Percutaneous pelvic fixation model: an affordable and realistic simulator for pelvic trauma training.

PURPOSE: To describe the construction and use of a percutaneous pelvic fixation model, evaluate its translational validity among fellowship-trained orthopedic trauma surgeons, and investigate the importance of specific criteria for effective competency-based assessment of pelvic fixation techniques. METHODS: Five orthopedic trauma surgeons were asked to place percutaneous wires on a pelvic fixation model, including anterior column (antegrade/retrograde), posterior column (antegrade/retrograde), supra-acetabular, transsacral, and iliosacral. Evaluation criteria included successful wire placement, redirections, cortical breaches, procedure duration, radiation exposure, and quality of fluoroscopic views. Following completion, participants were provided a survey to rate the model. RESULTS: There were no differences between approaches on successful screw placement, wire redirections, or fluoroscopic quality. Antegrade approaches to the anterior and posterior columns took longer (p = 0.008) and used more radiation (p = 0.02). There was also a trend toward more cortical breaches with the antegrade anterior column approach (p = 0.07). Median ratings among surgeons were 4 out of 5 for their overall impression and its accuracy in tactile response, positioning constraints, and fluoroscopic projections. Learning parameters considered most important to the progression of trainees (most to least important) were successful screw placement, corridor breaches, wire redirections, quality of fluoroscopic views, radiation exposure, and procedure duration. CONCLUSION: In being affordable, accessible, and realistic, this percutaneous pelvic fixation model represents an opportunity to advance orthopedic surgery education globally. Future research is needed to validate the findings of this pilot study and to expand upon how trainees should be evaluated within simulations and the operating room to optimize skill progression.

Spinal cord compression in thoracolumbar burst fractures: application of high-definition three-dimensional exoscope in minimally invasive lateral surgery.

STUDY DESIGN: Spinal cord decompression in thoracolumbar burst fractures is challenging. Development of minimally invasive approaches and the improvement in new magnification technologies allowed a better and safer surgical treatment for these complex spinal injuries. We reported our experience in the minimally invasive surgical treatment of thoracolumbar burst fractures with spinal cord compression supported by high-definition (HD) three-dimensional (3D) Video-assisted telescope operating monitor (VITOM) or exoscope. OBJECTIVES: To assess the role and potential advantages of exoscope in the minimally invasive surgery of traumatic thoracolumbar spinal cord compression comparing traditional magnification systems. SETTING: The study was conducted in a Northern Italy Spinal Trauma Center. METHODS: We reported 10 consecutive thoracolumbar (T11-L2) burst fractures associated with spinal cord compression treated with minimally invasive corpectomy and exoscope-assisted spinal decompression. Three main indicators were retrospectively analyzed: surgical time, blood loss, and intraoperative complications. The data were compared with those obtained from an equal sample of 10 procedures performed by the same surgeon with the same technique, but traditional microscope assisted. User impressions in terms of ergonomics, magnification, and image quality were rated differently. RESULTS: A small reduction of surgical time and blood loss were observed in the exoscope assisted group. There were no intraoperative complications attributed to visualization mode or conversion to the traditional microscope in any procedure. In our experience the exoscope allowed a better magnification and image definition with better ergonomics and user-friendliness. CONCLUSIONS: In our preliminary experience the exoscope new technology is a safe and effective tool for spinal cord minimally invasive decompression in thoracolumbar burst fractures. The stereoscopic vision provided by 3D images seems to be crucial in hand eye coordination. There are clear advantages in terms of maneuverability, wide field of view, deep focus, and more comfortable posture for the spinal surgeon.

Italian Consensus Conference on Guidelines for preoperative treatment in acetabular fractures.

Preoperative management of acetabular fracture is a major problem and no consensus has been reached in literature on the optimal treatment of this problem. We present the results of the First Italian Consensus Conference on Acetabular fracture. An extensive review of the literature has been undertaken by the organizing committee and forwarded to the panel. Members were appointed by surgical experience with acetabular fractures. From November 2017 to January 2018, the organizing committee undertook the critical revision and prepared the presentation to the Panel on the day of the Conference. Then 11 recommendations were presented according to the 11 submitted questions. The Panel voted the recommendations after discussion and amendments with the audience. Later on, a second debate took place in September 2018 to reach a unanimous consent. We present results of the following questions: does hip dislocation require reduction? Should hip reduction be performed as soon as possible? In case of unsuccessful reduction of the dislocation after attempts in the emergency department, how should it be treated? If there is any tendency toward renewed dislocation, how should it be treated? Should Computed Tomography (CT) scan be performed before reduction? Should traction be used? How can we treat the pain? Is preoperative ultrasound exam to rule out vein thrombosis always necessary? Is tranexamic acid intravenous (IV) preoperatively recommended? Which antibiotic prophylactic protocols should be used? Is any preoperative heterotopic ossification prophylaxis suggested? In this article we present the indications of the First Italian Consensus Conference: a hip dislocation should be reduced as soon as possible. If unsuccessful, surgeon may repeat the attempts optimizing the technique. Preoperative CT scan is not mandatory before reduction. Skeletal traction is not indicated in most of the acetabular fracture. Standard pain and antibiotic prophylactic protocols for trauma patient should be used. Preoperative ultrasound exam is not recommended in all acetabular fracture. Tranexamic acid should be preoperatively used. There is no indication for preoperative heterotopic ossification.

Genetic transformation of Brevibacterium linens strains producing high amounts of diverse sulphur compounds.

By its numerous properties and importance in cheese technology (production of colour, flavour, bacteriocins and resistance to salt) Brevibacterium linens is a major cheese ripening bacteria. However, the genetic approach of such biological functions has been hindered, up to now, by the lack of tools necessary to realise genetic modifications in this species. Our objective was to demonstrate that it is possible to genetically modify several strains exhibiting interesting technological properties, especially the production of sulphur compounds. We worked with a phenotypically and genetically diverse collection of 11 strains. We genetically transformed several Brevi. linens with acceptable rates with plasmids classically used to transform lactic acid bacteria and other Gram+ bacteria. These results open up new prospects to investigate the most interesting Brevi. linens metabolic pathways both at the biochemical and genetic level.

Identification and functional analysis of the gene encoding methionine-gamma-lyase in Brevibacterium linens.

The enzymatic degradation of L-methionine and subsequent formation of volatile sulfur compounds (VSCs) is believed to be essential for flavor development in cheese. L-methionine-gamma-lyase (MGL) can convert L-methionine to methanethiol (MTL), alpha-ketobutyrate, and ammonia. The mgl gene encoding MGL was cloned from the type strain Brevibacterium linens ATCC 9175 known to produce copious amounts of MTL and related VSCs. The disruption of the mgl gene, achieved in strain ATCC 9175, resulted in a 62% decrease in thiol-producing activity and a 97% decrease in total VSC production in the knockout strain. Our work shows that L-methionine degradation via gamma-elimination is a key step in the formation of VSCs in B. linens.

Casein utilization by Streptococcus thermophilus results in a diauxic growth in milk.

In milk, Streptococcus thermophilus displays two distinct exponential growth phases, separated by a nonexponential one, during which proteinase synthesis was initiated. During the second exponential phase, utilization of caseins as the source of amino acids resulted in a decrease in growth rate, presumably caused by a limiting peptide transport activity.