for orthopedic surgeons. We present a 60-year-old female with a history of spinal fusion and total hip arthroplasty. The patient underwent extension of the previous fusion with sacropelvic fixation, and 5 months later she presented with left posterior prosthetic hip dislocation which required sedation and closed reduction. CONCLUSION: Even with no change in lumbar lordosis or pelvic tilt and adequate acetabular cup position, extension of the fusion construct may predispose patients to dislocation. This may be the result of an increased lever arm acting at the hip joint, thereby leading to instability.

County Rurality is Associated with Increased Tumor Size and Decreased Survival in Patients with Ewing Sarcoma.

Background: Ewing Sarcoma (ES) is an aggressive tumor affecting adolescents and young adults. Prior studies investigated the association between rurality and outcomes, although there is a paucity of literature focusing on ES. Objective: This study aims to determine whether ES patients in rural areas are subject to adverse outcomes. Methods: This study utilized the Surveillance, Epidemiology, and End Results (SEER) database. A Poisson regression model was used with controls for race, sex, median county income, and age to determine the association between rurality and tumor size. A multivariate Cox Proportional Hazard Model was utilized, controlling for age, race, gender, income, and tumor size. Results: There were 868 patients eligible for analysis, with a mean age of 14.14 years. Of these patients, 97 lived in rural counties (11.18%). Metropolitan areas had a 9.50% smaller tumor size (p<0.0001), compared to non-metropolitan counties. Patients of Black race had a 14.32% larger tumor size (p<0.0001), and male sex was associated with a 15.34% larger tumor size (p<0.0001). The Cox Proportional Hazard model estimated that metropolitan areas had a 36% lower risk of death over time, compared to non-metropolitan areas (HR: 0.64, p ≤ 0.04). Conclusion: Patients in metropolitan areas had a smaller tumor size at time of diagnosis and had a more favorable survival rate for cancer-specific mortality compared to patients residing in rural areas. Further work is needed to examine interventions to reduce this discrepancy and investigate the effect of extremely rural and urban settings and why racial disparities occur.

Radiomics in Spine Surgery.

Radiomics is an emerging approach to analyze clinical images with the purpose of revealing quantitative features that are unvisible to the naked eye. Radiomic features can be further combined with clinical data and genomic information to formulate prediction models using machine learning algorithms or manual statistical analysis. While radiomics has been classically applied to tumor analysis, there is promising research in its application to spine surgery, including spinal deformity, oncology, and osteoporosis detection. This article reviews the fundamental principles of radiomic analysis, the current literature relating to the spine, and the limitations of this approach.

Utilization of Antibiotic Bone Cement in Spine Surgery: Pearls, Techniques, and Case Review.

Vertebral osteomyelitis (VO) encompasses a spectrum of spinal infections ranging from isolated mild vertebral osteomyelitis to severe diffuse infection with associated epidural abscess and fracture. Although patients can often be treated with an initial course of intravenous antibiotics, surgery is sometimes required in patients with sepsis, spinal instability, neurological compromise, or failed medical treatment. Antibiotic bone cement (ABC) has been widely used in orthopedic extremity surgery for more than 150 years, both for prophylaxis and treatment of bacterial infection. However, relatively little literature exists regarding its utilization in spine surgery. This article describes ABC utilization in orthopedic surgery and explains the technique of ABC utilization in spine surgery. Surgeons can choose from multiple premixed ABCs with variable viscosities, setting times, and antibiotics or can mix in antibiotics to bone cements themselves. ABC can be used to fill large defects in the vertebral body or disc space or in some cases to coat instrumentation. Surgeons should be wary of complications such as ABC extravasation as well as an increased difficulty with revision. With a thorough understanding of the properties of the cement and the methods of delivery, ABC is a powerful adjunct in the treatment of spinal infections.

Adult Spinal Deformity Correction in Patients with Parkinson Disease: Assessment of Surgical Complications, Reoperation, and Cost.

BACKGROUND: Parkinson disease (PD) is a neurodegenerative disorder that manifests with postural instability and gait imbalance. Correction of spinal deformity in patients with PD presents unique challenges. METHODS: The PearlDiver database was queried between 2010 and 2020 to identify adult patients with spinal deformity before undergoing deformity correction with posterior spinal fusion. Two cohorts were created representing patients with and without a preoperative diagnosis of PD. Outcome measures included reoperation rates, surgical technique, cost, surgical complications, and medical complications. Multivariable logistic regression adjusting for Charlson Comorbidity Index, age, gender, 3-column osteotomy, pelvic fixation, and number of levels fused was used to assess rates of reoperation and complications. RESULTS: In total, 26,984 patients met the inclusion criteria and were retained for analysis. Of these patients, 725 had a diagnosis of PD before deformity correction. Patients with PD underwent higher rates of pelvic fixation (odds ratio [OR], 1.33; P < 0.001) and 3-column osteotomies (OR, 1.53; P < 0.001). On adjusted regression, patients with PD showed increased rates of reoperation at 1 year (OR, 1.37; P < 0.001), 5 years (OR, 1.32; P < 0.001), and overall (OR, 1.33; P < 0.001). Patients with PD also experienced an increased rate of medical complications within 30 days after deformity correction including deep venous thrombosis (OR, 1.60; P = 0.021), pneumonia (OR, 1.44; P = 0.039), and urinary tract infections (OR, 1.54; P < 0.001). Deformity correction in patients with PD was associated with higher 90-day cost (P = 0.007). CONCLUSIONS: Patients with PD undergoing long fusion for deformity correction are at significantly increased risk of 30-day medical complications and revision procedures after 1 year, controlling for comorbidities, age, and invasiveness. Surgeons should consider the risk of complications, subsequent revision procedures, and increased cost.

Reduction of adolescent grade IV L5-S1 spondylolisthesis with anterior joystick manipulation during a combined anterior and posterior surgical approach: A case report.

Background: High-grade isthmic spondylolisthesis poses a clinical challenge in the pediatric and adolescent population. Current surgical management using posterior-based approaches may lead to incomplete reduction and restoration of listhesis, disc height, and lordosis. Combined anterior and posterior approach addresses these issues but has been infrequently reported, mainly in the treatment of low-grade isthmic spondylolisthesis. Neither offers good disc space visualization and control of spinal alignment during reduction. Case Description: A healthy 17-year-old female presented with 9 months of progressively worsening lower back pain radiating down the left lower extremity and 3 inches of height loss. Diagnosis of grade IV L5-S1 spondylolisthesis was made using plain radiographs, CT, and MRI. Management with combined anterior and posterior fusion, involving the manual manipulation of segments using an anterior pedicle screw joystick, was pursued. Outcome: Satisfactory alignment, solid arthrodesis, no complications, and improved patient reported outcomes. Conclusions: Combined anterior and posterior fusion with anterior joystick manipulation allowed for full reduction of grade IV spondylolisthesis and restoration of disc/foraminal height and L5-S1 segmental lordosis without neurological complication. Although less commonly performed in children and adolescents, this surgical approach can assist in restoring optimal alignment in isthmic spondylolisthesis.

Longitudinal Assessment of Modern Spine Surgery Training: 10-Year Follow-up of a Nationwide Survey of Residency and Spine Fellowship Program Directors.

Spine surgeons complete training through residency in orthopaedic surgery (ORTH) or neurosurgery (NSGY). A survey was conducted in 2013 to evaluate spine surgery training. Over the past decade, advances in surgical techniques and the changing dynamics in fellowship training may have affected training and program director (PD) perceptions may have shifted. Methods: This study is a cross-sectional survey distributed to all PDs of ORTH and NSGY residencies and spine fellowships in the United States. Participants were queried regarding characteristics of their program, ideal characteristics of residency training, and opinions regarding the current training environment. χ2 tests were used to compare answers over the years. Results: In total, 241 PDs completed the survey. From 2013 to 2023, NSGY increased the proportion of residents with >300 spine cases (86%-100%) while ORTH remained with >90% of residents with < 225 cases (p < 0.05). A greater number of NSGY PDs encouraged spine fellowship even for community spine surgery practice (0% in 2013 vs. 14% in 2023, p < 0.05), which continued to be significantly different from ORTH PDs (∼88% agreed, p > 0.05). 100% of NSGY PDs remained confident in their residents performing spine surgery, whereas ORTH confidence significantly decreased from 43% in 2013 to 25% in 2023 (p < 0.05). For spinal deformity, orthopaedic PDs (92%), NSGY PDs (96%), and fellowship directors (95%), all agreed that a spine fellowship should be pursued (p = 0.99). In both 2013 and 2023, approximately 44% were satisfied with the spine training model in the United States. In 2013, 24% of all PDs believed we should have a dedicated spine residency, which increased to 39% in 2023 (fellowship: 57%, ORTH: 38%, NSGY: 21%) (p < 0.05). Conclusion: Spine surgery training continues to evolve, yet ORTH and neurological surgery training remains significantly different in case volumes and educational strengths. In both 2013 and 2023, less than 50% of PDs were satisfied with the current spine surgery training model, and a growing minority believe that spine surgery should have its own residency training pathway. Level of Evidence: IV.

Treatment of adult deformity surgery by orthopedic and neurological surgeons: trends in treatment, techniques, and costs by specialty.

BACKGROUND CONTEXT: Surgery to correct adult spinal deformity (ASD) is performed by both neurological surgeons and orthopedic surgeons. Despite well-documented high costs and complication rates following ASD surgery, there is a dearth of research investigating trends in treatment according to surgeon subspeciality. PURPOSE: The purpose of this investigation was to perform an analysis of surgical trends, costs and complications of ASD operations by physician specialty using a large, nationwide sample. STUDY DESIGN/SETTING: Retrospective cohort study using an administrative claims database. PATIENT SAMPLE: A total of 12,929 patients were identified with ASD that underwent deformity surgery performed by neurological or orthopedic surgeons. OUTCOME MEASURES: The primary outcome was surgical case volume by surgeon specialty. Secondary outcomes included costs, medical complications, surgical complications, and reoperation rates (30-day, 1-year, 5-year, and total). METHODS: The PearlDiver Mariner database was queried to identify patients who underwent ASD correction from 2010 to 2019. The cohort was stratified to identify patients who were treated by either orthopedic or neurological surgeons. Surgical volume, baseline characteristics, and surgical techniques were examined between cohorts. Multivariable logistic regression was employed to assess the cost, rate of reoperation and complication according to each subspecialty while controlling for number of levels fused, rate of pelvic fixation, age, gender, region and Charlson Comorbidity Index (CCI). Alpha was set to 0.05 and a Bonferroni correction for multiple comparisons was utilized to set the significance threshold at p ≤.000521. RESULTS: A total of 12,929 ASD patients underwent deformity surgery performed by neurological or orthopedic surgeons. Orthopedic surgeons performed most deformity procedures accounting for 64.57% (8,866/12,929) of all ASD operations, while the proportion treated by neurological surgeons increased 44.2% over the decade (2010: 24.39% vs 2019: 35.16%; p<.0005). Neurological surgeons more frequently operated on older patients (60.52 vs 55.18 years, p<.0005) with more medical comorbidities (CCI scores: 2.01 vs 1.47, p<.0005). Neurological surgeons also performed higher rates of arthrodesis between one and six levels (OR: 1.86, p<.0005), three column osteotomies (OR: 1.35, p<.0005) and navigated or robotic procedures (OR: 3.30, p<.0005). Procedures performed by orthopedic surgeons had significantly lower average costs as compared to neurological surgeons (orthopedic surgeons: $17,971.66 vs neurological surgeons: $22,322.64, p=.253). Adjusted logistic regression controlling for number of levels fused, pelvic fixation, age, sex, region, and comorbidities revealed that patients within neurosurgical care had similar odds of complications to orthopaedic surgery. CONCLUSIONS: This investigation of over 12,000 ASD patients demonstrates orthopedic surgeons continue to perform the majority of ASD correction surgery, although neurological surgeons are performing an increasingly larger percentage over time with a 44% increase in the proportion of surgeries performed in the decade. In this cohort, neurological surgeons more frequently operated on older and more comorbid patients, utilizing shorter-segment fixation with greater use of navigation and robotic assistance.

A comparison of different activated carbon performances on catalytic ozonation of a model azo reactive dye.

The objective of this study is to compare the performances of catalytic ozonation processes of two activated carbons prepared from olive stone (ACOS) and apricot stone (ACAS) with commercial ones (granular activated carbon-GAC and powder activated carbon-PAC) in degradation of reactive azo dye (Reactive Red 195). The optimum conditions (solution pH and amount of catalyst) were investigated by using absorbencies at 532, 220 and 280 nm wavelengths. Pore properties of the activated carbon (AC) such as BET surface area, pore volume, pore size distribution, and pore diameter were characterized by N(2) adsorption. The highest BET surface area carbon (1,275 m(2)/g) was obtained from ACOS with a particle size of 2.29 nm. After 2 min of catalytic ozonation, decolorization performances of ACOS and ACAS (90.4 and 91.3%, respectively) were better than that of GAC and PAC (84.6 and 81.2%, respectively). Experimental results showed that production of porous ACs with high surface area from olive and apricot stones is feasible in Turkey.