Explicit Finite Element Models Accurately Predict Subject-Specific and Velocity-Dependent Kinetics of Sideways Fall Impact

The majority of hip fractures in the elderly are the result of a fall from standing or from a lower height. Current injury models focus mostly on femur strength while neglecting subject-specific loading. This article presents an injury modeling strategy for hip fractures related to sideways falls that takes subject-specific impact loading into account. Finite element models (FEMs) of the human body were used to predict the experienced load and the femoral strength in a single model. We validated these models for their predicted peak force, effective pelvic stiffness, and fracture status against matching ex vivo sideways fall impacts (n = 11) with a trochanter velocity of 3.1 m/s. Furthermore, they were compared to sideways impacts of volunteers with lower impact velocities that were previously conducted by other groups. Good agreement was found between the ex vivo experiments and the FEMs with respect to peak force (root mean square error [RMSE] = 10.7%, R² = 0.85) and effective pelvic stiffness (R² = 0.92, RMSE = 12.9%). The FEMs were predictive of the fracture status for 10 out of 11 specimens. Compared to the volunteer experiments from low height, the FEMs overestimated the peak force by 25% for low BMI subjects and 8% for high BMI subjects. The effective pelvic stiffness values that were derived from the FEMs were comparable to those derived from impacts with volunteers. The force attenuation from the impact surface to the femur ranged between 27% and 54% and was highly dependent on soft tissue thickness (R² = 0.86). The energy balance in the FEMS showed that at the time of peak force 79% to 93% of the total energy is either kinetic or was transformed to soft tissue deformation. The presented FEMs allow for direct discrimination between fracture and nonfracture outcome for sideways falls and bridge the gap between impact testing with volunteers and impact conditions representative of real life falls. © 2019 American Society for Bone and Mineral Research.     

How to assess fetal metabolic acidosis from cord samples.

The degree of metabolic acidosis at birth has been calculated in cord artery and vein samples from 21 term fetuses with cord artery pH less than 7.20. The aim of the study was to compare base deficit values calculated from either Siggaard-Andersen alignment nomogram (BD blood) or the Acid-Base chart (BD extra cellular fluid, BDecf). BDblood was found to be consistently higher in the cord artery as compared with BDecf, 13.2 +/- 3.5 and 9.9 +/- 2.9 mmol/l (Mean +/- SD), respectively. A significant correlation was found between cord artery PCO2 and BDblood whereas BDecf appeared unaffected by PCO2. In cases with cord entanglement BDecf a-v differences were increased to 3.4 +/- 2.3 mmol/l as compared with the small a-v difference noted in acidotic cases without cord entanglement, 1.1 +/- 1.25 mmol/l. It is speculated that with acutely emerging, intermittent asphyxia due to cord compression, a cord artery and vein difference in metabolic acidosis may exist and where the vein captures the basal level and the artery the acute changes. It is concluded that BDecf in both cord artery and vein add valuable information on the mechanisms behind metabolic acidosis.     

Counterfactual (‘if only’) thinking in women with chronic widespread pain

The study explored the counterfactual thinking that women with chronic and widespread pain showed in response to what they themselves considered to be particularly stressful situations. Counterfactual thinking in 125 women sick‐listed due to chronic and widespread pain was investigated in terms of structure, function and control focus. The women were asked, for each of three types of problems that they indicated in a questionnaire to affect them most strongly, to describe a typical occurrence of it and to complete a counterfactual sentence in connection with it of the type ‘If only . . .’. The majority of counterfactuals pertained to predominantly somatic problems (e.g. musculo‐skeletal problems, pain and fatigue) classified as being affective rather than preparative and self‐focused rather than external, whereas in counterfactuals relating to predominantly psychological/psychosocial problems a preparative function and an external focus were more prominent. The numbers of problems listed and the numbers of situations responded to counterfactually were positively correlated. The counterfactuals, although often related to somatic problems, generally concerned psychological or psychosocial matters such as finances and paid or unpaid work. A contextual approach to elucidating counterfactual thinking based on subjects' own experiences is seen as providing valuable insight into what bothers them most. Copyright © 2006 John Wiley & Sons, Ltd.     

Neoplastic and inflammatory processes of the peritoneum, omentum, and mesentery: diagnosis with CT.

Disease processes in the peritoneum, omentum, and mesentery occasionally are not recognized at radiologic examination. The authors have used computed tomography (CT) to categorize the radiologic appearances of the more common abnormalities into three basic patterns: (a) solid but relatively well-defined masses, (b) cystic-appearing masses, and (c) ill-defined or infiltrative processes. The most common solid masses to affect these anatomic regions are secondary neoplasms, which are associated with enhancement of the peritoneum on contrast material-enhanced CT scans and, typically, ascites. The various cystic-appearing masses (including cystic lymphangioma, cystic mesothelioma, teratoma, and loculated ascites) and infiltrating masses (such as peritoneal mesothelioma, retractile mesenteritis, desmoid, and carcinoid) must be differentiated on the basis of clinical findings and additional imaging findings (eg, CT depiction of fat and calcium in teratomas and the radiating appearance of carcinoids). Although the CT appearances of some of the abnormalities overlap, classifying them by pattern is helpful in narrowing the range of the differential diagnosis.     

A cholesterol embolism following coronary angioplasty. A case report

Cholesterol embolism is a rare but serious complication of heart catheterization. We report a patient in whom cholesterol embolization syndrome developed after coronary angioplasty complicated by an acute myocardial infarction which was treated with streptokinase and heparin. The clinical outcome was satisfactory. Cholesterol embolism occurrence might have been precipitated in this patient by thrombolytic and anticoagulant therapy.