Severe plastic deformation (SPD) processes offer the possibility of improving the mechanical properties of metallic materials by grain refinement. However, this great potential has so far mostly been ...applied on a laboratory scale or on small series. Equal-Channel Angular Pressing (ECAP) also enables to integrate the advantages in industrial processes with large output—so far, mainly for bars or thick plates. In this paper, we investigate the ECAP process for sheet metal. Preliminary investigations have shown that cracks form on the surface when aluminum AA5083 sheets are processed. To solve this problem, we determined the Johnson–Cook fracture criterion for the material and modeled the process numerically. The simulation was carried out with the superposition of a backpressure and subsequently implemented and validated experimentally. The semi-finished sheet metal products from the ECAP investigation were then mechanically characterized with microhardness measurements and tensile tests. In addition, the microstructure was investigated with Electron Back Scatter Diffraction (EBSD). Even comparatively small amounts of backpressure (10 MPa) already result in a significant suppression of the crack formation in the numerical and experimental investigations. The microhardness measurements indicate a more homogeneous strain distribution for a sufficient level of applied backpressure which enables the processing of crack-free sheets in multiple ECAP passes. As with ECAP of bulk materials, tensile tests on the processed sheets show a reduced elongation to failure (− 73%) but a significantly increased yield strength (+ 157%) compared to the initial condition of the material. Distinct substructures are found in the EBSD measurements and explain this behavior. The findings provide the basis for using ECAP on an application-oriented scale and demonstrate an advanced manufacturing method for the production of high-strength aluminum sheets.
Abstract
Preinjury anticoagulation therapy (AT) is associated with a higher risk for major bleeding. We aimed to evaluated the influence of preinjury anticoagulant medication on the clinical course ...after moderate and severe trauma. Patients in the TraumaRegister DGU ≥ 55 years who received AT were matched with patients not receiving AT. Pairs were grouped according to the drug used: Antiplatelet drugs (APD), vitamin K antagonists (VKA) and direct oral anticoagulants (DOAC). The primary end points were early (< 24 h) and total in-hospital mortality. Secondary endpoints included emergency surgical procedure rates and surgery rates. The APD group matched 1759 pairs, the VKA group 677 pairs, and the DOAC group 437 pairs. Surgery rates were statistically significant higher in the AT groups compared to controls (APD group: 51.8% vs. 47.8%, p = 0.015; VKA group: 52.4% vs. 44.8%, p = 0.005; DOAC group: 52.6% vs. 41.0%, p = 0.001). Patients on VKA had higher total in-hospital mortality (23.9% vs. 19.5%, p = 0.026), whereas APD patients showed a significantly higher early mortality compared to controls (5.3% vs. 3.5%, p = 0.011). Standard operating procedures should be developed to avoid lethal under-triage. Further studies should focus on detailed information about complications, secondary surgical procedures and preventable risk factors in relation to mortality.
Our research explores the immunomodulatory effects of sulforaphane (SFN), a well-known nuclear factor erythroid 2-related factor 2 (Nrf2) pathway agonist, on the sterile inflammation of and ...ischemia-reperfusion injuries to the liver after hemorrhagic shock (HS) followed by resuscitation (R). Male C57/BL6 wild-type and transgenic ARE-
mice were exposed to mean arterial pressure-controlled HS. Fluid resuscitation was performed after 90 min of HS, and SFN was administrated intraperitoneally after that. The animals were sacrificed at 6 h, 24 h, and 72 h after resuscitation, and their livers were extracted to perform H&E staining and myeloperoxidase (MPO) activity analysis. The Kupffer cells were isolated for cytokines profile measurements and Nrf2 immunofluorescence staining. Further, the ARE-
mice were used to assess hepatic Nrf2 activity
. We identified that SFN-activated Kupffer cells' Nrf2 pathway and modulated its cytokines expression, including TNF-α, MCP-1, KC/CXCL1, IL-6, and IL-10. Furthermore, SFN mitigated liver ischemia-reperfusion injury, as evidenced by the downregulation of the Suzuki score and the enhanced hepatic Nrf2 activity. The
SFN treatment decreased neutrophils infiltration, as shown by the decreased MPO levels. Our study shows that SFN can decrease HS/R-induced hepatic ischemia-reperfusion injury and modulate the activity of Kupffer cells
an Nrf2-dependent pathway.
Hemorrhagic shock/resuscitation (HS/R) is closely associated with overwhelming oxidative stress and systemic inflammation. As an effective activator of the nuclear factor-erythroid factor 2 related ...factor 2 (Nrf2) pathway, sulforaphane (SFN) exerts antioxidant and anti-inflammatory effects. We explored SFN's effects on alveolar macrophages (AMs), systemic inflammation, and pulmonary damage in an isolated murine HS/R model. Male C57/BL6 wild type and transgenic antioxidant response element (ARE)-luciferase (luc) mice (both n = 6 per group) were exposed to either pressure-controlled HS/R (mean arterial pressure 35-45 mm Hg for 90 min) or sham procedure (surgery without HS/R) or were sacrificed without intervention (control group). Fluid resuscitation was performed via the reinfusion of withdrawn blood and 0.9% saline. Sulforaphane or 0.9% saline (vehicle) was administrated intraperitoneally. Mice were sacrificed 6, 24, or 72 h after resuscitation. Bioluminescence imaging of ARE-luc mice was conducted to measure pulmonary Nrf2 activity. Plasma was collected to determine systemic cytokine levels. Alveolar macrophages were isolated before measuring cytokines in the supernatant and performing immunofluorescence staining, as well as Western blot for intracellular Nrf2. Histological damage was assessed via the acute lung injury score and wet/dry ratio.Hemorrhagic shock/resuscitation was associated with pulmonary Nrf2 activation. Sulforaphane enhanced pulmonary Nrf2 activity and the Nrf2 activation of AM, while it decreased lung damage. Sulforaphane exerted down-regulatory effects on AM-generated and systemic pro-inflammatory mediators, while it did not have such effects on IL-10.In conclusion, SFN beneficially enhances pulmonary Nrf2 activity and promotes Nrf2 accumulation in AMs' nuclei. This may exert not only local protective effects but also systemic effects via the down-regulation of pro-inflammatory cytokines. The administration of Nrf2 activator post-HS/R may represent an innovative treatment strategy.
Purpose
The modified Trauma-Induced Coagulopathy Clinical Score (mTICCS) presents a new scoring system for the early detection of the need for a massive transfusion (MT). This easily applicable score ...was validated in a large trauma cohort and proven comparable to more established complex scoring systems. However, the inter-rater reliability of the mTICCS has not yet been investigated.
Methods
Therefore, a dataset of 15 randomly selected and severely injured patients (ISS ≥ 16) derived from the database of a level I trauma centre (2010–2015) was used. Moreover, 15 severely injured subjects that received MT were chosen from the same databank. A web-based survey was sent to medical professionals working in the field of trauma care asking them to evaluate each patient using the mTICCS.
Results
In total, 16 raters (9 residents and 7 specialists) completed the survey. Ratings from 15 medical professionals could be evaluated and led to an ICC of 0.7587 (95% Bootstrap confidence interval (BCI) 0.7149–0.8283). A comparison of working experience specific ICC (
n
= 7 specialists, ICC: 0.7558, BCI: 0.7076–0.8270;
n
= 8 residents, ICC: 0.7634, BCI: 0.7183–0.8335) showed no significant difference between the two groups (
p
= 0.67).
Conclusion
In summary, reliability values need to be considered when making clinical decisions based on scoring systems. Due to its easy applicability and its almost perfect inter-rater reliability, even with non-specialists, the mTICCS might therefore be a useful tool to predict the early need for MT in multiple trauma.
Zusammenfassung
Hintergrund
Die Distorsion des oberen Sprunggelenks (OSG) ist eine der häufigsten Verletzungen des Bewegungsapparates. Das Verletzungsmuster bestimmt die zu wählende Therapie und ist ...entscheidend für das Outcome.
Die isolierte Ruptur
des Außenbandapparates ist die häufigste strukturelle Verletzung.
Hierfür wird leitliniengerecht eine konservative Therapie empfohlen, für Kombinationsverletzungen besteht hingegen hinsichtlich des diagnostischen und therapeutischen Vorgehens keine einheitliche Vorgehensweise. Ziel der bundesweiten Umfrage war es, einen Überblick über die aktuelle diagnostische Strategie und die gängigen therapeutischen Konzepte in Deutschland zu gewinnen.
Material und Methoden
Mitglieder der Deutschen Gesellschaft für Orthopädie und Unfallchirurgie (DGOU) wurden eingeladen, an einer online Umfrage zum diagnostischen und zum therapeutischen Vorgehen bei OSG-Distorsion mit einem Fragebogen, bestehend aus 20 Fragen, teilzunehmen. Neben Fragen zur Fachrichtung und zum Tätigkeitsfeld wurden die Teilnehmer gebeten, ihr diagnostisches und therapeutisches Vorgehen darzustellen.
Ergebnisse
Insgesamt nahmen 806 Teilnehmer an der Umfrage teil. Die Mehrzahl der Befragten waren Orthopäden und Unfallchirurgen und in der Klinik tätig. Bei der Erstvorstellung werden der Schubladen Test (89,5 %) und der Inversions‑/Eversionstest (81,6 %) am häufigsten durchgeführt. Eine Röntgenuntersuchung führen 88,1 % regelhaft bei Erstvorstellung durch, 26,5 % auch eine sonographische Untersuchung. Die isolierte Verletzung des Lig. fibulotalare anterius (LFTA) behandeln 99,7 % konservativ, in 78,8 % der Fälle mit Vollbelastung in der Orthese. Die vollständige Außenbandruptur würden 79,9 % konservativ behandeln. Eine kombinierte Außenbandruptur mit Syndesmosenverletzung würden 30,1 % der Befragten konservativ behandeln.
Diskussion
Aufgrund der Heterogenität der Verletzungsmuster nach einer OSG-Distorsion bestehen keine einheitlichen diagnostischen und therapeutischen Behandlungsempfehlungen. Die Ottawa Ankle Rules und die Sonographie werden trotz der guten Studienlage nur wenig eingesetzt. Die isolierte LFTA-Ruptur wird von einem Großteil der Befragten leitliniengerecht diagnostiziert und behandelt. Bei kombinierten Verletzungen des Innen- und Außenbandapparates entscheidet sich die Mehrheit für ein konservatives Vorgehen, was durch die Literatur bei geringer Evidenz als gerechtfertigt erscheint. Kombinierte Verletzungen der Syndesmose und des Außenbandapparates würde die Mehrzahl der Befragten operativ behandeln, was ebenfalls mit den Empfehlungen der Literatur korreliert. Der Versorgungsstandard in Deutschland entspricht somit weitgehend den Literaturempfehlungen.
Graphic abstract
Although the treatment of multiple-injured patients has been improved during the last decades, sepsis and multiple organ failure (MOF) still remain the major cause of death. Following trauma, ...profound alterations of a large number of physiological systems can be observed that may potentially contribute to the development of sepsis and MOF. This includes alterations of the neuroendocrine and the immune system. A large number of studies focused on posttraumatic changes of the immune system, but the cause of posttraumatic immune disturbance remains to be established. However, an increasing number of data indicate that the bidirectional interaction between the neuroendocrine and the immune system may be an important mechanism involved in the development of sepsis and MOF. The aim of this article is to highlight the current knowledge of the neuroendocrine modulation of the immune system during trauma and sepsis.
Ankle sprains are one of the most frequent injuries of the musculoskeletal system. The injury pattern determines the treatment and are crucial for the outcome. Nonoperative treatment is commonly ...recommended for isolated injuries of the lateral ligaments but no standard strategy exists in combined ankle ligament injuries. The goal of this national survey was to achieve an overview about the current diagnostic strategies and common treatment concepts in Germany.
All members of the German Society for Orthopaedics and Trauma Surgery (DGOU) were invited to participate in an anonymous survey about the diagnostic and therapeutic approach in cases of ankle sprains. The online survey consisted of 20 questions. Besides questions about the speciality and scope of activities the participants were ask to depict their diagnostic and therapeutic strategy.
A total of 806 participants completed the survey. Most of them were orthopedic trauma surgeons and worked in a hospital. During the first presentation the anterior drawer test (89.5%) and the inversion/eversion test (81.6%) were most commonly used, 88.1% always make an X‑ray examination and 26.5% an ultrasonography examination. Isolated injuries of the anterior fibulotalar ligament (LFTA) were treated nonoperatively by 99.7% of the participants, 78.8% recommend full weight bearing in an orthesis, 78.8% treat the complete rupture of the lateral ligaments without operation whereas 30.1% stated that they would treat a combined lateral ligaments rupture with an injury of the syndesmosis nonoperatively.
Due to the heterogeneity of injury patterns after ankle sprain no consistent recommendations for diagnostics and treatment exist. The Ottawa ankle rules and ultrasonography were not often utilized despite of the good evidence. The isolated rupture of the LFTA is diagnosed and treated according to the national guidelines by most of the participants. In cases of combined injuries of the lateral and medial ankle ligaments the majority choose a nonoperative treatment strategy which is justified by the guidelines with a low level of evidence. Combined injuries of the syndesmosis and the lateral ankle ligaments were treated operatively, which also correlates with the recommendations in the literature. The standard care of ankle sprain in Germany is in accordance with the recommendations from the current literature.
It was hypothesized that strontium (Sr)-doped β-tricalcium phosphate (TCP)-based scaffolds have a positive effect on the regeneration of large bone defects (LBD). Readouts in our mice models were ...nuclear factor-kappa beta (NF-κB) activity and vascular endothelial growth factor receptor-2 (VEGFR-2) promoter activity during the healing process. A 2-mm critical-size femoral fracture was performed in transgenic NF-κB- and VEGFR-2-luciferase reporter mice. The fracture was filled with a 3D-printed β-TCP scaffold with or without Sr. A bioluminescence in-vivo imaging system was used to sequentially investigate NF-κB and VEGFR-2 expression for two months. After sacrifice, soft and osseous tissue formation in the fracture sites was histologically examined. NF-κB activity increased in the β-TCP + Sr group in the latter stage (day 40-60). VEGFR-2 activity increased in the + Sr group from days 0-15 but decreased and showed significantly less activity than the β-TCP and non-scaffold groups from days 40-60. The new bone formation and soft tissue formation in the + Sr group were significantly higher than in the β-TCP group, whereas the percentage of osseous tissue formation in the β-TCP group was significantly higher than in the β-TCP + Sr group. We analyzed longitudinal VEGFR-2 promoter activity and NF-κB activity profiles, as respective agents of angiogenesis and inflammation, during LBD healing. The extended inflammation phase and eventually more rapid resorption of scaffold caused by the addition of strontium accelerates temporary bridging of the fracture gaps. This finding has the potential to inform an improved treatment strategy for patients who suffer from osteoporosis.
Purpose
Surgically treated calcaneal fractures have a high risk of postoperative wound healing complications and a prolonged length of hospital stay (LOS). The aim of this study was to identify ...predictor variables of impaired wound healing (IWH) and LOS in surgically treated patients with isolated calcaneal fractures.
Methods
This retrospective cohort study analyzed data on patients aged 18 years or older who were admitted to a level I trauma center with isolated calcaneal fractures between 2008 and 2018. Multivariable regression models were used to identify predictor variables.
Results
In total, 89 patients (age: 45.4 years; SD: 15.1) were included. In 68 of these patients, low-profile locking plate osteosynthesis was performed, and a minimally invasive approach (MIA) (percutaneous single screws/K-wire or low-profile locking plating via a sinus tarsi approach) was applied in 21 patients. Multivariable regression analysis revealed that a higher preoperative Böhler’s angle (
β
= − 0.16 days/degree, 95% CI − 0.25, − 0.08,
p
= 0.004) and MIA (
β
= − 5.04 days, 95% CI − 8.52, − 1.56,
p
= 0.002) reduced the LOS. A longer time-to-surgery (
β
= 1.04 days/days, 95% CI 0.66, 1.42
p
= 0.001) and IWH increased the LOS (
β
= 7.80 days, 95% CI 4.48, 11.12,
p
= 0.008). In a subsequent multivariable regression analysis, two variables, open fractures (OR: 14.6, 95% CI 1.19, 180.2,
p
= 0.030) and overweight (BMI > 24) (OR: 3.65, 95% CI 1.11, 12.00,
p
= 0.019), increased the risk of IWH.
Conclusion
Advanced treatment algorithms for open fractures are needed to reduce the risk of IWH.
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