Defense Threat Reduction Agency

The purpose of this study was to cull lessons from Toronto's experiences with large-scale quarantine during the outbreak of Severe Acute Respiratory Syndrome in early 2003. We focused on issues that affected the population's willingness to comply with quarantine. Information was acquired from interviews, telephone polling, and focus groups. Issues of quarantine legitimacy, criteria for quarantine, and the need to allow some quarantined healthcare workers to leave their homes to go to work were identified. Also important was the need to answer questions from people entering quarantine about the continuation of their wages, salaries, and other forms of income while they were not working, and about the means by which they would be supplied with groceries and other services necessary for daily living. The threat of enforcement had less effect on compliance than did the credibility of compliance-monitoring. Fighting boredom and other psychological stresses of quarantine, muting the forces of stigma against those in quarantine, and crafting and delivering effective and believable communications to a population of mixed cultures and languages also were critical. The need for officials to develop consistent quarantine policies, procedures, and public messages across jurisdictional boundaries was paramount.

The β-polytype of Ga 2 O 3 has a bandgap of ∼4.8 eV, can be grown in bulk form from melt sources, has a high breakdown field of ∼8 MV.cm −1 and is promising for power electronics and solar blind UV detectors, as well as extreme environment electronics (high temperature, high radiation, and high voltage (low power) switching. High quality bulk Ga 2 O 3 is now commercially available from several sources and n-type epi structures are also coming onto the market. There are also significant efforts worldwide to grow more complex epi structures, including β-(Al x Ga 1x ) 2 O 3 /Ga 2 O 3 and β-(In x Ga 1−x ) 2 O 3 /Ga 2 O 3 heterostructures, and thus this materials system is poised to make rapid advances in devices. To fully exploit these advantages, advances in bulk and epitaxial crystal growth, device design and processing are needed. This article provides some perspectives on these needs.

Among the many questions unanswered for the COVID-19 pandemic are the origin of SARS-CoV-2 and the potential role of intermediate animal host(s) in the early animal-to-human transmission. The discovery of RaTG13 bat coronavirus in China suggested a high probability of a bat origin. Here we report molecular and serological evidence of SARS-CoV-2 related coronaviruses (SC2r-CoVs) actively circulating in bats in Southeast Asia. Whole genome sequences were obtained from five independent bats (Rhinolophus acuminatus) in a Thai cave yielding a single isolate (named RacCS203) which is most related to the RmYN02 isolate found in Rhinolophus malayanus in Yunnan, China. SARS-CoV-2 neutralizing antibodies were also detected in bats of the same colony and in a pangolin at a wildlife checkpoint in Southern Thailand. Antisera raised against the receptor binding domain (RBD) of RmYN02 was able to cross-neutralize SARS-CoV-2 despite the fact that the RBD of RacCS203 or RmYN02 failed to bind ACE2. Although the origin of the virus remains unresolved, our study extended the geographic distribution of genetically diverse SC2r-CoVs from Japan and China to Thailand over a 4800-km range. Cross-border surveillance is urgently needed to find the immediate progenitor virus of SARS-CoV-2.

Between January 1989 and December 1994, 94 patients (96 knees) had a two-stage reimplantation for treatment of an infected total knee arthroplasty. All patients were treated with an interval antibiotic-loaded static cement spacer and had antibiotic-loaded bone cement for prosthesis fixation at the time of reimplantation. The purpose of this study was to assess the long-term risk of reinfection and the mechanical durability of these reimplantation arthroplasties. Patients were followed up for a median of 7.2 years (range, 2.5-13.2 years). At final followup, 15 knees (16%) had required reoperation. Nine knees (9%) had component removal for reinfection and six knees (6%) were revised for aseptic loosening. The median time to reoperation for reinfection was 1 year (range, 0.1-9.8 years). The risk of recurrent infection was not correlated with the type of organism, patient demographics, or method of prosthesis fixation at reimplantation. The survivorship free of implant removal for any reason was 90% (confidence intervals, 83.9-96.4%) at 5 years and 77.3% (confidence intervals, 65.5-89.6%) at 10 years. The survivorship free of implant removal for reinfection was 93.5% (confidence intervals, 88.5-98.7%) at 5 years and 85% (confidence intervals, 73.8-96.3%) at 10 years. Survival free of revision for mechanical failure (aseptic loosening or radiographic loosening) was 96.2% (confidence intervals, 92-100%) at 5 years and 91% (confidence intervals, 80.8-98.3%) at 10 years. These results suggest that the high likelihood of early success after two-stage reimplantation of an infected TKA is well maintained throughout long-term followup, with a modest rate of late recurrent infection or mechanical implant failure.

UNLABELLED: We previously reported preoperative depression, anxiety, and pain were associated with greater pain, more utilization of healthcare resources, and worse outcome 1 year after total knee arthroplasty. We asked whether these outcomes persisted over time and whether patients with unexplained heightened pain early after surgery were ultimately satisfied. We prospectively followed and evaluated 83 patients (109 TKAs) 5 years postoperative. The mean age was 66 years; 55% were women. Preoperative pain and depression predicted lower Knee Society score mostly related to lower function subscores. Although anxiety was associated with greater pain, worse function, and more use of resources in the first year after surgery, anxiety did not affect ultimate outcome. Most patients required a full year to recover from surgery but with negligible improvements in most parameters afterward. However, patients with heightened, unexplained pain at 1 year had progressive improvement in pain over several years. By 5 years, nearly all of these patients were satisfied. Therefore, assuming good range of motion and well-aligned implants, most patients with pain 1 year after surgery can be reassured pain ultimately improves. Depression drives long-term outcomes; the Knee Society score is influenced by psychologic variables and does not solely reflect issues related to the knee. Expansion of this tool to include measures sensitive to psychologic and other health factors should be considered. LEVEL OF EVIDENCE: Level I, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

History Although cartilage lesions had been directly examined and described as far back as the early 20th century, the etiology of chondromalacia of the patella was not well understood when Outerbridge published his first paper on the subject in 1961 [15]. In this initial study, he evaluated the cartilage of the patella during 196 medial meniscectomies to better understand how chondromalacia progressed and which areas of the patella were primarily affected. He found that chondromalacia was most common on the medial facet as a result of constant friction with a rim on the upper border of the medial femoral condyle. He also noted the incidence of chondromalacia of the patella to be approximately 50% in patients who underwent open medial meniscectomy, even in the absence of symptoms. To better understand the etiology of chondromalacia of the patella, Outerbridge developed his classification system describing varying severity of cartilage lesions by direct visualization, which he continued to use in his subsequent papers [15-17]. Since the introduction of Outerbridge’s classification system originally designed for chondromalacia of the patella, it has been adapted to include the entire knee in 1989 and other joints since then [2, 8, 13]. In addition to Outerbridge’s scheme, there are several other classification schemes describing chondral lesions. These include the modified Collins [6] and French Society of Arthroscopy (FSA) systems [13] designed for the knee as well as Beck’s [3] and Konan’s [9] designed for the hip. Aside from the studies referenced in this review, there is very little reported on the Collins or FSA classification systems. Collins’ system was published before Outerbridge’s original paper but, along with the FSA system, has failed to gain widespread popularity. The Beck scheme is based on findings during surgical dislocation of the hip and Konan’s classification is fairly new with only two studies assessing its reliability [1]. Despite other proposed systems, the Outerbridge system continues to be the most widely used, which warrants investigation into its reliability. Purpose In 1961, when the Outerbridge system was originally developed, it was used as a purely descriptive system to better understand the etiology of chondromalacia of the patella. Since then, it has been used to describe cartilage lesions in the knee, hip, and shoulder [2, 7, 8, 19]. The system is largely used to facilitate communication between surgeons. Although it has not been demonstrated to guide treatment, several studies have used the Outerbridge scheme to group patients for clinical research and for prognostic purposes [2, 7, 8, 19]. Accurately defining defect severity is also important for surgical planning and patient education. Description Based on direct visualization of the joint, either arthroscopic or open, the Outerbridge classification system was developed to be a simple, easy-to-use, and reproducible grading system of articular cartilage lesions. The system assigns a grade of 0 through IV to the chondral area of interest (Fig. 1). Grade 0 signifies normal cartilage. Grade I chondral lesions are characterized by softening and swelling, which often require tactile feedback with a probe or other instrument to assess. A Grade II lesion describes a partial-thickness defect with fissures that do not exceed 0.5 inches in diameter or reach subchondral bone. Grade III is fissuring of the cartilage with a diameter > 0.5 inches with an area reaching subchondral bone. The most severe is Grade IV, which includes erosion of the articular cartilage that exposes subchondral bone [15, 16].Fig. 1 A-F: These intraoperative arthroscopic images demonstrate examples of Outerbridge classification grades: (A) Grade I; (B-C) Grade II; (D) Grade III; (E-F) Grade IV.Validation Studies that have evaluated the reliability of Outerbridge’s classification system either use arthroscopic video or another imaging modality for comparison. The studies that have looked at the reproducibility of the scheme using arthroscopy videos have shown interobserver reliability ranging from a κ coefficient of 0.28 to 0.52 and intraobserver reproducibility ranging from a κ coefficient of 0.29 to 0.8 (Table 1) [1, 4, 5, 10, 11]. In these studies. Brismar et al. [4], Cameron et al. [5], Marx et al. [11], and Amenabar et al. [1] all used fully trained orthopaedic surgeons for reviewers, whereas Lasmar et al. [10] had two third-year residents along with four orthopaedic surgeons review their videos, demonstrating a clear intraobserver reliability discrepancy between the levels of training (κ = -0.06 versus 0.50). Cameron et al. [5] also found a discrepancy in reliability based on level of experience with the two surgeons in practice for > 5 years having an interobserver agreement of κ = 0.72 and those surgeons with less experience averaging κ = 0.50. This study also found a 68% concordance between the participating observers’ arthroscopic evaluation and direct measurement with calipers (depth and width of lesions) at arthrotomy made by those same observers [5].Table 1.: Studies evaluating the reliability of the Outerbridge classification system of chondral lesionsBrismar et al.’s study [4] compared the modified Collins and FSA classification systems as well as Outerbridge and found no difference among the three, concluding that none of these classifications was sufficiently reliable for use in clinical research. Lasmar et al.’s study [10] also compared Outerbridge and FSA schemes with no difference between either interobserver or intraobserver reliability. The study by Amenabar et al. [1] evaluated chondral lesions of the hip using Outerbridge and two other classification systems designed for the hip (Beck [3] and Konan [9]). They found no difference between the systems regarding intraobserver reliability, but Konan’s system was noted to have superior interobserver reliability in the hip. Lower reliability with the Outerbridge system compared with other schemes was believed to be a result of the specific chondral damage pattern usually caused by femoroacetabular impingement and the anatomy of the chondrolabral junction [1]. Studies that used imaging as a method of comparison (Table 1) found an interobserver reliability ranging from fair (κ = 0.35, CT arthrograms) to almost perfect (κ = 0.93, MR images) [14, 18]. Among these studies, Omoumi et al. [14], who used radiologists to evaluate CT arthrograms without a direct visual comparison, was the only study to test intraobserver reliability (κ = 0.59–0.92). This study found that more experienced radiologists in general had higher κ values for intraobserver reliability. The highest interobserver reliability for Outerbridge’s scheme comes from Potter et al.’s [18] study that compared MR images of the knee with an arthroscopic evaluation. The two radiologists and three orthopaedic surgeons found an almost perfect (0.93) κ statistic. The Outerbridge system has also proven to have some prognostic value. Sofu et al. [19] has shown Grade III and IV knee lesions to have worse visual analog scores and Lysholm scores after arthroscopic partial meniscectomy. Bateman et al. [2] demonstrated worse functional outcomes after arthroscopic shoulder posterior labral tear repairs in patients with Grade III lesions or higher. Kemp et al. [8] also found that patients who had Outerbridge Grade III and IV lesions found during hip arthroscopy for femoroacetabular impingement had worse pain and function at 18 months postsurgery compared with lower grade chondral lesions. Limitations Although widely used both in clinical and research settings over the past several decades, the Outerbridge classification system has several limitations. The most common criticism of this classification is its inconsistent and poor reproducibility among orthopaedic surgeons. The overall interobserver reliability ranged only from weak (κ = 0.28) [1] to moderate (κ = 0.52) [5], whereas intraobserver agreement was slightly better ranging from weak (κ = 0.29) [10] to substantial (κ = 0.8) [5]. However, some studies have mentioned that the amount of experience among reviewers affects the reliability of the system with more experienced surgeons having better reliability [5, 10]. Arthroscopy may also make it somewhat difficult to adequately differentiate the size of the lesion between Grades 2 and 3 as well as visualizing the softness and swelling needed to assign a Grade 1 [1]. Such variations in reliability suggest that the criteria for the Outerbridge system needs modification and/or advanced imaging (MRI) implemented into the scheme. The current crude macroscopic method used in Outerbridge grades may work to communicate cartilage lesion severity between surgeons, but the literature does not support its reliability for research purposes. In the studies evaluating the reliability of the Outerbridge classification system through arthroscopic videos, there was a common limitation of small sample sizes, which ranged from six patients to 40 [1]. Additionally, there has been a relatively small number of studies validating the reliability of the Outerbridge classification system. In studies using direct visualization to assess this system, only five studies measured interobserver agreement and only four measured intraobserver agreement. Each study that evaluated the Outerbridge classification as the reference grading system used video recordings of knee arthroscopy, thus preventing grading surgeons from using tactile feedback as a cartilage assessment tool. This tactile feedback is especially critical because roughness and softening of the cartilage are important for appropriate grading [11]. Any future studies on the present Outerbridge system’s reliability should incorporate tactile feedback into the methodology, which may limit the study to only assessing interobserver reliability during arthroscopic surgery or the use of cadaver knees. The Outerbridge classification system also does not provide a clear correlation with disease prognosis or a guide to treatment. There are only a few studies that have shown some prognostic value to the Outerbridge system [2, 8, 12, 19] and no studies were found in this review that discuss treatment guidance. Because these are two key features that a classification system should incorporate, their absence remains a major limitation for this system. Conclusions The inter- and intraobserver agreement for the Outerbridge classification system for chondral lesions ranges from fair to substantial. This inconsistent reliability remains a substantial limitation of this system. Although the Outerbridge scheme remains the most widespread classification system for grading cartilage lesions, it fails to guide treatment decisions and there is little evidence that it provides much prognostic information. To further evaluate Outerbridge’s system, future research should include validation studies with larger sample sizes, methodology that allows for tactile feedback, and evaluation in a variety of joints for more accurate assessment of articular cartilage morphology. Outerbridge and similar macroscopic classification schemes that evaluate chondral lesions fail to provide the confidence needed for use in research settings. This system is > 50 years old and does not incorporate the advances in imaging technology over that timeframe. The best reliability found in this review compared arthroscopic and MR images. The authors recommend that the Outerbridge system and any future macroscopic grading system of chondral lesions need to incorporate advanced imaging (MRI) to achieve the reliability needed for a successful classification system.

BACKGROUND: Robotic-assisted TKA was introduced to enhance the precision of bone preparation and component alignment with the goal of improving the clinical results and survivorship of TKA. Although numerous reports suggest that bone preparation and knee component alignment may be improved using robotic assistance, no long-term randomized trials of robotic-assisted TKA have shown whether this results in improved clinical function or survivorship of the TKA. QUESTIONS/PURPOSES: In this randomized trial, we compared robotic-assisted TKA to manual-alignment techniques at long-term follow-up in terms of (1) functional results based on Knee Society, WOMAC, and UCLA Activity scores; (2) numerous radiographic parameters, including component and limb alignment; (3) Kaplan-Meier survivorship; and (4) complications specific to robotic-assistance, including pin-tract infection, peroneal nerve palsy, pin-site fracture, or patellar complications. METHODS: This study was a registered prospective, randomized, controlled trial. From January 2002 to February 2008, one surgeon performed 975 robotic-assisted TKAs in 850 patients and 990 conventional TKAs in 849 patients. Among these patients 1406 patients were eligible for participation in this study based on prespecified inclusion criteria. Of those, 100% (1406) patients agreed to participate and were randomized, with 700 patients (750 knees) receiving robotic-assisted TKA and 706 patients (766 knees) receiving conventional TKA. Of those, 96% (674 patients) in the robotic-assisted TKA group and 95% (674 patients) in the conventional TKA group were available for follow-up at a mean of 13 (± 5) years. In both groups, no patient older than 65 years was randomized because we anticipated long-term follow-up. We evaluated 674 patients (724 knees) in each group for clinical and radiographic outcomes, and we examined Kaplan-Meier survivorship for the endpoint of aseptic loosening or revision. Clinical evaluation was performed using the original Knee Society knee score, the WOMAC score, and the UCLA activity score preoperatively and at latest follow-up visit. We also assessed loosening (defined as change in the position of the components) using plain radiographs, osteolysis using CT scans at the latest follow-up visit, and component, and limb alignment on mechanical axis radiographs. To minimize the chance of type-2 error and increase the power of our study, we assumed the difference in the Knee Society score to be 25 points to match the MCID of the Knee Society score with a SD of 5; to be able to detect a difference of this size, we calculated that a total of 628 patients would be needed in each group in order to achieve 80% power at the α = 0.05 level. RESULTS: Clinical parameters at the latest follow-up including the Knee Society knee scores (93 ± 5 points in the robotic-assisted TKA group versus 92 ± 6 points in the conventional TKA group [95% confidence interval 90 to 98]; p = 0.321) and Knee Society knee function scores (83 ± 7 points in the robotic-assisted TKA group versus 85 ± 6 points in the conventional TKA group [95% CI 75 to 88]; p = 0.992), WOMAC scores (18 ± 14 points in the robotic-assisted TKA group versus 19 ± 15 points in the conventional TKA group [95% CI 16 to 22]; p = 0.981), range of knee motion (125 ± 6° in the robotic-assisted TKA group versus 128 ± 7° in the conventional TKA group [95% CI 121 to 135]; p = 0.321), and UCLA patient activity scores (7 points versus 7 points in each group [95% CI 5 to 10]; p = 1.000) were not different between the two groups at a mean of 13 years' follow-up. Radiographic parameters such as the femorotibial angle (mean 2° ± 2° valgus in the robotic-assisted TKA group versus 3° ± 3° valgus in the conventional TKA group [95% CI 1 to 5]; p = 0.897), femoral component position (coronal plane: mean 98° in the robotic-assisted TKA group versus 97° in the conventional TKA group [95% CI 96 to 99]; p = 0.953; sagittal plane: mean 3° in the robotic-assisted TKA group versus 2° in the conventional TKA group [95% CI 1 to 4]; p = 0.612) and tibial component position (coronal plane: mean 90° in the robotic-assisted TKA group versus 89° in the conventional TKA group [95% CI 87 to 92]; p = 0.721; sagittal plane: 87° in the robotic-assisted TKA group versus 86° in the conventional TKA group [95% CI 84 to 89]; p = 0.792), joint line (16 mm in the robotic-assisted TKA group versus 16 mm in the conventional TKA group [95% CI 14 to 18]; p = 0.512), and posterior femoral condylar offset (24 mm in the robotic-assisted TKA group versus 24 mm in the conventional TKA group [95% CI 21 to 27 ]; p = 0.817) also were not different between the two groups (p > 0.05). The aseptic loosening rate was 2% in each group, and this was not different between the two groups. With the endpoint of revision or aseptic loosening of the components, Kaplan-Meier survivorship of the TKA components was 98% in both groups (95% CI 94 to 100) at 15 years (p = 0.972). There were no between-group differences in terms of the frequency with which complications occurred. In all, 0.6% of knees (four) in each group had a superficial infection, and they were treated with intravenous antibiotics for 2 weeks [corrected]. No deep infection occurred in these knees. In the conventional TKA group, 0.6% of knees (four) had motion limitation (< 60°) [corrected]. CONCLUSIONS: At a minimum follow-up of 10 years, we found no differences between robotic-assisted TKA and conventional TKA in terms of functional outcome scores, aseptic loosening, overall survivorship, and complications. Considering the additional time and expense associated with robotic-assisted TKA, we cannot recommend its widespread use. LEVEL OF EVIDENCE: Level I, therapeutic study.

UNLABELLED: Fifty consecutive patients with late infected total knee arthroplasties were treated by debridement and removal of all components and cement, preserving the collateral ligaments. At the time of debridement, an articulating spacer was made to allow partial weightbearing and range of motion of the knee during rehabilitation. This spacer was implanted using antibiotic-impregnated bone cement. For this purpose, 4.8 g powdered tobramycin was mixed with 40 g Simplex cement. Cement was applied early to the components, but applied late to the femur, tibia, and patella to allow molding to the defects and bone without adherence to bone. Patients had tailored intravenous antibiotic therapy for 6 weeks for treatment of various gram-positive and gram-negative organisms. All patients had cemented revision total knee arthroplasty using antibiotic-impregnated cement with standard cementing techniques. Range of motion before reimplantation was 6 degrees -91 degrees . Followup averaged 73 months (range, 24-150 months). The average modified Hospital for Special Surgery knee score after revision was 89 points (range, 70-100 points) with 90% good to excellent results, excluding the results of patients with reinfection. Range of motion after reimplantation was 4 degrees -104 degrees. Six patients had recurrences of infection, and one patient with a poor postoperative range of motion had a fusion. Use of an articulating spacer achieved soft tissue compliance, allowed for ease of operation, reduced postoperative pain, improved function, and eradicated infection equal to standards reported in the literature. LEVEL OF EVIDENCE: Therapeutic study, Level IV (case series-no, or historical controls).

Smoothed particle hydrodynamics is extended to a normalized, staggered particle formulation with boundary conditions. A companion set of interpolation points is introduced that carry the stress, velocity gradient, and other derived field variables. The method is stable, linearly consistent, and has an explicit treatment of boundary conditions. Also, a new method for finding neighbours is introduced which selects a minimal and robust set and is insensitive to anisotropy in the particle arrangement. Test problems show that these improvements lead to increased accuracy and stability. Published in 2000 by John Wiley & Sons, Ltd.

Textiles capable of capture and detoxification of toxic chemicals, such as chemical-warfare agents (CWAs), are of high interest. Some metal–organic frameworks (MOFs) exhibit superior reactivity toward CWAs. However, it remains a challenge to integrate powder MOFs into engineered materials like textiles, while retaining functionalities like crystallinity, adsorptivity, and reactivity. Here, we present a simple method of electrospinning UiO-66-NH 2, a zirconium MOF, with polyvinylidene fluoride (PVDF). The electrospun composite, which we refer to as “MOFabric”, exhibits comparable crystal patterns, surface area, chlorine uptake, and simulant hydrolysis to powder UiO-66-NH 2 . The MOFabric is also capable of breaking down GD ( O -pinacolyl methylphosphonofluoridae) faster than powder UiO-66-NH 2. Half-life of GD monitored by solid-state NMR for MOFabric is 131 min versus 315 min on powder UiO-66-NH 2 .

The present publication surveys several applications of in silico (i.e., computational) toxicology approaches across different industries and institutions. It highlights the need to develop standardized protocols when conducting toxicity-related predictions. This contribution articulates the information needed for protocols to support in silico predictions for major toxicological endpoints of concern (e.g., genetic toxicity, carcinogenicity, acute toxicity, reproductive toxicity, developmental toxicity) across several industries and regulatory bodies. Such novel in silico toxicology (IST) protocols, when fully developed and implemented, will ensure in silico toxicological assessments are performed and evaluated in a consistent, reproducible, and well-documented manner across industries and regulatory bodies to support wider uptake and acceptance of the approaches. The development of IST protocols is an initiative developed through a collaboration among an international consortium to reflect the state-of-the-art in in silico toxicology for hazard identification and characterization. A general outline for describing the development of such protocols is included and it is based on in silico predictions and/or available experimental data for a defined series of relevant toxicological effects or mechanisms. The publication presents a novel approach for determining the reliability of in silico predictions alongside experimental data. In addition, we discuss how to determine the level of confidence in the assessment based on the relevance and reliability of the information.

UNLABELLED: Adjuvant treatment or filling agents have been recommended for reducing recurrence rates of giant-cell tumors of bone. However, reports of low recurrence rates without either caused us to question this concept. We retrospectively reviewed 193 patients treated during a 27-year period, comparing our results with historic controls. One hundred thirty-seven patients had curettage as a primary treatment, and of these, 26 (19%) had local recurrences. The local recurrence rate of giant-cell tumors confined to bone (Campanacci Grades I and II) was only 7% compared with 29% in tumors with extraosseous extension (Campanacci Grade III). Six patients (4%) had a fracture after curettage. Twenty-nine patients who were referred to us with local recurrences after treatment elsewhere had curettage, and 10 (34%) of these patients had local recurrences develop. Twenty-seven patients had excision as their primary treatment, and two (7%) of these patients had local recurrence develop. We recommend primary curettage for intraosseous giant-cell tumors without adjuvant treatment or filling agents, but tumors with soft tissue extension or with local recurrence require more aggressive treatment. LEVEL OF EVIDENCE: Therapeutic study, Level IV (case series--no, or historical control group). See the Guidelines for Authors for a complete description of levels of evidence.

Syndesmosis screws have significant problems including loosening, breakage, the need for removal, and late diastasis. A new technique of syndesmosis fixation is proposed in this study, in which a heavy suture is placed across the syndesmosis, which has been looped and tightened through cortical button anchors on either side of the ankle. Indirect placement of the medial button avoids a medial incision. Sixteen patients had this suture-button fixation in a prospective clinical study. Mean American Orthopaedic Foot and Ankle Society ankle scores were significantly better in patients who had suture-button fixation than in a comparative group of 16 patients who had syndesmosis screw fixation at 3 months (91 versus 80, respectively) and at 12 months postoperatively (93 versus 83, respectively). Return to work was faster (2.8 months in patients who had suture-button fixation versus 4.6 months who had syndesmosis screw fixation), and no patients who had suture-buttons required secondary surgery for implant removal. Axial computed tomography scanning at 3 months showed maintenance of reduction. Suture-button fixation is simple, safe, and effective. Patients have had improved outcomes and faster rehabilitation, without needing routine implant removal. It may become the treatment of choice in patients with a syndesmosis injury.

Modular acetabular augments were implanted in 16 patients (16 hips) for support of an uncemented hemispheric acetabular component during revision acetabular reconstruction. Based on the classification of Paprosky, acetabular bone defects were classified as 2A in one hip, 2B in three hips, 2C in one hip, 3A in five hips, and 3B in six hips. Preoperatively, the prosthetic femoral head centers were located at a mean horizontal distance of 18.6 mm (range, -3-46 mm), and a mean vertical distance of 27.6 mm (range, -16-52 mm) from the approximate femoral head center. Postoperatively, the prosthetic femoral head centers were located at a mean horizontal distance of 10.4 mm (range, 1-25 mm), and a mean vertical distance of 7.4 mm (range, -15-25 mm). At final followup, no implant had evidence of migration or loosening. At early clinical followup, this modular acetabular augment system seems helpful in acetabular reconstructions that cannot be treated with an uncemented hemispheric cup that would have required other forms of treatment such as structural allografts, acetabular cages, bilobed acetabular components, or custom acetabular components. Longer term followup is required to determine whether there are untoward effects of using a modular acetabular reconstructive system.

In a prospective randomized controlled trial, one group of 50 patients had total knee arthroplasty using conventional instruments; another group of 50 patients had total knee arthroplasty using a fluoroscopy-based computer navigation system. The variability of postoperative alignment of the lower limb in the coronal and saggital plane, early clinical outcome scores, and morbidity of the procedure were compared. In addition, the image-based computer navigation system was used to assess the following presumptions: the accuracy of the calculation of the kinematic center of rotation of the hip and the reliability of full-leg standing xrays in determining overall coronal alignment of the lower limb. Variability in the coronal plane was significantly reduced in the computer-assisted surgery group compared with the conventional group (p < 0.0001). Early clinical outcome and complication rates were similar for both groups. The correlation between full-leg standing xrays and the computer navigation system for determining the mechanical alignment of the lower limb in the coronal plane was high (r = 0.987). The maximum deviation between the calculated kinematic center of rotation of the hip and the fluoroscopically determined anatomic center of the hip was 5 mm (mean, 1.6 mm). An image based computer-assisted system can be safely used and leads to a consistent and perfect postoperative alignment in the coronal plane.

This paper reports the results of a series of tests designed to determine the melting and subsequent deposition behavior of volcanic ash cloud materials in modern gas turbine engine combustors and high-pressure turbine vanes. The specific materials tested were Mt. St. Helens ash and a soil blend containing volcanic ash (black scoria) from Twin Mountain, NM. Hot section test systems were built using actual engine combustors, fuel nozzles, ignitors, and high-pressure turbine vanes from an Allison T56 engine can-type combustor and a more modern Pratt and Whitney F-100 engine annular-type combustor. A rather large turbine inlet temperature range can be achieved using these two combustors. The deposition behavior of volcanic materials as well as some of the parameters that govern whether or not these volcanic ash materials melt and are subsequently deposited are discussed.

Abstract This study documents the global distribution and characteristics of diurnally varying low-level jets (LLJs), including their horizontal, vertical, and temporal structure, with a special emphasis on highlighting the underlying commonalities and unique qualities of the various nocturnal jets. Two tools are developed to accomplish this goal. The first is a 21-yr global reanalysis performed with the fifth-generation Pennsylvania State University–NCAR Mesoscale Model (MM5) using a horizontal grid spacing of 40 km. A unique characteristic of the reanalysis is the availability of hourly three-dimensional output, which permits the full diurnal cycle to be analyzed. Furthermore, the horizontal grid spacing of 40 km better resolves many physiographic features that host LLJs than other widely used global reanalyses. This makes possible a detailed examination of the systematic onset and cessation of the jets, including time–height representations of the diurnal cycle. The second tool is an index of nocturnal LLJ (NLLJ) activity based upon the vertical structure of the wind’s temporal variation, where the temporal variation is defined in local time. The first available objectively constructed global maps of recurring NLLJs are created from this index, where the various NLLJs can be simultaneously viewed at or near their peak time. These maps not only highlight all of the locations where NLLJs are known to recur, but they also reveal a number of new jets. The authors examine the basic mechanisms that give rise to the NLLJs identified in four disparate locations, each having a profound influence on the regional climate. The first, the extensively studied Great Plains NLLJ, is used to confirm the veracity of the global analysis and the index of NLLJ activity. It also provides context for three of the many newly identified NLLJs: 1) Tarim Pendi in northwest China; 2) Ethiopia in eastern Africa; and 3) Namibia–Angola in southwest Africa. Jets in these four regions illustrate the variety of physiographic and thermal forcing mechanisms that can produce NLLJs.

Double-bundle anterior cruciate ligament (ACL) reconstruction is intended to replicate the anatomy and the function of the anteromedial and posterolateral bundles of the native ACL to improve patients' satisfaction and knee stability. We prospectively assigned 75 consecutive patients with an isolated ACL lesion to one of three sequential groups of 25 patients each. Group I received a single-bundle, single-incision transtibial ACL reconstruction. Groups II and III received a double-bundle reconstruction with a single-incision transtibial technique or a double-bundle, twoincision outside-in technique, respectively. We obtained subjective International Knee Documentation Committee and Knee Injury and Osteoarthritis Outcome Score evaluations and objective International Knee Documentation Committee scores and KT-1000 measurements preoperatively and at followup. All patients reached a minimum followup of 2 years. KT side-to-side difference in Groups I, II, and III were 2.4, 1.6 and 1.4 mm, respectively. Group III had fewer patients with a positive pivot shift than Group I. The double-bundle double-incision outside-in ACL reconstruction resulted in improved anteroposterior stability and less residual pivot shift than single-incision single-bundle technique.

BACKGROUND: Artificial-intelligence algorithms derive rules and patterns from large amounts of data to calculate the probabilities of various outcomes using new sets of similar data. In medicine, artificial intelligence (AI) has been applied primarily to image-recognition diagnostic tasks and evaluating the probabilities of particular outcomes after treatment. However, the performance and limitations of AI in the automated detection and classification of fractures has not been examined comprehensively. QUESTION/PURPOSES: In this systematic review, we asked (1) What is the proportion of correctly detected or classified fractures and the area under the receiving operating characteristic (AUC) curve of AI fracture detection and classification models? (2) What is the performance of AI in this setting compared with the performance of human examiners? METHODS: The PubMed, Embase, and Cochrane databases were systematically searched from the start of each respective database until September 6, 2018, using terms related to "fracture", "artificial intelligence", and "detection, prediction, or evaluation." Of 1221 identified studies, we retained 10 studies: eight studies involved fracture detection (ankle, hand, hip, spine, wrist, and ulna), one addressed fracture classification (diaphyseal femur), and one addressed both fracture detection and classification (proximal humerus). We registered the review before data collection (PROSPERO: CRD42018110167) and used the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). We reported the range of the accuracy and AUC for the performance of the predicted fracture detection and/or classification task. An AUC of 1.0 would indicate perfect prediction, whereas 0.5 would indicate a prediction is no better than a flip-of-a-coin. We conducted quality assessment using a seven-item checklist based on a modified methodologic index for nonrandomized studies instrument (MINORS). RESULTS: For fracture detection, the AUC in five studies reflected near perfect prediction (range, 0.95-1.0), and the accuracy in seven studies ranged from 83% to 98%. For fracture classification, the AUC was 0.94 in one study, and the accuracy in two studies ranged from 77% to 90%. In two studies AI outperformed human examiners for detecting and classifying hip and proximal humerus fractures, and one study showed equivalent performance for detecting wrist, hand and ankle fractures. CONCLUSIONS: Preliminary experience with fracture detection and classification using AI shows promising performance. AI may enhance processing and communicating probabilistic tasks in medicine, including orthopaedic surgery. At present, inadequate reference standard assignments to train and test AI is the biggest hurdle before integration into clinical workflow. The next step will be to apply AI to more challenging diagnostic and therapeutic scenarios when there is absence of certitude. Future studies should also seek to address legal regulation and better determine feasibility of implementation in clinical practice. LEVEL OF EVIDENCE: Level II, diagnostic study.

Continued advancements in sequencing technologies have fueled the development of new sequencing applications and promise to flood current databases with raw data. A number of factors prevent the seamless and easy use of these data, including the breadth of project goals, the wide array of tools that individually perform fractions of any given analysis, the large number of associated software/hardware dependencies, and the detailed expertise required to perform these analyses. To address these issues, we have developed an intuitive web-based environment with a wide assortment of integrated and cutting-edge bioinformatics tools in pre-configured workflows. These workflows, coupled with the ease of use of the environment, provide even novice next-generation sequencing users with the ability to perform many complex analyses with only a few mouse clicks and, within the context of the same environment, to visualize and further interrogate their results. This bioinformatics platform is an initial attempt at Empowering the Development of Genomics Expertise (EDGE) in a wide range of applications for microbial research.