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Biomedical subjects

K Püschel

Publications and source records attributed to K Püschel.

At least 19 recordsLinked to original sources
PubMed2007

[The calcaneus as the site of manifestation for osteoporosis-associated fractures: age- and sex-specific changes in calcaneal morphology correlate with the incidence and severity of intra-articular calcaneal fractures].

BACKGROUND: While it is recognized that trauma energy at the time of injury is an important factor in the pathogenesis and severity of calcaneal fractures, the possible role of changes in calcaneal microarchitecture remains largely undefined. The purpose of this study was to determine whether the calcaneal bone structure changes with age and to address if local bone mass is of clinical relevance in respect to the occurrence and complexity of calcaneal fractures. MATERIAL AND METHODS: The radiographic and clinical data of 182 patients with intra-articular calcaneal fractures were analyzed to provide correlative clinical evidence for a relation between local bone mass and fractures of the calcaneus. To measure bone mass, 60 calcanei were harvested from 30 age- and gender-matched patients at autopsy. RESULTS: The average age at the time of fracture was higher in females (46.0+/-18.3 years) than in males (39.9+/-13.9 years). Furthermore, the relative frequency of fractures during aging shifted from males to females and the frequency of compound fractures was higher in females (65%) than in males (48%). The calcaneal bone mass was significantly reduced by 19% in older females (female symbol 20-40 years: 292 mg/cm(3); female symbol 61-80 years: 237 mg/cm(3); p<0.05). CONCLUSION: The calcaneus displayed age- and gender-related changes in its microarchitecture that are known to reduce the biomechanical stability of trabecular bone. These results suggest that bone mass and structure are risk factors in respect to the occurrence and severity of calcaneal fractures.

Adult↗
PubMed2007

[Subdental synchondrosis. Computed tomographic and histologic investigation on morphological aspects of fracture at the base of the dens in 36 human axis specimens].

BACKGROUND: During development of the axis, four different ossification centers are formed. The two cranial ossification centers are demarcated from the ossification center of the vertebral corpus by a subdental synchondrosis. During further development the subdental synchondrosis--which is thought to close spontaneously--might not close completely, which leads to the necessity for differentiating synchondrotic remnants from a fracture at the base of the dens (type II according to Anderson and D'Alonzo). RESULTS: To characterize the architecture of the axis with particular attention to the subdental synchondrosis, the axis was harvested from 36 age- and gender-matched patients covering the human aging process from adolescence to senescence. In all specimens bone mineral density (BMD) was measured by peripheral quantitative computed tomography (pQCT). Morphological analysis after undecalcified processing of all specimens revealed a persistency of the subdental synchondrosis in 87% of all patients. Histological characterization of the subdental synchondrosis showed a cartilaginous structure interspersed with focal mineralization. Furthermore, static histomorphometric analysis revealed that trabecular bone volume and cortical thickness were significantly reduced within the base of the axis as compared to the dens and the corpus, respectively. CONCLUSION: Taken together, these results provide evidence that the base of the axis is a structurally distinct region. Besides well-recognized biomechanical aspects, these results suggest that the structure of the base of the axis might contribute to the occurrence of fractures of the axis and offer an additional explanation for the observation of nonunion after type II dens fractures.

Adolescent↗
PubMed2006

Locked vs. unlocked plate osteosynthesis of the proximal humerus - a biomechanical study.

BACKGROUND: Locked plates (internal fixators) have been found to be an optimal method for the fixation in proximal humeral fractures. In a biomechanical cadaver study the difference between locked and non-locked osteosyntheses was investigated. METHODS: Paired humeri were harvested, bone density measured. Locked internal fixators were mounted on one specimen; identical plate-screw-systems without locking mechanism applied to the contralateral specimen for comparison. After that, a transverse subcapital osteotomy was performed. With 7 pairs of humeri static tests with increasing axial loads and with 5 pairs dynamic tests with 10 N preload and 80 N maximal axial load for up to 1 million cycles were performed. RESULTS: In the static experiments the elastic stiffness of the construct was 74% higher in the locked group (median 80 N/mm, quartile range 77-86 N/mm) compared with the non-locked group (46 N/mm, 35.5-56.5 N/mm). The difference was statistically significant (Wilcoxon test for paired samples, P<0.05). Similarly, the linear range until failure was definitely extended in the locked group by 64% (92 N, 89-98 N vs. 56 N, 36.5-73.5 N, P<0.05). Under dynamic loading the non-locked group showed fixation failures between 97,000 and 500,000 cycles. In the locked group no failure was observed until the end of the experiment at 1 million cycles (P<0.0.5). The final deformation was found to be 1 mm (median, quartil range 1.0-1.2 mm) in the non-locked group and 0.3 mm (0.2-0.3 mm) in the locked group (P<0.05). The differences were found equally in lower as well as in higher bone density specimen. INTERPRETATION: Because of the optimal load transfer between implant and cancellous bone, a locked screw plate interface will reduce fixation failure in proximal humeral fractures.

Biomechanical Phenomena↗
PubMed2006

Application of ultrasonography to postmortem examination. Diagnosis of pericardial tamponade.

In postmortem examination, it is difficult to diagnose pericardial tamponade in a dead body from the findings of conventional external examination alone. However, ultrasonography is a common diagnostic tool for pericardial tamponade in clinical practice. We studied the postmortem diagnosis of pericardial tamponade at external examination level by applying an ultrasonographic device. The ultrasonographic findings were compared with the conventional autopsy findings. Among 455 cases of forensic autopsy in Hamburg and Tokyo conducted within 5 days after death, we successfully diagnosed 11 cases of pericardial tamponade by ultrasound imaging prior to autopsy, and failed to diagnose pericardial tamponade in only two cases. In addition, 79 cases of external examination conducted at the Tokyo Medicinal Examiner's Office were also examined with ultrasonography, and we diagnosed three cases of pericardial tamponade and five cases of pericardial effusion. The differences in ultrasonographic findings between tamponade and effusion were relatively clear. Although autopsy provides definitive evidence for the cause of death, sometimes autopsy cannot be performed due to some social factors. In such cases, conventional external examination alone cannot establish a cause of death by pericardial tamponade, and application of diagnostic imaging technique will be helpful. While CT and/or MRI may provide more detailed information than ultrasound imaging, these techniques require special equipment, room and specialist, and most of all involves high cost, which is perhaps the most important consideration in the present atmosphere of medical cost containment. On the other hand, the ultrasonographic devices we use are compact, and can be used directly at the scene of death. Postmortem application of ultrasonography may be a valuable adjunct in the work of medical examiners and forensic pathologists.

Aged↗
PubMed2006

Migration and cyclic motion of a new short-stemmed hip prosthesis--a biomechanical in vitro study.

BACKGROUND: Uncemented, short-stemmed hip prostheses have been developed to reduce the risk of stress shielding and to preserve femural bone stock. The long-term success of these implants is yet uncertain. Prerequisite for osseointegration is sufficient primary stability. In this study the cyclic motion and migration patterns of a new short-stemmed hip implant were compared with those for two clinically successful shaft prostheses. METHODS: The prostheses were implanted in paired fresh human femura and loaded dynamically (gait cycle) with increasing load (max 2,100 N) up to 15,000 cycles. Relative displacements between prosthesis and bone were recorded using a 3D-video analysis system. FINDINGS: The short stem displayed a biphasic migration pattern with stabilisation at maximum load. Initial migration was predominantly into varus and was greater than that for the shaft prostheses. Failure occurred in cases of poor bone quality and malpositioning. Cyclic motion of the short prosthesis was less than that for the shaft prostheses. Surface finish showed no effect. System stiffness for the new stem was lower than for the shaft prostheses. INTERPRETATION: The new stem tended to migrate initially more than the shaft prostheses, but stabilised when cortical contact was achieved or the cancellous bone was compacted sufficiently. Bone quality and correct positioning were important factors for the short stem. The lower cyclic motion of the new stem should be favourable for bony ingrowth. The lower system bending stiffness with the new implant indicated a more physiological loading of the bone and should thereby reduce the effects of stress shielding.

Adult↗
PubMed2006

[Self-inflicted finger-amputation: insurance fraud or accidental injury?].

A 50-year-old surgeon was working with his electrical circle saw as a do-it-yourselfer. He was alone, nobody witnessed his mishap when he amputated his left index finger. He claimed high financial compensation from two accident insurance companies because of his disability. A long series of medical expertises followed. The juridical procedures took 12 years in total. All higher authorities had to deal with the forensic medical implications. Finally, the high court (Bundesgerichtshof) decided that the complainant would receive no compensation because he gave two very different descriptions. Concerning the reconstruction of the accident, the first version was unlikely from a biomechanical point of view. The decision of the court was solely based on the violation of the obligation to give a clear presentation of the course of events (Obliegenheitsverletzung).

Accidents↗
PubMed2006

Analysis of jumping/falling distance from a height.

The kinematic motion analysis of 50 jumps from a height of 5m demonstrated distinguishable maxima of jumping distances between passive and active jumps (1.0-3.4 and 3.7-7.1 m, respectively). The variation of several parameters concerning the 'take-off' mechanism showed less influence regarding the jumping distances. The congruence of the trajectory of the 'free-flight' domains of the jumps and the simple model for the parabola of an inclined throw has been proven. Thus, a prediction of the distance range for heights up to 20 m was extrapolated.

Accidental Falls↗
PubMed2006

[Atrial myocardial perforation due to catheter ablation of the cavotricuspid isthmus].

A 79-year-old man died 3.5 hours after catheter ablation of atrial fibrillation due to pericardial tamponade. Autopsy and consecutive microscopic examinations furnished evidence of electrothermical necroses topographically arranged regularly adjacent to the pulmonary veins in the left atrium and across the area of the isthmus in the right atrium with a rupture of the right atrial wall in the area of a coagulation spot. The post-mortem findings and pathogenetic considerations for the delayed pericardial tamponade are discussed.

Aged↗
PubMed2005

Subgaleal hematoma in child abuse.

The mother brought her 31/2-year-old son to a paediatric clinic as his forehead was swollen and bluish in appearance. She was unable to give any explanation for this lesion. Clinically it was noted that a very visible and also palpable, doughy swelling was present both in the forehead as well as the hard skull areas. Some hours later, a massive bilateral periocular haematoma appeared. Whilst X-rays were unable to provide any diagnostic help, the sonographic examination of the skull carried out on the same day revealed an extensive subgaleal haematoma. This phenomenon is described in radiological literature as "scalping" and is caused by the use of considerable, blunt violence against the head (shear stresses, e.g. by pulling at the hair). The mother's boyfriend later confessed forceful pulling of the hair.

Child Abuse↗
PubMed2005

Forensic aspects of 40 accidental autoerotic deaths in Northern Germany.

Between 1983 and 2003, 40 accidental autoerotic fatalities have been investigated. in the Institute of Legal Medicine in Hamburg. Only 50% (n=20) were autopsied (13 legal autopsies, 6 for scientific purposes and 1 for an insurance company). All the victims were males, aged between 13 and 79 years (among them five children and adolescents, the deceased mainly between 20 and 40 years). The paraphiliacs utilized a great range of devices and props as fetishism, sexual aids or pain-stimulating agents, like intimate feminine garments, ropes, chains, bondages, locks, pornographic magazines, condoms, rubber items, and chemical anaesthetics. The cause of death was strangulation in 20 cases (17 x hanging, 3 x ligature strangulation), 11 x suffocation (8 x under plastic bags, 3 x with face-masks, 2 x thoracic compression, 1 x positional asphyxia, and 1 x cocaine intoxication). Five cases without autopsy remained unclear because of missing morphological and toxicological findings; it could not be differentiated between asphyxiation/intoxication/natural disease, although the scene characteristics seemed to be typical for autoerotic deaths. It is emphasized that the findings at the scene, the morphological and toxicological examination of the dead body (full autopsy as prerequisite) by experienced investigators and the personal history of the deceased have to be evaluated very carefully and intensely to reconstruct the accidental fatal autoerotic course accurately and undoubtedly (to exclude the possibility of sexual homicide, neglected killing, or suicide).

Adolescent↗
PubMed2005

Unusual phenomenology of autoerotic fatalities.

Between 1983 and 2003 forty accidental autoerotic deaths (all males, 13-79 years old) have been investigated at the Institute of Legal Medicine in Hamburg. Three cases with a rather unusual scenery are described in detail: (1) a 28-year-old fireworker was found hanging under a bridge in a peculiar bound belt system. The autopsy and the reconstruction revealed signs of asphyxiation, feminine underwear, and several layers of plastic clothing. (2) A 16-year-old pupil dressed with feminine plastic and rubber utensils fixed and strangulated himself with an electric wire. (3) A 28-year-old handicapped man suffered from progressive muscular dystrophy and was nearly unable to move. His bizarre sexual fantasies were exaggerating: he induced a nurse to draw plastic bags over his body, close his mouth with plastic strips, and put him in a rubbish container where he died from suffocation.

Adolescent↗
PubMed2005

[Legal aspects of deadly acute appendicitis].

Appendicitis is diagnosed by synoptic evaluation of typical symptoms, laboratory tests and sonography. The only therapy is a prompt operation. The main reason for appendicitis mortality is the condition not detected or not detected in time. The case of a 50 year old male who died from a non-detected perityphlitic appendicitis with abscesses in the liver is presented. Only if appendicitis can be reliably ruled out an operation is not indicated. The not performed surgical intervention is often interpreted as a treatment error by the courts. In doubt, an operation should therefore be performed.

Abdomen, Acute↗
PubMed2004

The history of forensic entomology in German-speaking countries.

Megnin's book "La fauna des cadaveres" published in 1894 in France is generally accepted as a mile-stone in forensic entomology. It is hardly known that at the same time this topic was likewise explored in the German-speaking countries. Even PMI estimation based on developmental data of blowflies was performed. After a more descriptive period in the first half of the 20th century the complexity and variability of insects' biological behavior were detected and formally investigated. Improved technical facilities, enhanced comprehension of scientific studies and multidisciplinary cooperation, enabled rapid progress in forensic entomology during the last decades. With the European Association for Forensic Entomology founded in 2002 the frame work for a high standard of competency at an international level was constituted.

Entomology↗
PubMed2004

Fatal and non-fatal injuries caused by crossbows.

Today in modern times, traumatic injuries caused by crossbows are a rarity. The largest collection of cases so far is presented in this study, consisting of four fatalities (two homicides and two suicides) and two non-fatal injuries (grievous bodily harm and an accident). All the victims were male having an age between 31 and 54. The weapons, which were used, were mainly high-performance precision crossbows with telescopic sights and hunting bolts. The parts of the body involved were the facial/head area in three of the cases and the thorax in three of them. There were either deep or total penetration injuries to the cranium and thorax with the bolt remaining in the wound in four out of six cases. The persons with non-fatal crossbow injuries exhibited comparatively few symptoms, despite the sometimes extensive involvement of the interior of the cranium (cerebrocranial penetration, in one instance). The two cases of suicide favoured the body areas often found with gun-users. The aetiological classification of crossbow injuries may be difficult after the removal of the bolt. The external morphology is strongly dependent on the type of tip used. Multiple-bladed hunting broadheads produce radiating incised wounds, whereas conical field tips produce circular to slitlike defects. Correspondingly, the external injuries can be reminiscent of the effects of a violent attack by sharp force or of a gunshot wound. The possibility, supported by clinical data, that the victim might have the ability to act or even to survive for a period of time, even with penetration of the brain, should be taken into account when the cause of death is being investigated.

Accidents↗
PubMed2004

Analysis of 683 drug packages seized from "body stuffers".

The wrappings and contents of 683 drug containers (bubbles) seized from 154 street dealers have been analysed since 2001, when the law enforcement policy in Hamburg, Germany, allowed the application of emetics to be used by so-called body stuffers for the recovery of swallowed drug packages. Of the bubbles recovered 96% contained cocaine. Cases of intoxication have not yet been observed but a 20-year-old man with a previously unknown toxic cardiomyopathy died 3 days after a sudden cardiac arrest which followed the forced application of ipecacuanha via correctly placed nasogastral tube.

Cocaine↗
PubMed2004

Application of compact ultrasound imaging device to postmortem diagnosis.

In regions with low autopsy rates, forensic examiners often have to rely on external findings. Imaging techniques can assist the external examination and provide a more objective diagnosis. The SonoSite 180, a portable ultrasound device, was used for the examination of dead bodies. The influence of different degrees of decomposition was estimated. Even in cases with intestinal gas formation images of internal organs could be obtained with special techniques. Various pathological findings were detected by ultrasound and verified by autopsy (e.g. pericardial tamponade, cardiac hypertrophy, fatty liver, aortic aneurysm, metastatic liver, etc.). The experiences with the SonoSite 180 are promising. The device can be carried to the death scene or to the morgue and therefore serve as a valuable tool for medicolegal applications.

Aorta, Abdominal↗
PubMed2004

Pathologic features of suicidal complete decapitations.

Despite high suicide rates all over the world, complete decapitation as a consequence of violent suicide methods is exceptionally rare and there is always a potential for confusion with homicide as well as with body dismemberment or mutilation. We analyzed the phenomenology and morphology of 10 cases (six male, four female; individual age 18-60 years) of suicidal complete decapitation that were subjected to medico-legal autopsies at the Institute of Legal Medicine, University of Hamburg, Germany, between 1995 and 2002. All decapitations occurred while the person was alive as proven by signs of vitality. Blood alcohol levels were positive in five cases and ranged between 28 and 202 mg/dl. The applied methods of suicide were running over by a train in eight cases and hanging in two cases. In suicidal hanging resulting in complete decapitation the wound margins were clear-cut with an adjacent sharply demarcated circumferential band-like abrasion zone showing a homogenous width, the latter determined by the thickness of the rope. In decapitations due to railway interference a broad spectrum of pathologic alterations such as the co-existence of irregular, ragged and sharp-edged wound margins, vascular and nervous pathways forming bridges in the depth of the wound and bruising could be observed. In such cases skin abrasion zones were generally not circumferential and showed a heterogenous width. Concerning hanging-related complete decapitations, our findings are well in line with those of other authors, namely that heavy body weight of the suicidal, fall from a great height and in some cases inelastic and/or thin rope material used for the noose are the determining factors decisive for complete decapitation.

Adolescent↗