A technique to quantify very low activities in regions of interest with a collimatorless detector

We present a new method to measure sub-microcurie activities of photon-emitting radionuclides in organs and lesions of small animals in vivo. Our technique, named the collimator-less likelihood fit, combines a very high sensitivity collimatorless detector with a Monte Carlo-based likelihood fit in order to estimate the activities in previously segmented regions of interest along with their uncertainties. This is done directly from the photon projections in our collimatorless detector and from the region of interest segmentation provided by an x-ray computed tomography scan. We have extensively validated our approach with 225Ac experimentally in spherical phantoms and mouse phantoms, and also numerically with simulations of a realistic mouse anatomy. Our method yields statistically unbiased results with uncertainties smaller than 20% for activities as low as ~111 Bq (3 nCi) and for exposures under 30 minutes. We demonstrate that our method yields more robust recovery coefficients when compared to SPECT imaging with a commercial pre-clinical scanner, specially at very low activities. Thus, our technique is complementary to traditional SPECT/CT imaging since it provides a more accurate and precise organ and tumor dosimetry, with a more limited spatial information. Finally, our technique is specially significant in extremely low-activity scenarios when SPECT/CT imaging is simply not viable.

A high concentration CO2 pool over the Indo-Pacific Warm Pool

Anthropogenic emissions have produced significant amount of carbon dioxide (CO₂) in the atmosphere since the beginning of the industrial revolution. High levels of atmospheric CO₂ increases global temperature as CO₂ absorbs outgoing longwave radiation and re-emits. Though a well-mixed greenhouse gas, CO₂ concentration is not uniform in the atmosphere across different altitudes and latitudes. Here, we uncover a region of high CO₂ concentration (i.e. CO₂ pool) in the middle troposphere (500-300 hPa) over the Indo-Pacific Warm Pool (IPWP, 40° E-140° W, 25° S-25° N), in which the CO₂ concentration is higher than that of other regions in the same latitude band (20° N-20° S), by using CO₂ satellite measurements for the period 2002-2017. This CO₂ pool extends from the western Pacific to the eastern Indian Ocean. Much of the CO₂ pool is over the western Pacific Ocean (74.87%), and the remaining lies over the eastern Indian Ocean (25.13%). The rising branch of Walker circulation acts as a "CO₂ Chimney" that constantly transports CO₂ released from the natural, human-induced and ocean outgassing processes to the middle and upper troposphere. The CO₂ pool evolves throughout the year with an average annual trend of about 2.17 ppm yr^-1, as estimated for the period 2003-2016. Our analysis further reveals that La Niña (El Niño) events strengthen (weaken) the CO₂ pool in the mid-troposphere. The radiative forcing for the CO₂ pool suggests more warming in the region and is a grave concern for global warming and climate change.

Treatment of prostate cancer with CD46 targeted 225Ac alpha particle radioimmunotherapy

PURPOSE

Radiopharmaceutical therapy is changing the standard of care in prostate cancer (PCa) and other malignancies. We previously reported high CD46 expression in PCa and developed an antibody-drug conjugate and immunoPET agent based on the YS5 antibody, which targets a tumor-selective CD46 epitope. Here, we present the preparation, preclinical efficacy, and toxicity evaluation of [225Ac]DOTA-YS5, a radioimmunotherapy agent based on the YS5 antibody.

EXPERIMENTAL DESIGN

[225Ac]DOTA-YS5 was developed, and its therapeutic efficiency was tested on cell derived (22Rv1, DU145), and patient derived (LTL-545, LTL484) PCa xenograft models. Biodistribution studies were carried out on 22Rv1 tumor xenograft models to confirm the targeting efficacy. Toxicity analysis of the [225Ac]DOTA-YS5 was carried out on nu/nu mice to study short-term (acute) and long-term (chronic) toxicity.

RESULTS

Biodistribution study shows that [225Ac]DOTA-YS5 agent delivers high levels of radiation to the tumor tissue (11.64±1.37 %ID/g, 28.58±10.88 %ID/g, 29.35±7.76%ID/g, and 31.78±5.89 %ID/g at 24 h, 96 h, 168 h, and 408 h, respectively), compared to the healthy organs. [225Ac]DOTA-YS5 suppressed tumor size and prolonged survival in cell line and patient derived xenograft models. Toxicity analysis revealed that the 0.5 µCi activity levels showed toxicity to the kidneys, likely due to redistribution of daughter isotope 213Bi.

CONCLUSIONS

[225Ac]DOTA-YS5 suppressed the growth of cell-derived and patient-derived xenografts, including PSMA-positive and deficient models. Overall, this preclinical study confirms that [225Ac]DOTA-YS5 is a highly effective treatment and suggests feasibility for clinical translation of CD46 targeted radioligand therapy in PCa.

Comparison and calibration of dose delivered by137Cs and x-ray irradiators in mice

Objective.The Office of Radiological Security, U.S. Department of Energy's National Nuclear Security Administration, is implementing a radiological risk reduction program which seeks to minimize or eliminate the use of high activity radiological sources, including¹³⁷Cs, by replacing them with non-radioisotopic technologies, such as x-ray irradiators. The main goal of this paper is to evaluate the equivalence of the dose delivered by gamma- and x-ray irradiators in mice using experimental measurements and Monte Carlo simulations. We also propose a novel biophantom as anin situdose calibration method.Approach.We irradiated mouse carcasses and 3D-printed mouse biophantoms in a¹³⁷Cs irradiator (Mark I-68) and an x-ray irradiator (X-Rad320) at three voltages (160 kVp, 225 kVp and 320 kVp) and measured the delivered radiation dose. A Geant4-based Monte Carlo model was developed and validated to provide a comprehensive picture of gamma- and x-ray irradiation in mice.Main Results.Our Monte Carlo model predicts a uniform dose delivered in soft-tissue for all the explored irradiation programs and in agreement with the absolute dose measurements. Our Monte Carlo model shows an energy-dependent difference between dose in bone and in soft tissue that decreases as photon energy increases. Dose rate depends on irradiator and photon energy. We observed a deviation of the measured dose from the target value of up to -9% for the Mark I-68, and up to 35% for the X-Rad320. The dose measured in the 3D-printed phantoms are equivalent to that in the carcasses within 6% uncertainty.Significance.Our results suggest that 320 kVp irradiation is a good candidate to substitute¹³⁷Cs irradiation barring a few caveats. There is a significant difference between measured and targeted doses for x-ray irradiation that suggests a strong need forin situcalibration, which can be achieved with 3D-printed mouse biophantoms. A dose correction is necessary for bone doses, which can be provided by a Monte Carlo calculation. Finally, the biological implications of the differences in dose rates and dose per photon for the different irradiation methods should be carefully assessed for each small-animal irradiation experiment.

Small-scale (sub-organ and cellular level) alpha-particle dosimetry methods using an iQID digital autoradiography imaging system

Targeted radiopharmaceutical therapy with alpha-particle emitters (αRPT) is advantageous in cancer treatment because the short range and high local energy deposition of alpha particles enable precise radiation delivery and efficient tumor cell killing. However, these properties create sub-organ dose deposition effects that are not easily characterized by direct gamma-ray imaging (PET or SPECT). We present a computational procedure to determine the spatial distribution of absorbed dose from alpha-emitting radionuclides in tissues using digital autoradiography activity images from an ionizing-radiation quantum imaging detector (iQID). Data from ²¹¹At-radioimmunotherapy studies for allogeneic hematopoietic cell transplantation in a canine model were used to develop these methods. Nine healthy canines were treated with 16.9-30.9 MBq ²¹¹At/mg monoclonal antibodies (mAb). Lymph node biopsies from early (2-5 h) and late (19-20 h) time points (16 total) were obtained, with 10-20 consecutive 12-µm cryosections extracted from each and imaged with an iQID device. iQID spatial activity images were registered within a 3D volume for dose-point-kernel convolution, producing dose-rate maps. The accumulated absorbed doses for high- and low-rate regions were 9 ± 4 Gy and 1.2 ± 0.8 Gy from separate dose-rate curves, respectively. We further assess uptake uniformity, co-registration with histological pathology, and requisite slice numbers to improve microscale characterization of absorbed dose inhomogeneities in αRPT.

The relationship of weather with daily physical activity and the time spent out of home in older adults from Germany – the ActiFE study

Background

There is a need for a comprehensive evaluation of the associations between varieties of weather conditions on the time spent out-of-home (TOH) and on walking duration (WD) among older adults. We aim to investigate the extent to which various weather parameters (temperature, solar radiation, sunshine duration, humidity, windspeed, and rain) determine daily WD the TOH in older adults.

Methods

The ActiFE (Activity and Function in Older People in Ulm) study is a prospective study of participants aged 65 years or older who wore an accelerometer and kept a movement diary in up to three temporally separated waves from 2009 to 2018 for a duration up to seven days per wave (up to three weeks in summary). We used weather data from a weather station near the participants‘ homes. Age-adjusted and gender-stratified generalized mixed models were used to predict WD and TOH (with 95% confidence interval (CI)) within and between weather categories. Generalized additive models were computed for the single predictions at the weather quartile boundaries. Cubic splines (with 95% pointwise confidence bands (CB)) visualized the continuous course of the weather values.

Results

Higher temperatures, solar radiation and more hours of sunshine, led to an increase in WD and TOH, while higher precipitation, humidities and windspeeds led to a decrease. Women had in general higher WD and TOH times than men.

Conclusions

Our data suggest that weather parameters have a considerable influence on PA and TOH. Future analyses and interpretation of PA data should therefore account for weather parameters.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11556-022-00286-0.

[Outcome of a survey on antibiotic prescribing in veterinary medicine]

INTRODUCTION

As part of the national strategy on antibiotic resistance (StAR), a therapy guide for the prudent prescription of antimicrobial agents in animals was developed. To facilitate its implementation in the veterinary practice, the therapy recommendations contained therein have been translated to the user-friendly decision support AntibioticScout.ch. In this context, we conducted a non-representative survey to assess the level of awareness as well as usage of this guide and the AntibioticScout.ch decision support. Based on case studies with typical diseases in dogs, cats and cattle, it was shown that the veterinarians participating in the survey strive to handle antibiotics responsibly and to prescribe them with restraint. Nevertheless, the survey points to possible improvements in the antibiotic therapy. In particular, the StAR guidelines or AntibioticScout.ch can be useful to the practicing veterinarians for taking into account all relevant decision criteria in the optimal selection of a suitable antimicrobial agent.

Fracture Risk Following an Atypical Femoral Fracture

Atypical femoral fractures (AFFs) occurring during the course of osteoporosis treatment usually lead to discontinuation of anti-resorptive (AR) drugs. However, the risk of fracture after an AFF is unknown. We conducted a follow-up study of patients with AFF matched 1:3 for age and gender with patients with a peripheral major osteoporotic fracture (pMOF), in the setting of a fracture liaison service, to investigate the incidence of subsequent low-trauma fractures. Fifty-five patients with AFF (95% women, age [mean ± standard deviation] 75 ± 10 years, 89% exposed to AR drugs), followed for 6.2 ± 3.7 years, were compared to 165 matched controls with a pMOF (hip 85%) followed for 4.3 ± 2.6 years. During the follow-up, 38% of patients in the AFF group and 16% in the pMOF group received AR therapies. Continuation of AR drugs after an AFF was associated with contralateral AFF in 27% of subjects. The risks of new low-trauma, major osteoporotic and imminent (within 2 years) fractures, were similar between the two groups: incidence rate ratio (95% confidence interval [CI]) of subsequent fracture following AFF relative to pMOF, 1.30 (95% CI, 0.82-2.04), 1.28 (95% CI, 0.74-2.15), and 1.11 (95% CI, 0.54-2.15), respectively. Moreover, the risk of sustaining multiple fractures per participant was significantly increased among patients with AFF compared to pMOF (hazard ratio 1.48 [95% CI, 1.00-2.19]; p = 0.049). When taking mortality into account, the risk of subsequent fractures tended to be higher in the AFF group (sub-hazard ratio 1.42 [95% CI, 0.95-2.12]). In conclusion, patients who sustained an AFF are at high risk of subsequent fragility fractures, at least equal or even greater to the risk observed after a pMOF. However, continuation of AR drugs increases the risk of contralateral AFF. Therefore, optimal modalities for secondary fracture prevention after AFF require further evaluation. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Short stem total hip arthroplasty with the direct anterior approach demonstrates suboptimal fixation

PURPOSE

Short stems use has increased substantially despite variable results reported in the literature. The purpose of this study was to report the rate of complications using a short stem implanted through the direct anterior approach (DAA), and to evaluate mid-term clinical and radiological results focusing on femoral stem fixation.

METHODS

Between April 2009 and November 2014, 698 elective total hip arthroplasties (THAs) were performed using a fully hydroxyapatite-coated short stem (AMIStem-H®). The mean age was 65.7 years (SD 12.6). Patients were invited for clinical and radiological evaluation, and to complete patient-reported outcomes questionnaires at two and five years after surgery. The mean follow-up was 6.2 years (range 2-9.73 years).

RESULTS

During the study period, 59 (8.5%) patients died and 24 (3.4%) were lost to follow-up. There were six (0.9%) dislocations and 12 (1.7%) fractures, seven occurred intra-operatively. Twenty-nine (4.2%) THAs required revision surgery. Eleven THAs were revised for aseptic loosening of the stem at a mean 4.9 years (1.2-7.3 years). Five years after surgery, radiographs of 324 THAs (324/425 eligible = 76.2%) were available. Stem subsidence ≥ 2 mm was present in 42 cases (12.9%), proximal radiolucencies in 101 hips (31.5%), cortical thickening in 52 (16.0%), and a pedestal in 219 (67.6%). An Engh score between - 10 and 0 was associated with lower HHS pain subscore (p = 0.005), a higher risk of stem revision for aseptic loosening (18.8% vs. 2.7%; p = 0.008), and was more frequent in younger patients with ASA score 1.

CONCLUSION

Patients presenting radiological alterations at five years had an increased risk of revision for aseptic stem loosening and also inferior clinical results. Our study warrants further continued scrutiny of mid- and long-term survivorship of the AMIStem-H®, with radiological results at five years indicating suboptimal fixation of the stem in younger and active patients.

Clinical and radiographic predictors of acute compartment syndrome in the treatment of tibial shaft fractures: a retrospective cohort study

Background

The purpose of this study was to evaluate the association between epidemiological, clinical and radiographic factors of patients with tibial shaft fractures and the occurrence of acute compartment syndrome.

Methods

270 consecutive adult patients sustaining 273 tibial shaft fractures between January 2005 and December 2009 were included in this retrospective cohort study. The outcome measure was acute compartment syndrome. Patient-related (age, sex), fracture-related (high- vs. low-energy injury, isolated trauma vs. polytrauma, closed vs. open fracture) and radiological parameters (AO/OTA classification, presence or absence of a noncontiguous tibial plateau or pilon fracture, distance from the centre of the tibial fracture to the talar dome, distance between tibial and fibular fracture if associated, and angulation, translation and over-riding of main tibial fragments) were evaluated regarding their potential association with acute compartment syndrome. Univariate analysis was performed and each covariate was adjusted for age and sex. Finally, a multivariable logistic regression model was built, and odds ratios and 95% confidence intervals were obtained. Statistical significance was defined as p < 0.05.

Results

Acute compartment syndrome developed in 31 (11.4%) cases. In the multivariable regression model, four covariates remained statistically significantly associated with acute compartment syndrome: polytrauma, closed fracture, associated tibial plateau or pilon fracture and distance from the centre of the tibial fracture to the talar dome ≥15 cm.

Conclusions

One radiological parameter related to the occurrence of acute compartment syndrome has been highlighted in this study, namely a longer distance from the centre of the tibial fracture to the talar dome, meaning a more proximal fracture. This observation may be useful when clinical findings are difficult to assess (doubtful clinical signs, obtunded, sedated or intubated patients). However, larger studies are mandatory to confirm and refine the prediction of acute compartment syndrome occurrence. Radiographic signs of significant displacement were not found to be correlated to acute compartment syndrome development. Finally, the higher rate of acute compartment syndrome occurring in tibial shaft fractures associated to other musculoskeletal, thoraco-abdominal or cranio-cerebral injuries must raise the level of suspicion of any surgeon managing multiply injured patients.

Lazy Sundays: role of day of the week and reactivity on objectively measured physical activity in older people

Background

The aim of this study was to assess the effect of day of the week and wearing a device (reactivity) on objectively measured physical activity (PA) in older people.

Methods

Walking duration as a measure for PA was recorded from 1333 German community-dwelling older people (≥65 years, 43.8% women) over 5 days using accelerometers (activPAL). Least-square means of PA with 95%-confidence intervals (95%-CI) from multi-level analysis were calculated for each day of the week and each measurement day (days after sensor attachment).

Results

Walking duration on Sundays was significantly lower compared to working days (Sunday vs. Monday-Friday: − 12.8 min (95%-CI: − 14.7; − 10.9)). No statistically significant difference compared to working days was present for Saturdays. The linear slope for measurement day and walking duration was marginal and not statistically significant.

Conclusions

Studies using PA sensors in older people should assess Sundays and working days to adequately determine the activity level of the participants.

[An update for the treatment of osteoid osteoma]

Osteoid osteoma is frequent benign tumor, descripted initially by Bergstrand in 1930 followed by Jaffe in 1935. The painful feature of the osteoid osteoma explains the specific consideration by the medical community for this entity. The debate was focused on pathologic and imaging pattern as well as the treatment modalities. Currently, the treatment options are varied and percutaneous treatment is increasingly used. The radiofrequency is widely validated as efficient method without serious adverse and with low rate of recurrence. We hope through this this work to revue the current knowledge of the treatment of osteoid osteoma.

Femoral head subchondral impaction on CT: what does it mean in patients with acetabular fracture?

OBJECTIVE

To evaluate the prevalence of isolated femoral head impactions associated with acetabular fractures and to assess whether impactions may be predictive of the development of delayed major complications requiring total hip arthroplasty.

MATERIALS AND METHODS

A total of 128 consecutive adult patients with acetabular fracture and no femoral head fracture were included. Admission CTs were re-interpreted for the presence of hip dislocation and femoral head impactions. Radiological and clinical reports were reviewed in patients in whom conservative management of the femoral head was attempted, to determine if total hip arthroplasty was eventually required over a 48-month follow-up period. Univariate and multivariate analyses were performed to assess whether impaction is an independent predictor of failure of conservative management.

RESULTS

Impaction was found in 40% of all patients (51 out of 128), in 58% of those with dislocation (19 out of 33), and in 34% of those without dislocation (32 out of 95; p < 0.05). One hundred and five patients underwent conservative management of the femoral head; 12.5% of them (13 out of 105) eventually required total hip arthroplasty. An impaction was present in 77% of the latter (10 out of 13) and in 33% of patients with successful conservative management (30 out of 92; p = 0.0042). At multivariate analysis, impaction and dislocation were significantly and independently associated with a higher risk for delayed total hip arthroplasty (odds ratio of 4.8 and 4.0 respectively).

CONCLUSION

Femoral head impactions are frequently seen on CT of patients with acetabular fractures; they are independent predictive factors for the need for delayed total hip arthroplasty. They should be systematically mentioned in the CT report.

[AntibioticScout.ch: Decision support for the prudent use of antimicrobials: Application in cattle]

INTRODUCTION

The administration of antibiotics in livestock has been criticized for many years, in particular because of an inappropriate use and the appearance of antibiotic residues in the environment, which can promote the emergence and spread of resistant bacteria. However, antibiotics are essential for the successful and sustainable control of bacterial pathogens. With the aim of optimizing the use of antibiotics in food animals and minimizing the prevalence of resistant bacteria, AntibioticScout. ch provides a decision aid for the prudent use of antimicrobial drugs. This approach emphasizes the importance of supportive therapy and the hallmarks of preventive concepts. Procedures to improve animal health and animal welfare in accordance with the principles of good veterinary practice are primary and effective tools to reduce the use of antimicrobial drugs. The necessary reduction in the use of antibiotics must, therefore, be accompanied by appropriate management strategies in animal husbandry. In particular, hygiene, animal welfare and biosecurity measures are crucial to ensure an optimal health status in farm animals.

Aberrant use and poor quality of trypanocides: a risk for drug resistance in south western Ethiopia

BACKGROUND

Trypanocidal drugs have been used to control African animal trypanosomosis for several decades. In Ethiopia, these drugs are available from both authorized (legal) and unauthorized (illegal) sources but documentation on utilization practices and quality of circulating products is scanty. This study looked at the practices of trypanocidal drug utilization by farmers and the integrity of active ingredient in trypanocides sold in Gurage zone, south western Ethiopia. The surveys were based on a structured questionnaire and drug quality determination of commonly used brands originating from European and Asian companies and sold at both authorized and unauthorized markets. One hundred farmers were interviewed and 50 drug samples were collected in 2013 (Diminazene aceturate = 33 and Isometamidium chloride = 17; 25 from authorized and 25 from unauthorized sources). Samples were tested at the OIE-certified Veterinary Drug Control Laboratory (LACOMEV) in Dakar, Senegal, by using galenic standards and high performance liquid chromatography.

RESULTS

Trypanosomosis was found to be a major threat according to all interviewed livestock keepers in the study area. Diminazene aceturate and isometamidium chloride were preferred by 79% and 21% of the respondents respectively, and 85% of them indicated that an animal receives more than six treatments per year. About 60% of these treatments were reported to be administered by untrained farmers. Trypanocidal drug sources included both unauthorized outlets (56%) and authorized government and private sources (44%). A wide availability and usage of substandard quality drugs was revealed. Twenty eight percent of trypanocidal drugs tested failed to comply with quality requirements. There was no significant difference in the frequency of non-compliance between diminazene-based and isometamidium chloride products (P = 0.87) irrespective of the marketing channel (official and unofficial). However, higher rates of non-compliant trypanocides were detected for drugs originating from Asia than from Europe (P = 0.029).

CONCLUSION

The findings revealed the presence of risk factors for the development of drug resistance, i.e. wide distribution of poor quality drugs as well as substandard administration practices. Therefore, it is strongly recommended to enforce regulatory measures for quality control of veterinary drugs, to expand and strengthen veterinary services and to undertake trypanocidal drug efficacy studies of wider coverage.

[AntibioticScout.ch: A decision supporting tool for antimicrobial stewardship: application to companion animal medicine]

INTRODUCTION

Bacterial resistances to antimicrobial drugs pose serious public health challenges. The observed increase of resistances is attributed to the uncontrolled, massive and often unnecessary administration of antibiotics both in human and veterinary medicine. To support the responsible use of antimicrobials in animals and help veterinarians selecting the most suitable antimicrobial drugs, we developed the AntibioticScout.ch as a comprehensive decision supporting tool providing online access to the current knowledge of rational antibiotic prescription practices. User-friendly search functions allow for the fast and efficient retrieval of information that is structured in this database by animal species, organ systems and therapeutic indications. In addition, an online form allows to report treatment failures in order to identify problematic cases as well as ensuing risks and take appropriate mitigation measures. The present report describes the workflow of this decision support system applied to the prudent use of antimicrobials in companion animal medicine.

[AntibioticScout: Online tool for antimicrobial stewardship in veterinary medicine]

INTRODUCTION

Resistances to antimicrobials pose serious public health challenges. This issue concerns both human and veterinary medicine and can only be solved by a multidisciplinary approach. A comprehensive concept is, therefore, being worked out within the StAR (strategy antibiotic resistance) program in order to preserve the effectiveness of antibiotics for humans as well as animals. In this context, the AntibioticScout (www.AntibioticScout. ch) offers a new online tool for the prudent use of antibiotics in veterinary medicine. By involving all stakeholders, the guidelines included in the AntibioticScout will result in a nationwide accepted standard for the treatment of bacterial infections in animals. An additional system for the rapid reporting of cases of suspected lack of efficacy of antimicrobials is integrated to allow early detection of emerging resistance and the immediate launch of risk mitigation measures. A first version of the AntibioticScout for the treatment of dogs, cats and horses is available by the end of 2016. All stakeholders are now invited to contribute to the development of the AntibioticScout decision support.

Pigmented villonodular synovitis of the hip

Pigmented villonodular synovitis (PVNS) is a rare disease that can affect any joint, bursa or tendon sheath.The hip is less frequently affected than the knee, and hence is less discussed in scientific journals.PVNS of the hip mainly occurs in young adults, requiring early diagnosis and adequate treatment to obtain good results.There is no consensus on the management of PVNS of the hip in current literature.We will discuss the options for surgical intervention in hip PVNS using a literature review of clinical, biological, etiological, histological and radiographic aspects of the disease. Cite this article: Steinmetz S, Rougemont A-L, Peter R. Pigmented villonodular synovitis of the hip. EFORT Open Rev 2016;1:260-266. DOI: 10.1302/2058-5241.1.000021.

Comparison of dual-mobility cup and unipolar cup for prevention of dislocation after revision total hip arthroplasty

Background and purpose - Revision total hip arthroplasty (THA) is associated with higher dislocation rates than primary THA. We compared the risk of dislocation within 6 months and all-cause re-revision during the whole study period using either the dual-mobility cup or the unipolar cup. Methods - We used a prospective hospital registry-based cohort including all total and cup-only revision THAs performed between 2003 and 2013. The cups used were either dual-mobility or unipolar; the choice was made according to the preference of the surgeon. 316 revision THAs were included. The mean age of the cohort was 69 (25-98) years and 160 THAs (51%) were performed in women. The dual-mobility group (group 1) included 150 THAs (48%) and the mean length of follow-up was 31 (0-128) months. The unipolar group (group 2) included 166 THAs (53%) and the mean length of follow-up was 52 (0-136) months. Results - The incidence of dislocation within 6 months was significantly lower with the dual-mobility cup than with the unipolar cup (2.7% vs. 7.8%). The unadjusted risk ratio (RR) was 0.34 (95% CI: 0.11-1.02) and the adjusted RR was 0.28 (95% CI: 0.09-0.87). The number of patients needed to treat with a dual-mobility cup in order to prevent 1 case of dislocation was 19. The unadjusted incidence rate ratio for all-cause re-revision in the dual-mobility group compared to the unipolar group was 0.6 (95% CI: 0.3-1.4). Interpretation - Use of a dual-mobility rather than a unipolar cup in revision THA reduced the risk of dislocation within 6 months.

Multidrug resistance mediated by co-carriage of extended-spectrum beta-lactamases, AmpC and New Delhi metallo-beta-lactamase-1 genes among carbapenem-resistant Enterobacteriaceae at five Indian medical centres

In this study, we evaluated the coexistence of extended-spectrum beta-lactamases (ESBL), AmpC and New Delhi metallo-beta-lactamase-1 (NDM-1) genes among carbapenem-resistant Enterobacteriaceae (CRE) recovered prospectively from patients at multiple sites. The study included 285 CRE strains from 2782 Gram-negative Bacilli collected from multiple centres during 2007-2010, of which 87 were characterised. Standard and reference laboratory methods were used for resistance determination. Detection of blaNDM-1 , blaAmpC , blaTEM , blaSHV and blaCTX-M was done by polymerase chain reaction. High levels of antimicrobial resistance observed among study isolates. Co-carriage of ESBLs, AmpC and NDM-1 was 26.3%. Nosocomial origin among the co-carriage isolates was 64.3%, with 9.2% associated mortality.

Impact of clinical osteoarthritis of the hip, knee and hand on self-rated health in six European countries: the European Project on OSteoArthritis

PURPOSE

Osteoarthritis (OA) has been shown to be associated with decreased physical function, which may impact upon a person's self-rated health (SRH). Only a few studies have examined the association between OA and SRH in the general population, but to date none have used a clinical definition of OA. The objectives are: (1) To examine the cross-sectional association between clinical OA and fair-to-poor SRH in the general population; (2) To examine whether this association differs between countries; (3) To examine whether physical function is a mediator in the association between clinical OA and SRH.

METHODS

Baseline data of the European Project on OSteoArthritis (EPOSA) were used, which includes pre-harmonized data from six European cohort studies (n = 2709). Clinical OA was defined according to the American College of Rheumatology criteria. SRH was assessed using one question: How is your health in general? Physical function was assessed using the Western Ontario and McMaster Universities OA Index and Australian/Canadian OA Hand Index.

RESULTS

The prevalence of fair-to-poor SRH ranged from 19.8 % in the United Kingdom to 63.5 % in Italy. Although country differences in the strength of the associations were observed, clinical OA of the hip, knee and hand were significantly associated with fair-to-poor SRH in five out of six European countries. In most countries and at most sites, the association between clinical OA and fair-to-poor SRH was partly or fully mediated by physical function.

CONCLUSIONS

Clinical OA at different sites was related to fair-to-poor SRH in the general population. Most associations were (partly) mediated by physical functioning, indicating that deteriorating physical function in patients with OA should be a point of attention in patient care.

[Occupational gratification crisis and sickness absence in Germany: Cross-sectional results from the lidA-study]

BACKGROUND

Demographic change is leading to a shrinking and ageing workforce in industrialized nations. Therefore, sickness absence may become a relevant problem. Increasing absenteeism and retirement rates due to mental disorders raise the question of an association between work-related stress and sickness absence. Studies on this matter, particularly in older employees, are rare.

OBJECTIVES

We studied for the first time in Germany the relationship between effort-reward imbalance (ERI) and overall or long-term sickness absence.

MATERIALS AND METHODS

LidA ( "Living at Work") is a German cohort study on work, age, health, and work participation. A total of 6,339 employees born in 1959 and 1965 who were subject to social insurance contributions were interviewed nationwide using a representative sample concept. The response rate was 27.3 %. The sample showed high representativeness and no selectivity relating to 16 sociodemographic items. Sickness absence was defined as at least one long-term sickness absence with at least 43 days of absenteeism. Work-related stress was parameterized by ERI tertiles. Multiple logistic regression adjusting for age, sex, mental disorders, social status, and working time was performed.

RESULTS

High levels of work-related stress were significantly associated with overall and long-term sickness absence among older employees after adjusting for covariates.

CONCLUSIONS

Our unique findings on work-related stress and sickness absence in Germany are in agreement with the results of most international studies. Reducing work-related stress could help to preserve the workforce.

[Is the association between mental disorders and sickness absence independent of sociodemographic factors?]

AIM

Mental diseases are highly prevalent and of increasing meaning for absenteeism. The association of absenteeism with vertical and horizontal dimensions of socioeconomic status is well-known. Against this background we investigated the independent association between mental diseases and absenteeism or long-time absenteeism of socioeconomic aspects.

MATERIAL AND METHODS

Basis of this nationwide exploratory survey were the 6 339 employees born in 1959 or 1965 and subject to statutory health insurance of the first wave of the lidA-cohort study 2011. The stepwise logistic regression analysis was used for the investigation of the effects of mental diseases on absenteeism or long-term absenteeism after adjustment for education, occupational position, income, gender, age, working-time and -stress.

RESULTS

After adjustment for socioeconomic factors highly significant associations between mental diseases and absenteeism or even more long-term absenteeism were observed. These associations stayed significant after additional adjustment for work-related factors.

CONCLUSION

Mental diseases were independent of sociodemographic factors and work-related factors (working-time and -stress) associated with absenteeism or with long-term absenteeism. Unspecific programmes for the prevention and rehabilitation of mental diseases may contribute to the reduction of absenteeism. Apart from that causes of absenteeism in highly affected socioeconomic groups should be investigated.

Is there a significant seasonality in the occurrence of osteoarticular infections?

Clinical experience suggests fluctuation in the occurrence of osteoarticular infections. We performed a single-centre study during 2004-2012, dividing each year into the four seasons according to the Gregorian calendar. A total of 455 episodes of osteoarticular infections were retrieved. There were 91 prosthetic joint infections (45 of haematogenous origin) and 159 cases of septic arthritis. The median period between early symptoms and diagnosis of infection was 27 days. The overall number of infections per season, cumulated over the 8-year study period, was 119 in spring, 129 in summer, 95 in fall, and 112 in winter, which did not reflect any significant seasonal fluctuation. None of the different subgroups of infections, namely arthroplasties (p for trend = 0.755), haematogenous arthroplasty infections (p = 0.493), gram-negative episodes or arthritis (p = 0.290), showed any season-related fluctuation. We conclude that osteoarticular infections, including haematogenous prosthetic joint infections, do not show any significant seasonality.

A comparative assessment of small-head metal-on-metal and ceramic-on-polyethylene total hip replacement

Large-head metal-on-metal (MoM) total hip replacements (THR) have given rise to concern. Comparative studies of small-head MoM THRs over a longer follow-up period are lacking. Our objective was to compare the incidence of complications such as infection, dislocation, revision, adverse local tissue reactions, mortality and radiological and clinical outcomes in small-head (28 mm) MoM and ceramic-on-polyethylene (CoP) THRs up to 12 years post-operatively. A prospective cohort study included 3341 THRs in 2714 patients. The mean age was 69.1 years (range 24 to 98) and 1848 (55.3%) were performed in women, with a mean follow-up of 115 months (18 to 201). There were 883 MoM and 2458 CoP bearings. Crude incidence rates (cases/1000 person-years) were: infection 1.3 vs 0.8; dislocation 3.3 vs 3.1 and all-cause revision 4.3 vs 2.2, respectively. There was a significantly higher revision rate after ten years (adjusted hazard ratio 9.4; 95% CI 2.6 to 33.6) in the MoM group, and ten of 26 patients presented with an adverse local tissue reaction at revision. No differences in mortality, osteolysis or clinical outcome were seen. In conclusion, we found similar results for small-head MoM and CoP bearings up to ten years post-operatively, but after ten years MoM THRs had a higher risk of all-cause revision. Furthermore, the presence of an adverse response to metal debris seen in the small-head MOM group at revision is a cause for concern.

[Popliteal cysts: etiologic and therapeutic approach]

In children and adults, a popliteal cyst frequently coexists with an intra-articular disorder of the knee. Its mode of presentation consists of a palpable mass at the level of the popliteal fossa. The cyst is a recess of the synovial cavity of the knee, often associated to a chronic effusion. In children, the etiology may be primary with a development directly from the medial gastrocnemius-semimembranous bursa. In adults, it is usually secondary to degenerative or inflammatory disease of the knee. A communication between the intraarticular space and the cystic cavity can be often found. The aim of this study is to review epidemiology, pathogenesis, symptomatology, diagnosis and treatment options.

Prospective evaluation of renal function, serum vitamin D level, and risk of fall and fracture in community-dwelling elderly subjects

SUMMARY

This prospective study in elderly showed that kidney function plays a minor role in explaining the high prevalence of vitamin D deficiency seen in noninstitutionalized elderly subjects. However, 25-hydroxyvitamin D levels were clearly inversely associated with risk for first fall, which was especially seen in subjects with calcium levels above median.

INTRODUCTION

Few prospective studies in elderly exist that have investigated the association of renal dysfunction and vitamin D status on risk of falls. The aim of this study is to evaluate the association of renal function with 25-hydroxyvitamin D (25-OH-D) levels and, secondly, to assess the role of both factors on the risk of falls and subsequent bone fractures.

METHODS

This is a prospective population-based cohort study among noninstitutionalized elderly subjects during a 1-year follow-up. 25-OH-D levels and renal function were estimated, the latter by cystatin C-based equations. Information on falls was assessed prospectively.

RESULTS

Overall, 1,385 subjects aged 65 and older were included in the study (mean age 75.6 years), of whom 9.2 % had a 25-OH-D serum level above 75 nmol/L (US units 30 ng/mL); 41.4 %, between 50 and 75 nmol/L (US units 20 to 29 ng/mL, insufficiency); and 49.4 %, <50 nmol/L (US units <20 ng/mL, deficiency). We found no association of chronic kidney disease with risk of first fall. In contrast, 25-OH-D serum categories were clearly associated with risk of first fall and we found evidence of effect modification with calcium levels. In the group with a calcium level above the median (≥ 9.6 mg/dL), subjects with 25-OH-D serum level between 50 and 75 nmol/L and with concentrations <50 nmol/L had a hazard rate ratio (HRR) of 1.75 (1.03-2.87) and 1.93 (1.10-3.37) for risk of first fall. 25-OH-D serum levels were also associated with several markers of inflammation and hemodynamic stress.

CONCLUSIONS

We demonstrated an association of 25-OH-D serum levels and risk of first fall, which was especially evident in subjects with serum calcium in upper normal, independent of renal function.

Rare case of obturator hernia in a patient with Marfan's syndrome

Obturator hernia is a very rare type of abdominal hernia which constitutes <1 % of all the hernias. It is an important cause of small bowel obstruction which is associated with a high mortality rate if left untreated. Obturator hernia typically occurs in an elderly women or patients with chronically raised intraabdominal pressure or previous multiple pregnancies. We report a case of obstructed obturator hernia in a young female patient with Marfan's syndrome complicated with dissecting aortic aneurysm and chronic kidney disease. Though recurrent and incisional hernia constitutes one of the minor diagnostic criteria of Marfan's syndrome, obturator hernia being a very rare entity, has been reported very rarely in a patient with Marfan's syndrome.

[Work, age, health, and work participation. A theoretical model]

Research into the associations between work, age, and health and the impact of these associations on employment status has focused on health as a crucial determinant of staying on the job. In our paper, we ask whether concentrating on health is still feasible, particularly when considering the change in demographics and the increasing proportion of older people in the workplace. We introduce a theoretical model describing health as a variable that indirectly influences leaving employment. According to our model, the immediate decision to leave employment is due to work motivation and work ability. These two factors may require intervention activities different from those needed to improve health. Our model explains employment participation as a result of complex associations between work, socioeconomic status, lifestyle, and health especially with work ability and work motivation. The complexity of these processes should be considered in studies by conducting longitudinal investigations like the German lidA study (http://www.lida-studie.de). If the model is verified in scientific studies like lidA, it can be used as a basis for preventive and intervening activities in practice, i.e., in politics, enterprises, and science.

Estimates of the relative and absolute diurnal contributions of fasting and post-prandial plasma glucose over a range of hyperglycaemia in type 2 diabetes

AIMS

To re-examine the relative and absolute contributions of fasting/pre-prandial glucose (FPG) and post-prandial glucose (PPG) to 24-h hyperglycaemia and HbA1c respectively in non-insulin treated subjects with type 2 diabetes (T2DM).

MATERIALS AND METHODS

A total of 52 T2DM subjects (37 men) had daytime 12h plasma glucose (PG) profiles determined in response to three serial identical test meals commencing at 08 00h with pre-prandial and frequent post-prandial blood samples collected. The overnight PG profile was derived by projecting the 20 00h glucose concentration to the pre-breakfast value at 08 00h. PPG exposure was calculated above fasting/pre-prandial value for each meal. Excess hyperglycaemia was calculated based on a PG>5.5mmol/L with fasting hyperglycaemia being the difference between the two measurements. The subjects were divided into five groups according to the HbA1c (Group 1<7.0%; Group 2: 7.0-<7.5; Group 3: 7.5-<8.0%; Group 4: 8.0-<9.0%; Group 5:≥9.0%). The 24h relative contribution of PPG exposure and fasting hyperglycaemia to excess hyperglycaemia and the absolute contribution of PPG and fasting hyperglycaemia to excess HbA1c (HbA1c - 5.1%) was calculated.

RESULTS

With deteriorating glycaemia, the relative contribution of PPG exposure decreased across the groups from 43.5% (HbA1c<7.0%) to 17.8% (HbA1c≥9.0%), whilst the contributions of fasting hyperglycaemia increased from 56.5% to 82.2% (P=0.004), respectively. The absolute contributions of PPG to excess HbA1c was 0.7%, which remained relatively stable across the spectrum of HbA1c, whilst fasting hyperglycaemia increased significantly from groups 1 to 5 (P<0.001).

CONCLUSIONS

Fasting hyperglycaemia contributes substantially in all groups, increasing as HbA1c deteriorates. The absolute contribution of PPG to excess HbA1c did not vary across the range of HbA1c, representing a significant relative contribution even in well-controlled subjects with a HbA1c<7.0%.

Unstable pelvic ring injury with hemodynamic instability: what seems the best procedure choice and sequence in the initial management?

INTRODUCTION

Most fatalities related to pelvic ring injuries occur early and are caused by massive retroperitoneal bleeding. The objective of our study is to determine the optimal sequence of surgical procedures to restore hemodynamic stability in patients with unstable pelvic ring injuries.

PATIENTS AND METHODS

This was a retrospective review of all patients with pelvic fractures and hemodynamic instability admitted to our level 1 trauma center between January 1998 and December 2008. We entered into our polytrauma database the following patient characteristics: age, sex, mechanism of injury, Injury Severity Score (ISS), classification of injury, timing of operative intervention, and type of operative procedures. Patients were divided into four groups (according to the sequence of surgical procedures performed within 24 hours following admission), as follows: group 1: patients treated with external fixation only; group 2: patients receiving external fixation followed by angiography; group 3: patients receiving external fixation followed by laparotomy ± angiography; and group 4: patients treated by immediate laparotomy or angiography before skeletal fixation.

RESULTS

Eighty of 136 patients admitted with a pelvic fracture were classified, as unstable AO/OTA type B or C pelvic ring injury, and 70/80 were hemodynamically unstable. Eight patients died shortly after arrival and two remained stable without requiring any early procedure. Sixty patients went immediately to the operating room. Twenty-nine patients were placed in group 1 with 100% survival, 12 in group 2 with 91% survival, 11 in group 3 with 82% survival, and eight patients placed in group 4 with 0% survival (P<0.001).

CONCLUSIONS

The management of hemorrhagic instability linked to pelvic ring disruption involves a sequence of therapeutic events, which is more important than the events themselves. Pelvic bone stabilization by pelvic clamp or external fixator followed by arteriography seems to be the more secure. Angiographic embolization is the method of choice whenever haemodynamic instability coexists with an unstable pelvic disruption. Laparotomy and packing are restricted to extreme severe cases in remote hospitals with skillful surgeons! Actually aortic balloon is a good solution to control uncontrollable bleeding.

LEVEL OF EVIDENCE

Level IV. Retrospective study.