Instantly adhesive and ultra-elastic patches for dynamic organ and wound repair.

Bioadhesive materials and patches are promising alternatives to surgical sutures and staples. However, many existing bioadhesives do not meet the functional requirements of current surgical procedures and interventions. Here, we present a translational patch material that exhibits instant adhesion to tissues (2.5-fold stronger than Tisseel, an FDA-approved fibrin glue), ultra-stretchability (stretching to >300% its original length without losing elasticity), compatibility with rapid photo-projection (<2 min fabrication time/patch), and ability to deliver therapeutics. Using our established procedures for the in silico design and optimization of anisotropic-auxetic patches, we created next-generation patches for instant attachment to tissues while conforming to a broad range of organ mechanics ex vivo and in vivo. Patches coated with extracellular vesicles derived from mesenchymal stem cells demonstrate robust wound healing capability in vivo without inducing a foreign body response and without the need for patch removal that can cause pain and bleeding. We further demonstrate a single material-based, void-filling auxetic patch designed for the treatment of lung puncture wounds.

Do Hypoalbuminaemia Increase the Risk of Surgical Site Infection in Neck of Femur Fracture Patients: A Systematic Review and Meta-Analysis.

Serum albumin plays an important role in physiological and inflammatory haemostasis, and low serum levels are linked with an increased incidence of surgical site infections (SSI). Although this has been demonstrated in the spine and elective arthroplasty settings, there is a paucity of evidence with regard to the effect of low serum albumin on rates of SSI following surgery for adult patients suffering from traumatic and acute hip fractures. A systematic review was conducted using the PRISMA guidelines. Four databases were searched for randomised controlled trials (RCTs), cohort studies, and case-controlled studies. The risk of bias was assessed using the Newcastle-Ottawa Score (NOS). Data was collected and pooled using RevMan Web software. Results were reported as odds ratios (OR) with 95% confidence intervals (CI) and statistical significance of p <0.05. An inverse variance model was used in the meta-analysis. Six retrospective studies (five cohorts and one case-control) with a total of 43,059 patients were included. 45.3% (n=19 496) had low serum albumin (<3.5 g/dL). Hypoalbuminemia was associated with a significantly higher risk of any form of SSI (OR 1.25, p=0.008) and deep SSI (OR 1.76, p=0.05). There was no statistical significance between hypoalbuminemia and the incidence of superficial SSI (OR 1.06, p=0.77). Organ-space SSI was associated with hypoalbuminemia, although one study reported this with poor statistical significance (OR 8.74, p<0.054). Hypoalbuminemia increases the risk of most forms of surgical site infections, both superficial and deep. There is a weak conclusion to draw between the incidence of deep-space organ infections and low serum albumin.

Determining the ideal osteotomy for stemless total shoulder replacement: a cadaveric study.

HYPOTHESIS: We sought to determine the angle of osteotomy that produces a circular humeral cut surface. METHODS: A total of 49 cadaveric shoulders, from 25 cadavers, underwent sequential humeral head osteotomy from 180° (vertical, in line with the humeral diaphyseal shaft), in 10° increments, until the rotator cuff insertion was encountered. At each stage, the anteroposterior (AP) and superoinferior (SI) distances were recorded. The data were analyzed for normality and then assessed to determine the optimum cut angle. RESULTS: The AP/SI ratio is an indication of roundness. Plotting values of 1 - AP/SI (ie, error) vs. cut angle allowed us to plot the likelihood of producing a circular cut surface using a third-order curve that created the best fit to the data set (R2 = 0.99). The results from this study suggest that the optimum osteotomy angle that produces a circular cut surface is 23° from the vertical. The cohort data illustrated that at this angle, the average roundness error was 1% with a 95% confidence limit of <1%. There was no significant difference (P > .05) between sexes. CONCLUSION: The humeral head shape changes from oval to circular and then to an oval cut surface as the osteotomy angle increases from the vertical toward the horizontal. The range of angles within which the cut surface is circular, within a 10% error margin, is 18°-27° from the vertical, which is much less than the traditional osteotomy angle of 45°.

Detecting pulmonary nodules by using ultrasound multiple scattering.

Although X-Ray Computed Tomography (CT) is widely used for detecting pulmonary nodules inside the parenchyma, it cannot be used during video-assisted surgical procedures. Real-time, non-ionizing, ultrasound-based techniques are an attractive alternative for nodule localization to ensure safe resection margins during surgery. Conventional ultrasound B-mode imaging of the lung is challenging due to multiple scattering. However, the multiple scattering contribution can be exploited to detect regions inside the lung containing no scatterers. Pulmonary nodules are homogeneous regions in contrast to the highly scattering parenchyma containing millions of air-filled alveoli. We developed a method relying on mapping the multiple scattering contribution inside the highly scattering lung to detect and localize pulmonary nodules. Impulse response matrices were acquired in ex-vivo pig and dog lungs using a linear array transducer to semi-locally investigate the backscattered field. Extracting the multiple-scattering contribution using singular-value decomposition and combining it with a depression detection algorithm allowed us to detect and localize regions with less multiple scattering, associated with the nodules. The feasibility of this method was demonstrated in five ex-vivo lungs containing a total of 20 artificial nodules. Ninety-five percent of the nodules were detected. Nodule depth and diameter significantly correlated with their ex-vivo CT-estimated counterparts (R = 0.960, 0.563, respectively).

Should the Tibiotalar Angle Be Measured Using an AP or Mortise Radiograph? Does It Matter?

Understanding the tibiotalar angle (TTA) is key to planning for deformity correction. The TTA is an important radiographic tool to determine alignment or malalignment of the ankle and hindfoot. Two methods of measuring the TTA have been described: the midline TTA (MTTA) and the lateral TTA (LTTA). The aim of this study was to compare the 2 angles as measured on mortise and anteroposterior (AP) radiographs in a series of normal and pathological cases. A radiographic review was performed of sequential ankle AP and mortise radiographs taken between January 2016 and September 2017 across 4 specialist orthopedic centers. Patients were categorized into a normal group, where patients had normal radiological appearances, and an arthritis group, where patients had radiographic arthritis. The MTTA and the LTTA were measured. The overall mean ± standard deviation MTTA was 88.7° ± 5.1°, and mean LTTA was 87.5° ± 5.2° (p < .01). There was no statistically significant difference between the MTTA and LTTA in the normal group or on AP radiographs alone (p = .09). There was a statistically significant difference between the MTTA and LTTA in the arthritis group (p < .01) and when measured on mortise radiographs (p = .02). The MTTA had no difference when measured on the AP and mortise radiographs. There was a statistically significant difference in the LTTA between AP and mortise radiographs (p = .04). We have shown the MTTA to be a reliable and reproducible tool in all patients, on AP and mortise radiographs. The type of radiograph does not alter the measurement of deformity. In contrast, we have shown the LTTA to be unreliable and statistically different when measured on AP and mortise radiographs.

Disassociation at the head-trunnion interface: an unseen complication of modular hip hemiarthroplasty.

A woman in her mid-90s underwent a left uncemented bipolar hemiarthroplasty for an intracapsular femoral neck fracture. Postoperative radiographs at 48h showed a disassociation of the left femoral prosthesis at the head-trunnion interface, with the bipolar head remaining in the acetabulum. There was no preceding trauma and the patient had mobilised postoperatively. The hip was revised to a monopolar head, and the patient's hip was protected postoperatively in a brace limiting flexion and external rotation. At 30 days following revision she was mobilising pain-free with a stable hip. Disassociation at the head-trunnion interface has never been reported in hip hemiarthroplasty, and is only described in relation to primary or revision total hip replacements (THR) following dislocation or trauma to the THR. This demonstrates a potential complication of modular prostheses for trauma.

Effect of a vascular endothelial cadherin antagonist in a rat lung transplant model.

BACKGROUND: Adherens junctions are critically important in control of endothelial cell permeability. Bß15-42 is a peptide product of fibrin degradation that binds to vascular endothelial cadherin, the major component of endothelial adherens junctions. We tested the hypothesis that Bß15-42 improves lung function in our rat lung transplant model. METHODS: Bß15-42 was administered to donors before lung retrieval and to recipients by continuous intravenous infusion, or just to recipients, or neither. Recipients were monitored, anesthetized and ventilated, for 6 hours. Outcome measures were indices of lung function (edema [wet-to-dry weight ratio], oxygenation, dynamic compliance) and bronchoalveolar fluid measures of inflammation (protein, cell count, differential, and cytokines). RESULTS: Bß15-42 therapy was associated with improved graft lung function, including less edema, and improved oxygenation and airway pressure, particularly if Bß15-42 was administered to both the donor and recipient. However, Bß15-42 had little or no effect on bronchoalveolar fluid measures of inflammation. Analysis of bronchoalveolar fluid protein concentration showed Bß15-42 may enhance alveolar fluid clearance. CONCLUSIONS: Bß15-42 may be a useful therapy to reduce edema and improve graft function after lung transplant, alone or as an adjunct to other therapies.

In vitro modeling of nonhypoxic cold ischemia-reperfusion simulating lung transplantation.

OBJECTIVE: Although anoxia/reoxygenation of cultured cells has been used to model lung ischemia-reperfusion injury, this does not accurately mimic events experienced by lung cells while a lung is retrieved from a donor, stored, and transplanted. We developed an in vitro model of nonhypoxic ischemia-reperfusion injury to simulate these events. METHODS: Human umbilical vein endothelial cells underwent simulated cold ischemia by replacing 37 degrees C culture media with 4 degrees C Perfadex (Vitrolife, Kungsbacka, Sweden) solution for 5 hours in 100% O(2). Culture dishes were allowed to warm to room temperature for 1 hour (implantation), and then Perfadex solution was replaced with 37 degrees C culture media (reperfusion). RESULTS: During cold ischemia, the human umbilical vein endothelial cell filamentous actin cytoskeleton quickly became rearranged, and gaps developed in the previously confluent monolayer occupying 20% of the surface area. Simulated reperfusion resulted in reorganization to a confluent monolayer. Development of gaps was not due to enhanced necrosis based on lactate dehydrogenase retention assay. Endothelial cytoskeletal rearrangement could account for early edema caused by ischemia-reperfusion injury with reperfusion. Mitogen-activated protein kinase and nuclear factor kappaB activation occurred with simulated reperfusion despite normoxia. Levels of the proinflammatory cytokines interleukin 6 and interleukin 8 were significantly increased in media at the end of reperfusion. CONCLUSIONS: Exposing human umbilical vein endothelial cells to simulated cold ischemia without hypoxia causes reversible cytoskeletal alterations, activation of inflammatory pathways, and elaboration of cytokines. Because this model accurately depicts events occurring during lung transplantation, it will be useful to explore mechanisms regulating lung cell response to this unique form of ischemia-reperfusion injury.

Benign bone tumours in Western Australia, 1972-1996.

AIMS: To review the benign bone tumours accessioned by the Bone Tumour Registry (BTR) of Western Australia (WA) during the years 1972-1996 and to determine the incidence of the more common types. METHODS: Information was extracted from the Registry database using 58 selected fields. RESULTS: During the 25 year period, 849 benign tumours were accessioned and incidence rates have been calculated for 86 chondromas, 68 osteoid osteomas, 47 giant cell tumours, 32 chondroblastomas, 15 periosteal chondromas and 13 chondromyxoid fibromas. CONCLUSION: The BTR provides a valuable resource for the study of primary bone tumours. This review has established reliable incidence rates for the six most common benign tumours. Such information is rarely available for benign tumours. It has also disclosed that osteoblastoma is only four times less frequent than osteosarcoma, which is five times higher than published figures from North America.

Changes in the American interventional radiology literature: comparison over a 10-year time period.

PURPOSE: To determine the changes that occurred regarding interventional radiologic research in the major American radiology journals between 1992-1993 and 2002-2003. METHODS: Articles published in three major American radiology journals (Journal of Vascular and Interventional Radiology, American Journal of Roentgenology, and Radiology) during two distinct 24-month time periods (1992-1993 and 2002-2003) were evaluated. All articles judged to be pertinent to the interventional radiologic community were included. Investigations included in journal subheadings other than "interventional" or "vascular radiology" were included if the emphasis of the article was on a vascular imaging modality or peripheral intervention. Exclusions included: case reports, technical reports, letters to the editor, breast interventions, and primary neurointerventions. Data were collected regarding the affiliations of the primary author (nationality, hospital type, department); primary category of interest of the investigation; funding information; and study design variables. Two-by-two chi-squared statistical analyses were performed comparing the variables from the early and late data sets. RESULTS: A total of 405 articles met the inclusion criteria for the early data set (1992-1993); 488 articles met the inclusion criteria for the late data set (2002-2003). Variables that demonstrated a statistically significant decrease from the early data set to the late data set included: articles in which the primary author was from a department of radiology (91.1% vs. 86.3%; p < 0.025); articles written by a primary author who was American (69.4% vs. 44.6%; p < 0.001); and articles with a primary category of investigation that had a nonvascular intervention focus (22.7% vs. 11.9%; p < 0.001). Variables that demonstrated a statistically significant increase from the early data set to the late data set included primary authors from Western Europe (18.0% vs. 30.1%; p < 0.001) and Asia (6.6% vs. 18.4%; p < 0.001), the primary field of investigation, with significant increases noted for primary cancer interventions (6.5% vs. 13.3%; p < 0.001), gynecologic interventions (0.2% vs. 4.5%; p < 0.001), stent-grafts (0 vs. 2.9%; p < 0.001), and spine interventions (0 vs. 1.8%; p < 0.01). Studies receiving funding also demonstrated a significant increase when comparing the early and late data sets (11.3% vs. 23.0%, respectively; p < 0.001). CONCLUSIONS: Articles published in the American radiologic literature have changed significantly over the past 10 years. Primary authors are more likely to be nonradiologists and less likely to be American. Investigations dealing primarily with nonvascular interventions are less common; however, some forms of intervention (particularly cancer interventions) are seen more frequently in the literature. The percentage of funded projects has more than doubled in the same time frame.

Trends in lung pH and PO2 after circulatory arrest: implications for non-heart-beating donors and cell culture models of lung ischemia-reperfusion injury.

BACKGROUND: A better understanding of lung tissue environment after circulatory arrest would allow more accurate cell culture models to study ischemia-reperfusion lung injury and facilitate retrieval of lungs from non-heart-beating donors. METHODS: To establish the time course of changes in pH and PO2 in lung tissue after circulatory arrest, 12 Sprague-Dawley rats were sacrificed. After sternotomy, pH and PO2 microelectrodes were inserted into the lungs and sealed by application of Focal Seal. Rats were maintained at normothermia (37 degrees C). Two groups of rats (n = 6 atelectatic, n = 6 room air-inflated) were followed for 4 hours after arrest, when lung tissue adenine nucleotide levels were measured by chromatography and cell death was quantified by trypan blue exclusion. Human umbilical vein endothelial cells underwent simulated ischemia and 6 hours of cold storage by replacement of culture medium with cold Perfadex. Interleukin (IL)-6 and IL-8 were measured in medium 21 hours later by enzyme-linked immunosorbent assay (ELISA). RESULTS: In both groups of rats, lung [H+] increased linearly with time. In atelectatic lungs, PO2 fell precipitously, but in inflated lungs, PO2 decreased linearly for 60 to 75 minutes post-mortem and then became stable. After 4 hours at 37 degrees C, most parenchymal lung cells were dead in both groups. IL-6 and IL-8 levels increased significantly in medium of cultured endothelial cells subjected to cold storage without hypoxia. CONCLUSIONS: In room-air-inflated lungs maintained at 37 degrees C, oxygen consumption continues for at least 1 hour after circulatory arrest. Warm atelectasis is poorly tolerated. Hypothermic storage can induce elaboration of cytokines by endothelial cells in the absence of hypoxia.

Primary malignant bone tumours in Western Australia, 1972-1996.

AIMS: To study the incidence of primary malignant bone tumours in Western Australia (WA) from 1972 to 1996 using the database of the WA Bone Tumour Registry (BTR) and to compare these rates with those in the United States of America (USA). In addition, to undertake a linkage study between the BTR database and that of the WA Cancer Registry (WACR) for the years 1980-1996 to determine if the BTR records could be regarded as population-based and valid for determining incidence rates in WA. METHODS: For each year of the review, standardised incidence rates were calculated for osteosarcoma, chondrosarcoma, Ewing's sarcoma and for all bone sarcomas combined. For comparison, incidence rates were calculated using data obtained from the Surveillance, Epidemiology and End Results (SEER) Program Registry in the USA. RESULTS: Excluding myeloma, there were 263 cases of primary malignant bone tumours. Osteosarcoma (94 cases), chondrosarcoma (64 cases) and Ewing's sarcoma (49 cases), were the three most common and represented 78.7% of all primary bone sarcomas. Age-sex-standardised incidence rates for osteosarcoma in WA were 28% lower than in the USA. For chondrosarcoma and Ewing's sarcoma, no significant difference was found between rates in WA and the USA. CONCLUSIONS: The BTR provides a valuable resource for the study of primary bone tumours. This review has established reliable incidence rates for individual types of bone sarcoma. In both geographical sites there is a slight upward trend in the incidence of primary bone sarcoma.