Influence of acetabular cup thickness on seating and primary stability in total hip arthroplasty.

Insufficient primary stability of acetabular hip cups is a complication resulting in early cup loosening. Available cup designs vary in terms of wall thickness, potentially affecting implant fixation. This study investigated the influence of different wall thicknesses on the implantation process and the resulting primary stability using excised human acetabula. Implantations were performed using a powered impaction device providing consistent energy with each stroke. Two different wall thicknesses were compared in terms of seating progress, polar gap remaining after implantation, bone-to-implant contact area, cup deflection, and lever out moment. Thin-walled cups showed higher lever out resistance (p < 0.001) and smaller polar gaps (p < 0.001) with larger bone contact toward the dome of the cup (p < 0.001) compared to thick-walled cups. Small seating steps at the end of the impaction process were observed if a high number of strokes were needed to seat the cup (p = 0.045). A high number of strokes led to a strain release of the cup during the final strokes (p = 0.003). This strain release is indicative for over-impaction of the cup associated with bone damage and reduced primary stability. Adequate cup seating can be achieved with thin-walled cups with lower energy input in comparison to thicker ones. Thin-walled cups showed improved primary stability and enable implantation with lower energy input, reducing the risk of over-impaction and bone damage. Additional strokes should be avoided as soon as no further seating progress has been observed.

Postmortem computed tomography differentiation between intraperitoneal decomposition gas and pneumoperitoneum.

PURPOSE: The aim of this study is to investigate the ability of postmortem computed tomography (PMCT) to distinguish intraperitoneal decomposition gas from pneumoperitoneum due to intestinal perforation. METHODS: This retrospective study investigated the factors affecting intraperitoneal gas in two groups of 14 decedents as detected by postmortem CT performed in the Department of Legal Medicine of Hamburg University. The first group died with a cause of death associated with intestinal perforation, and the second group with other different natural causes of death. These factors include postmortem interval, gas volume, gas distribution, radiology alteration index (RAI), and pneumoperitoneum-associated pathology. RESULTS: The findings of this study showed the appearance of specific gas distribution patterns and a significant increase in gas volumes in the cases of intestinal perforation. Moreover, postmortem interval and the pneumoperitoneum-associated pathology could help distinguish postmortem-generated gas from pneumoperitoneum. CONCLUSION: Based on the findings of this study, we propose that these findings can improve the proper detection of intestinal perforation cases in the future.

Replication of SARS-CoV-2 in adipose tissue determines organ and systemic lipid metabolism in hamsters and humans.

Zickler et al. describe SARS-CoV-2 RNA in post-mortem samples of human adipose tissue. In the hamster model, SARS-CoV-2 propagation in adipose tissue leads to specific changes in lipid metabolism, which are reflected in lipidome patterns of hamster and human plasma.

Diagnostic value of multiphase postmortem computed tomography angiography in selected cases of blunt traumatic deaths.

OBJECTIVES: Recently, multiphase postmortem computed tomography angiography (MPMCTA) has been proven as a reliable tool in the diagnosis of vascular pathology, while its potential efficiency in the detection of soft tissue lesions is ignored. In this study, we have evaluated the overall diagnostic value of MPMCTA in the diagnosis of blunt traumatic deaths in selected cases to determine its additional advantages and limitations in order to identify its potential applications. METHODS: This prospective study examined 14 decedents presented to the Department of Legal Medicine of Hamburg University that alleged death due to blunt trauma. For each case, MPMCTA and conventional autopsy findings were compared. Both radiological and autopsy findings are divided according to the body regions in addition to the detection of the cause of death. RESULTS: Both MPMCTA and the conventional autopsy showed the major findings but not all findings. MPMCTA was better in the demonstration of vascular and skeletal lesions, while the diagnosis of parenchymal injury remains autopsy-dependent. The efficiency of MPMCTA for detection of haemorrhage was relatively affected by the blood amount and the location of the bleeding source. The presented MPMCTA-related artefacts interfered with the accurate diagnosis of certain injuries. CONCLUSION: The combination of MPMCTA with conventional autopsy appears to be the gold standard for investigation of blunt traumatic deaths. Depending on the death circumstances and the expected findings, MPMCTA can be performed alone in selected cases.

Severe bone loss and multiple fractures in SCN8A-related epileptic encephalopathy.

Mutations in the SCN8A gene encoding the neuronal voltage-gated sodium channel Nav1.6 are known to be associated with epileptic encephalopathy type 13. We identified a novel de novo SCN8A mutation (p.Phe360Ala, c.1078_1079delTTinsGC, Exon 9) in a 6-year-old girl with epileptic encephalopathy accompanied by severe juvenile osteoporosis and multiple skeletal fractures, similar to three previous case reports. Skeletal assessment using dual energy X-ray absorptiometry (DXA), high-resolution peripheral quantitative computed tomography (HR-pQCT) and serum analyses revealed a combined trabecular and cortical bone loss syndrome with elevated bone resorption. Likewise, when we analyzed the skeletal phenotype of 2week-old Scn8a-deficient mice we observed reduced trabecular and cortical bone mass, as well as increased osteoclast indices by histomorphometric quantification. Based on this cumulative evidence the patient was treated with neridronate (2mg/kg body weight administered every 3months), which fully prevented additional skeletal fractures for the next 25months. Taken together, our data provide evidence for a negative impact of SCN8A mutations on bone mass, which can be positively influenced by anti-resorptive treatment.

Interpersonal violence in road rage. Cases from the Medico-Legal Center for Victims of Violence in Hamburg.

Aggressive behavior in traffic is a widespread phenomenon. Up to 90% of the population are involved in mild forms such as shouting or gesturing. More dramatic cases with injury to individuals affect at least 1100 people in the US annually. Certain factors such as a male sex, a young age and an urban residency have been identified to contribute to the likelihood of road rage. Central to this analysis is the determination of specific features regarding the conflicting parties, the crime scene and the injury pattern in violent offenses related to traffic. In a retrospective study spanning 10 years, cases of road rage-linked injuries were identified amongst patients at the Medico-Legal Center of the Institute of Legal Medicine in Hamburg, Germany. The data were digitized and then analyzed using descriptive statistics via SPSS. There are disproportionately large numbers of males (85.7%) and motorists (61.2%) amongst road rage perpetrators. Usually the conflicting parties have no prior relationship (89.7%). In 68.1% of the cases, the violence applied was exclusively physical. Objects were utilized in 31.0% of all cases, and in more than half (55.6%) of these cases the vehicle was used as a weapon. The resulting trauma in road rage is mostly blunt and applied to the face and the extremities. There are characteristic features regarding the demographics, time and place of incident, as well as severity and pattern of injury in road rage associated offenses. Identifying these factors may lead to appropriate measures in the reduction of road rage.

Virtual autopsy with multiphase postmortem computed tomographic angiography versus traditional medical autopsy to investigate unexpected deaths of hospitalized patients: a cohort study.

BACKGROUND: "Virtual" autopsy by postmortem computed tomography (PMCT) can replace medical autopsy to a certain extent but has limitations for cardiovascular diseases. These limitations might be overcome by adding multiphase PMCT angiography. OBJECTIVE: To compare virtual autopsy by multiphase PMCT angiography with medical autopsy. DESIGN: Prospective cohort study. (ClinicalTrials.gov: NCT01541995) SETTING: Single-center study at the University Medical Center Hamburg-Eppendorf, Hamburg, Germany, between 1 April 2012 and 31 March 2013. PATIENTS: Hospitalized patients who died unexpectedly or within 48 hours of an event necessitating cardiopulmonary resuscitation. MEASUREMENTS: Diagnoses from clinical records were compared with findings from both types of autopsy. New diagnoses identified by autopsy were classified as major or minor, depending on whether they would have altered clinical management. RESULTS: Of 143 eligible patients, 50 (35%) had virtual and medical autopsy. Virtual autopsy confirmed 93% of all 336 diagnoses identified from antemortem medical records, and medical autopsy confirmed 80%. In addition, virtual and medical autopsy identified 16 new major and 238 new minor diagnoses. Seventy-three of the virtual autopsy diagnoses, including 32 cases of coronary artery stenosis, were identified solely by multiphase PMCT angiography. Of the 114 clinical diagnoses classified as cardiovascular, 110 were confirmed by virtual autopsy and 107 by medical autopsy. In 11 cases, multiphase PMCT angiography showed "unspecific filling defects," which were not reported by medical autopsy. LIMITATION: These results come from a single center with concerted interest and expertise in postmortem imaging; further studies are thus needed for generalization. CONCLUSION: In cases of unexpected death, the addition of multiphase PMCT angiography increases the value of virtual autopsy, making it a feasible alternative for quality control and identification of diagnoses traditionally made by medical autopsy. PRIMARY FUNDING SOURCE: University Medical Center Hamburg-Eppendorf.

Biomechanical evaluation of 3 stabilization methods on acromioclavicular joint dislocations.

BACKGROUND: Traumatic acromioclavicular (AC) joint dislocations can be addressed with several surgical stabilization techniques. The aim of this in vitro study was to evaluate biomechanical features of the native joint compared with 3 different stabilization methods: locking hook plate (HP), TightRope (TR), and bone anchor system (AS). HYPOTHESIS: The HP provides higher stiffness than the anatomic reconstruction techniques. STUDY DESIGN: Controlled laboratory study. METHODS: A new biomechanical in vitro model of the AC joint was used to analyze joint stability after surgical repair (HP, TR, and AS). Eighteen cadaveric specimens were randomized for bone density and diameter in the midclavicle section. Joint stiffness was measured by applying an axial load and a defined physiological range of motion for internal and external rotations and upward and downward rotations. Data were recorded at 3 stages: for the native joint after dissecting the AC ligaments, directly after repair, and after axial cyclic loading (1000 cycles with 20 and 70 N at 1 Hz). To evaluate which implant mimics physiological joint properties best, axial stiffness of vertical stability was assessed in combination with rotation. Finally, static loading in the superior direction was applied until failure of the joints occurred. RESULTS: Axial stiffness of the TR and AS groups was 2-fold higher than for the HP group and the native joint (67.1, 66.1, and 22.5 N/mm, respectively; P < .004). Decreased load-to-failure rates were recorded in the HP group compared with the TR and AS groups (248.9 ± 72.7, 832.0 ± 401.4, and 538.0 ± 166.1 N, respectively). The stiffness of the rotations was not significantly different between the treatment methods but was lower in horizontal and downward rotations compared with the native state. Thus, native AC ligaments contributed a significant share to joint stiffness. CONCLUSION: The TR and AS groups demonstrated higher vertical load capacity. Compared with the TR and AS, the HP demonstrated an axial stiffness closest to the native joint. For restoring physiological properties, reconstruction of the AC ligaments may be necessary. CLINICAL RELEVANCE: The results show different biomechanical properties of the HP and anatomic reconstructions.

Virtual autopsy as an alternative to traditional medical autopsy in the intensive care unit: a prospective cohort study.

BACKGROUND: Autopsy is an important educational and quality-control tool in the intensive care unit (ICU), but rates of traditional medical autopsies have declined worldwide. "Virtual" autopsy involving only advanced radiographic techniques might provide an alternative approach to postmortem examinations. OBJECTIVE: To assess the value of postmortem multidetector computed tomography as an alternative to medical autopsy. DESIGN: Prospective cohort study. (ClinicalTrials.gov registration number: NCT01040520) SETTING: 9 ICUs in a single academic medical center. Consent for both medical and virtual autopsies was sought from the families of all consecutive patients who died in the ICU between 1 January and 30 June 2010. Clinical records were reviewed to determine whether unsuspected autopsy findings would have altered care if known (major diagnosis) or would not have altered care (minor diagnosis). RESULTS: Of 285 patients, 47 underwent both virtual and medical autopsy. Of 196 clinical diagnoses made before death, 173 (88%) were identified by virtual autopsy and 183 (93%) by medical autopsy. Fourteen new major and 88 new minor diagnoses were detected by any autopsy method. The main diagnoses missed by virtual autopsy were cardiovascular events (9 of 72) and cancer (12 of 30). In contrast, medical autopsy missed 13 traumatic fractures and 2 pneumothoraces. Among 115 additional patients in whom only virtual autopsy was performed, 11 new major diagnoses were made. LIMITATION: Virtual autopsy was performed in only 57% of patients (n = 162); among this group, consent for traditional medical autopsy was obtained for only one third. CONCLUSION: Virtual autopsy may be useful for identifying diagnoses that traditionally have been identified by medical autopsy. This may also hold true, at least in part, for the educational aspect of medical autopsy (confirming antemortem clinical diagnoses). Further studies are required to confirm these preliminary results. PRIMARY FUNDING SOURCE: University Medical Center Hamburg-Eppendorf, Germany.

Phenotypic diversity in chondromyxoid fibroma reveals differentiation pattern of tumor mimicking fetal cartilage canals development: an immunohistochemical study.

Chondromyxoid fibroma represents a rare benign cartilaginous tumor of young patients occurring in a subcortical metaphyseal location. The histogenesis of chondromyxoid fibroma has not yet been postulated, even though the conventional histology and recent immunohistochemical studies on phenotype of the mesenchymal cells and extracellular matrix components suggested its origin in immature cartilage. Therefore, we wished to compare the morphological pattern of immature cartilage tissue with chondromyxoid fibroma to investigate a possible developmental counterpart of chondromyxoid fibroma. Archival paraffin-embedded tissues from 4 fetal femora and 10 cases of chondromyxoid fibroma were analyzed simultaneously using histochemistry (safranin O) and established immunohistochemical antibodies (CD34, CD163, and smooth muscle actin). Vascularized cartilage canals growing into the fetal cartilage from the perichondrium displayed characteristic glomeruloid structures with central arterioles within the immature mesenchymal stroma and numerous superficial sinusoidal blood vessels accompanied by macrophage infiltration. Similarly, each case of chondromyxoid fibroma demonstrated admixture of two characteristic components: immature fibrous tissue of vascularized stroma with accumulation of macrophages in areas of superficial sinusoidal proliferation, and variable amounts of lobulated chondroid tissue. Based on the observed substantial morphological similarity between the cartilage canals and chondromyxoid fibroma, we suggest that the chondromyxoid fibroma represents a neoplasm originating from or mimicking the fetal cartilage canals within the immature cartilage.

Cardiac injuries in car occupants in fatal motor vehicle collisions--an autopsy-based study.

Motor vehicle accidents contribute widely to population morbidity and mortality around the world, and cardiac injuries are a major factor determining outcome. Autopsy reports from 380 motor vehicle occupants who died in motor vehicle crashes in Adelaide, Australia, and Hamburg, Germany, over a 6-year period were reviewed, analysing the presence and type of cardiac injuries and their correlation with factors such as crash type, presence of seatbelt/airbag and vehicle speed as well as with the presence of other injuries which might predict the presence of cardiac injuries in a clinical setting. 21.1% had cardiac injuries identified macroscopically autopsy or histology. Cardiac injuries were the only cause of death or contributed to a fatal outcome in 76% of these cases. Sternal fractures and left-sided serial rib fractures were predictive of cardiac injury.

Microarchitecture of the radial head and its changes in aging.

Fractures of the radial head are common; however, it remains to be determined whether the radial head has to be considered as a typical location for fractures associated with osteoporosis. To investigate whether the human radial head shows structural changes during aging, we analyzed 30 left and 30 right human radial heads taken from 30 individuals. The specimens taken from the left side were analyzed by peripheral quantitative computed tomography (pQCT) and micro-CT. The specimens taken from the right elbow joint were analyzed by radiography and histomorphometry. In these specimens pQCT revealed a significant decrease of total and cortical bone mineral density (BMD(to) BMD(co)) with aging, regardless of sex. Histomorphometry revealed a significant reduction of cortical thickness (Ct.Th), bone volume per tissue volume (BV/TV), and trabecular thickness (Tb.Th) in male and female specimens. In this context, mean BV/TV and mean trabecular number (Tb.N) values were significantly lower and, accordingly, mean trabecular separation (Tb.Sp) was significantly higher in female samples. The presented study demonstrates that the radial head is a skeletal site where different age- and sex-related changes of the bone structure become manifest. These microarchitectural changes might contribute to the pathogenesis of radial head fractures, especially in aged female patients where trabecular parameters (BMD(tr) and Tb.Sp) change significantly for the worse compared to male patients.

Age- and sex-related changes of humeral head microarchitecture: histomorphometric analysis of 60 human specimens.

Fractures of the humeral head are frequent and will further increase due to demographic changes. Prior to operative fracture treatment, the regional differences of bone quality, especially of elderly people, have to be carefully considered to assure stable implant fixation. However, conclusive data concerning the variation of histomorphometric parameters are still lacking. Consequently, the purpose of this study was to analyze the age- and sex-related changes in bone microarchitecture. For that reason, 60 proximal humeri were harvested from patients at autopsy. Twelve regions of interest (ROI) were defined for each centered coronar humeral head slice and the specimens were subjected to radiographic, histological, and histomorphometric analyses. We could demonstrate that in contrast to men, women over 60 years of age had a significant age-related decrease in bone mass. The most prominent decrease was observed in the region of the greater tuberosity, which represents an osteoporotic fracture site. The most superior and medially located part of the centered coronar humeral head slice showed, independent from age and sex, the highest bone mass and can therefore be considered as the best location for subchondral screw placement. Taken together, our study revealed distinct sex-related changes of the humeral head bone microarchitecture with aging, which should be considered in implant positioning.

Pancreas and liver injury are associated in individuals with increased alcohol consumption.

BACKGROUND & AIMS: Although chronic pancreatitis and liver cirrhosis are common sequelae of excess alcohol consumption, the 2 conditions are rarely associated. We studied the prevalence of simultaneous liver cirrhosis and chronic pancreatitis in alcoholics. METHODS: Postmortem autopsy data from 620 individuals with a history of excess alcohol consumption and 100 nonalcoholics (controls) were analyzed. The individuals were classified into groups based on macroscopic observations of pancreas (no injury, acute pancreatitis, fibrosis, and chronic pancreatitis) and liver (no injury, moderate steatosis, severe steatosis, and cirrhosis). The same classification system was used for histological data, which was used to confirm and correlate macroscopic results. RESULTS: Out of the 183 patients with liver cirrhosis, 33 (18%) had chronic pancreatitis and 93 (51%) had pancreatic fibrosis. Out of the 230 patients with severe steatosis, 37 (16%) had chronic pancreatitis and 97 (42%) were found to have a pancreatic fibrosis. Thirty-three (39%) with chronic pancreatitis also showed liver cirrhosis and 37 (44%) showed severe steatosis. Thirty-eight percent of the patients with a pancreatic fibrosis were found also to have liver cirrhosis and in another 40% severe steatosis. Thirty-five patients showed neither hepatic or pancreatic injury. We found no chronic pancreatitis or liver cirrhosis in the control group (n = 100). CONCLUSIONS: Contrary to common belief there is a close association between pancreatic and hepatic injury in patients with increased alcohol consumption, and the degree of organ damage between the 2 organs correlate.

Impaired gastric acidification negatively affects calcium homeostasis and bone mass.

Activation of osteoclasts and their acidification-dependent resorption of bone is thought to maintain proper serum calcium levels. Here we show that osteoclast dysfunction alone does not generally affect calcium homeostasis. Indeed, mice deficient in Src, encoding a tyrosine kinase critical for osteoclast activity, show signs of osteopetrosis, but without hypocalcemia or defects in bone mineralization. Mice deficient in Cckbr, encoding a gastrin receptor that affects acid secretion by parietal cells, have the expected defects in gastric acidification but also secondary hyperparathyroidism and osteoporosis and modest hypocalcemia. These results suggest that alterations in calcium homeostasis can be driven by defects in gastric acidification, especially given that calcium gluconate supplementation fully rescues the phenotype of the Cckbr-mutant mice. Finally, mice deficient in Tcirg1, encoding a subunit of the vacuolar proton pump specifically expressed in both osteoclasts and parietal cells, show hypocalcemia and osteopetrorickets. Although neither Src- nor Cckbr-deficient mice have this latter phenotype, the combined deficiency of both genes results in osteopetrorickets. Thus, we find that osteopetrosis and osteopetrorickets are distinct phenotypes, depending on the site or sites of defective acidification.

Brief communication: Two and three-dimensional analysis of bone mass and microstructure in a bog body from the Iron Age.

Human remains from peat bogs, called "bog bodies," have yielded valuable insights into human history because of their excellent preservation of soft tissue. On the other hand, the acidic environment of the peat leads to an extensive demineralization of skeletal elements, complicating their analysis. We studied the skeleton of the bog body "Moora" dated to approximately 650 B.C. Nondestructive evaluation of the bone was made using contact X-rays, peripheral quantitative computed tomography (pQCT) analysis, multislice computed tomography (CT) and high resolution micro computed tomography (microCT) imaging. Two thousand seven hundred years in the acidic environment of the bog led to a loss of 92.7% of bone mineral density. Despite this demineralization and in contrast to other bog bodies, the spatial structure of the bones of "Moora" is exceptionally well preserved. We found Harris lines and were able to obtain the first three-dimensional data on the trabecular microstructure of the bone of a young woman from the early Iron Age.

A scanning electron microscopy-based approach to quantify resorption lacunae applied to the trabecular bone of the femoral head.

Resorption lacunae (RL) are discussed as stressors that can increase the risk of mechanical failure in a trabecular network. Quantification of RL has previously been described through the parameter eroded surface/bone surface (ES/BS) as established by light microscopy (LM) analysis, but the results have been inconsistent and contradictory. Using scanning electron microscopy (SEM), a new study design for quantitative evaluation is introduced. To test its applicability a pilot study was executed with trabecular bone dissected from a femoral head of 28 autopsy subjects (14 female and 14 male). A 2.4 x 2.8 x 1.0 mm sample was excised 1.5 cm below the joint surface of each specimen in coronal medial slices of the femoral head and examined. A virtual grid with 1050 squares superimposed over the generated SEM image allowed determination of the ratio of squares containing RL to squares with an unaffected trabecular surface (RL/U). Classical ES/BS was assessed in parallel sections of the samples. The SEM, and to a lesser extent the qualitative different LM analysis, indicated a gender independent predominance of RL in subjects older than 50 years. This pilot study suggests that the new study design could be useful for acquiring quantitative RL data.