Accuracy and repeatability of the Microsoft Azure Kinect for clinical measurement of motor function

Quantitative assessment of motor function is increasingly applied in fall risk stratification, diagnosis, and disease monitoring of neuro-geriatric disorders of balance and gait. Its broad application, however, demands for low-cost and easy to use solutions that facilitate high-quality assessment outside laboratory settings. In this study, we validated in 30 healthy adults (12 female, age: 32.5 [22 - 62] years) the performance and accuracy of the latest generation of the Microsoft RGB-D camera, i.e., Azure Kinect (AK), in tracking body motion and providing estimates of clinical measures that characterise static posture, postural transitions, and locomotor function. The accuracy and repeatability of AK recordings was validated with a clinical reference standard multi-camera motion capture system (Qualisys) and compared to its predecessor Kinect version 2 (K2). Motion signal quality was evaluated by Pearson's correlation and signal-to-noise ratios while the accuracy of estimated clinical parameters was described by absolute and relative agreement based on intraclass correlation coefficients. The accuracy of AK-based body motion signals was moderate to excellent (RMSE 89 to 20 mm) and depended on the dimension of motion (highest for anterior-posterior dimension), the body region (highest for wrists and elbows, lowest for ankles and feet), and the specific motor task (highest for stand up and sit down, lowest for quiet standing). Most derived clinical parameters showed good to excellent accuracy (r .84 to .99) and repeatability (ICC(1,1) .55 to .94). The overall performance and limitations of body tracking by AK were comparable to its predecessor K2 in a cohort of young healthy adults. The observed accuracy and repeatability of AK-based evaluation of motor function indicate the potential for a broad application of high-quality and long-term monitoring of balance and gait in different non-specialised environments such as medical practices, nursing homes or community centres.

A Changing Home: A Cross-Sectional Study on Environmental Degradation, Resettlement and Psychological Distress in a Western German Coal-Mining Region

Unwelcome environmental changes can lead to psychological distress, known as “solastalgia”. In Germany, the open-pit mining of brown coal results in environmental changes as well as in the resettlement of adjacent villages. In this study, we investigated the risk of open-pit mining for solastalgia and psychological disorders (e.g., depression, generalized anxiety and somatization) in local communities. The current residents and resettlers from two German open-pit mines were surveyed concerning environmental stressors, place attachment, impacts and mental health status. In total, 620 people responded, including 181 resettlers, 114 people from villages threatened by resettlement and 325 people from non-threatened villages near an open-pit mine. All groups self-reported high levels of psychological distress, approximately ranging between 2−7.5 times above the population average. Respondents from resettlement-threatened villages showed the worst mental health status, with 52.7% indicating at least moderate somatization levels (score sum > 9), compared to 28% among resettlers. We observed a mean PHQ depression score of 7.9 (SD 5.9) for people from resettlement-threatened villages, 7.4 (SD 6.0) for people from not-threatened villages, compared to 5.0 (SD 6.5) for already resettled people (p < 0.001). In conclusion, the degradation and loss of the home environment caused by open-pit mining was associated with an increased prevalence of depressive, anxious and somatoform symptoms in local communities. This reveals a need for further in-depth research, targeted psychosocial support and improved policy frameworks, in favor of residents’ and resettlers’ mental health.

Approaches to mapping an undergraduate medical curriculum to a national competency-based catalogue of learning outcomes

BACKGROUND

Curriculum mapping plays an increasing role in the design and implementation of competency-based medical education. We present an exemplary mapping of an institutional undergraduate medical curriculum to a national competency-based outcome framework to compare approaches to mapping procedures in their capacity to depict the relative coverage.

METHODS

The mapping process was performed by a small working group that continuously reconciled its findings. In step 1, we mapped the course objectives of our programme (Charité Berlin, Germany) to the National Competency-Based Catalogue of Learning Outcomes Medicine (NKLM). In step 2, we employed three primarily quantitative approaches (single, multiple, and subordinate match) and one primarily qualitative approach (content comparison) to derive the degree of NKLM coverage.

RESULTS

In step 1, we mapped a total of 4400 programme objectives to 2105 NKLM objectives. In step 2, the quantitative approaches provided a general overview of the pattern of coverage, while the qualitative approach required more effort but provided a better representation of the scope and depth of coverage.

DISCUSSION

The mapping approach chosen markedly impacts on the results how of well an institutional curriculum covers a national standard. This study highlights the need for more rigour in the methodology and reporting of curriculum mapping.

Modeling ternary fluids in contact with elastic membranes

We present a thermodynamically consistent model of a ternary fluid interacting with elastic membranes. Following a free-energy modeling approach for the fluid phases, we derive the governing equations for the dynamics of the ternary fluid flow and membranes. We also provide the numerical framework for simulating such fluid-structure interaction problems. It is based on the lattice Boltzmann method for the ternary fluid (Eulerian description) and a finite difference representation of the membrane (Lagrangian description). The ternary fluid and membrane solvers are coupled through the immersed boundary method. For validation purposes, we consider the relaxation dynamics of a two-dimensional elastic capsule placed at a fluid-fluid interface. The capsule shapes, resulting from the balance of surface tension and elastic forces, are compared with equilibrium numerical solutions obtained by surface evolver. Furthermore, the Galilean invariance of the proposed model is proven. The proposed approach is versatile, allowing for the simulation of a wide range of geometries. To demonstrate this, we address the problem of a capillary bridge formed between two deformable capsules.

Instrumental Assessment of Stepping in Place Captures Clinically Relevant Motor Symptoms of Parkinson's Disease

Fluctuations of motor symptoms make clinical assessment in Parkinson's disease a complex task. New technologies aim to quantify motor symptoms, and their remote application holds potential for a closer monitoring of treatment effects. The focus of this study was to explore the potential of a stepping in place task using RGB-Depth (RGBD) camera technology to assess motor symptoms of people with Parkinson's disease. In total, 25 persons performed a 40 s stepping in place task in front of a single RGBD camera (Kinect for Xbox One) in up to two different therapeutic states. Eight kinematic parameters were derived from knee movements to describe features of hypokinesia, asymmetry, and arrhythmicity of stepping. To explore their potential clinical utility, these parameters were analyzed for their Spearman's Rho rank correlation to clinical ratings, and for intraindividual changes between treatment conditions using standard response mean and paired t-test. Test performance not only differed between ON and OFF treatment conditions, but showed moderate correlations to clinical ratings, specifically ratings of postural instability (pull test). Furthermore, the test elicited freezing in some subjects. Results suggest that this single standardized motor task is a promising candidate to assess an array of relevant motor symptoms of Parkinson's disease. The simple technical test setup would allow future use by patients themselves.

Substantial direct fitness gains of workers in a highly eusocial ant

Hamilton's theory of inclusive fitness suggests that helpers in animal societies gain fitness indirectly by increasing the reproductive performance of a related beneficiary. Helpers in cooperatively breeding birds, mammals and primitively eusocial wasps may additionally obtain direct fitness through inheriting the nest or mating partner of the former reproductive. Here, we show that also workers of a highly eusocial ant may achieve considerable direct fitness by producing males in both queenless and queenright colonies. We investigated the reproductive success of workers of the ant Temnothorax crassispinus in nature and the laboratory by dissecting workers and determining the origin of males by microsatellite analysis. We show that workers are capable of activating their ovaries and successfully producing their sons independently of the presence of a queen. Genotypes revealed that at least one fifth of the males in natural queenright colonies were not offspring of the queen. Most worker-produced males could be assigned to workers that were unrelated to the queen, suggesting egg-laying by drifting workers.

Body size and sperm quality in queen- And worker-produced ant males

Workers of many species of social Hymenoptera have functional ovaries and are capable of laying haploid, unfertilized eggs, at least in the absence of a queen. Except for honeybees, it remains largely unknown whether worker-produced males have the same quality as queen-produced males and whether workers benefit in direct fitness by producing their sons. Previous studies in the monogynous ant Temnothorax crassispinus revealed that a high proportion of males in natural and laboratory colonies are worker offspring. Here, we compare longevity, body size, sperm length and sperm viability between queen- and worker-produced males. We either split queenright colonies into queenright and queenless halves or removed the queen from a fraction of the queenright colonies and then examined the newly produced males. Male quality traits varied considerably among colonies but differed only slightly between queen- and worker-produced males. Worker-produced males outnumbered queen-produced males and also had a longer lifespan, but under certain rearing conditions sperm from queen-produced males had a higher viability.

Module-detection approaches for the integration of multilevel omics data highlight the comprehensive response of Aspergillus fumigatus to caspofungin

Background

Omics data provide deep insights into overall biological processes of organisms. However, integration of data from different molecular levels such as transcriptomics and proteomics, still remains challenging. Analyzing lists of differentially abundant molecules from diverse molecular levels often results in a small overlap mainly due to different regulatory mechanisms, temporal scales, and/or inherent properties of measurement methods. Module-detecting algorithms identifying sets of closely related proteins from protein-protein interaction networks (PPINs) are promising approaches for a better data integration.

Results

Here, we made use of transcriptome, proteome and secretome data from the human pathogenic fungus Aspergillus fumigatus challenged with the antifungal drug caspofungin. Caspofungin targets the fungal cell wall which leads to a compensatory stress response. We analyzed the omics data using two different approaches: First, we applied a simple, classical approach by comparing lists of differentially expressed genes (DEGs), differentially synthesized proteins (DSyPs) and differentially secreted proteins (DSePs); second, we used a recently published module-detecting approach, ModuleDiscoverer, to identify regulatory modules from PPINs in conjunction with the experimental data. Our results demonstrate that regulatory modules show a notably higher overlap between the different molecular levels and time points than the classical approach. The additional structural information provided by regulatory modules allows for topological analyses. As a result, we detected a significant association of omics data with distinct biological processes such as regulation of kinase activity, transport mechanisms or amino acid metabolism. We also found a previously unreported increased production of the secondary metabolite fumagillin by A. fumigatus upon exposure to caspofungin. Furthermore, a topology-based analysis of potential key factors contributing to drug-caused side effects identified the highly conserved protein polyubiquitin as a central regulator. Interestingly, polyubiquitin UbiD neither belonged to the groups of DEGs, DSyPs nor DSePs but most likely strongly influenced their levels.

Conclusion

Module-detecting approaches support the effective integration of multilevel omics data and provide a deep insight into complex biological relationships connecting these levels. They facilitate the identification of potential key players in the organism’s stress response which cannot be detected by commonly used approaches comparing lists of differentially abundant molecules.

Electronic supplementary material

The online version of this article (10.1186/s12918-018-0620-8) contains supplementary material, which is available to authorized users.

The effect of a compression bandage on the distribution of radiodense contrast medium after palmar digital nerve blocks

BACKGROUND

Studies have shown proximal diffusion of injected drugs in perineural blocks; such diffusion may affect specificity of the nerve block.

OBJECTIVES

To investigate the effect of a compression bandage applied to the pastern region on proximal diffusion of contrast medium injected over the palmar digital nerves.

STUDY DESIGN

Experimental study, randomised cross-over design.

METHODS

Radiodense contrast medium was injected over the lateral and medial palmar digital nerves of the left front limb of nine mature horses. Each horse was injected on two separate occasions, once with a 5 cm wide compression bandage applied proximal to the injection site and once without. The order of the two treatments was randomised with a wash-out period between treatments of at least 7 days. Radiographs were obtained at 5, 10, 20 and 30 min and distribution of the contrast column assessed.

RESULTS

Proximal distribution of the contrast medium was significantly reduced (P<0.01) with compression bandage. Furthermore, the compression bandage inhibited lymphatic drainage of the injected contrast medium.

MAIN LIMITATIONS

Clinical effect of the differences in diffusion length was not assessed.

CONCLUSIONS

The compression bandage reduced proximal diffusion and lymphatic drainage of contrast material causing it to stay localised around the injection site. Use of compression bandages could thus result in increased specificity of the nerve block and potentially prolong its effect.

Emergence of coexisting ordered states in active matter systems

Active systems can produce a far greater variety of ordered patterns than conventional equilibrium systems. In particular, transitions between disorder and either polar- or nematically ordered phases have been predicted and observed in two-dimensional active systems. However, coexistence between phases of different types of order has not been reported. We demonstrate the emergence of dynamic coexistence of ordered states with fluctuating nematic and polar symmetry in an actomyosin motility assay. Combining experiments with agent-based simulations, we identify sufficiently weak interactions that lack a clear alignment symmetry as a prerequisite for coexistence. Thus, the symmetry of macroscopic order becomes an emergent and dynamic property of the active system. These results provide a pathway by which living systems can express different types of order by using identical building blocks.

Ancient symbiosis confers desiccation resistance to stored grain pest beetles

Microbial symbionts of insects provide a range of ecological traits to their hosts that are beneficial in the context of biotic interactions. However, little is known about insect symbiont-mediated adaptation to the abiotic environment, for example, temperature and humidity. Here, we report on an ancient clade of intracellular, bacteriome-located Bacteroidetes symbionts that are associated with grain and wood pest beetles of the phylogenetically distant families Silvanidae and Bostrichidae. In the saw-toothed grain beetle Oryzaephilus surinamensis, we demonstrate that the symbionts affect cuticle thickness, melanization and hydrocarbon profile, enhancing desiccation resistance and thereby strongly improving fitness under dry conditions. Together with earlier observations on symbiont contributions to cuticle biosynthesis in weevils, our findings indicate that convergent acquisitions of bacterial mutualists represented key adaptations enabling diverse pest beetle groups to survive and proliferate under the low ambient humidity that characterizes dry grain storage facilities.

Aortic Elongation and Stanford B Dissection: The Tübingen Aortic Pathoanatomy (TAIPAN) Project

OBJECTIVE/BACKGROUND

Aortic elongation has not yet been considered as a potential risk factor for Stanford type B dissection (TBD). The role of both aortic elongation and dilatation in patients with TBD was evaluated.

METHODS

The aortic morphology of a healthy control group (n = 236) and patients with TBD (n = 96) was retrospectively examined using three dimensional computed tomography imaging. Curved multiplanar reformats were used to examine aortic diameters at defined landmarks and aortic segment lengths.

RESULTS

Diameters at all landmarks were significantly larger in the TBD group. The greatest diameter difference (56%) was measured in dissected descending aortas (p < .001). The segment with the most considerable difference between the study groups with regard to elongation was the non-dissected aortic arch of patients with TBD (36%; p < .001). Elongation in the aortic arch was accompanied by a diameter increase of 21% (p < .001). In receiver-operating curve analysis, the area under the curve was .85 for the diameter and .86 for the length of the aortic arch.

CONCLUSIONS

In addition to dilatation, aortic arch elongation is associated with the development of TBD. The diameter and length of the non-dissected aortic arch may be predictive for TBD and may possibly be used for risk assessment in the future. This study provides the basis for further prospective evaluation of these parameters.

Subjective and objective assessment of physical activity in multiple sclerosis and their relation to health-related quality of life

Background

Physical activity (PA) is frequently restricted in people with multiple sclerosis (PwMS) and aiming to enhance PA is considered beneficial in this population. We here aimed to explore two standard methods (subjective plus objective) to assess PA reduction in PwMS and to describe the relation of PA to health-related quality of life (hrQoL).

Methods

PA was objectively measured over a 7-day period in 26 PwMS (EDSS 1.5–6.0) and 30 matched healthy controls (HC) using SenseWear mini® armband (SWAmini) and reported as step count, mean total and activity related energy expenditure (EE) as well as time spent in PA of different intensities. Measures of EE were also derived from self-assessment with IPAQ (International Physical Activity Questionnaire) long version, which additionally yielded information on the context of PA and a classification into subjects’ PA levels. To explore the convergence between both types of assessment, IPAQ categories (low, moderate, high) were related to selected PA parameters from objective assessment using ANOVA. Group differences and associated effect sizes for all PA parameters as well as their relation to clinical and hrQoL measures were determined.

Results

Both, SWAmini and IPAQ assessment, captured differences in PA between PwMS and HC. IPAQ categories fit well with common cut-offs for step count (p = 0.002) and mean METs (p = 0.004) to determine PA levels with objective devices. Correlations between specifically matched pairs of IPAQ and SWAmini parameters ranged between r .288 and r .507. Concerning hrQoL, the lower limb mobility subscore was related to four PA measures, while a relation with patients’ report of general contentment was only seen for one.

Conclusions

Both methods of assessment seem applicable in PwMS and able to describe reductions in daily PA at group level. Whether they can be used to track individual effects of interventions to enhance PA levels needs further exploration. The relation of PA measures with hrQoL seen with lower limb mobility suggests lower limb function not only as a major target for intervention to increase PA but also as a possible surrogate for PA changes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12883-016-0783-0) contains supplementary material, which is available to authorized users.

PATIENT REGISTRATION USING PHOTOGRAMMETRIC SURFACE RECONSTRUCTION FROM SMARTPHONE IMAGERY

In navigated surgery the patient’s body has to be co-registered with presurgically acquired 3D data in order to enable navigation of the surgical instrument. For this purpose the body surface of the patient can be acquired by means of photogrammetry and co-registered to corresponding surfaces in the presurgical data. In this paper this task is exemplarily solved for 3D data of human heads using the face surface to establish correspondence. We focus on investigation of achieved geometric accuracies reporting positioning errors in the range of 1 mm.

Validity of visual perceptive computing for static posturography in patients with multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) patients frequently have postural control impairment but quantitative posturography is difficult to perform in clinical care. Recent technology facilitates new posturography approaches.

OBJECTIVE

To evaluate construct validity of visual perceptive computing (VPC) for static posturography to study postural control in MS patients.

METHODS

A total of 90 MS patients and 59 healthy controls (HCs) performed three stance tests: open, closed and tandem stance. Static posturography was performed using a VPC system with Microsoft Kinect. Clinical assessments included Expanded Disability Status Scale (EDSS), Timed-25-Foot-Walk, Short-Maximum-Speed-Walk and 12-item MS Walking Scale (MSWS-12) questionnaire. Reliability was assessed with intra-class correlation coefficients at retest.

RESULTS

As a group, MS patients performed worse than HCs in all tests. The closed stance test showed best applicability and reliability. With closed eyes, in 36.7% of patients, the three-dimensional mean angular sway velocity (MSV-3D) was above HCs' 95th percentile. Higher MSV-3D was associated with decreased walking speed (p < 0.001); worse clinical scores, mainly attributable to the cerebellar functional system score (p < 0.001); and reflected in self-reported walking disability (MSWS-12, p < 0.001).

CONCLUSION

Postural control can be reliably assessed by VPC-based static posturography in patients with MS. Abnormal postural control seems to predominantly reflect involvement of cerebellar circuits with impact on gait and walking disability.

Investigation of Some Sulphur Halides — An Application of the Pseudopotential Method

Semilocal pseudopotentials are used in combination with a density-functional approximation for the correlation energy and special optimized basis sets to investigate the sulphur halides SF, SF2, SF3, FSSF, SSF2, SCl, SCl2, ClSSCl and SSCl2. It turns out that the inclusion of d-orbitals in the basis set playes a significant role with respect to the quality of the calculated molecular parameters. Properties of SF3 are calculated for the first time, and the differences between the disulphur difluorides and the disulphur dichlorides are explained.

Neutron matter at next-to-next-to-next-to-leading order in chiral effective field theory

Neutron matter presents a unique system for chiral effective field theory because all many-body forces among neutrons are predicted to next-to-next-to-next-to-leading order (N(3)LO). We present the first complete N(3)LO calculation of the neutron matter energy. This includes the subleading three-nucleon forces for the first time and all leading four-nucleon forces. We find relatively large contributions from N(3)LO three-nucleon forces. Our results provide constraints for neutron-rich matter in astrophysics with controlled theoretical uncertainties.

Acute aortic dissection type A

Background

Acute aortic dissection type A (AADA) is a life-threatening vascular emergency. Clinical presentation ranges from pain related to the acute event, collapse due to aortic rupture or pericardial tamponade, or manifestations of organ or limb ischaemia. The purpose of this review was to clarify important clinical issues of AADA management, with a focus on diagnostic and therapeutic challenges.

Methods

Based on a MEDLINE search the latest literature on this topic was reviewed. Results from the German Registry for Acute Aortic Dissection Type A (GERAADA) are also described.

Results

Currently, the perioperative mortality rate of AADA is below 20 per cent, the rate of definitive postoperative neurological impairment approaches 12 per cent and the long-term prognosis after surviving the acute phase of the disease is good. Many pathology- and therapy-associated factors influence the outcome of AADA, including prompt diagnosis with computed tomography and better cerebral protection strategies during aortic arch reconstruction. Endovascular technologies are emerging that may lead to less invasive treatment options.

Conclusion

AADA is an emergency that can present with a wide variety of clinical scenarios. Advances in the surgical management of this complex disease are improving outcomes.

Particle stress in suspensions of soft objects

In a suspension of extended objects such as colloidal particles, capsules or vesicles, the contribution of particles to the stress is usually evaluated by first determining the stress originating from a single particle (e.g. via integrating the fluid stress over the surface of a particle) and then adding up the contributions of individual particles. While adequate for a computation of the average stress over the entire system, this approach fails to correctly reproduce the local stress. In this work, we propose and validate a variant of the method of planes which overcomes this problem. The method is particularly suited for many-body interactions arising from, for example, shear and bending rigidity of red blood cells.

[Aortic valve stenosis: transcatheter aortic valve implantation (TAVI) – transarterial or transapical approach]

The calcified aortic stenosis is the dominating valve disease. Patients affected are most common elderly people in the 8 (th) or 9 (th) decade of their life who often show associated comorbidities like reduced left ventricular function, impaired renal function, pulmonary hypertension, and further diseases (Diabetes mellitus, stroke, COPD). In many cases perioperative morbidity and mortality are too high for surgical valve replacement and up to 30 % of patients are rejected. Nevertheless, prognosis of aortic stenosis is worse if the typical symptoms like dyspnea on exertion, syncope, and angina occur. The transcatheter aortic valve implantation is a new method treating this particular group of patients. The aortic valve bioprothesis consists of a balloon-expandable stent or a self-expandable frame, in which a valve of bovine or porcine pericardium is incorporated. The implantation is performed by retrograde access via the femoral or subclavian artery; the balloon-expandable prosthesis can also be implanted by transapical approach. Recently, the PARTNER trial and other studies demonstrate a high implantation success rate and better survival in comparison to standard therapy but exhibit also cerebral vascular and peripheral vascular complications. A further reduction of the available delivery systems and new types of valves which are under experimental tests and clinical evaluation contribute to this development.

Second-order convergence of the deviatoric stress tensor in the standard Bhatnagar-Gross-Krook lattice Boltzmann method

It is shown numerically that the deviatoric stress tensor is second-order accurate in the bulk Bhatnagar-Gross-Krook lattice Boltzmann (LB) method. In an earlier work [T. Krüger, Phys. Rev. E 79, 46704 (2009)], we have already predicted the second-order convergence. However, numerical simulations using a duct flow were not fully in line with this prediction. In particular, the convergence rate of the stress tensor was observed to depend on the LB boundary condition. In the present paper, we examine a pure bulk system, the decaying Taylor-Green vortex flow. Our prediction on the second-order accuracy of the stress tensor is unambiguously evidenced via these studies.

Acoustic driven flow and lattice Boltzmann simulations to study cell adhesion in biofunctionalized mu-fluidic channels with complex geometry

Accurately mimicking the complexity of microvascular systems calls for a technology which can accommodate particularly small sample volumes while retaining a large degree of freedom in channel geometry and keeping the price considerably low to allow for high throughput experiments. Here, we demonstrate that the use of surface acoustic wave driven microfluidics systems successfully allows the study of the interrelation between melanoma cell adhesion, the matrix protein collagen type I, the blood clotting factor von Willebrand factor (vWF), and microfluidic channel geometry. The versatility of the tool presented enables us to examine cell adhesion under flow in straight and bifurcated microfluidic channels in the presence of different protein coatings. We show that the addition of vWF tremendously increases (up to tenfold) the adhesion of melanoma cells even under fairly low shear flow conditions. This effect is altered in the presence of bifurcated channels demonstrating the importance of an elaborate hydrodynamic analysis to differentiate between physical and biological effects. Therefore, computer simulations have been performed along with the experiments to reveal the entire flow profile in the channel. We conclude that a combination of theory and experiment will lead to a consistent explanation of cell adhesion, and will optimize the potential of microfluidic experiments to further unravel the relation between blood clotting factors, cell adhesion molecules, cancer cell spreading, and the hydrodynamic conditions in our microcirculatory system.

Postoperative analgesia with parecoxib, acetaminophen, and the combination of both: a randomized, double-blind, placebo-controlled trial in patients undergoing thyroid surgery

BACKGROUND

We assessed the analgesic efficacy of parecoxib, acetaminophen, and the combination of both compared with placebo in patients undergoing elective thyroid or parathyroid surgery.

METHODS

We randomized 140 patients to receive one of the following i.v. treatments using a double-blinded double-dummy technique: placebo, 80 mg 24 h(-1) parecoxib, 5 g 24 h(-1) acetaminophen, or 80 mg parecoxib plus 5 g acetaminophen. We provided rescue analgesia with piritramide delivered by a patient-controlled analgesia device. We measured opioid consumption and pain intensity over 24 h after operation.

RESULTS

Patient characteristic data, anaesthetic, and surgical characteristics of the patients in the four groups were similar. Parecoxib, acetaminophen, and the combination significantly reduced opioid requirements during 24 h after surgery [mean (sd) 12.5 (10.9) mg for parecoxib, 14.2 (12.3) mg for acetaminophen, and 11.9 (10.7) mg for combination] compared with placebo [23.5 (15.3) mg, P<0.05]. However, the combination of parecoxib and acetaminophen did not have any advantage over individual drugs in terms of opioid consumption in our trial (P>0.05).

CONCLUSIONS

Parecoxib and acetaminophen effectively reduce postoperative opioid requirements after thyroid or parathyroid surgery. The combination of these drugs is not associated with a further reduction in opioid consumption.

Theoretical Considerations: Implant Positional Index Design

Rotational freedom of implant positional indices in two-piece implants was investigated. The aim of the study was to determine, analytically, the rotational freedom of three different positional index designs, based on the hypothesis that it is not influenced by their geometric principle. Regular polygonal, polygon profile, and cam-groove patterns were analyzed. Schematic descriptions were made and idealized equations developed. Parameters influencing the extent of rotational freedom were identified for the different positional index designs. A general equation that describes the rotational freedom of differently designed indices was also formulated. The present analysis showed that the rotational freedom of positional indices can be analytically calculated and is influenced by different parameters. The rotational freedom of the positional index of commonly used implant-abutment connections depends on their geometric design and size.