Mechanical assessment of two hybrid plate designs for pancarpal canine arthrodesis under cyclic loading.

Pancarpal canine arthrodesis (PCA) sets immobilization of all three carpal joints via dorsal plating to result in bony fusion. Whereas the first version of the plate uses a round hole (RH) for the radiocarpal (RC) screw region, its modification into an oval hole (OH) in a later version improves versatility in surgical application. The aim of this study was to mechanically investigate the fatigue life of the PCA plate types implementing these two features-PCA-RH and PCA-OH. Ten PCA-RH and 20 PCA-OH stainless steel (316LVM) plates were assigned to three study groups (n = 10). All plates were pre-bent at 20° and fixed to a canine forelimb model with simulated radius, RC bone and third metacarpal bone. The OH plates were fixed with an RC screw inserted either most proximal (OH-P) or most distal (OH-D). All specimens were cyclically tested at 8 Hz under 320 N loading until failure. Fatigue life outcome measures were cycles to failure and failure mode. Cycles to failure were higher for RH plate fixation (695,264 ± 344,023) versus both OH-P (447,900 ± 176,208) and OH-D (391,822 ± 165,116) plate configurations, being significantly different between RH and OH-D, p = 0.03. No significant difference was detected between OH-P and OH-D configurations, p = 0.09. Despite potential surgical advantages, the shorter fatigue life of the PCA-OH plate design may mitigate its benefits compared to the plate design with a round radiocarpal screw hole. Moreover, the failure risk of plates with an oval hole is increased regardless from the screw position in this hole. Based on these findings, the PCA plate with the current oval radiocarpal screw hole configuration cannot be recommended for clinical use.

How Canada can unlock health system capacity with technology: The value of long-term, value-based partnerships with technology providers.

Peter Varga is the Chief Transformation Officer at HealthHub Solutions, Canada's leading provider of bedside patient engagement technology. Leslie Motz is the Executive Vice President of Patient Services and Chief Nursing Executive at Joseph Brant Hospital in Burlington, Ontario. In this article, Peter and Leslie examine Canada's ranking among OECD countries on the performance of its healthcare system and propose how optimizing processes around technology purchase and implementation can maximize the value that it can bring to improving health system performance.

New computational fluid dynamics-based method for morphological and functional assessment in cardiovascular skill training.

Objective: During cardiovascular surgical skill training, the direct quantification regarding surgical performance is still lacking, including transferring clinically relevant information. Methods: We introduced a novel computational fluid dynamics-based method in support of vascular surgical hands-on training, which applies continuous self-assessment in vascular anastomoses. The validation of the methodology was implemented in comparing with conventional training courses. Results: The fifth and seventh consecutive anastomoses of the experimental group showed significantly improved results regarding anastomosis quality when compared with the control group. Conclusions: Consecutive demonstration of three-dimensional morphology and functional assessment of anastomoses results in improved practical performance among learners regarding anastomosis quality.

Biomechanical Assessment of Fracture Loads and Patterns of the Odontoid Process.

STUDY DESIGN: Laboratory study. OBJECTIVE: This study aimed to investigate the biomechanical competence and fracture characteristics of the odontoid process. SUMMARY OF BACKGROUND DATA: Odontoid fractures of the second cervical vertebra (C2) represent the most common spine fracture type in the elderly. However, very little is known about the underlying biomechanical fracture mechanisms. MATERIALS AND METHODS: A total of 42 C2 human anatomic specimens were scanned via computed tomography, divided in six groups, and subjected to combined quasistatic loading at -15°, 0°, and 15° in sagittal plane and -50° and 0° in transverse plane until fracturing. Bone mineral density (BMD), height, fusion state of the ossification centers, stiffness, yield load, and ultimate load were assessed. RESULTS: While lowest values for stiffness, yield load, and ultimate load were observed at load inclination of 15° in sagittal plane, no statistically significant differences were observed between the study groups ( P ≥0.235). BMD correlated positively with yield load ( r2 =0.350, P <0.001) and ultimate load ( r2 =0.955, P <0.001) but not with stiffness ( r2 =0.082, P =0.07). The specimens with clearly distinguishable fusion of the ossification centers revealed less data scattering of the biomechanical outcomes. CONCLUSION: Load direction plays a subordinate role in traumatic fractures of the odontoid process. BMD was associated with significant correlation to the biomechanical outcomes. Thus, odontoid fractures appear to result from of an interaction between the load magnitude and bone quality.

Adaptive local thresholding can enhance the accuracy of HR-pQCT-based trabecular bone morphology assessment.

High-resolution peripheral quantitative computed tomography (HR-pQCT) devices can scan extremities at bone microstructural level in vivo and are used mainly in research of bone diseases. Two HR-pQCT scanners are commercially available to date: XtremeCT (first generation) and XtremeCT-II (second generation) from Scanco Medical AG (Switzerland). Recently, we have proposed an adaptive local thresholding (AT) technique and showed that it can improve quantification accuracy of bone microstructural parameters, with visually less sharp cone-beam CT (CBCT) images providing a similar accuracy than XtremeCT. The aim of this study was to evaluate whether the AT segmentation technique could enhance the accuracy of HR-pQCT in quantifying bone microstructural images and to assess whether the agreement between XtremeCT and XtremeCT-II could be improved. Nineteen radii were scanned with three scanners from Scanco Medical AG: (1) XtremeCT at 82 µm, (2) XtremeCT-II at 60.7 µm and (3) the small animal microCT scanner VivaCT40 at 19 µm voxel size. The scans were segmented applying two different methods, once following the manufacturer standard technique (ST), and once by means of AT. Three-dimensional (3D) morphological analysis was performed on the trabecular volume of the segmented images using the manufacturer's standard software to calculate bone volume fraction (BV/TV), trabecular thickness (Tb.Th), separation (Tb.Sp) and number (Tb.N). The average accuracy of XtremeCT improved from R2 = 0.76 (ST) to 0.85 (AT) and reached the same level of accuracy as XtremeCT-II with ST (R2 = 0.86). The largest improvements were obtained for BV/TV and Tb.Th. For XtremeCT-II, mean accuracy improved slightly from R2 = 0.86 (ST) to 0.89 (AT). For both segmentations and both scanners, the standard section was quantified slightly more accurate than the subchondral section. The agreement between the scanners was enhanced from R2 = 0.89 (ST) to 0.98 (AT). In conclusion, AT can enhance the accuracy of XtremeCT to quantify distal radius bone microstructural parameters close to XtremeCT-II level and increases the agreement between the two HR-pQCT scanners. High-resolution peripheral quantitative computed tomography, segmentation, bone microstructural parameters.

Novel coronavirus epidemic in the Hungarian population, a cross-sectional nationwide survey to support the exit policy in Hungary.

After months of restrictive containment efforts to fight the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) epidemic, European countries are planning to reopen. To support the process, we conducted a cross-sectional survey among the Hungarian population to estimate the prevalence of infectious cases and prior SARS-CoV-2 exposure. A representative sample (n = 17,787) for the Hungarian population of 14 years or older living in private households (n = 8,283,810) was selected. The study was performed within 16 days after 50 days of restrictions, when the number of confirmed cases was stable low. Naso- and oropharyngeal smears and blood samples were collected for PCR and antibody testing. The testing was accompanied by a questionnaire about symptoms, comorbidities, and contacts. Design-based prevalence estimates were calculated. In total, 10,474 individuals (67.7% taken into account a sample frame error of 2315) of the selected sample participated in the survey. Of the tested individuals, 3 had positive PCR and 69 had positive serological test. Population estimate of the number of SARS-CoV-2 infection and seropositivity were 2421 and 56,439, respectively, thus active infection rate (2.9/10,000) and the prevalence of prior SARS-CoV-2 exposure (68/10,000) was low. Self-reported loss of smell or taste and body aches were significantly more frequent among those with SARS-CoV-2. In this representative, cross-sectional survey of the Hungarian population with a high participation rate, the overall active infection rate was low in sync with the prevalence of prior SARS-CoV-2 exposure. We demonstrated a potential success of containment efforts, supporting an exit strategy. NCT04370067, 30.04.2020.

Geometrical accuracy evaluation of an affordable 3D printing technology for spine physical models.

OBJECTIVE: The aim of the study is to develop a workflow to establish geometrical quality criteria for 3D printed anatomical models as a guidance for selecting the most suitable 3D printing technologies available in a clinical environment. METHODS: We defined the 3D geometry of a 25-year-old male patient's L4 vertebra and the geometry was then printed using two technologies, which differ in printing resolution and affordability: Fused Deposition Modelling (FDM) and Digital Light Processing (DLP). In order to measure geometrical accuracy, the 3D scans of two physical models were compared to the virtual input model. To compare surface qualities of these printing technologies we determined surface roughness for two regions of interest. Finally, we present our experience in the clinical application of a physical model in a congenital deformity case. RESULTS: The analysis of the distribution of the modified Hausdorff distance values along the vertebral surface meshes (99% of values <1 mm) of the 3D printed models provides evidence for high printing accuracy in both printing techniques. Our results demonstrate that the surface qualities, measured by roughness are adequate (~99% of values <0.1 mm) for both physical models. Finally, we implemented the FDM physical model for surgical planning. CONCLUSION: We present a workflow capable of determining the quality of 3D printed models and the application of a high quality and affordable 3D printed spine physical model in the pre operative planning. As a result of the visual guidance provided by the physical model, we were able to define the optimal trajectory of the screw insertion during surgery.

[Bone age - alternatives for skeletal maturity assessment for the EOS scanner]. / Csontkor ­ a csontrendszeri érettség mérésének lehetosége EOS készülékkel.

INTRODUCTION: Hand and wrist bone age assessment methods cannot be performed when using the recommended patient position within the EOS scanner. AIM: We aimed to assess alternative methods for use with the EOS. METHOD: After investigating 9 alternatives, five methods were selected - cervical vertebra (Hassel-Farman), iliac crest (Risser 'plus'), hip (Oxford), knee (O'Connor), calcaneus (Nicholson) - and applied to EOS scans of 114, 2-21-year-old normal individuals. Intraclass correlation coefficient tests for reliability and Spearman correlation with calendar age were assessed. RESULTS: Intra- and interobserver reliabilities were all excellent, except with the knee method (0.865 - 'good'). Calcaneal and cervical methods were the fastest to apply (mean 17.5 s, 33.4 s per evaluation), however, calcanei were unassessable in 14% of scans (versus 1% of cervical). All methods correlated significantly with calendar age (r>0.829, p<0.05). Difficulties were principally absent (12%) or obscured (23%) landmarks. CONCLUSION: Bone age assessment is possible with all 5 methods, however, the Hassel-Farman method proved to be easily useable, fast and reliable. Orv Hetil. 2019; 160(16): 619-628.

Correlation Between Cone-Beam Computed Tomography and High-Resolution Peripheral Computed Tomography for Assessment of Wrist Bone Microstructure.

High-resolution peripheral quantitative computed tomography (HR-pQCT) is considered as the best technique to measure bone microarchitecture in vivo. However, a breakthrough for medical applications is inhibited because of the restricted field of view (∼9 mm) and a relatively long acquisition time (∼3 minutes). The goal of this study was to compare the accuracy of cone-beam computed tomography (CBCT) and HR-pQCT and to determine the agreement between CBCT and HR-pQCT in quantifying bone structural parameters. Nineteen trapezia of arthritic patients were scanned four times ex vivo: 1) CBCT (NewTom 5G, Cefla, at 75 µm); 2) HR-pQCT (XTremeCT-I, Scanco, at 82 µm); 3) HR-pQCT (XTremeCT-II, Scanco, at 60.7 µm); and 4) microCT (SkyScan1172, Bruker, at 19.84 µm). XTremeCT-I and XtremeCT-II were reconstructed, segmented, and analyzed following the manufacturer's guidelines. CBCT was reconstructed with in-house developed software and analyzed twice: once with an adaptive segmentation technique combined with a direct analysis method (AT-DM) and once with a Laplace-Hamming filtering technique combined with an indirect analysis method (LH-IM). Parameters of interest included bone volume fraction (BV/TV) and trabecular thickness (Tb.Th), separation (Tb.Sp), and number (Tb.N). The analyses of the CBCT data showed that the AT-DM analysis correlated better with microCT for BV/TV, Tb.Sp, and Tb.N, whereas the LH-IM technique correlated better for Tb.Th. Evaluated over all parameters, the coefficient of determination for XtremeCT-I, XtremeCT-II, and CBCT were higher as R2 = 0.68, 0.72, and 0.67, respectively. For CBCT, the correlations improved when three samples with very thin trabeculae close to each other were excluded and became similar to those for XtremeCT-I and XtremeCT-II. Interesting for clinical practice is that those bones could be identified automatically with the CBCT scanner. We conclude that CBCT produced similar accuracy as HR-pQCT in bone morphometric analyses of trapezia. The broader range of application, larger field of view, and shorter acquisition time make CBCT a valuable alternative to HR-pQCT. © 2019 American Society for Bone and Mineral Research.

BMD-based assessment of local porosity in human femoral cortical bone.

Cortical pores are determinants of the elastic properties and of the ultimate strength of bone tissue. An increase of the overall cortical porosity (Ct.Po) as well as the local coalescence of large pores cause an impairment of the mechanical competence of bone. Therefore, Ct.Po represents a relevant target for identifying patients with high fracture risk. However, given their small size, the in vivo imaging of cortical pores remains challenging. The advent of modern high-resolution peripheral quantitative computed tomography (HR-pQCT) triggered new methods for the clinical assessment of Ct.Po at the peripheral skeleton, either by pore segmentation or by exploiting local bone mineral density (BMD). In this work, we compared BMD-based Ct.Po estimates with high-resolution reference values measured by scanning acoustic microscopy. A calibration rule to estimate local Ct.Po from BMD as assessed by HR-pQCT was derived experimentally. Within areas of interest smaller than 0.5 mm2, our model was able to estimate the local Ct.Po with an error of 3.4%. The incorporation of the BMD inhomogeneity and of one parameter from the BMD distribution of the entire scan volume led to a relative reduction of the estimate error of 30%, if compared to an estimate based on the average BMD. When applied to the assessment of Ct.Po within entire cortical bone cross-sections, the proposed BMD-based method had better accuracy than measurements performed with a conventional threshold-based approach.

Long-term costs and survival of prostate cancer: a population-based study.

PURPOSE: There is a rising interest in measuring the societal burden of malignancies including prostate cancer. However, population-based studies reporting incidence costs of prostate cancer in the long term are lacking in Europe. The objectives of the study are to analyse the long-term costs and survival of prostate cancer patients treated by radical prostatectomy (RP) or conservative management (nRP). METHODS: A retrospective claims data analysis of the National Health Insurance Found Administration of Hungary between 01.01.2002 and 31.10.2013 was carried out. Annual incidence costs related to prostate cancer and overall survival were calculated for a cohort of patients diagnosed between 2002 and 2005. RESULTS: Altogether 17,642 patients were selected; 2185 (12%) of them have undergone RP. The annual incidence rate ranged between 4177 and 4736 cases. Mean age of RP and nRP patients was 59.4 (SD 5.9) and 71.0 (8.4) years, respectively. The mean survival time of the RP patients was significantly longer compared to nRP patients both in the total sample (11.2 vs. 7.4 years; p < 0.001) and in the subgroup <70 years (11.3 vs. 8.8 years; p < 0.001). At the end of the 12-year follow-up, RP patients had a higher (0.83 vs. 0.68), while nRP patients had a slightly lower (0.35 vs. 38) probability of being alive compared with the age-matched general male population. The long-term cumulative costs of the RP and nRP patients amounted to €4448 and €8616. The main driver of the cost difference was the high drug costs in the nRP group. CONCLUSIONS: To our knowledge, this study applied the longest time-window in reporting population-based incidence costs in Europe. We found that not only RP patients lived longer but they had significantly lower total long-term costs than nRP patients. Therefore, radical prostatectomy is a cost-effective strategy in prostate cancer.

Reliability of the spinal instability neoplastic scale among radiologists: an assessment of instability secondary to spinal metastases.

OBJECTIVE: The spinal instability neoplastic scale (SINS) is a new classification system for tumor-related spinal instability. The SINS may prove to be a valuable tool for radiologists to communicate with oncologists and surgeons in a standardized evidence-based manner. The objective of this study was to determine the inter- and intraobserver reliability and validity of the SINS among radiologists. MATERIALS AND METHODS: Thirty-seven radiologists from 10 international sites used the SINS to categorize the degree of spinal instability in 30 patients with spinal tumors. To assess validity, we compared the SINS scores assigned by the radiologists with the SINS scores of 11 spine oncology surgeons (reference standard). Each total SINS score (range, 0-18 points) was converted into one of the following three clinical categories: 0-6 points, stable; 7-12 points, potentially unstable; and 13-18 points, unstable. In addition, each total SINS score was converted into a binary scale: 0-6 points was defined as stable, and 7-18 points was considered a current or possible instability for which surgical consultation is recommended. RESULTS: Radiologists using the SINS binary scale showed excellent (κ = 0.88) validity, substantial (κ = 0.76) interobserver agreement, and excellent (κ = 0.82) intraobserver reproducibility. Radiologists rated all unstable cases and 621 of 629 (98.7%) potentially unstable cases with a SINS score of 7 or more points, thus appropriately initiating a referral for surgical assessment. CONCLUSION: SINS is a reliable tool for radiologists rating tumor-related spinal instability. It accurately discriminates between stable and potentially unstable or unstable lesions and, therefore, can guide the need for surgical consultation.

[The economic burden of prostate cancer. A systematic literature overview of registry-based studies]. / A prosztatarák gazdasági terhe nagy betegregiszterek alapján. Irodalmi áttekintés.

INTRODUCTION: Prostate cancer, the most frequent malignant disease in males in Europe, accounts for a great proportion of health expenditures. AIM: A systematic review of registry-based studies about the cost-of-illness and related factors of prostate cancer, published in the last 10 years. METHOD: A MEDLINE-based literature review was carried out between January 1, 2003 and October 1, 2013. RESULTS: Fifteen peer-reviewed articles met the criteria of interest. In developed countries radiotherapy, surgical treatment and hormone therapy account for the greatest per capita costs. In Europe early stage tumours (4-7000 €, 2006), while in the USA metastatic prostate cancer (19 900-25 500 $, 2004) was associated with highest per capita expenses. In Europe the greatest costs incurred within the initial treatment (6400 €/6 months, 2008), while in the USA within the end-of-life care (depending on age: 62 200-93 400 $, 2010). CONCLUSIONS: Despite public health importance of prostate cancer, the cost-of-illness literature from Europe is relatively small.

Reliability of the Spinal Instability Neoplastic Score (SINS) among radiation oncologists: an assessment of instability secondary to spinal metastases.

BACKGROUND: The Spinal Instability Neoplastic Score (SINS) categorizes tumor related spinal instability. It has the potential to streamline the referral of patients with established or potential spinal instability to a spine surgeon. This study aims to define the inter- and intra-observer reliability and validity of SINS among radiation oncologists. METHODS: Thirty-three radiation oncologists, across ten international sites, rated 30 neoplastic spinal disease cases. For each case, the total SINS (0-18 points), three clinical categories (stable: 0-6 points, potentially unstable: 7-12 points, and unstable: 13-18 points), and a binary scale ('stable': 0-6 points and 'current or possible instability'; surgical consultation recommended: 7-18 points) were recorded. Evaluation was repeated 6-8 weeks later. Inter-observer agreement and intra-observer reproducibility were calculated by means of the kappa statistic and translated into levels of agreement (slight, fair, moderate, substantial, and excellent). Validity was determined by comparing the ratings against a spinal surgeon's consensus standard. RESULTS: Radiation oncologists demonstrated substantial (κ=0.76) inter-observer and excellent (κ=0.80) intra-observer reliability when using the SINS binary scale ('stable' versus 'current or possible instability'). Validity of the binary scale was also excellent (κ=0.85) compared with the gold standard. None of the unstable cases was rated as stable by the radiation oncologists ensuring all were appropriately recommended for surgical consultation. CONCLUSIONS: Among radiation oncologists SINS is a highly reliable, reproducible, and valid assessment tool to address a key question in tumor related spinal disease: Is the spine 'stable' or is there 'current or possible instability' that warrants surgical assessment?