1,720,971 research outputs found
A new hydrate-based recovery process for removing chlorinated hydrocarbons from aqueous solutions
No full textThe main objective of this study was to check the feasibility of the newly proposed hydrate-based chlorinated hydrocarbon (CHC) recovery process for removing chlorinated hydrocarbons from aqueous solutions. Two key process variables of hydrate phase equilibria and formation kinetics were closely examined to develop the overall conceptual design of this technology. First, the ternary four-phase (H-L-W-L-CHC-V) hydrate equilibria of aqueous solutions containing methylene chloride (CH2Cl2), carbon tetrachloride (CCl4) 1,2-dichloroethane (CH2ClCH2Cl), 1,1,1-trichloroethane (CH3CCl3), and 1,1-dichloroethylene (CH2 = CCl2) were measured at various temperature and pressure conditions using three different types of help gases (CO2, N-2, CH4). The help gas + water + chlorinated hydrocarbons systems greatly reduced the hydrate-forming pressure, which confirmed the mixed hydrates with chlorinated hydrocarbons more stabilized than the simple hydrates consisting of a help gas and water. The degree of stabilization was found to follow the order of 1,2-dichloroethane < 1,1-dichloroethylene < methylene chloride <less than> 1,1,1-trichloroethane < carbon tetrachloride. For the N-2 + water + carbon tetrachloride system, the formation pressure reduction as much as 96% was observed at 279.35 K. Second, the formation kinetic experiments of carbon dioxide hydrates containing chlorinated hydrocarbons were conducted under isothermal and isobaric conditions. The consumption rate of carbon dioxide gas became fast at the early time of the growth period, gradually decreased, and finally went to the complete hydration. The proposed hydrate-based recovery process appears to be very simple from the operational point of view because no special facilities requiring sensitive and complex function are needed. Another advantage is that this process only requires carbon dioxide as a hydrate former. Best of all, this process can he applied to separation and recovery of other organic pollutants dissolved in aqueous solutions without changing the basic concept.This research was performed for the Greenhouse Gas
Research Center, one of the Critical Technology-21 Programs,funded by the Ministry of Science and Technology of Korea
and also partially supported by the Brain Korea 21 Project
AURA: Arthroscopic Ultrasound-Assisted All-Inside Repair of Lateral Ankle Ligament
No full textArthroscopic ultrasound-assisted all-inside repair of lateral ankle ligament is a minimally invasive procedure that addresses chronic lateral ankle instability. This technique uses ultrasound guidance to facilitate accurate anchor placement and precise suture positioning, potentially reducing the risk of iatrogenic injury and improving anatomical repair. The combination of arthroscopy and ultrasound is expected to be more accurate and safer. In addition, it enables simultaneous treatment of intra-articular pathologies. This study describes the surgical method and discusses its potential advantages in clinical practice
Nail-preserving excision of glomus tumor in the second toe: Case report and literature review
Full text linkIntroduction: This case report describes the diagnosis of a glomus tumor in the second toe of a 38-year-old female, followed by surgical treatment utilizing a transungual approach to preserve the nail. This study highlights the diagnostic challenges and surgical strategies to treat such tumors while preserving nail integrity. Patient concerns: Pain occurred once a week, but over time, it increased, and just before seeking medical attention, she experienced pain more than 5 times a day. The pain worsened when cold water touched her toe. Diagnosis: We observed a slight hump indicating nail plate deformity, and the patient exhibited severe pinpoint tenderness (positive Love test) in the affected area. Color duplex ultrasound was performed for further investigation, revealing a hypervascular hypoechoic nodule measuring 0.5 cm in size at the nail bed of the right second toe. Intervention: The surgery was performed under digital nerve block anesthesia using a modified transungual nail-preserving approach for the excision of the glomus tumor. Outcomes: The pain that was reported prior to the surgery has improved postoperatively, and the recovery has been uneventful without any other complication. Conclusion: This paper provides a comprehensive examination of a rare glomus tumor in the second toe, elucidating both diagnostic intricacies and treatment modalities. It emphasizes the dual necessity of achieving total tumor excision while also considering aesthetic outcomes. The insights presented herein are intended to serve as valuable guidance for clinicians confronted with similar clinical scenarios, underlining the delicate interplay between effective tumor management and the preservation of cosmetic integrity
Three-phase Equilibria Measurements and Structure Analysis of the Mixed Gas Hydrates in Bulk and Porous Media
No full textPseudoaneurysm-Induced Pain Following Ankle Arthroscopy: A Case Report and Literature Review
No full textBACKGROUND Arthroscopic surgery is esteemed for its arthroscopic lateral ligament repair to treating ankle ligament injuries, characterized by a low complication rate. Nevertheless, rare complications such as pseudoaneurysms require careful monitoring and a strategic approach to management during the postoperative follow-up period. This case report details a 42-year-old man with chronic instability in his left ankle. The aim of this paper is to present a case report and conduct a literature review on the rare complication of pseudoaneurysm following arthroscopic procedures. CASE REPORT A 42-year-old man with chronic instability in his left ankle was experiencing severe pain and limited motion following arthroscopic lateral ligament repair surgery. He was diagnosed with a pseudoaneurysm of the left anterior tibial artery and an intra-articular hematoma in the left ankle joint, indicated by MRI and Doppler ultrasound findings. Initial conservative management was followed by interventional procedures, including thrombin injection and balloon tamponade. After these interventions proved unsuccessful, surgical intervention for anterior tibial artery reconstruction and hematoma evacuation was performed. The surgical interventions resulted in the closure of the pseudoaneurysm and improvement in the patient's pain. CONCLUSIONS This case underscores the challenges involved in diagnosing and managing pseudoaneurysm and hematoma after ankle surgery, highlighting the necessity for thorough evaluation and a comprehensive treatment strategy
Analgesic effectiveness of continuous versus single-injection adductor canal block in addition to continuous popliteal sciatic nerve block for bimalleolar and trimalleolar ankle fracture surgery: Prospective randomized controlled trial
No full textBackground: The adductor canal block is a well-known procedure for controlling postoperative pain after medial malleolus fracture surgery. Continuous nerve block is a viable option for blocking pain for a longer period although the literature on this subject is scarce. Therefore, this study aimed to compare continuous adductor canal block (cACB) group to single-injection adductor canal block (sACB) group in those with bimalleolar or trimalleolar ankle fractures. The procedure was performed in addition to a continuous sciatic nerve block for postoperative pain relief and patient satisfaction. Methods: The study included 57 patients who had bimalleolar or trimalleolar ankle fractures and underwent open reduction and internal fixation between August 2016 and June 2018. Each patient received a continuous sciatic nerve block and was divided into two groups: those who received cACB and those who received sACB. Each postoperative pain was scored at 4, 8, 12, 24, 48, and 72 h after surgery. Additionally, the consumption of rescue medications and patient satisfaction were evaluated. Results: The two groups displayed no disparity in medial side ankle pain at 4 h and 8 h after surgery, but significantly higher pain in the sACB group at 12, 24, 48, and 72 h after surgery. However, there was no difference in the pain at the lateral side of ankle and consumption of rescue medication. In addition, the cACB group showed more satisfaction than the sACB group did. Conclusion: CACB is better than sACB in terms of postoperative pain control and patient satisfaction. cACB can be used for postoperative pain control in ankle fractures involving the medial malleolus. Level of evidence: Prospective Randomized Controlled Trial, Level 2
Learning curve of a novice foot and ankle surgeon in minimally invasive calcaneal fracture surgery via the sinus tarsi approach
No full textThe sinus tarsi approach has gained popularity for treating calcaneal fractures; however, limited research exists on the learning curve among novice orthopedic surgeons. This study aimed to assess the learning curve of junior orthopedic surgeons who have recently completed their fellowship, focusing on surgical efficiency and clinical outcomes. From October 2022 to January 2024, 50 cases of calcaneal fractures (12 Sanders type 2, 23 type 3, and 15 type 4) were treated using the sinus tarsi approach at a single Level 1 trauma center. The cumulative sum test was employed to identify case cutoffs for key surgical parameters. Pre- and postoperative X-rays and computed tomography (CT) were analyzed to measure the Bohler angle, hindfoot varus angle, and posterior facet step-off. Operative time, intraoperative C-arm fluoroscopy use, and postoperative complications, including infections and revision surgeries, were also evaluated. Significant postoperative improvements were observed: the Bohler angle increased from 12.2 degrees to 26.3 degrees , hindfoot varus angle decreased from 15.2 degrees to 5.3 degrees , and posterior facet step-off was reduced from 14.1 mm to 0.56 mm. Consistent correction of the Bohler angle and hindfoot varus angle was achieved after 21 cases, while posterior facet step-off correction reached proficiency after 26 cases. Reduction quality was classified as Excellent (n = 24), Good (n = 13), Fair (n = 8), and Poor (n = 5), with Excellent or Good outcomes achieved consistently after 21 cases. The mean operative time was 104 min, decreasing from 124.2 min to 85.2 min after 24 cases. The average number of fluoroscopy shots was 141, decreasing from 206.4 in the first 19 cases to 95.1 thereafter. Complications included six revision surgeries, one infection, four cases of insufficient posterior facet correction, and one case of screw penetration. Novice foot and ankle surgeons can achieve surgical proficiency in the sinus tarsi approach for calcaneal fracture fixation after approximately 20 to 26 cases. This learning curve was reflected by improved operative efficiency, reduced fluoroscopy use, and consistent radiographic correction of the Bohler angle, hindfoot varus angle, and posterior facet step-off
Stabilization Effect of THF, Propylene Oxide, 1,4-Dioxane and Acetone on Methane and Nitrogen Hydrates : Experimental Data adn Thermodynamics Model
No full textIncidence and Risk Factors of Deep Vein Thrombosis after Foot and Ankle Surgery
Full text linkBackground: Deep vein thrombosis (DVT) is a common complication in orthopedic surgery and has the potential to lead to fatal complications such as pulmonary thromboembolism. However, the precise incidence and risk factors for DVT in the foot and ankle fields remain unclear. This study aimed to analyze the prevalence of DVT and identify its risk factors after foot and ankle surgery. Methods: Between September 2020 and July 2023, screening duplex ultrasonography was performed on 278 patients who underwent foot and ankle surgery and required immobilization. The findings from screening duplex ultrasonography were assessed in conjunction with the symptoms present at the time of diagnosis. Heterogeneous demographic data that could serve as potential risk factors for DVT, including diagnosis, body mass index, and other medical histories, were examined alongside pertinent surgery-related data, such as tourniquet time. Results: Among the 278 individuals, DVT occurred in 41 patients (14.7%). Among these, 92.7% originated at the calf level and the majority were asymptomatic. The cases originating above the calf accounted for 3 cases, representing 7.3% of patients diagnosed with DVT (1.1% of the entire screened population). Acute trauma, history of previous DVT, and old age were identified as statistically significant risk factors for DVT occurrence, with odds ratios of 2.44 (p = 0.04), 6.40 (p = 0.02), and 1.16 (p = 0.03), respectively. Conclusions: After foot and ankle surgery, DVT occurred in 14.7% of cases. Acute trauma, history of DVT, and old age were identified as risk factors for DVT. These findings highlight the necessity of careful monitoring and appropriate prophylactic interventions for high-risk patients. Further investigation is required to determine effective prophylactic strategies for this patient population
Intraoperative assessment of hindfoot alignment using C-arm fluoroscopy
No full textBackground: Hindfoot malalignment can cause various foot and ankle problems. For better surgical performance and correction of hindfoot malalignments, reliable intraoperative determination of hindfoot alignment is essential. However, there is no standard method for the intraoperative assessment of hindfoot alignment. We devised an intraoperative modified Méary posteroanterior (IOPPA) view to assess intraoperative hindfoot alignment. This study aimed to compare this intraoperative method with other radiographic hindfoot alignment measurements. Methods: Thirty-seven patients (47 feet) with various foot and ankle conditions scheduled to undergo surgery were prospectively recruited. Before surgery, the Saltzman, long axial, and modified Méary views were taken in a controlled and standardized fashion. IOPPA views were obtained under simulated weight bearing conditions using C-arm fluoroscopy in the operating room before surgery. The relationship between the IOPPA view and the three radiographic hindfoot alignments was evaluated using Pearson's correlation. Results: The mean hindfoot alignment angle was varus 3.50° (CI, varus 1.91 to 5.08) on the Saltzman view, varus 2.00° (CI, varus 0.60 to 3.39) on the long axial view, varus 0.13° (CI, valgus 1.41 to varus 1.67) on the modified Méary view, and varus 1.32° (CI, valgus 0.02 to varus 2.65) on IOPPA view. The IOPPA view and the three other hindfoot alignment views were found to be significantly correlated (r = 0.60 for the Saltzman view, r = 0.50 for the long axial view, r = 0.71 for the modified Méary view, P < .05). The intraobserver ICC (Intraclass Correlation Coefficient) value was 0.974 and interobserver ICC (Intraclass Correlation Coefficient) value was 0.988 for the IOPPA view (P < .001). Conclusion: There was a statistically significant correlation between the IOPPA view and the other three hindfoot alignment views. We also found that interobserver and intraobserver ICC values were excellent. This study proposes that the IOPPA view can be used as a reliable intraoperative assessment tool for hindfoot alignment. Level of evidence: Prospective study
- …
