Vascular injuries after minor blunt upper extremity trauma: pitfalls in the recognition and diagnosis of potential "near miss" injuries

<p>Abstract</p> <p>Background</p> <p>Low energy trauma to the upper extremity is rarely associated with a significant vascular injury. Due to the low incidence, a high level of suspicion combined with appropriate diagnostic algorithms are mandatory for early recognition and timely management of these potentially detrimental injuries.</p> <p>Methods</p> <p>Review of the pertinent literature, supported by the presentation of two representative "near miss" case examples.</p> <p>Results</p> <p>A major diagnostic pitfall is represented by the insidious presentation of significant upper extremity arterial injuries with intact pulses and normal capillary refill distal to the injury site, due to collateral perfusion. Thus, severe vascular injuries may easily be missed or neglected at the upper extremity, leading to a long-term adverse outcome with the potential need for a surgical amputation.</p> <p>Conclusion</p> <p>The present review article provides an outline of the diagnostic challenges related to these rare vascular injuries and emphasizes the necessity for a high level of suspicion, even in the absence of a significant penetrating or high-velocity trauma mechanism.</p

The Prevalence and Clinical Implications of Comorbid Back Pain in Shoulder Instability: A Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Instability Cohort Study.

Background:Understanding predictors of pain is critical, as recent literature shows that comorbid back pain is an independent risk factor for worse functional and patient-reported outcomes (PROs) as well as increased opioid dependence after total joint arthroplasty. Purpose/Hypothesis:The purpose of this study was to evaluate whether comorbid back pain would be predictive of pain or self-reported instability symptoms at the time of stabilization surgery. We hypothesized that comorbid back pain will correlate with increased pain at the time of surgery as well as with worse scores on shoulder-related PRO measures. Study Design:Cross-sectional study; Level of evidence, 3. Methods:As part of the Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Instability cohort, patients consented to participate in pre- and intraoperative data collection. Demographic characteristics, injury history, preoperative PRO scores, and radiologic and intraoperative findings were recorded for patients undergoing surgical shoulder stabilization. Patients were also asked, whether they had any back pain. Results:The study cohort consisted of 1001 patients (81% male; mean age, 24.1 years). Patients with comorbid back pain (158 patients; 15.8%) were significantly older (28.1 vs 23.4 years; P &lt; .001) and were more likely to be female (25.3% vs 17.4%; P = .02) but did not differ in terms of either preoperative imaging or intraoperative findings. Patients with self-reported back pain had significantly worse preoperative pain and shoulder-related PRO scores (American Shoulder and Elbow Surgeons score, Western Ontario Shoulder Instability Index) (P &lt; .001), more frequent depression (22.2% vs 8.3%; P &lt; .001), poorer mental health status (worse scores for the RAND 36-Item Health Survey Mental Component Score, Iowa Quick Screen, and Personality Assessment Screener) (P &lt; .01), and worse preoperative expectations (P &lt; .01). Conclusion:Despite having similar physical findings, patients with comorbid back pain had more severe preoperative pain and self-reported symptoms of instability as well as more frequent depression and lower mental health scores. The combination of disproportionate shoulder pain, comorbid back pain and mental health conditions, and inferior preoperative expectations may affect not only the patient's preoperative state but also postoperative pain control and/or postoperative outcomes

Mapping Meaning : Critical Cartographies for Participatory Water Management in Taita Hills, Kenya

Participation of local people is often neglected in natural resource management, which leads to failure to understand the social aspects and historical construction of environmental problems. Participatory mapping can enhance the communication of local spatial knowledge for management processes and challenge the official maps and other spatial representations produced by state authorities and scientists. In this study, we analyze what kind of social meanings can be revealed through a multimethod participatory mapping process focusing on water resources in Taita Hills, Kenya. The participatory mapping clearly complicates the simplified image of the physical science mappings, typically depicting natural water supply, by addressing the impacts of contamination, inadequate infrastructure, poverty, distance to the sources, and restrictions in their uses on people's access to water. Moreover, this shared exercise is able to trigger discussion on issues that cannot always be localized but still contribute to place making. Local historical accounts reveal the social and political drivers of the current water-related problems, making explicit the political ecology dynamics in the area.Peer reviewe

Immunopurification of Pathological Prion Protein Aggregates

Background: Prion diseases are fatal neurodegenerative disorders that can arise sporadically, be genetically inherited or acquired through infection. The key event in these diseases is misfolding of the cellular prion protein (PrP) into a pathogenic isoform that is rich in β-sheet structure. This conformational change may result in the formation of PrP, the prion isoform of PrP, which propagates itself by imprinting its aberrant conformation onto PrP molecules. A great deal of effort has been devoted to developing protocols for purifying PrP for structural studies, and testing its biological properties. Most procedures rely on protease digestion, allowing efficient purification of PrP27-30, the protease-resistant core of PrP. However, protease treatment cannot be used to isolate abnormal forms of PrP lacking conventional protease resistance, such as those found in several genetic and atypical sporadic cases. Principal Findings: We developed a method for purifying pathological PrP molecules based on sequential centrifugation and immunoprecipitation with a monoclonal antibody selective for aggregated PrP. With this procedure we purified full-length PrP and mutant PrP aggregates at electrophoretic homogeneity. PrP purified from prion-infected mice was able to seed misfolding of PrP in a protein misfolding cyclic amplification reaction, and mutant PrP aggregates from transgenic mice were toxic to cultured neurons. Significance: The immunopurification protocol described here isolates biologically active forms of aggregated PrP. These preparations may be useful for investigating the structural and chemico-physical properties of infectious and neurotoxic PrP aggregates

Charged and Hydrophobic Surfaces on the A Chain of Shiga-Like Toxin 1 Recognize the C-Terminal Domain of Ribosomal Stalk Proteins

Shiga-like toxins are ribosome-inactivating proteins (RIP) produced by pathogenic E. coli strains that are responsible for hemorrhagic colitis and hemolytic uremic syndrome. The catalytic A1 chain of Shiga-like toxin 1 (SLT-1), a representative RIP, first docks onto a conserved peptide SD[D/E]DMGFGLFD located at the C-terminus of all three eukaryotic ribosomal stalk proteins and halts protein synthesis through the depurination of an adenine base in the sarcin-ricin loop of 28S rRNA. Here, we report that the A1 chain of SLT-1 rapidly binds to and dissociates from the C-terminal peptide with a monomeric dissociation constant of 13 µM. An alanine scan performed on the conserved peptide revealed that the SLT-1 A1 chain interacts with the anionic tripeptide DDD and the hydrophobic tetrapeptide motif FGLF within its sequence. Based on these 2 peptide motifs, SLT-1 A1 variants were generated that displayed decreased affinities for the stalk protein C-terminus and also correlated with reduced ribosome-inactivating activities in relation to the wild-type A1 chain. The toxin-peptide interaction and subsequent toxicity were shown to be mediated by cationic and hydrophobic docking surfaces on the SLT-1 catalytic domain. These docking surfaces are located on the opposite face of the catalytic cleft and suggest that the docking of the A1 chain to SDDDMGFGLFD may reorient its catalytic domain to face its RNA substrate. More importantly, both the delineated A1 chain ribosomal docking surfaces and the ribosomal peptide itself represent a target and a scaffold, respectively, for the design of generic inhibitors to block the action of RIPs

Morel-Lavallée Lesion of the Knee in a Recreational Frisbee Player

Traumatic swelling/effusion in the knee region is a relatively common presenting complaint among athletes and nonathletes. Due to its broad differential diagnosis, a comprehensive evaluation beginning with history and physical examination are recommended. Knee joint effusion can be differentiated from other types of swelling by careful physical examination. Imaging, including plain radiography, ultrasound, and magnetic resonance imaging (MRI), is preferred modality. Aspiration of a local fluctuating mass may help with the diagnosis and management of some of these conditions. We present a case of a 26-year-old gentleman with superomedial Morel-Lavallée lesion (MLL) of the knee with history of a fall during a Frisbee game. His MLL was successfully treated with therapeutic aspiration and compression wrap without further sequelae. MLL is a rare condition consisting of a closed degloving injury caused by pressure and shear stress between the subcutaneous tissue and the superficial fascia or bone. Most commonly, MLL is found over the greater trochanter and sacrum but in rare cases can occur in other regions of the body. In most cases, concurrent severe injury mechanisms and concomitant fractures are present. MLL due to sports injuries are very rare. Therapeutic strategies may vary from compression wraps and aspiration to surgical evacuation

The “Sublabral Window” in Arthroscopic Posterior Shoulder Instability Surgery: Description of a Technique for Safe Posterior Glenoid Preparation

Arthroscopic posterior labral repairs for posterior shoulder instability can be challenging. Preparation of the capsulolabral tissue and glenoid bony surface is critical. Iatrogenic injury to the articular cartilage and unwarranted truncation of the capsulolabral tissue are concerns during preparation. As a result, several techniques have been described to potentially avoid these complications. We describe an additional technique for improving access and preparing the capsulolabral tissue and glenoid surface through a “sublabral window.” This technique approaches the posterior labrum and glenoid through an already established posterior portal and mitigates iatrogenic injury to the labrum and articular cartilage. The technique is rather simple and easily adaptable