Revealing latent pole and zone line information in atom probe detector maps using crystallographically correlated metrics.

Poles and zone lines observed within atom probe field evaporation images are useful for a range of atom probe crystallography studies, including calibration of the reconstruction and crystallographic characterisation of microstructural features such as grain boundaries. However, this information is not always readily apparent. Techniques for plotting crystallographically correlated metrics contained within atom probe data to enhance pole and zone line contrast across the detector space are developed. This includes consideration of the electric field, molecular ions, lattice structure retained within the reconstruction, specific elemental species, the number of pulses between detection events, and the lateral distance between sequential detection events. These approaches are then applied to experimental atom probe tomography datasets on technically pure Al, nanocrystalline Al, highly doped Si, and additively manufactured Inconel 738, Haynes 282, and Ti-6Al-4V. The results facilitate the extension of atom probe crystallography studies to a broader range of crystalline datasets where crystallographic information is not readily apparent from existing methods, as well as a deeper understanding of field evaporation behaviour during an atom probe experiment.

Acute surgical management of traumatic knee dislocations--Average follow-up of 10 years.

BACKGROUND: Traumatic knee dislocations have been managed historically by means of either delayed reconstruction or non-operative methods. More recently, there has been a trend towards early reconstruction. There is no clear consensus in the literature as to how such patients should be managed and in what time frame. OBJECTIVE: The aim of this study was to establish the long-term outcome of patients who underwent acute surgical management of their traumatic knee dislocation. METHODS: Thirty-six patients with traumatic knee dislocations were treated by multi-ligament reconstruction. All surgical interventions occurred within 21 days of presentation. The collateral ligament complexes were primarily repaired where possible and reconstructions were performed with either autograft, allograft or the ligament augmentation and reconstruction system (LARS) synthetic graft. RESULTS: The mean time to surgery was 12 days (1 to 21) with a mean follow-up of 10.1 years (7 to 19). The International Knee Documentation Committee (IKDC) assessment demonstrates that 56% of patients went on to have "nearly normal" knee function and the average Tegner-Lysholm score of 80 (57 to 91), is consistent with good function. The Knee Outcome score (KOS) was 84% for Activities of Daily Living and 74% for Sports. CONCLUSION: This study demonstrates a high level of overall knee function following the acute surgical reconstruction of traumatic knee dislocations. LEVEL OF EVIDENCE: Level 2B: Cohort Study with Outcome Measures.

The Royal College of Ophthalmologists' National Ophthalmology Database Study of cataract surgery: report 2, relationships of axial length with ocular copathology, preoperative visual acuity, and posterior capsule rupture.

PURPOSE: To describe the relationships of axial length with ocular copathology, preoperative visual acuity, and posterior capsule rupture rates in patients undergoing cataract surgery.DesignThe Royal College of Ophthalmologists' National Ophthalmology Database (NOD) study. METHODS: Anonymised data on 180 114 eyes from 127 685 patients undergoing cataract surgery between August 2006 and November 2010 were collected prospectively from 28 sites. Data parameters included: demographics, biometry, ocular copathology, visual acuity measurements, and surgical complications including posterior capsule rupture, or vitreous loss or both (PCR). RESULTS: Consultant surgeons performed a higher proportion of operations on eyes whose axial length were at the extremes. Glaucoma and age related macular degeneration were more common in eyes with shorter axial lengths, whilst previous vitrectomy was associated with longer axial lengths. Eyes with brunescent or white cataracts or amblyopia were more common at both axial length extremes. Preoperative visual acuities were similar for eyes with axial length measurements up to approximately 28 mm and worse for eyes with longer axial length measurements. PCR rates showed little change with axial length (overall mean 1.95%, 95% CI: 1.89 to 2.01%), except for a borderline increase in eyes with axial length <20.0 mm where rates were 3.6% (95% CI: 2.0 to 6.3%). The likelihood of PCR in eyes with axial length <20.0 mm was 1.88 times higher than those of ≥20.0 mm (P=0.0373). CONCLUSION: Rates of ocular comorbidities vary by axial length. PCR rates in eyes with very short or long axial lengths were lower than expected.

The Royal College of Ophthalmologists' National Ophthalmology Database study of cataract surgery: report 1, visual outcomes and complications.

AIMS: To describe the outcomes of cataract surgery in the United Kingdom. METHODS: Anonymised data on 180 114 eyes from 127 685 patients undergoing cataract surgery between August 2006 and November 2010 were collected prospectively from 28 sites. Outcome measures included intraoperative and postoperative complication rates, and preoperative and postoperative visual acuities. RESULTS: Median age at first eye surgery was 77.1 years, 36.9% cases had ocular co-pathology and 41.0% patients underwent cataract surgery on both eyes. Preoperative visual acuity was 0.30 logMAR or better in 32.0% first eyes and 47.7% second eyes. Postoperative best-measured visual acuity was 0.00 and 0.30 logMAR or better in 50.8 and 94.6% eyes without ocular co-pathology, and 32.5 and 79.9% in eyes with co-pathology. For eyes without co-pathology, postoperative uncorrected distance visual acuity was 0.00 and 0.30 logMAR or better in 27.3 and 80.9% eyes. Posterior capsule rupture or vitreous loss or both occurred in 1.95% cases, and was associated with a 42 times higher risk of retinal detachment surgery within 3 months and an eight times higher risk of endophthalmitis. CONCLUSION: These results provide updated data for the benchmarking of cataract surgery. Visual outcomes, and the rate of posterior capsule rupture or vitreous loss or both appear stable over the past decade.

Biomechanical testing of a concept of posterior pelvic reconstruction in rotationally and vertically unstable fractures.

The purpose of this study was to assess the stability of a developmental pelvic reconstruction system which extends the concept of triangular osteosynthesis with fixation anterior to the lumbosacral pivot point. An unstable Tile type-C fracture, associated with a sacral transforaminal fracture, was created in synthetic pelves. The new concept was compared with three other constructs, including bilateral iliosacral screws, a tension band plate and a combined plate with screws. The pubic symphysis was plated in all cases. The pelvic ring was loaded to simulate single-stance posture in a cyclical manner until failure, defined as a displacement of 2 mm or 2°. The screws were the weakest construct, failing with a load of 50 N after 400 cycles, with maximal translation in the craniocaudal axis of 12 mm. A tension band plate resisted greater load but failure occurred at 100 N, with maximal rotational displacement around the mediolateral axis of 2.3°. The combination of a plate and screws led to an improvement in stability at the 100 N load level, but rotational failure still occurred around the mediolateral axis. The pelvic reconstruction system was the most stable construct, with a maximal displacement of 2.1° of rotation around the mediolateral axis at a load of 500 N.

Crescent fracture-dislocation of the sacroiliac joint: a functional classification.

Crescent fracture dislocations are a well-recognised subset of pelvic ring injuries which result from a lateral compression force. They are characterised by disruption of the sacroiliac joint and extend proximally as a fracture of the posterior iliac wing. We describe a classification with three distinct types. Type I is characterised by a large crescent fragment and the dislocation comprises no more than one-third of the sacroiliac joint, which is typically inferior. Type II fractures are associated with an intermediate-size crescent fragment and the dislocation comprises between one- and two-thirds of the joint. Type III fractures are associated with a small crescent fragment where the dislocation comprises most, but not all of the joint. The principal goals of surgical intervention are the accurate and stable reduction of the sacroiliac joint. This classification proves useful in the selection of both the surgical approach and the reduction technique. A total of 16 patients were managed according to this classification and achieved good functional results approximately two years from the time of the index injury. Confounding factors compromise the summary short-form-36 and musculoskeletal functional assessment instrument scores, which is a well-recognised phenomenon when reporting the outcome of high-energy trauma.

Early detection of arterial bleeding in acute pelvic trauma.

OBJECTIVE: To determine the accuracy of intravenous contrast-enhanced computerized tomography (CECT) in the detection of potentially life-threatening retroperitoneal hemorrhage in patients sustaining pelvic fractures, acetabular fractures or both. DESIGN: Retrospective review of sequential patients identified over a 1-year period by using a prospectively collected trauma database at two Level I trauma centers. MATERIALS AND METHODS: A group of patients admitted to one of two Level I trauma centers with pelvic or acetabular injuries between September 1, 1995, and September 30, 1996, was identified by using a prospectively collected trauma database. From this cohort, we selected those individuals who had undergone intravenous CECT scanning within 24 hours after admission and who had an Abbreviated Injury Score more than 3 because of their pelvic injury. Those individuals who required arterial embolization for uncontrolled hemodynamic shock were categorized as having "significant arterial bleeding" attributable to their pelvic injury. Individuals who regained hemodynamic ,stability without embolization were categorized as having "no significant arterial bleeding." Two observers who were blinded to clinical information and the results of angiography reviewed all injury radiographs and computed tomographic scans. The presence or absence of contrast extravasation on intravenous CECT was recorded. Each case was then categorized into a 2 x 2 table depending on the presence of contrast extravasation on CECT and the need for arterial embolization to determine the accuracy of the "contrast extravasation sign." RESULTS: Of the 192 eligible patients, 111 met the inclusion criteria. Eleven patients required an angiogram for ongoing hemodynamic instability. The sensitivity of extravasation on contrast enhanced computed tomography representing a significant arterial bleeding was 80%, and the specificity was 98%. The predictive value of a positive contrast "extravasation sign" was 80%, whereas the predictive value of a negative test was 98%. The likelihood ratio of a positive test was 40.4, and the likelihood ratio of a negative test was 0.204. CONCLUSION: The finding of contrast extravasation on CECT is highly suggestive of significant arterial bleeding that requires early angiographic embolization to restore hemodynamic stability.

Traumatic massive air leak treated with prolonged double lumen intubation and high frequency ventilation: case report.

A case is presented of unilateral traumatic massive air leak successfully treated with prolonged double-lumen endobronchial intubation and unilateral high frequency intermittent positive pressure ventilation, while the "good" lung was ventilated conventionally. The problems encountered are described and the rationale for this management are discussed.

Grading asthma severity: using the APS component of the Apache II system.

OBJECTIVE: Measurement of severity is fundamental to the description and comparison of case series, treatment regimens and disease outcomes. This study examines the Acute Physiology Score (APS) as a severity measure of an acute "life-threatening" asthma attack. DESIGN: The APS in the emergency department (ED) and ICU, demographic, treatment and outcome variables were prospectively studied. Relationships between severity, treatment and progress were investigated. In addition, patients were stratified according to ED APS and differences between the participating hospitals were examined. SETTING: Emergency Departments and Intensive Care Units of two New Zealand hospitals. PATIENTS: 64 admissions to the ICUs following an acute episode of asthma. INTERVENTIONS: Standard management of acute asthma as practised at the two participating hospitals. MEASUREMENTS AND RESULTS: Both the treatment delivered (intravenous salbutamol, sodium bicarbonate and IPPV) and the rate of improvement as defined by change in APS between the ED and the ICU were found to be strongly related to ED APS. Similarly, the length of stay in the ICU correlated with the ICU APS. Stratification on the basis of ED APS allowed small but significant differences in patient physiologic derangement, dose of salbutamol, use of IPPV and incidence of complications to be detected between patients at the two hospitals. CONCLUSION: This prospective study involving two hospitals validates the APS as a method for measuring the severity of an acute asthma attack. It demonstrates how correction for severity can be used to compare treatment and outcome variables in different case series.

Diagnostic peritoneal lavage: integration with clinical information to improve diagnostic performance.

Management of abdominal trauma requires both the detection of injuries sustained and an ability to distinguish patients who require operative repair from those who do not. In this prospective study of 200 patients receiving diagnostic peritoneal lavage (DPL) following blunt trauma, relationships among DPL result, clinical features (information from initial patient assessment), and laparotomy outcome were investigated. The DPL result alone predicted requirement for laparotomy with an accuracy of 93%, a specificity of 96%, a sensitivity of 85%, a positive predictive value (PV-Positive) of 87%, and a negative predictive value (PV-Negative) of 95%. Combining clinical features with the DPL result reduced the number of unnecessary laparotomies (increased PV-Positive and specificity), but increased the number of missed necessary laparotomies (decreased PV-Negative and sensitivity). The best diagnostic performance was found by combining the DPL result with circulatory status, which, in this series of patients, predicted necessary laparotomy with an accuracy of 95%, a specificity of 99%, a sensitivity of 81%, a PV-Positive of 98%, and a PV-Negative of 94%.

Theophylline poisoning--a review of 64 cases.

Sixty-four cases of theophylline poisoning were reviewed. All but two cases represented international self poisoning. The majority of patients were young females who presented acutely after ingestion of sustained release preparations prescribed for asthma. Serum theophylline levels (mean 365 mumol/l, SD 177) indicated a high risk of toxicity. Electrolyte and metabolic abnormalities (hypokalaemia, hypomagnesaemia, hypophosphataemia, hyperglycaemia, acid-base disturbances and leucocytosis) were common. Serum potassium, serum glucose, leucocyte count and length of stay in the intensive care unit all correlated strongly with maximum serum theophylline level (p less than 0.001). The low incidence of life-threatening manifestations of severe toxicity (hypotension, serious arrhythmias or seizures) and excellent outcome, contrasts with many previous reports. The results support the use of a management regimen which emphasizes intensive supportive therapy and restricts the use of charcoal haemoperfusion.

Effect of cigarette smoking on postural muscle tremor.

In a study of the effect of smoking on postural reflexes--specifically postural muscle tremor--in man, amplitude of postural muscle tremor, when tested in 30 subjects, was increased to a significant degree immediately following the smoking of one cigarette. Tremor amplitude continued to be significantly increased one-half hour after smoking ceased. There was no significant change in the frequency of tremor. Measurement was made using a piezo crystal accelerometer attached to the third fingers of both hands. Effects were recorded with a Sanborn Twin Viso Recorder. The findings, that smoking does affect postural reflexes, have implications for the formulation of nursing therapies, particularly in areas such as rehabilitation nursing, where the use of postural reflexes is the primary mode of intervention.