Christine Feja

Comparative anatomical measurements of osseous structures in the ovine and human knee

The ovine stifle has been increasingly used as a large animal model for the human knee. Still, comparative anatomical measurements of the knee in sheep and humans are missing. Thus, the purpose of this study was to describe and measure the osseous anatomy of the ovine stifle in comparison to the human knee. Twenty-four stifles of skeletal-mature merino-sheep and 24 human cadaver knees were obtained and distances between selected anatomical structures of the distal femur, the proximal tibia, and the patella were measured digitally and documented. Based on these, intercondylar ratio, tibial aspect ratio, patella aspect ratio and the cortical index were calculated. Regarding epicondylar width, lateral condylar width, medial condylar width and the tibial dimensions, the ovine stifle can be considered as a human knee scaled down by one third. However, sheep have a smaller trochlear width and a narrower femoral intercondylar notch than humans resulting in lower relative values for intercondylar width and intercondylar height. The distal femurs cortical index is the same in both species. In contrast, sheep have a massive bone stock below their tibial plateau and a proximal tibial shaft with remarkably thick cortical bone. The ovine stifle can be regarded as a useful model for the human knee. However, future studies should consider the differences in the femoral intercondylar notch width, the patellofemoral joints biomechanics and the proximal tibias cortical bone stock.

Ethanol-glycerin fixation with thymol conservation: A potential alternative to formaldehyde and phenol embalming

Anatomical fixation and conservation are required to prevent specimens from undergoing autolysis and decomposition. While fixation is the primary arrest of the structures responsible for autolysis and decomposition, conservation preserves the state of fixation. Although commonly used, formaldehyde has been classified as carcinogenic to humans. For this reason, an adequate substitute was developed. Ethanol‐glycerin fixation and thymol conservation are described and compared with formaldehyde and phenol in this technical report. The setup, tissue qualities, financial aspects, and health concerns of this method are discussed. Ethanol‐glycerin fixation and thymol conservation provide outstanding haptic and optic tissue qualities. Typical formaldehyde and phenol effects, such as skin, airway, and eye irritation, as well as carcinogenic effects, can be circumvented by using ethanol‐glycerin and thymol instead. Ethanol‐glycerin fixation is more expensive than formaldehyde and requires an explosion‐proof facility. However, the absence of health effects and its convincing tissue qualities balance these higher costs. Therefore, ethanol‐glycerin fixation and thymol conservation provide a potential alternative and complement established fixation techniques. The use of carcinogenic formaldehyde and toxic phenol can be effectively restricted through the use of the described method. Anat Sci Educ.

Comparison of modified Thiel embalming and ethanol-glycerin fixation in an anatomy environment: Potentials and limitations of two complementary techniques.

Thiel‐fixed specimens have outstandingly lifelike visual and haptic properties. However, the original Thiel method is expensive and requires an elaborate setup. It is therefore of principal interest to modify the Thiel method in order to make it available to a broader user group. A modified Thiel embalming method will be described in detail and compared to ethanol‐glycerin fixation with the help of illustrative examples. The visual properties, haptic properties, the usability for performing histological investigations, costs and potential health aspects will be considered. Tissues fixed with the modified Thiel technique gave results similar to the original method, providing more realistic visual and haptic properties than ethanol‐glycerin embalming. However, Thiel fixation is significantly more expensive and requires more precautions to minimize potential health hazards than ethanol‐glycerin‐fixed tissues. In contrast to ethanol‐glycerin‐fixed specimens, the Thiel‐fixed specimens are not suitable for histological investigations. Both modes of fixation are inappropriate for biomechanical testing. Modified Thiel embalming simplifies the availability of body donors with lifelike properties and has cost‐saving advantages to the original technique. Thiel‐embalmed body donors are ideally suited for clinical workshops but have restrictions for student dissection courses in facilities with limited storage space, air circulation or technical staff. Vice versa, ethanol‐glycerin‐fixed body donors are well suited for student dissection courses in such an environment but are limited in their use for clinical workshops. Modified Thiel embalming therefore ideally complements ethanol‐glycerin fixation in order to provide customized solutions for clinical workshops and student dissection courses in a wide range of applications. Anat Sci Educ 8: 74–85.

Substitution of Formaldehyde in Cross Anatomy Is Possible

The recent publication by Hauptmann et al. (1) in the Journal provided clear evidence for increased mortality from cancer induced by exposure to formalin, as outlined by The Final Report on Carcinogens Background Document for Formaldehyde of the National Toxicology Program (2). Hauptmanns data, along with a report by Figure 1. A–C) Examples of ethanol-and glycerin-fixed human tissue specimens are shown. A) The Erbs punctum nervo-sum (asterisk) is depicted in the lateral view of a dissected neck. Note the vivid color of the underlying sternocleidomas-toid muscle (M). C = clavicula, D = deltoid muscle, G = great auricular nerve, Pg = parotid gland, S = supraclavicular nerves, T = transverse cervical nerve. Specimen was fixed for 12 months before picture was taken. B) The opened left ventricle shows the aortic valve (V), the papillary muscles (P), and the ostia to the left coronary artery (Ol) and to the right coronary artery (Or). A = aorta, Ct = chordae ten-dineae, L = left ventricular myocardium, Tc = trabeculae carneae. Specimen was fixed for 15 months before picture was taken. C) The situs thoracis with peri-cardium (Pc), lungs (Ld = Lobus dexter, Ls = Lobus sinister), and phrenic nerve (Pn). Note the preservation of the neuro-vascular bundle of the ventral medias-tinum (Pv = pericardiacophrenic vessels). A = aorta, Iv = internal thoracic vessels, Vs = superior vena cava, Tp = truncus pulmonalis. The specimen was fixed for 12 months before picture was taken. Viegas et al. (3) demonstrating that medical students are exposed to formalin concentrations greater than 5 ppm during macro-scopic examinations, have caused medical institutions to reconsider the use of for-malin to fix and preserve cadavers and tissues. The emerging data indicating the toxicity of formalin have resulted in the closure of German dissecting rooms in medical schools and could potentially result in poor gross anatomy training and strongly affect the quality of medical staff education. A recent complaint by surgeons that a lack of knowledge in anatomy is already prevalent among young doctors (4) indicates that the development of new nontoxic fixatives are necessary to allow medical students to adequately study gross anatomy in a safe environment. To address this problem, the Institute of Anatomy at Universität Leipzig has developed an approach to conserve human cadavers for dissection courses with the use of a fixative consisting mainly of eth-anol and glycerin. This room temperature 1.5% glycerin solution is perfused …

Human Vagus Nerve Branching in the Cervical Region

Background Vagus nerve stimulation is increasingly applied to treat epilepsy, psychiatric conditions and potentially chronic heart failure. After implanting vagus nerve electrodes to the cervical vagus nerve, side effects such as voice alterations and dyspnea or missing therapeutic effects are observed at different frequencies. Cervical vagus nerve branching might partly be responsible for these effects. However, vagus nerve branching has not yet been described in the context of vagus nerve stimulation. Materials and Methods Branching of the cervical vagus nerve was investigated macroscopically in 35 body donors (66 cervical sides) in the carotid sheath. After X-ray imaging for determining the vertebral levels of cervical vagus nerve branching, samples were removed to confirm histologically the nerve and to calculate cervical vagus nerve diameters and cross-sections. Results Cervical vagus nerve branching was observed in 29% of all cases (26% unilaterally, 3% bilaterally) and proven histologically in all cases. Right-sided branching (22%) was more common than left-sided branching (12%) and occurred on the level of the fourth and fifth vertebra on the left and on the level of the second to fifth vertebra on the right side. Vagus nerves without branching were significantly larger than vagus nerves with branches, concerning their diameters (4.79 mm vs. 3.78 mm) and cross-sections (7.24 mm2 vs. 5.28 mm2). Discussion Cervical vagus nerve branching is considerably more frequent than described previously. The side-dependent differences of vagus nerve branching may be linked to the asymmetric effects of the vagus nerve. Cervical vagus nerve branching should be taken into account when identifying main trunk of the vagus nerve for implanting electrodes to minimize potential side effects or lacking therapeutic benefits of vagus nerve stimulation.

Detection of articular perforations of the proximal humerus fracture using a mobile 3D image intensifier – a cadaver study

BackgroundThe purpose of this study was to investigate the accuracy of perforation detection with multiplanar reconstructions using a mobile 3D image intensifier.MethodsIn 12 paired human humeri, K-wires perforating the subchondral bone and placed just below the cartilage level were directed toward five specific regions in the humeral head. Image acquisition was initiated by a fluoroscopy scan. Within a range of 90°, 45° external rotation (ER) and 45° internal rotation (IR). The number and percentage of detected perforating screws were grouped and analyzed. Furthermore, the fluoroscopic images were converted into multiplanar CT-like reconstructions. Each K-wire perforation was characterized as “detected” or “not detected”.ResultsIn the series of fluoroscopy images in the standard neutral position at 30° internal rotation, and 30° external rotation, the perforations of all K-wires (n = 56) were detected. Twenty-nine (51.8%) of them were detected in one AP view, 22 (39.3%) in two AP views, and five (8.9%) in three AP views. All K-wire perforations (100%, n = 56) were detected in multiplanar reconstructions.ConclusionIn order to reveal all of the intraoperative and postoperative screw perforations in a “five screw configuration”, conventional AP images should be established in both the neutral positions (0°), at 30° internal rotation and 30° external rotation. Alternatively, the intraoperative 3D scan with multiplanar reconstructions enables a 100% rate of detection of the screw perforations.

Implementation of clinical references for undergraduates in anatomy

This study evaluates the implementation of clinical references in undergraduate medical education. For this purpose, images of typical diagnostic, intraoperative and clinical findings were integrated into two different teaching formats and adapted to the learning objectives of the Institute of Anatomy in Leipzig. Paper based questionnaires were used to evaluate the status quo (without clinical images) and the optimal time of implementation, as well as the benefit for the students of human medicine. Three test groups were drawn from two preclinical semesters (2014 and 2015). The first group in 2014 represents the control group, which did not have any image-supported clinical references but only defined learning objectives regarding the five exams in special anatomy. Primary implementation took place in the dissection course (second semester) as automatically running Power Point presentations while secondary implementation was during one of the five clinical seminars within the fourth semester. All groups were asked to evaluate the pros and cons through a self-developed paper-based questionnaire. The analysis was performed employing Microsoft Excel and SPSS. It has been demonstrated that most of the students welcome and appreciate the implementation of appropriate images as a valuable support in understanding clinical references. On the contrary, the dissection course did not seem to be the right time for this implementation. In keeping with previous studies, the important role of anatomy in medical education was outlined. A close collaboration between preclinical and clinical physicians concerning educational matters was presented. Considering these approaches, high-quality and sustainable education can be provided. Better patient care and education of young academics should be the motivation.