Does surgeon volume influence the outcome after hip hemiarthroplasty for displaced femoral neck fractures; early outcome, complications, and survival of 752 cases

Introduction: Surgeon volume of hip arthroplasties is of importance with regard to complication and revision rates in total hip arthroplasty. For hip hemiarthroplasty, the effect of surgeon volume on outcome is far less studied. We analyzed the outcome of hip hemiarthroplasties performed by orthopedic surgeons in a retrospective cohort in different volume categories, focusing on early survival of the prosthesis and complications. Methods: Between March 2009 and January 2014, 752 hemiarthroplasties were performed for intracapsular femoral neck fracture by 27 orthopedic surgeons in a large Dutch teaching hospital. Surgeons were divided into four groups, a resident group and three groups based on the number of total hip arthroplasties and hemiarthroplasties performed per year: a low-volume ( 35 arthroplasties per year). Outcome measures were stem survival using a competing risk analysis, complication rates, and mortality. Chi-square tests were used to compare complication rates and mortality between groups. Results: Patients were followed for a minimum of 2 years or until revision or death. Overall 60% of the patients included had died at time of follow-up. We found comparable stem survival rates in the low-volume group (n = 48), moderate-volume group (n = 201), high-volume group (n = 446), and resident group (n = 57). There were no significant differences between the groups with regard to dislocation rate, incidence of periprosthetic fracture, infection, and mortality. Conclusion: Surgeon volume and experience did not influence early outcome and complication rates in hip hemiarthroplasty. Hemiarthroplasty can safely be performed by both experienced hip surgeons and low-volume surgeons

ARGES: Radial segregation and helical instabilities in metal halide lamps studied under microgravity conditions in the international space station

HID lamps (High-Intensity Discharge) are gaining ground in the lighting industry because of their very high energy efficiency (up to 40%). In these lamps, which are operated in the arc regime and which are contained in a ceramic balloon, filled with argon or xenon, mercury, and salts of various rare earth metals and iodine), de-mixing occurs. This de-mixing is driven by differences in diffusion velocities of molecules and atoms. Furthermore, helical instabilities might occur in the lamp. Both phenomena are severely modified under 1 G conditions: convection will bend a horizontally burning arc channel upwards, and a vertically burning arc channel will exhibit convective cells. This makes it impossible to study these phenomena on the ground. If a proper understanding of these phenomena is to be gained, experiments under microgravity are necessary. The main objectives of the experiment are: (1) determination of the critical factors for the onset of helical instabilities in HID lamps and (2) characterisation of the radial de-mixing processes by radially resolved high-resolution emission spectroscopy. To this end, special hardware has been designed and built which houses a very compact high-resolution spectrometer, a video camera and a caroussel with 20 lamps in it. The lamps are measured consecutively. The experiments have been performed successfully by the Dutch astronaut Andre´ Kuipers on board the International Space Station during the Dutch Soyuz Mission DELTA on 24 and 25 April 2004. Especially the helical instabilities part yielded immediate and surprising results: the arc channel does bend, but does not rotate under microgravity. This fact is very important in improving the performance of the lamps, especially since the instabilities occur mainly in the most efficient lamps. © Z-Tec Publishing, Bremen

Predicting mortality of individual patients with COVID-19: A multicentre Dutch cohort

Objective Develop and validate models that predict mortality of patients diagnosed with COVID-19 admitted to the hospital. Design Retrospective cohort study. Setting A multicentre cohort across 10 Dutch hospitals including patients from 27 February to 8 June 2020. Participants SARS-CoV-2 positive patients (age ≥18) admitted to the hospital. Main outcome measures 21-day all-cause mortality evaluated by the area under the receiver operator curve (AUC), sensitivity, specificity, positive predictive value and negative predictive value. The predictive value of age was explored by comparison with age-based rules used in practice and by excluding age from the analysis. Results 2273 patients were included, of whom 516 had died or discharged to palliative care within 21 days after admission. Five feature sets, including premorbid, clinical presentation and laboratory and radiology values, were derived from 80 features. Additionally, an Analysis of Variance (ANOVA)-based data-driven feature selection selected the 10 features with the highest F values: age, number of home medications, urea nitrogen, lactate dehydrogenase, albumin, oxygen saturation (%), oxygen saturation is measured on room air, oxygen saturation is measured on oxygen therapy, blood gas pH and history of chronic cardiac disease. A linear logistic regression and non-linear tree-based gradient boosting algorithm fitted the data with an AUC of 0.81 (95% CI 0.77 to 0.85) and 0.82 (0.79 to 0.85), respectively, using the 10 selected features. Both models outperformed age-based decision rules used in practice (AUC of 0.69, 0.65 to 0.74 for age >70). Furthermore, performance remained stable when excluding age as predictor (AUC of 0.78, 0.75 to 0.81). Conclusion Both models showed good performance and had better test characteristics than age-based decision rules, using 10 admission features readily available in Dutch hospitals. The models hold promise to aid decision-making during a hospital bed shortage

Reduced Cancer Incidence in Huntington's Disease: Analysis in the Registry Study

Background: People with Huntington's disease (HD) have been observed to have lower rates of cancers. Objective: To investigate the relationship between age of onset of HD, CAG repeat length, and cancer diagnosis. Methods: Data were obtained from the European Huntington's disease network REGISTRY study for 6540 subjects. Population cancer incidence was ascertained from the GLOBOCAN database to obtain standardised incidence ratios of cancers in the REGISTRY subjects. Results: 173/6528 HD REGISTRY subjects had had a cancer diagnosis. The age-standardised incidence rate of all cancers in the REGISTRY HD population was 0.26 (CI 0.22-0.30). Individual cancers showed a lower age-standardised incidence rate compared with the control population with prostate and colorectal cancers showing the lowest rates. There was no effect of CAG length on the likelihood of cancer, but a cancer diagnosis within the last year was associated with a greatly increased rate of HD onset (Hazard Ratio 18.94, p < 0.001). Conclusions: Cancer is less common than expected in the HD population, confirming previous reports. However, this does not appear to be related to CAG length in HTT. A recent diagnosis of cancer increases the risk of HD onset at any age, likely due to increased investigation following a cancer diagnosis

Clinical and genetic characteristics of late-onset Huntington's disease

Background: The frequency of late-onset Huntington's disease (&gt;59 years) is assumed to be low and the clinical course milder. However, previous literature on late-onset disease is scarce and inconclusive. Objective: Our aim is to study clinical characteristics of late-onset compared to common-onset HD patients in a large cohort of HD patients from the Registry database. Methods: Participants with late- and common-onset (30–50 years)were compared for first clinical symptoms, disease progression, CAG repeat size and family history. Participants with a missing CAG repeat size, a repeat size of ≤35 or a UHDRS motor score of ≤5 were excluded. Results: Of 6007 eligible participants, 687 had late-onset (11.4%) and 3216 (53.5%) common-onset HD. Late-onset (n = 577) had significantly more gait and balance problems as first symptom compared to common-onset (n = 2408) (P &lt;.001). Overall motor and cognitive performance (P &lt;.001) were worse, however only disease motor progression was slower (coefficient, −0.58; SE 0.16; P &lt;.001) compared to the common-onset group. Repeat size was significantly lower in the late-onset (n = 40.8; SD 1.6) compared to common-onset (n = 44.4; SD 2.8) (P &lt;.001). Fewer late-onset patients (n = 451) had a positive family history compared to common-onset (n = 2940) (P &lt;.001). Conclusions: Late-onset patients present more frequently with gait and balance problems as first symptom, and disease progression is not milder compared to common-onset HD patients apart from motor progression. The family history is likely to be negative, which might make diagnosing HD more difficult in this population. However, the balance and gait problems might be helpful in diagnosing HD in elderly patients