ABSTRACT
BACKGROUND: Clinical prediction models (CPM), such as the SCOAP-CERTAIN tool, can be utilized to enhance decision-making for lumbar spinal fusion surgery by providing quantitative estimates of outcomes, aiding surgeons in assessing potential benefits and risks for each individual patient. External validation is crucial in CPM to assess generalizability beyond the initial dataset. This ensures performance in diverse populations, reliability and real-world applicability of the results. Therefore, we externally validated the tool for predictability of improvement in oswestry disability index (ODI), back and leg pain (BP, LP). METHODS: Prospective and retrospective data from multicenter registry was obtained. As outcome measure minimum clinically important change was chosen for ODI with ≥ 15-point and ≥ 2-point reduction for numeric rating scales (NRS) for BP and LP 12 months after lumbar fusion for degenerative disease. We externally validate this tool by calculating discrimination and calibration metrics such as intercept, slope, Brier Score, expected/observed ratio, Hosmer-Lemeshow (HL), AUC, sensitivity and specificity. RESULTS: We included 1115 patients, average age 60.8 ± 12.5 years. For 12-month ODI, area-under-the-curve (AUC) was 0.70, the calibration intercept and slope were 1.01 and 0.84, respectively. For NRS BP, AUC was 0.72, with calibration intercept of 0.97 and slope of 0.87. For NRS LP, AUC was 0.70, with calibration intercept of 0.04 and slope of 0.72. Sensitivity ranged from 0.63 to 0.96, while specificity ranged from 0.15 to 0.68. Lack of fit was found for all three models based on HL testing. CONCLUSIONS: Utilizing data from a multinational registry, we externally validate the SCOAP-CERTAIN prediction tool. The model demonstrated fair discrimination and calibration of predicted probabilities, necessitating caution in applying it in clinical practice. We suggest that future CPMs focus on predicting longer-term prognosis for this patient population, emphasizing the significance of robust calibration and thorough reporting.
ABSTRACT
Yellow catfish Tachysurus fulvidraco is an important commercial fish species in South Korea. However, due to their current declines in its distribution area and population size, it is being released from hatchery populations into wild populations. Hatchery populations also produced from wild broodstocks are used for its captive breeding. We reported 15 new microsatellite DNA markers of T. fulvidraco to identify the genetic diversity and structure of its hatchery and wild populations, providing baseline data for useful resource development strategies. The observed heterozygosity of the hatchery populations ranged from 0.816 to 0.873, and that of the wild populations ranged from 0.771 to 0.840. Their inbreeding coefficient ranged from -0.078 to 0.024. All populations experienced a bottleneck (p < 0.05), with effective population sizes ranging from 21 to infinity. Their gene structure was divided into two groups with STRUCTURE results of K = 2. It was confirmed that each hatchery population originated from a different wild population. This study provides genetic information necessary for the future development and conservation of fishery resources for T. fulvidraco.
Subject(s)
Catfishes , Animals , Catfishes/genetics , Republic of Korea , Population Density , Fisheries , Microsatellite Repeats/geneticsABSTRACT
Bone morphogenetic protein-2 (BMP-2) is used in the treatment of degenerative spinal disease and vertebral fractures, spine fusion, dental surgery, and facial surgery. However, high doses are associated with side effects such as inflammation and osteophytes. In this study, we performed spinal fusion surgery on mini-pigs using BMP-2 and a HA/ß-TCP hydrogel carrier, and evaluated the degree of fusion and osteophyte growth according to time and dosage. Increasing the dose of BMP-2 led to a significantly higher fusion rate than was observed in the control group, and there was no significant difference between the 8-week and 16-week samples. We also found that the HA + ß-TCP hydrogel combination helped maintain the rate of BMP-2 release. In conclusion, the BMP-2-loaded HA/ß-TCP hydrogel carrier used in this study overcame the drawback of potentially causing side effects when used at high concentrations by enabling the sustained release of BMP-2. This method is also highly efficient, since it provides mineral matter to accelerate the fusion rate of the spine and improve bone quality.
Subject(s)
Bone Morphogenetic Protein 2 , Recombinant Proteins , Spinal Fusion , Animals , Humans , Bone Morphogenetic Protein 2/therapeutic use , Hydrogels , Recombinant Proteins/therapeutic use , Spinal Fusion/methods , Swine , Swine, Miniature , Transforming Growth Factor beta/pharmacologyABSTRACT
This study examined the abundance of microplastics (MPs) in 106 fish from 22 species inhabiting three sites of the Han River, South Korea. In total, 1753 MPs from 106 fish samples were identified with an average abundance of 15.60 ± 13.45 MPs per individual fish (MPs indiv-1) in the North Han River, 16.35 ± 12.32 MPs indiv-1 in the South Han River, and 20.14 ± 10.01 MPs indiv-1 in downstream of the Han River, indicating that the fish in the downstream of the Han River was the most contaminated by MPs. The dominant size of MPs detected in fish ranged between 0.1 and 0.2 mm, and the most common polymer types found in fish were polypropylene (PP) (≥40%) and polyethylene (PE) (≥23%), followed by polytetrafluoroethylene (PTFE) (≥16%) at all sampling locations. A significant correlation was observed between the log-transformed number of MPs with log-transformed fish length (p < 0.01) and with log-transformed fish weight (p < 0.01). The Kruskal-Wallis test disclosed a significant difference in the number of MPs among the feeding habits (p < 0.01), indicating that omnivorous and insectivorous fish contained more MPs than carnivorous and herbivorous fish. In addition, fish habitat result showed that pelagic fish contained a higher level of MPs than demersal fish, but no significant differences in the number of MPs among fish habitats were observed (p > 0.05).
Subject(s)
Microplastics , Water Pollutants, Chemical , Animals , Environmental Monitoring , Plastics , Republic of Korea , Water Pollutants, Chemical/analysisABSTRACT
BACKGROUND: Indications and outcomes in lumbar spinal fusion for degenerative disease are notoriously heterogenous. Selected subsets of patients show remarkable benefit. However, their objective identification is often difficult. Decision-making may be improved with reliable prediction of long-term outcomes for each individual patient, improving patient selection and avoiding ineffective procedures. METHODS: Clinical prediction models for long-term functional impairment [Oswestry Disability Index (ODI) or Core Outcome Measures Index (COMI)], back pain, and leg pain after lumbar fusion for degenerative disease were developed. Achievement of the minimum clinically important difference at 12 months postoperatively was defined as a reduction from baseline of at least 15 points for ODI, 2.2 points for COMI, or 2 points for pain severity. RESULTS: Models were developed and integrated into a web-app ( https://neurosurgery.shinyapps.io/fuseml/ ) based on a multinational cohort [N = 817; 42.7% male; mean (SD) age: 61.19 (12.36) years]. At external validation [N = 298; 35.6% male; mean (SD) age: 59.73 (12.64) years], areas under the curves for functional impairment [0.67, 95% confidence interval (CI): 0.59-0.74], back pain (0.72, 95%CI: 0.64-0.79), and leg pain (0.64, 95%CI: 0.54-0.73) demonstrated moderate ability to identify patients who are likely to benefit from surgery. Models demonstrated fair calibration of the predicted probabilities. CONCLUSIONS: Outcomes after lumbar spinal fusion for degenerative disease remain difficult to predict. Although assistive clinical prediction models can help in quantifying potential benefits of surgery and the externally validated FUSE-ML tool may aid in individualized risk-benefit estimation, truly impacting clinical practice in the era of "personalized medicine" necessitates more robust tools in this patient population.
Subject(s)
Spinal Fusion , Back Pain/diagnosis , Back Pain/etiology , Back Pain/surgery , Female , Humans , Lumbar Vertebrae/surgery , Male , Middle Aged , Models, Statistical , Prognosis , Spinal Fusion/methods , Treatment OutcomeABSTRACT
No medication has been approved for secondary injuries after traumatic brain injury (TBI). While free radicals are considered a major mediator of secondary injury, conventional antioxidants only have modest clinical efficacy. Here, we synthesized CX201 consisting of core cerium oxide nanoparticles coated with 6-aminocaproic acid and polyvinylpyrrolidone in aqueous phase. CX201 with 3.49 ± 1.11 nm of core and 6.49 ± 0.56 nm of hydrodynamic diameter showed multi-enzymatic antioxidant function. Owing to its excellent physiological stability and cell viability, CX201 had a neuroprotective effect in vitro. In a TBI animal model, an investigator-blinded randomized experiment showed a single intravenously injected CX201 significantly improved functional recovery compared to the control. CX201 reduced lipid peroxidation and inflammatory cell recruitment at the damaged brain. These suggest ultrasmall CX201 can efficiently reduce secondary brain injuries after TBI. Given the absence of current therapies, CX201 may be proposed as a novel therapeutic strategy for TBI.
Subject(s)
Brain Injuries, Traumatic , Brain Injuries , Cerium , Nanoparticles , Neuroprotective Agents , Aminocaproic Acid/therapeutic use , Animals , Antioxidants/pharmacology , Antioxidants/therapeutic use , Brain Injuries, Traumatic/drug therapy , Cerium/therapeutic use , Free Radicals/therapeutic use , Neuroprotective Agents/therapeutic use , Polymers/therapeutic use , PovidoneABSTRACT
Artificial intelligence is poised to influence various aspects of patient care, and neurosurgery is one of the most uprising fields where machine learning is being applied to provide surgeons with greater insight about the pathophysiology and prognosis of neurological conditions. This chapter provides a guide for clinicians on relevant aspects of machine learning and reviews selected application of these methods in intramedullary spinal cord tumors. The potential areas of application of machine learning extend far beyond the analyses of clinical data to include several areas of artificial intelligence, such as genomics and computer vision. Integration of various sources of data and application of advanced analytical approaches could improve risk assessment for intramedullary tumors.
Subject(s)
Spinal Cord Neoplasms , Spinal Neoplasms , Artificial Intelligence , Humans , Machine Learning , Neurosurgical Procedures , Spinal Cord Neoplasms/surgeryABSTRACT
BACKGROUND: The use of social media to communicate and disseminate knowledge has increased exponentially, especially in the field of neurosurgery. 'Neurosurgery cocktail' (NC) was developed by a group of young neurosurgeons as a means of sharing didactic materials and clinical experiences via social media. It connects 35.000 neurosurgeons worldwide on multiple platforms, primarily Facebook and Twitter. Given the rising utilization of social media in neurosurgery, the popularity of NC has also increased since its inception. In this study, the authors surveyed the social media analytics of NC for both Facebook and Twitter. Besides, we reviewed the literature on the use of social media in neurosurgery. METHODS: Facebook and Twitter metrics were extracted through each respective platform's analytics tools from December 2020 (earliest available date for data analysis) through January 2021. A literature search was conducted using PubMed (MEDLINE) and Scopus databases. RESULTS: On Facebook, as of January 2021, the group had a total of 25.590 members (87.6% male), most commonly (29%) between 35 and 44 years of age with over 100 countries were represented. As of January 2021, they had amassed 6457 followers on Twitter. During the last 28 d between December 2020 and January 2021, the account published 65 tweets that garnered a total of 196,900 impressions. Twelve articles were identified in our literature review on the use of social media within the neurosurgical community. CONCLUSIONS: NC is one of the most widely utilized neurosurgical social media resources available. Sharing knowledge has been broadened thanks to the recent social media evolution, and NC has become a leading player in disseminating neurosurgical knowledge.
Subject(s)
Communication , Neurosurgery , Social Media , Biomedical Research , Female , Humans , Information Dissemination , Male , NeurosurgeonsABSTRACT
OBJECTIVE: Nonmedical use of prescription stimulants (NPS) continues to be a concern on college campuses. Previous research demonstrates a strong link between NPS and use of other substances, particularly alcohol and marijuana among college students. Simultaneous use of NPS with other substances has become an increasing concern. Given the high rates of NPS and simultaneous NPS with other substances, research examining substance use patterns and motives among students is warranted. Method: This study evaluated group differences in alcohol and marijuana use patterns, consequences, and motives among college students: a) with no NPS history (No NPS); b) engaged in NPS with no simultaneous use (Non-Sim NPS); and c) engaged in simultaneous NPS with alcohol and/or marijuana (Sim NPS). Participants included 1,108 students from three universities who reported past-year marijuana and alcohol use. Results: Overall, 32.8% reported lifetime NPS with 12.5% indicating NPS in the previous 3 months, of which 51.1% reported simultaneous NPS with alcohol and 40.2% with marijuana. Significant group differences for all drinking and marijuana outcomes were found, with heaviest rates among the Sim NPS group, followed by the Non-Sim NPS group, and the No NPS group. The Sim NPS group reported greater motives for using marijuana to alter the effects of other substances. Conclusions: College students engaged in simultaneous NPS with alcohol and marijuana are a high-risk group that should be the focus of prevention and intervention programs in the campus setting.
Subject(s)
Cannabis , Central Nervous System Stimulants , Alcohol Drinking/epidemiology , Humans , Motivation , Prescriptions , UniversitiesABSTRACT
Stem cell therapy is one of the most promising candidate treatments for spinal cord injury. Research has shown optimistic results for this therapy, but clinical limitations remain, including poor viability, engraftment, and differentiation. Here, we isolated novel peripheral nerve-derived stem cells (PNSCs) from adult peripheral nerves with similar characteristics to neural-crest stem cells. These PNSCs expressed neural-crest specific markers and showed multilineage differentiation potential into Schwann cells, neuroglia, neurons, and mesodermal cells. In addition, PNSCs showed therapeutic potential by releasing the neurotrophic factors, including glial cell-line-derived neurotrophic factor, insulin-like growth factor, nerve growth factor, and neurotrophin-3. PNSC abilities were also enhanced by their development into spheroids which secreted neurotrophic factors several times more than non-spheroid PNSCs and expressed several types of extra cellular matrix. These features suggest that the potential for these PNSC spheroids can overcome their limitations. In an animal spinal cord injury (SCI) model, these PNSC spheroids induced functional recovery and neuronal regeneration. These PNSC spheroids also reduced the neuropathic pain which accompanies SCI after remyelination. These PNSC spheroids may represent a new therapeutic approach for patients suffering from SCI.
Subject(s)
Spheroids, Cellular/transplantation , Spinal Cord Injuries/therapy , Spinal Cord Regeneration , Stem Cell Transplantation/methods , Animals , Cells, Cultured , Neural Stem Cells/cytology , Neurogenesis , Peripheral Nerves/cytology , Rats , Rats, Sprague-Dawley , Schwann Cells/cytology , Spheroids, Cellular/cytologyABSTRACT
This study aimed to comparatively assess cervical sagittal alignment, progression of ossification of the posterior longitudinal ligament (OPLL), and health-related quality of life (HRQOL) outcomes between patients who underwent cervical laminoplasty (CL) and those who underwent cervical laminectomy with fusion (LF) for cervical OPLL at more than three levels. We retrospectively evaluated consecutive 91 patients with cervical OPLL undergoing CL (n = 49) or LF (n = 42) who were followed up for at least 24 months (mean 38.6 months). We analyzed radiological measurements (C2-7 sagittal vertical axis [C2-7 SVA], C0-2 angle, C2-7 lordotic angle, T1 slope, and range of motion [ROM]), OPLL thickness, and clinical outcomes (visual analog scale [VAS], neck disability index [NDI], Short Form-36, and Japanese Orthopaedic Association [JOA] scores). Compared with preoperative levels, postoperative C2-7 SVA increased significantly increased in the LF (15.05 mm) and CL (7.86 mm) groups (P = 0.0021). Loss of cervical lordosis and ROM was significantly larger in the cervical LF group (P = 0.0296, P = 0.0004). Improvements in HRQOL, JOA recovery ratio, and VAS were similar between both groups, while NDI improved more significantly in the CL group (P = 0.0425). The postoperative neck VAS correlated positively with the change (Δ) of C2-7 SVA (P = 0.0174) and negatively with the change (Δ) of C2-7 lordotic angle (P = 0.0354). Progression of OPLL thickness in the LF (0.31 ± 0.37 mm) was significantly smaller than in the CL group (1.09 ± 0.64 mm) (P < 0.0001). CL was superior to LF in preserving cervical ROM, preoperative cervical lordosis, and minimizing neck disability. The stabilization obtained by adding instrumented fusion could suppress the progression of OPLL thickness.
Subject(s)
Cervical Vertebrae/diagnostic imaging , Cervical Vertebrae/surgery , Laminectomy/methods , Laminoplasty/methods , Neurosurgical Procedures/methods , Ossification of Posterior Longitudinal Ligament/diagnostic imaging , Ossification of Posterior Longitudinal Ligament/surgery , Spinal Cord Diseases/surgery , Spinal Fusion/methods , Adult , Aged , Female , Humans , Laminectomy/adverse effects , Laminoplasty/adverse effects , Lordosis/diagnostic imaging , Male , Middle Aged , Neck Pain/diagnosis , Neck Pain/surgery , Pain Measurement , Retrospective Studies , Spinal Cord Diseases/diagnostic imaging , Treatment OutcomeABSTRACT
Recently, a bioactive glass ceramic (BGC) has been developed for use as intervertebral cages for anterior cervical discectomy and fusion (ACDF). However, the effectiveness and safety of BGC cages remain to be evaluated. We completed a retrospective comparison of the radiological and clinical outcomes of 36 patients (52 levels) who underwent ACDF with a BGC cage and 35 patients (54 levels) using allograft bone. The following variables were compared between the two groups: the visual analog (VAS) neck and arm pain score and the neck disability index (NDI), measured before surgery and 1 year after; the change in Cobb's angle, between the C2 and C7 vertebrae, the global sagittal angle, and disc height compared from before surgery to 1 year after; and the rate of spinal fusion and cage subsidence at 1 and 2 years after surgery. The VAS and NDI scores were not different between the two groups. Similarly, the spinal fusion rate was not different between the BGC and allograft bone group at 1 year (73% and 87%, respectively; p = 0.07) and 2 years (94% and 91%, respectively; p = 0.54) after surgery. However, the rate of cage subsidence was higher in the allograft bone (43%) than the BGC (19%) group (p = 0.03), as was the rate of instrument-related failure (p = 0.028), with a specifically higher incidence of implant fracture or failure in the allograft bone group (p = 0.025). Overall, our findings indicate that BGC cages provide a feasible and safe alternative to allograft bone for ACDF.
Subject(s)
Bone Plates , Bone Transplantation/methods , Ceramics , Cervical Vertebrae/surgery , Diskectomy/methods , Spinal Fusion/methods , Adult , Aged , Bone Transplantation/adverse effects , Cervical Vertebrae/diagnostic imaging , Disability Evaluation , Female , Humans , Male , Middle Aged , Neck Pain/surgery , Pain Measurement , Retrospective Studies , Treatment OutcomeABSTRACT
BACKGROUND: Cortical bone trajectory (CBT) technique has a theoretical benefit for patients with osteoporosis, and leads to reduce screw loosening. However, there are no reports of complications and outcomes of CBT. METHODS: Consecutive patients (n = 34) with degenerative lumbar spines who underwent PLIF between December 2013 and December 2015 and were followed up for at least six months were analyzed in this study. Bone mineral density, fusion rate, cage subsidence, C-arm, screw loosening, screw violation, trajectory angle of the screw, Hounsfield unit and extent of facetectomy were examined. Outcome assessments were obtained in all patients preoperatively and postoperatively. RESULTS: There were 34 patients and 73 screw levels. After the surgery with cortical screw fixation and PLIF, patients had good clinical outcomes. However, ten of the 34 patients had problems with cortical screw fixation such as screw loosening or cage migration. In the patients with screw loosening, two underwent revision surgery due to cage migration, and one had an infection. Incorrect trajectory angles of the screw were significantly related with screw loosening. Low BMD and HU at screw fixation level were associated with screw loosening. Cage subsidence was statistically related with clinical outcomes. CONCLUSION: The cortical screw offers improved clinical outcomes since it requires minimal muscle dissection. However, we have experienced some early complications using this technique. To reduce complications such as screw loosening, an exact insertion angle of the screw and osteoporotic bone quality should be considered carefully.
ABSTRACT
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease caused by the death of motor neurons in the spinal cord and brainstem. ALS has a diverse genetic origin; at least 20 genes have been shown to be related to ALS. Most familial and sporadic cases of ALS are caused by variants of the SOD1, C9orf72, FUS, and TARDBP genes. Genome editing using clustered regularly interspaced short palindromic repeats/CRISPR-associated system 9 (CRISPR/Cas9) can provide insights into the underlying genetics and pathophysiology of ALS. By correcting common mutations associated with ALS in animal models and patient-derived induced pluripotent stem cells (iPSCs), CRISPR/Cas9 has been used to verify the effects of ALS-associated mutations and observe phenotype differences between patient-derived and gene-corrected iPSCs. This technology has also been used to create mutations to investigate the pathophysiology of ALS. Here, we review recent studies that have used CRISPR/Cas9 to understand the genetic underpinnings of ALS.
Subject(s)
Amyotrophic Lateral Sclerosis/therapy , CRISPR-Cas Systems , Targeted Gene Repair/methods , Amyotrophic Lateral Sclerosis/genetics , Animals , C9orf72 Protein/genetics , DNA-Binding Proteins/genetics , Humans , RNA-Binding Protein FUS/genetics , Superoxide Dismutase-1/geneticsABSTRACT
All-solid-state batteries (ASSBs) have lately received enormous attention for electric vehicle applications because of their exceptional stability by engaging all-solidified cell components. However, there are many formidable hurdles such as low ionic conductivity, interface instability, and difficulty in the manufacturing process, for its practical use. Recently, carbon, one of the representative conducting agents, turns out to largely participate in side reactions with the solid electrolyte, which finally leads to the formation of insulating side products at the interface. Although the battery community mentioned that parasitic reactions are presumably attributed to carbon itself or the generation of electronic conducting paths lowering the kinetic barrier for reactions, the underlying origin for such reactions as well as appropriate solutions have not been provided yet. In this study, for the first time, it is verified that the functional group on carbon is an origin for causing negative effects on interfacial stability and a graphitized hollow nanocarbon as a promising solution for improving-electrochemical performance is introduced. This work offers an invaluable lesson that a relatively minor part, such as a conducting agent, in ASSBs sometimes gives more positive impact on improving electrochemical performance than huge efforts for resolving other parts.
ABSTRACT
PURPOSE: Spinal cord gliomas are rare, and there is no consensus on the optimal radiotherapy (RT) regimen. Herein, we investigated therapeutic outcomes in spinal cord gliomas to obtain clues for the optimal RT regimen. METHODS: We assessed 45 patients who received RT for primary spinal cord non-ependymoma gliomas between 2005 and 2017: 37 (82%) received postoperative RT, 6 (13%) underwent definitive RT without surgery, and 2 (5%) received salvage RT for recurrent tumors. Craniospinal irradiation (CSI; median, 40â¯Gy) was administered in 4 patients with seeding at diagnosis; all other patients received local RT only (median, 50.4â¯Gy). RESULTS: In all 23 failures occurred (20 in patients without initial seeding +3 in patients with initial seeding and CSI; median follow-up, 33 months). The 2year overall survival and progression-free survival rates were 74 and 54%, respectively. Overall, 13 (32%) new seeding events outside the local RT field developed either first or subsequently. Tumor grade was significantly associated with survival endpoints (pâ¯= 0.009, 0.028) and overall seeding rates (pâ¯= 0.042). In grade II tumors, seeding developed in 23%, with a dismal prognosis (median, 10 months after RT). In grade III tumors, seeding developed in 45% with diverse prognosis. In grade IV tumors, seeding developed in 45%. The survival of patients with newly developed seeding was significantly worse than the others (2-year 50%, pâ¯< 0.001). CONCLUSION: To encompass a considerable rate of progressive disease seeding, aggressive treatment such as pre-emptive application of CSI needs to be considered for high-grade spinal cord gliomas with adverse features. Prophylactic CSI could be an option for survival prolongation and requires prospective validation.
Subject(s)
Craniospinal Irradiation , Glioma/radiotherapy , Spinal Cord Neoplasms/radiotherapy , Treatment Outcome , Adolescent , Adult , Child , Child, Preschool , Female , Glioma/mortality , Glioma/pathology , Glioma/surgery , Humans , Male , Meningeal Carcinomatosis/mortality , Meningeal Carcinomatosis/pathology , Meningeal Carcinomatosis/radiotherapy , Meningeal Carcinomatosis/surgery , Middle Aged , Neoplasm Grading , Neoplasm Recurrence, Local/mortality , Neoplasm Recurrence, Local/pathology , Neoplasm Recurrence, Local/radiotherapy , Neoplasm Recurrence, Local/surgery , Neoplasm Seeding , Prognosis , Radiotherapy, Adjuvant , Salvage Therapy , Spinal Cord Neoplasms/mortality , Spinal Cord Neoplasms/pathology , Spinal Cord Neoplasms/surgery , Survival RateABSTRACT
Silica aerogels possess low thermal conductivity but have a brittle nature, while their polymers tend to exhibit enhanced mechanical properties. In this study, we introduce a new approach to overcoming this brittle property of silica aerogels. Polypropylene/silica aerogel composites were prepared by thermally induced phase separation followed by a supercritical CO2 drying method. Silica aerogel was formed onto a polypropylene scaffold using a two-step sol-gel process with methyltrimethoxysilane as the silica precursor. Enhancement of the mechanical properties of the polypropylene/silica aerogel composite compared with a pristine methyltrimethoxysilane-based silica aerogel was observed. The effects of the latter on the microstructure and physical properties of the polypropylene/silica aerogel (hereafter referred to as the polymer matrix aerogel) composite were investigated. Compared with the polypropylene monolith, the polymer matrix aerogel composite demonstrated enhanced surface-chemical and microporous-structural properties such as higher hydrophobicity (135°), pore volume (0.18 cm³/g), average pore diameter (12.55 nm), and specific surface area (57.2 m²/g). This novel approach of incorporating methyltrimethoxysilane-based silica aerogel onto polypropylene when synthesizing the polymer matrix aerogel composite shows great potential as a durable superhydrophobic and corrosion resistant thermal insulating material.
ABSTRACT
To compare short-term and long-term surgical outcome patterns between anterior cervical corpectomy and fusion (ACCF) and laminoplasty (LP) in patients diagnosed with cervical ossification of the posterior longitudinal ligament (OPLL) and identify factors affecting surgical outcomes based on follow-up duration. During short-term follow-up period, surgical outcomes between ACCF and LP were similar. However, there were several reports that long-term surgical outcomes were superior in the ACCF compared with LP. Surgical outcomes between ACCF and LP according to follow-up period changed. This study enrolled 70 patients who underwent ACCF and 63 patients who underwent LP between 2005 and 2012. Patterns of surgical outcomes were analyzed in accordance with surgical procedures. Furthermore, these patients were divided into two subgroups in respect of follow-up duration: the short-term group (less than 48 months) and the long-term group (more than 48 months) group. Occupying ratio, type of OPLL, shape of ossified lesion, cervical sagittal alignment, grade of signal intensity on MRI, and Japanese Orthopedic Association (JOA) score were examined. Surgical outcomes of ACCF went into reverse at 48-month follow-up period. In the short-term group, JOA recovery rate had no difference between ACCF and LP. In the long-term group, the ACCF recovery rate (78.5 ± 31.0) was significantly higher than the LP recovery rate (48.4 ± 54.9) (P = 0.008). In the short-term group, old age (p = 0.011), hill shape (p = 0.013), and high grade of MRI signal intensity (p = 0.040) had negative effects on recovery rate. On the other hand, in the long-term group, LP (p = 0.021) and a high grade of MR signal intensity (p = 0.017) independently and negatively affected recovery rate. Long-term surgical outcomes of ACCF became better than those of LP at more than 48-month follow-up period. High-grade MRI signal changes and the LP surgical procedure were independent negative factors for long-term surgical outcomes in patients with OPLL. Direct decompression of the spinal cord with ACCF provides better long-term stable neurologic outcomes than LP.
Subject(s)
Cervical Vertebrae , Decompression, Surgical , Laminoplasty , Ossification of Posterior Longitudinal Ligament/surgery , Spinal Fusion , Adult , Aged , Female , Follow-Up Studies , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Recovery of Function , Time Factors , Treatment OutcomeABSTRACT
PURPOSE: To determine the classification scheme for osteoarthritis severity grading that most closely correlates with postoperative clinical outcomes and to identify the positive and negative prognostic factors for medial open-wedge high-tibial osteotomy (OWHTO). METHODS: Seventy-nine consecutive patients with primary varus osteoarthritis were treated using OWHTO. Arthritic grading was determined by arthroscopic assessment according to the modified Outerbridge classification and by radiographic classification according to the Kellgren-Lawrence (KL) grading scale on standing anteroposterior (AP) and 45° posteroanterior (PA) flexion weight-bearing radiography. Clinical outcome was assessed using the Oxford Knee Score (OKS), which was evaluated both preoperatively and at the postoperative 2-year follow-up after OWHTO. Multivariate regression analyses were used to explore and quantify the influence of baseline patient demographics, variables related to arthroscopic and radiological grades of arthritis, as well as postoperative alignment changes on the OKS. RESULTS: At the 2-year follow-up, the mean OKS had improved from 20 ± 4 to 39 ± 5 points (p < 0.001). The average mechanical femorotibial and mechanical medial proximal tibial angle (MPTA) changed from 6.9° ± 3.4° to valgus 2.7° ± 2.8° and from 85.6° ± 2.4° to 92.9° ± 3.7° (all p < 0.001). The osteoarthritis severity grade based on the KL scale was 2.4 ± 0.9 on standing AP radiography, 2.8 ± 0.9 on 45° PA flexion weight-bearing radiography (p = 0.003), and 3.4 ± 0.7 according to the modified Outerbridge classification. In the multivariate analyses, the KL grade on 45° PA flexion weight-bearing radiography (p = 0.01) and postoperative MPTA (p = 0.01) showed significant negative correlations with postoperative OKS at the 2-year follow-up. CONCLUSION: The KL grading system based on 45° PA flexion weight-bearing radiography showed the strongest significant negative correlation with postoperative OKS after the OWHTO procedure using three different common OA classification schemes, which should be considered to determine the surgical indication of HTO. The KL grading system based on 45° PA flexion weight-bearing radiography showed the strongest correlation with high-tibial osteotomy-surgical indications and the counselling of patients with advanced osteoarthritis. LEVEL OF EVIDENCE: IV.
Subject(s)
Osteoarthritis, Knee/diagnosis , Osteotomy/methods , Radiography/methods , Tibia/surgery , Adult , Aged , Arthroscopy , Female , Humans , Male , Middle Aged , Osteoarthritis, Knee/physiopathology , Osteoarthritis, Knee/surgery , Postoperative Period , Severity of Illness Index , Tibia/diagnostic imaging , Weight-Bearing/physiologyABSTRACT
BACKGROUND: Paranasal augmentation has commonly been performed utilizing alloplastic materials such as silicone or porous polyethylene. However, there are problems such as bone absorption, implant migration, and infection risk attributable to intraoral approaches. OBJECTIVES: The authors attempted anterior positioning of the alar crease junction as an adjunct method of rhinoplasty. The authors aimed to determine the long-term results of the intranasal approach for placement of multi-folded expanded polytetrafluorethylene (ePTFE). METHODS: A retrospective review was conducted of patients who underwent intranasal surgical approach for paranasal augmentation employing multi-folded ePTFE implants in 19 septorhinoplasties who were followed-up for 3 to 10 years. Patient charts were reviewed for demographic information, concomitant operations, and complications. Preoperative and postoperative photographs were utilized to evaluate operative outcomes. The photographs were reformatted to 2-dimensional images employing standard photographic methods. RESULTS: Of the 19 patients treated, 17 were female and 2 were male; ages ranged from 18 to 58 years. All patients reported improvement in their lateral profiles and were pleased at follow-up. There were no major complications, no nerve or vascular supply compromise, and no cases of implant malposition. The average increase in soft tissue outline near the alar crease junction was more than 3.2 mm (P < 0.001), but the alar base did not became wider. CONCLUSIONS: Paranasal augmentation with multi-folded ePTFE is a simple, safe, and effective method that can readily improve the lateral profile. In particular, the intranasal approach combined with rhinoplasty can synergistically improve outcomes and lead to greater patient satisfaction.