Effect of Preoperative Corticosteroids on Postoperative Glucose Control in Total Joint Arthroplasty.

Background: Dexamethasone is a commonly used perioperative medication for the management of postoperative nausea and vomiting following total joint arthroplasty (TJA). However, concerns have been raised about its potential to cause hyperglycemia. This study aimed to investigate the impact of dexamethasone administration on glucose levels and complications in both diabetic and nondiabetic patients undergoing TJA. Methods: We performed a retrospective review of 1928 patients who underwent primary total knee and hip arthroplasty procedures at a large tertiary medical institution. Patients were divided into 2 groups based on whether they received preoperative dexamethasone. Postoperative blood glucose values and variability were measured, and data on complications were collected. We performed statistical analysis using descriptive analysis, multivariate logistic regression models, negative binomial regression, and a subset analysis to assess the impact of dexamethasone dose on postoperative glycemic control. Results: Preoperative dexamethasone did not significantly increase the mean glucose, fasting glucose, glucose variability, or 90-day complications in both the diabetic and nondiabetic groups. Nondiabetic patients who received dexamethasone had a significantly lower rate of intensive care unit admission (P < .01). Additionally, patients who received dexamethasone had a significantly shorter length of hospital stay compared to those who did not (P < .001). Conclusions: Preoperative dexamethasone administration is a safe and effective method for preventing postoperative nausea and vomiting in patients undergoing TJA without significant adverse effects on glucose levels, glucose variability, or infection rates in both diabetics and nondiabetics. Preoperative dexamethasone decreases postoperative length of stay.

Thirty-Day Outcomes After Acute Total Hip Arthroplasty Combined With Internal Fixation of Acetabular Fractures: A Multi-Institutional Database Analysis.

INTRODUCTION: The purposes of this study were to characterize the 30-day surgical risk of patients undergoing open reduction and internal fixation (ORIF) and total hip arthroplasty stratified by an acetabular fracture pattern and to compare postoperative complications with ORIF alone using a large database. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was queried to determine 30-day outcomes after the combined hip procedure (CHP) compared with ORIF alone between 2005 and 2020. Current Procedural Terminology codes categorized fracture patterns. Univariate analysis was performed using the chi-square, Fisher exact, or Wilcoxon rank sum test. Logistic regression models were fitted to evaluate for any differences in postoperative complications. Total hospital length of stay was compared. RESULTS: A total of 1,187 patients were identified. One hundred eighty-four patients underwent a CHP, consisting of 99 acetabular wall fractures, 45 elementary acetabular fractures, and 40 associated acetabular fractures. There was no notable difference in any surgical site infection, thromboembolic events, transfusion rates, 30-day revision surgery, and readmission, regardless of the fracture pattern when controlling for comorbidities. Total hospital length of stay was shorter for patients who underwent a CHP for acetabular wall fractures or elementary acetabular fractures (P < 0.001). CONCLUSION: This combined surgical approach appears to have a similar 30-day risk profile when compared with ORIF alone regardless of the fracture pattern.

Diagnosing periprosthetic joint infection.

Aims: The diagnosis of periprosthetic joint infection (PJI) can be challenging as the symptoms are similar to other conditions, and the markers used for diagnosis have limited sensitivity and specificity. Recent research has suggested using blood cell ratios, such as platelet-to-volume ratio (PVR) and platelet-to-lymphocyte ratio (PLR), to improve diagnostic accuracy. The aim of the study was to further validate the effectiveness of PVR and PLR in diagnosing PJI. Methods: A retrospective review was conducted to assess the accuracy of different marker combinations for diagnosing chronic PJI. A total of 573 patients were included in the study, of which 124 knees and 122 hips had a diagnosis of chronic PJI. Complete blood count and synovial fluid analysis were collected. Recently published blood cell ratio cut-off points were applied to receiver operating characteristic curves for all markers and combinations. The area under the curve (AUC), sensitivity, specificity, and positive and negative predictive values were calculated. Results: The results of the analysis showed that the combination of ESR, CRP, synovial white blood cell count (Syn. WBC), and polymorphonuclear neutrophil percentage (PMN%) with PVR had the highest AUC of 0.99 for knees, with sensitivity of 97.73% and specificity of 100%. Similarly, for hips, this combination had an AUC of 0.98, sensitivity of 96.15%, and specificity of 100.00%. Conclusion: This study supports the use of PVR calculated from readily available complete blood counts, combined with established markers, to improve the accuracy in diagnosing chronic PJI in both total hip and knee arthroplasties.

Utility of Blood Cell Ratio Combinations for Diagnosis of Periprosthetic Joint Infection.

Background: Periprosthetic joint infection (PJI) is a serious complication following joint replacement surgery, and its diagnosis can be challenging due to the similarity of symptoms to other conditions and the lack of confirmatory imaging tests. Platelet/mean platelet volume ratio (PVR), platelet/lymphocyte ratio, monocyte/lymphocyte ratio, and neutrophil/lymphocyte ratio have been proposed as potential markers to aid in the diagnosis of PJI. This study aimed to further assess the utility of these blood cell ratio combinations for the diagnosis of PJI. Methods: A retrospective chart review was conducted on patients who presented to a university hospital for evaluation for PJI or underwent aseptic revision surgery. All patients were reviewed for inclusion in the study. Data were collected on several markers, including complete blood counts, synovial fluid white blood cell count, and polymorphonuclear percentage. Receiver operator characteristic curve analysis was used to evaluate the diagnostic capabilities of the markers and marker combinations. Results: The combination of erythrocyte sedimentation rate, C-reactive protein, synovial white blood cell count, and synovial polymorphonuclear percentage, with PVR, had the highest area under the curve of 0.97, with a sensitivity of 94.3% and a specificity of 88.9%, and a positive predictive value of 97.1% and a negative predictive value of 80.0%. Conclusions: This study further supports the use of PVR calculated from complete blood count commonly ordered laboratory values obtained during routine complete blood counts when combined with established serum and synovial markers to increase the diagnostic accuracy for diagnosing PJI.

Knee Arthrodesis: An Analysis of Surgical Risk Factors and Complications Using a National Database.

Background: Knee arthrodesis is predominantly a salvage procedure. In present time, knee arthrodesis is mostly considered for cases of unreconstructable failed total knee arthroplasty after prosthetic joint infection or trauma. Knee arthrodesis has shown better functional outcomes than amputation for these patients but has a high complication rate. The purpose of this study was to characterize the acute surgical risk profile of patients undergoing a knee arthrodesis for any indication. Methods: The American College of Surgeons National Surgical Quality Improvement Program database was queried to determine 30-day outcomes after knee arthrodesis between 2005 and 2020. Demographics, clinical risk factors, and postoperative events were analyzed, along with reoperation and readmission rates. Results: A total of 203 patients that underwent a knee arthrodesis were identified. Forty-eight percent of patients had at least 1 complication. The most common complication was acute surgical blood loss anemia requiring a blood transfusion (38.4%), followed by organ space surgical site infection (4.9%), superficial surgical site infection (2.5%), and deep vein thrombosis (2.5%). Smoking was associated with higher rates of reoperation and readmission (odds ratio 9, P < .01, and odds ratio 6, P < .05). Conclusions: Overall, knee arthrodesis is a salvage procedure that has a high rate of early postoperative complications and is most often performed in patients at higher risk. Early reoperation is strongly associated with a poor preoperative functional status. Smoking places patients at higher risk of early complications.

Cost Analysis of Conversion Total Knee Arthroplasty: A Multi-Institutional Database Study.

BACKGROUND: Total knee arthroplasty (TKA) after prior knee surgery, also known as conversion TKA (convTKA), has been associated with higher complications, resource utilization, time, and effort. The increased surgical complexity of convTKA may not be reflected by the relative value units (RVUs) assigned under the current U.S. coding guidelines. The purpose of this study was to compare the RVUs of primary TKA and convTKA and to calculate the RVU per minute to account for work effort. METHODS: The American College of Surgeons National Surgical Quality Improvement Project (NSQIP) database was analyzed for the years 2005 to 2020. Current Procedural Terminology (CPT) code 27447 alone was used to identify patients who underwent primary TKA, and 27447 plus 20680 were used to identify convTKA. After 1:1 propensity score matching, 1,600 cases were assigned to each cohort. The 2023 Medicare Physician Fee Schedule RVU-to-dollar conversion factor from the U.S. Centers for Medicare & Medicaid Services (CMS) was used to calculate RVU dollar valuations per operative time. Complication rates were compared using a multivariate logistic regression model controlling for baseline characteristics. RESULTS: The mean operative time for TKA was 97.8 minutes, with a corresponding RVU per minute of 0.25, while the mean operative time for convTKA was 124.3 minutes, with an RVU per minute of 0.19 (p < 0.0001). Using the conversion factor of $33.06 per RVU, this equated to $8.11 per minute for TKA versus $6.39 per minute for convTKA. ConvTKA was associated with higher overall complication (10.9% versus 6.5%, p < 0.0001), blood transfusion (6.6% versus 3.7%, p < 0.01), reoperation (2.3% versus 0.94%, p < 0.0001), and readmission (3.7% versus 1.8%, p < 0.001) rates. CONCLUSIONS: The current billing guidelines lead to lower compensation for convTKA despite its increased complexity. The longer operative time, higher complication rate, and increased resource utilization may incentivize providers to avoid performing this operation. CPT code revaluation is warranted to reflect the time and effort associated with this procedure. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Prolonged hospital stay after arthroplasty for geriatric femoral neck fractures is associated with increased early mortality risk after discharge.

BACKGROUND: Recent studies show increasing mortality rates of geriatric femoral neck fracture patients with delays in operative treatment greater than 48 hours from injury. A less extensively studied area in this population is the effect of length of inpatient hospital stay (LOS) on outcomes. The purpose of this study was to determine the association of LOS after arthroplasty for geriatric femoral neck fractures with 30-day mortality risk. METHODS: This study is a retrospective review using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP), a nationally validated, outcomes-based database incorporating data from over 700 geographically diverse medical centers. It included 9005 patients, 65 years of age or older, who underwent either hemiarthroplasty or total hip arthroplasty for a femoral neck fracture between 2011 and 2018. Using multivariate analysis, risk of 30-day mortality based on surgery-to-discharge time was determined, expressed as odds ratios (OR) with 95% confidence intervals (CI). RESULTS: After controlling for sex, BMI, age, surgical procedure, American Society of Anesthesiologists (ASA) classification, and discharge location, the risk of mortality after discharge was increased with longer post-surgical length of stay [OR 2.5, P < .001]. CONCLUSION: Prolonged LOS after arthroplasty for geriatric femoral neck fractures is associated with increased 30-day mortality risk. Efforts made to target and mitigate modifiable risk factors responsible for delaying discharge may improve early outcomes in this population.

Risk Factors Associated With Extended Length of Hospital Stay After Geriatric Hip Fracture.

INTRODUCTION: Within the geriatric hip fracture population, there exists a subset of patients whose length of inpatient hospital stay is excessive relative to the average. A better understanding of the risk factors associated with this group would be of value so that targeted prevention efforts can be properly directed. The goal of this study was to identify and characterize the risk factors associated with an extended length of hospital stay (eLOS) in the geriatric hip fracture population. In addition, a statistical model was created to predict the probability of eLOS in a geriatric hip fracture patient. METHODS: The National Surgical Quality Improvement Program database (2005 to 2018) was searched for patients aged ≥65 years who underwent hip fracture surgery. Patients with a hospital stay greater than or equal to 14 days were considered to have an eLOS. A multivariate logistic regression model using 24 patient characteristics from two-thirds of the study population was created to determine independent risk factors predictive of having an eLOS; the remaining one-third of the population was used for internal model validation. Regression analyses were performed to determine preoperative and postoperative risk factors for having an eLOS. RESULTS: A total of 77,144 patients were included in the study. Preoperatively, male sex, dyspnea, ventilator use, chronic obstructive pulmonary disease, American Society of Anesthesiologist class 3 and 4, and increased admission-to-operation time were among the factors associated with higher odds of having an eLOS (all P < 0.001). Postoperatively, patients with acute renal failure had the highest likelihood of eLOS (odds ratio [OR] 7.664), followed by ventilator use >48 hours (OR 4.784) and pneumonia (OR 4.332). DISCUSSION: Among geriatric hip fracture patients, particular efforts should be directed toward optimizing those with preoperative risk factors for eLOS. Preemptive measures to target the postoperative complications with the strongest eLOS association may be beneficial for both the patient and the healthcare system as a whole.

Differentiation of Outcomes by Treatment Regimen and Histology in Central Nervous System Primary Embryonal Tumors.

BACKGROUND: Central nervous system (CNS) embryonal tumors are malignant neoplasms of undifferentiated embryonic cells that typically occur in the pediatric population. They are further divided into many subgroups by distinct histologic and genetic profiles. We present the largest study to date to identify differential survival outcomes within each subgroup by treatment regimen. METHODS: The SEER (Surveillance Epidemiology and End Results) database was queried from 1973 to 2015 for embryonal tumors of primary CNS origin (n = 3900). The effects of patient demographics, tumor characteristics, and treatment regimen were analyzed using a multivariate Cox proportional hazard model in CNS embryonal tumor subtypes divided into medulloblastoma, atypical teratoid/rhabdoid tumor, and primitive neuroectodermal tumor. RESULTS: No significant patient demographic factors were found to be associated with increased mortality. In all 3 CNS embryonal tumor subtypes, most monotherapy and combinatorial treatment paradigms showed a higher hazard ratio compared with gross total resection with adjuvant chemoradiotherapy (hazard ratio, 1.72-22.94; P < 0.05 for all). In a subgroup analysis of patients with medulloblastoma ≤3 years of age, patients who did not receive radiation showed lower survival probabilities at 1, 5, and 10 years (odds ratio [OR], 0.37, P < 0.0001; OR, 0.39, P < 0.0001; OR, 0.34, P < 0.0001, respectively). Kaplan-Meier analysis of medulloblastoma histologic subtypes showed that use of radiation imparted a higher survival probability in the desmoplastic/nodular medulloblastoma and medulloblastoma not otherwise specified groups (P < 0.001 for both). CONCLUSIONS: CNS embryonal tumors are highly malignant in all populations and the best survival is seen with aggressive combination therapies. Radiation therapy may have a role in prolonging survival in patients with medulloblastoma ≤3 years of age.

Transcriptomic Analyses of Inner Ear Sensory Epithelia in Zebrafish.

Analysis of gene expression has the potential to assist in the understanding of multiple cellular processes including proliferation, cell-fate specification, senesence, and activity in both healthy and disease states. Zebrafish model has been increasingly used to understand the process of hearing and the development of the vertebrate auditory system. Within the zebrafish inner ear, there are three otolith organs, each containing a sensory macula of hair cells. The saccular macula is primarily involved in hearing, the utricular macula is primarily involved in balance and the function of the lagenar macula is not completely understood. The goal of this study is to understand the transcriptional differences in the sensory macula associated with different otolith organs with the intention of understanding the genetic mechanisms responsible for the distinct role each organ plays in sensory perception. The sensory maculae of the saccule, utricle, and lagena were dissected out of adult Et(krt4:GFP)sqet4 zebrafish expressing green fluorescent protein in hair cells for transcriptional analysis. The total RNAs of the maculae were isolated and analyzed by RNA GeneChip microarray. Several of the differentially expressed genes are known to be involved in deafness, otolith development and balance. Gene expression among these otolith organs was very well conserved with less than 10% of genes showing differential expression. Data from this study will help to elucidate which genes are involved in hearing and balance. Furthermore, the findings of this study will assist in the development of the zebrafish model for human hearing and balance disorders. Anat Rec, 303:527-543, 2020. © 2019 American Association for Anatomy.

Zebrafish Model for Nonsyndromic X-Linked Sensorineural Deafness, DFNX1.

Hereditary deafness is often a neurosensory disorder and affects the quality of life of humans. Only three X-linked genes (POU class 3 homeobox 4 (POU3F4), phosphoribosyl pyrophosphate synthetase 1 (PRPS1), and small muscle protein X-linked (SMPX)) are known to be involved in nonsyndromic hearing loss. Four PRPS1 missense mutations have been found to associate with X-linked nonsyndromic sensorineural deafness (DFNX1/DFN2) in humans. However, a causative relationship between PRPS1 mutations and hearing loss in humans has not been well studied in any animal model. Phosphoribosyl pyrophosphate synthetase 1 (PRS-I) is highly conserved in vertebrate taxa. In this study, we used the zebrafish as a model to investigate the auditory role of zebrafish orthologs (prps1a and prps1b) of the human PRPS1 gene with whole mount in situ hybridization, reverse transcription polymerase chain reaction, phenotypic screening, confocal imaging, and electrophysiological methods. We found that both prps1a and prps1b genes were expressed in the inner ear of zebrafish. Splice-blocking antisense morpholino oligonucleotides (MO1 and MO2) caused exon-2 skip and intron-2 retention of prps1a and exon-2 skip and intron-1 retention of prps1b to knock down functions of the genes, respectively. MO1 and MO2 morphants had smaller otic vesicles and otoliths, fewer inner ear hair cells, and lower microphonic response amplitude and sensitivity than control zebrafish. Therefore, knockdown of either prps1a or prps1b resulted in significant sensorineural hearing loss in zebrafish. We conclude that the prps1 genes are essential for hearing in zebrafish, which has the potential to help us understand the biology of human deafness DFNX1/DFN2. Anat Rec, 303:544-555, 2020. © 2019 American Association for Anatomy.

Treatment and survival of primary intracranial germ cell tumors: a population-based study using SEER database.

INTRODUCTION: Primary intracranial germ cell tumors are rare neoplasms derived from gonadal cells. They are categorized as germinoma, non-germinomatous germ cell tumor (NGCCT), or teratoma, with the latter two sparking controversy regarding the role of different treatment strategies. We provide the largest multicenter analysis of treatment outcomes for iGCTs to date. METHODS: The Surveillance, Epidemiology, and End Result (SEER) database were used to record patient demographics, tumor, and treatment characteristics. Cox proportional hazards model and multiple comparisons for the Logrank test with Sidak correction was applied to compare the different treatment regimens and survival. RESULTS: 1043 iGCT cases were divided into three cohorts of Germinoma, Malignant Teratoma (MT), and NGGCT. The mean age was 17.7 years for germinoma, 9.5 years for MT, and 14.4 years for NGGCT groups. Males comprised 77% of overall patient population. For Germinomas, both biopsy (hazard ratio [HR] = 4.6) and resection (HR = 14.1) had significantly worse survival outcomes compared to solo radiation therapy, with no difference between radiation and chemotherapy. For MT, no treatment combination had significantly different survival outcomes compared to resection alone. For NGGCTs, resection + chemotherapy + radiotherapy (HR = 0.012) and resection + chemotherapy (HR = 0.0049) had significantly better survival compared to resection alone. CONCLUSION: In germinomas, radiotherapy alone had superior survival outcomes compared to biopsy and resection, but no change in survival when compared to chemotherapy alone. Addition of radiotherapy or chemotherapy did not improve survival in MTs when compared to resection alone. Adding chemotherapy in NGGCT patients undergoing resection improved survival compared to resection alone.

Adult Spinal Arteriovenous Malformations: Natural History and a Multicenter Study of Short-Term Surgical Outcomes.

OBJECTIVE: Spinal arteriovenous malformations (SAVMs) are a very rare and complex spinal cord pathology that require high clinical acumen to diagnose and treat. Management includes both nonoperative and operative paradigms. A review of the literature yields a paucity of data regarding the surgical outcomes of SAVMs, with the majority of data limited to single-center outcomes and/or small sample sizes. The purpose of this study was to use a multi-institutional international database to study the natural history of SAVMs. METHODS: We used the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database to select patients that underwent laminectomy for surgical excision of a SAVM between 2008 and 2017. RESULTS: The data from 196 patients were studied (65.8% male, 34.2% female). A majority of cases were in the thoracic region (53.6%), followed by thoracolumbar (31.6%) and cervical (14.8%) regions. The mean age was 57.4 years and 52.5% patients were graded ASA class 3-5 before the operation. The mean operation time was 215 minutes, with a significantly lower operative time for thoracic arteriovenous malformations (195.6 minutes) when compared with cervical (266.6 minutes) and thoracolumbar (223.7 minutes). The mean length of hospital stay was 6.4 days. Patients had a 6.6% readmission rate and a 4.6% reoperation rate within 30 days. CONCLUSIONS: This study presents the largest analysis of patients undergoing surgery for SAVMs and 30-day postoperative outcomes. Operative time differed based on SAVM location. The three most frequent complications (deep vein thrombosis, wound infection, and UTI) occurred at rates of 3.6% or less.

Primary Malignant Melanoma of the Brain: A Population-Based Study.

BACKGROUND: Primary melanocytic neoplasms of the central nervous system (CNS) are rare and account for 1% of all melanomas. This study used the Surveillance, Epidemiology, and End Results (SEER) database to evaluate the epidemiology of primary CNS melanoma and further characterize their treatment. METHODS: Data from the National Cancer Institute SEER program, collected from 1973-2015, were retrospectively analyzed. A total of 86 records of malignant melanoma cases with CNS as the primary site were identified, and 54 patients were studied based on the inclusion criteria. Demographic, tumor, and treatment regimen effectiveness were studied. RESULTS: A total of 54 patients were included in this study. Tumors were distributed evenly in size and localized primarily to the cerebral meninges and spinal cord. A total of 13% of patients underwent biopsy, 40.7% gross total resection (GTR), 7.4% subtotal resection (STR), 46.3% radiation therapy (RT), and 27.3% chemotherapy (CT) in a variety of treatment combinations. GTR alone and STR + RT resulted in increased disease-specific survival compared to biopsy alone, but no survival benefit was found with biopsy with RT and/or CT as well as STR alone. CONCLUSIONS: To our knowledge, this is the largest single database study completed for primary malignant melanoma of the CNS. The study identified the need for tumor resection for the proper treatment of these lesions, particularly GTR. GTR could be paired with adjuvant RT or RT + CT providing survival benefit as well. In cases when GTR is unable to be completed, STR + RT provides significant improvement in survival compared to biopsy alone.

Determining the role of adjuvant radiotherapy in the management of meningioma: a Surveillance, Epidemiology, and End Results analysis.

OBJECTIVEThe aim of this study was to illustrate the demographic characteristics of meningioma patients and observe the effect of adjuvant radiation therapy on survival by using the Surveillance, Epidemiology, and End Results (SEER) database. More specifically, the authors aimed to answer the question of whether adjuvant radiotherapy following resection of atypical meningioma confers a cause-specific survival benefit. Additionally, they attempted to add to previous characterizations of the epidemiology of primary meningiomas and assess the effectiveness of the standard of care for benign and anaplastic meningiomas. They also sought to characterize the efficacy of various treatment options in atypical and anaplastic meningiomas separately since nearly all other analyses have grouped these two together despite varying treatment regimens for these behavior categories.METHODSSEER data from 1973 to 2015 were queried using appropriate ICD-O-3 codes for benign, atypical, and anaplastic meningiomas. Patient demographics, tumor characteristics, and treatment choices were analyzed. The effects of treatment were examined using a multivariate Cox proportional hazards model and Kaplan-Meier survival analysis.RESULTSA total of 57,998 patients were included in the analysis of demographic, meningioma, and treatment characteristics. Among this population, cases of unspecified WHO tumor grade were excluded in the multivariate analysis, leaving a total of 12,931 patients to examine outcomes among treatment paradigms. In benign meningiomas, gross-total resection (HR 0.289, p = 0.013) imparted a significant cause-specific survival benefit over no treatment. In anaplastic meningioma cases, adjuvant radiotherapy imparted a significant survival benefit following both subtotal (HR 0.089, p = 0.018) and gross-total (HR 0.162, p = 0.002) resection as compared to gross-total resection alone. In atypical tumors, gross-total resection plus radiotherapy did not significantly change the hazard risk (HR 1.353, p = 0.628) compared to gross-total resection alone. Similarly, it was found that adjuvant radiation did not significantly benefit survival after a subtotal resection (HR 1.440, p = 0.644).CONCLUSIONSThe results of this study demonstrate that the role of adjuvant radiotherapy, especially after the resection of atypical meningioma, remains somewhat unclear. Thus, given these results, prospective randomized clinical studies are warranted to provide clear information on the effects of adjuvant radiation in meningioma treatment.

Acute Surgical Risk Profile of Intramedullary Spinal Cord Tumor Resection in Pediatric Patients: A Pediatric National Surgical Quality Improvement Program Analysis.

OBJECTIVE: The purpose of the present study was to characterize the acute (30-day) surgical risk profile of pediatric patients undergoing surgical resection of intramedullary spinal cord tumors (IMSCTs). METHODS: Preoperative factors were collected from the Pediatric American College of Surgeons National Surgical Quality Improvement Program database for patients identified by Current Procedural Terminology codes for laminectomy and International Classification of Diseases codes for IMSCTs from 2012 to 2016. The postoperative outcomes were compared by tumor location and type. RESULTS: The mean age of the 139 patients meeting all inclusion criteria was 8.7 years, with a male predominance (58.7%). The cervical and thoracic IMSCT populations had worst preoperative health status, as indicated by American Society of Anesthesiologists class, and a greater proportion of malignant tumors compared with the lumbar IMSCT population. No patient died; 8.6% of the patients were readmitted, and 6.5% required reoperation. Of the 12 readmissions, 8 were required for patients with malignant tumors. The patients with cervical IMSCTs returned to the operating room at a significantly greater rate than did the thoracic and lumbar IMSCT populations. Two common reasons for reoperation in the cervical population were issues related to respiration and hydrocephalus management. The complications included 13 cases of infection, 6 of urinary tract infection, and 5 cases of surgical site infection. CONCLUSIONS: Resection of IMSCTs in the pediatric population is a relatively low-risk procedure in terms of acute surgical complications. However, surgeons operating in the cervical spine should be aware of the increased risk of reoperation, in particular as it pertains to respiratory issues and hydrocephalus.

Quantum Capacitance Based Amplified Graphene Phononics for Studying Neurodegenerative Diseases.

Amyotrophic lateral sclerosis (ALS) is the most common adult-onset motor neuron disease (MND) characterized by a rapid loss of upper and lower motor neurons resulting in patient death from respiratory failure within 3-5 years of initial symptom onset. Although at least 30 genes of major effect have been reported, the pathobiology of ALS is not well understood. Compounding this is the lack of a reliable laboratory test which can accurately diagnose this rapidly deteriorating disease. Herein, we report on the phonon vibration energies of graphene as a sensitive measure of the composite dipole moment of the interfaced cerebrospinal fluid (CSF) that includes a signature-composition specific to the patients with ALS disease. The second-order overtone of in-plane phonon vibration energy (2D peak) of graphene shifts by 3.2 ± 0.5 cm-1 for all ALS patients studied in this work. Further, the amount of n-doping-induced shift in the phonon energy of graphene, interfaced with CSF, is specific to the investigated neurodegenerative disease (ALS, multiple sclerosis, and MND). By removing a severe roadblock in disease detection, this technology can be applied to study diagnostic biomarkers for researchers developing therapeutics and clinicians initiating treatments for neurodegenerative diseases.

C1-C2 Fusion Versus Occipito-Cervical Fusion for High Cervical Fractures: A Multi-Institutional Database Analysis and Review of the Literature.

OBJECTIVE: Type II odontoid fractures of the axis (C2) account for more than 20% of all cervical fractures. If an odontoid screw is contraindicated, the treatment approach for type II C2 fractures typically involves C1-C2 posterior fusion or occipito-cervical (O-C) fusion, each of which has distinct advantages and disadvantages. In this study, postoperative outcomes of C1-C2 fusion and O-C fusion for high cervical fractures were compared. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was queried to determine 30-day surgical outcomes of posterior C1-C2 fusion versus O-C fusion for adult patients with C2 fractures between 2005 and 2016. Demographics, operative factors, and postoperative events were analyzed, including returns to the operating room, readmission, and death. RESULTS: In total, 165 patients were identified. A majority of the patients (142, 86.1%) had independent functional status, although 133 (80.6%) had an American Society of Anesthesiologists classification ranging from 3 to 5, representing poor preoperative health. A significantly greater proportion of O-C (9.1%) versus C1-C2 fusion (1.7%) returned to the operating room (odds ratio 6.465, confidence interval 1.079-38.719, P = 0.041). The length of operation approached statistical significance (P = 0.053) between the 2 groups, with O-C fusion group having a longer average length of operation (196.4 minutes) versus the C1-C2 group (164.0 minutes). CONCLUSIONS: This study provides a snapshot of the risk profiles of C1-C2 and O-C fusion for C2 fracture, demonstrating a statistically higher risk of reoperation in O-C fusion versus C1-C2 fusion. Future randomized trials are needed to identify the preferred technique to improve patient outcomes.

Magnetic Drug Targeting: A Novel Treatment for Intramedullary Spinal Cord Tumors.

Most applications of nanotechnology in cancer have focused on systemic delivery of cytotoxic drugs. Systemic delivery relies on accumulation of nanoparticles in a target tissue through enhanced permeability of leaky vasculature and retention effect of poor lymphatic drainage to increase the therapeutic index. Systemic delivery is limited, however, by toxicity and difficulty crossing natural obstructions, like the blood spine barrier. Magnetic drug targeting (MDT) is a new technique to reach tumors of the central nervous system. Here, we describe a novel therapeutic approach for high-grade intramedullary spinal cord tumors using magnetic nanoparticles (MNP). Using biocompatible compounds to form a superparamagnetic carrier and magnetism as a physical stimulus, MNP-conjugated with doxorubicin were successfully localized to a xenografted tumor in a rat model. This study demonstrates proof-of-concept that MDT may provide a novel technique for effective, concentrated delivery of chemotherapeutic agents to intramedullary spinal cord tumors without the toxicity of systemic administration.

Magnetic kyphoplasty: A novel drug delivery system for the spinal column.

Vertebral compression fractures (VCFs) caused by metastatic malignancies or osteoporosis are devastating injuries with debilitating outcomes for patients. Minimally invasive kyphoplasty is a common procedure used for symptomatic amelioration. However, it fails in treating the underlying etiologies of VCFs. Use of systemic therapy is limited due to low perfusion to the spinal column and systemic toxicity. Localized delivery of drugs to the vertebral column can provide a promising alternative approach. A porcine kyphoplasty model was developed to study the magnetically guided drug delivery of systemically injected magnetic nanoparticles (MNPs). Jamshidi cannulated pedicle needles were placed into the thoracic vertebra and, following inflatable bone tamp expansion, magnetic bone cement was injected to the vertebral body. Histological analysis was performed after intravenous injection of MNPs. Qualitative analysis of harvested tissues revealed successful placement of magnetic cement into the vertebral body. Further quantitative analysis of histological sections of several vertebral bodies demonstrated enhanced accumulation of MNPs to regions that had magnetic cement injected during kyphoplasty compared to those that did not. By modifying the kyphoplasty bone cement to include magnets, thereby providing a guidance stimulus and a localizer, we were successfully able to guide intravenously injected magnetic nanoparticles to the thoracic vertebra. These results demonstrate an in-vivo proof of concept of a novel drug delivery strategy that has the potential to treat the underlying causes of VCFs, in addition to providing symptomatic support.