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Closed reduction and percutaneous pinning is still a preference for the treatment of supracondylar humerus fractures in children. However, no reports have shown the pin trajectory and the characteristics of the entry point so far. So we established a computational simulation model of the elbow to observe the trajectory of pinning for supracondylar humerus fractures. We reconstructed an adult elbow computationally and simulated pin placement through lateral and medial pinning. Pin trajectories were traced after placement and after the addition of the skin profile; the relative entry points of the pins were determined. We used the center of the dorsal olecranon inflection as an anatomic reference for the entry points of lateral pinning. Four quadrants were established based on the center of the dorsal olecranon inflection: upper medial quadrant, upper lateral quadrant, lower medial quadrant, and lower lateral quadrant (LLQ). The maximum angle of pinning through the lateral column was 64° ± 3°. The minimum angles of pinning through the lateral column and middle column were 37° ± 3° and 20° ± 2°, respectively. The range of safe angle pinning through the medial column was between 18° ± 2° and 57° ± 3° to avoid penetration of the olecranon fossa and the cortex of the medial column. The entry points of lateral pinning were within the lateral half of the LLQ, and the lateral one-third of the LLQ contained all entry points of the pins through the lateral column and minor points of the pins through the middle column. The exit points of the medial pinning were within the lateral fringe of the metaphyseal-diaphyseal junction region; entering from the inferior two-thirds of the medial epicondyle could lead to the exit points in the proximal half of the metaphyseal-diaphyseal junction region laterally. For lateral pinning, the entry points would be within the lateral half of the LLQ. For the pins through the lateral column, the entry points should be within the lateral one-third of the LLQ. For medial pinning, entering from the inferior two-thirds of the medial epicondyle would lead to a more proximal exit. [ABSTRACT FROM AUTHOR]

Introduction: Fusion of the occipitocervical or atlantoaxial vertebra is an accepted treatment option in upper cervical spine instability caused by cervical trauma or various other disorders. The C1-C2 fusion techniques have limitations which may be overcome by the lateral mass screws. Posterior screw placement in the atlas lateral mass avoids the loss of occipitocervical motion and enables posterior C1-C2 fusion in patients. This is followed in patients who are not suitable for transarticular screw fixation. Aim: To define ideal entry point, exit point, trajectory and dimensions of the lateral mass screw during the posterior screw fixation of atlas vertebra, to avoid damage to vertebral artery and contents of vertebral canal. Material and Methods: For this study 50 intact dried human atlas vertebrae from the Indian population were measured using a digital Vernier calliper that provides accurate resolution up to 0.01 mm and a goniometer. The measurements were entered in an excel sheet. Mean and standard deviation were calculated. Results: In the present study, the ideal entry point for the lateral mass screw to prevent damage to 1st part of vertebral artery was found to be the midpoint of pedicle analog of atlas. The ideal exit point for the screw to avoid injury vertebral canal contents and 2nd part of vertebral artery was on the anterior surface of lateral mass at a distance of 16.3 mm (SD=1.8) from the anterior tubercle. The horizontal angulation of screw trajectory was found to be 4 degrees medial and vertical angulation 5.4 degrees superior. The distance between entry point and ideal exit point was taken as the optimum length of screw (17.3 mm). The optimum width of screw was calculated by adding the distance of lateral mass inferior to pedicle analog and the thickness of vertebral artery groove (7.2 mm). Conclusion: The above findings and landmarks will be of great help to spine surgeons while performing posterior screw fixation of lateral mass of atlas vertebra.

Abstract Background Kirschner wire fixation remains to be the mainstream treatment modality in unstable or displaced supracondylar humerus fracture in children, with divergent lateral pins being the most preferred due to their sufficient stability and decreased risk of ulnar nerve injury. However, the entry point at which the proximal lateral pin can be inserted to achieve a more proximal exit and maximum divergence has not been reported. This study retrospectively analyzed the characteristics and factors influencing the entry and exit points of the proximal lateral pins. Methods The study was divided into two stages. In stage one, the entry and exit points of the proximal pins of lateral pinning configuration were analyzed from intra-operative radiographs of children treated for extension-type supracondylar humerus fractures. The coronal and sagittal pin angles formed by the proximal pins were also measured. Using the findings of stage one, we intentionally tried to achieve a more proximal exit with the proximal pins in stage two. Comparisons between groups of patients treated by random and intentional pinnings were done statistically. Results In the first stage, 47 (29.2%) of the 161 proximal pins exited above the metaphyseal-diaphyseal junction (MDJ) region. Of these, 85.1% entered from lateral and posterior to the ossific nucleus of the capitellum (ONC). The pin angles averaged 58.4° and 90.5° in the coronal and sagittal planes respectively. In the second stage, 47 (65.3%) proximal pins in the intended group exited above the MDJ region, while only 32 (36%) in the random group exited above the MDJ region. Conclusion While aiming at the upper border of the distal MDJ during pinning, lateral pins can easily achieve a higher, proximal exit above the MDJ if inserted from lateral and posterior to the ONC and parallel to the humeral shaft in the sagittal plane. Higher exit can also be easily achieved in younger patients and patients fixated with smaller diameter pins.

This paper developed an analytical solution for the problem of exit point evolution on the seepage face in the unconfined aquifer with sloping interface. A theoretical model for the groundwater drawdown problem in a half‐infinite aquifer with a sloping boundary is built in accordance with the linearized one‐dimensional Boussinesq equation and the Neumann boundary condition at the seepage point. The homotopy analysis method is then adopted for solving this dynamic boundary problem. By constructing two continuous deformations, the original problem could be converted into a group of subproblems with the same physical essence and similar mathematical solutions. To compare this analytical solution, a numerical model based on the finite volume method is developed, which employs adaptive grids to settle the dynamic boundary condition. The comparisons show that the analytical solution agrees with the numerical model well. The results are useful for the quantification of various hydrological problems. The methodology applied in this study is referential for other dynamic boundary problems as well. [ABSTRACT FROM AUTHOR]

Background: Kirschner wire fixation remains to be the mainstream treatment modality in unstable or displaced supracondylar humerus fracture in children, with divergent lateral pins being the most preferred due to their sufficient stability and decreased risk of ulnar nerve injury. However, the entry point at which the proximal lateral pin can be inserted to achieve a more proximal exit and maximum divergence has not been reported. This study retrospectively analyzed the characteristics and factors influencing the entry and exit points of the proximal lateral pins. Methods: The study was divided into two stages. In stage one, the entry and exit points of the proximal pins of lateral pinning configuration were analyzed from intra-operative radiographs of children treated for extension-type supracondylar humerus fractures. The coronal and sagittal pin angles formed by the proximal pins were also measured. Using the findings of stage one, we intentionally tried to achieve a more proximal exit with the proximal pins in stage two. Comparisons between groups of patients treated by random and intentional pinnings were done statistically. Results: In the first stage, 47 (29.2%) of the 161 proximal pins exited above the metaphyseal-diaphyseal junction (MDJ) region. Of these, 85.1% entered from lateral and posterior to the ossific nucleus of the capitellum (ONC). The pin angles averaged 58.4° and 90.5° in the coronal and sagittal planes respectively. In the second stage, 47 (65.3%) proximal pins in the intended group exited above the MDJ region, while only 32 (36%) in the random group exited above the MDJ region. Conclusion: While aiming at the upper border of the distal MDJ during pinning, lateral pins can easily achieve a higher, proximal exit above the MDJ if inserted from lateral and posterior to the ONC and parallel to the humeral shaft in the sagittal plane. Higher exit can also be easily achieved in younger patients and patients fixated with smaller diameter pins. [ABSTRACT FROM AUTHOR]

Seepage face and the corresponding exit point (EP) contribute to the sophisticated groundwater hydrodynamics in the coastal aquifer. Several analytical solutions have been presented to estimate the EP movement. Nevertheless, previous theoretical studies are all limited to the Darcy flow assumption which is not applicable under the wave induced swash condition. In this study, a more general condition taking into account the non-Darcy flow effect with the Forchheimer formula was considered. Applying the v -transform method, a new analytical solution was derived to represent the swash induced EP movement under the wave action. Subsequently, detailed analyses of the EP movement characteristics were conducted, upon which its temporal variation features, as well as the influence of the non-Darcy flow effect and beach slope, were scrutinized. In addition, a decay parameter is used to describe the further reduction of the aquifer storage coefficient resulting from the truncated capillary fringe. By inter-comparing the available experimental data with the newly derived analytical solution, the optimal decay parameter was found to be 0.46. These new findings are of great importance to extend our understandings of the wave induced groundwater hydrodynamics in the swash zone. • A new analytical solution for estimating the exit point (EP) movement under the wave-induced swash condition was derived. • EP movement quickly reaches its final equilibrium velocity soon after its formation. • Equilibrium EP moving velocity is insensitive to the strong non-Darcy flow condition. • Non-Darcy flow effect is pronounced for the large beach slope condition. • As for the truncated capillary fringe, the optimal decay parameter was found to be 0.46 regarding the available data. [ABSTRACT FROM AUTHOR]

This article reports on a study that was conducted to evaluate value addition in the learning attainments of students in higher education. The subjects in the study were telecommunication engineering students who pursued their programme of study between 2011 and 2013 at the Ghana Technology University College. Using descriptive statistics and regression analysis, the study sought to test the differences between the mean scores of three groups of students who were categorised based on their entry qualifications and final year cumulative weighted averages (CWAs). The first level of analysis was done by comparing the students’ entry qualifications with their CWAs at the end of the programme. The second level of analysis was done by comparing the students’ first year and final year CWAs in the core and general courses domains. The study concluded that the students’ entry qualifications and CWAs could measure value addition. [ABSTRACT FROM AUTHOR]

Osteomyelitis is a bone infection that can occur as a rare late complication of electrical burns. It may occur in any bony part of the body where there has been an electrical burn injury. Osteomyelitis occurs several weeks or months after the initial infection, and can persist for several months or years, and is difficult to manage. To our knowledge, to date, no chronic osteomyelitis of the femur has been reported after an electrical burn injury. The present case report is of a 40-year-old man who sustained a high voltage electrical burn injury involving his right upper and lower limbs as well as the posterior trunk. The estimated total body surface area burned was 20 %. He developed chronic osteomyelitis of the right femur several months after the initial injury. The upper extremities are the sites most frequently affected by chronic osteomyelitis following electrical burns. Staphylococcus aureus is the most common causative organism, and treatment entails a combined medical and surgical approach. Osteomyelitis of the long bones of the lower extremities is an uncommon complication of electrical burn injuries involving the lower limbs. We, however, advocate a high index of suspicion when faced with electrical burns of the lower extremity. • Osteomyelitis is a rare complication of electrical burn injury. • Electricity is a devastating cause of burn injury. • Electrical injuries often have entry and exit wounds. • The upper limb and cranial vault are the most common sites of osteomyelitis following electric burns. • It takes several months after an electrical burn injury for osteomyelitis to occur and treatment is often very difficult. [ABSTRACT FROM AUTHOR]