Postmortem multislice computed tomography and magnetic resonance imaging of odontoid fractures, atlantoaxial distractions and ascending medullary edema

Non-invasive imaging methods are increasingly entering the field of forensic medicine. Facing the intricacies of classical neck dissection techniques, postmortem imaging might provide new diagnostic possibilities which could also improve forensic reconstruction. The aim of this study was to determine the value of postmortem neck imaging in comparison to forensic autopsy regarding the evaluation of the cause of death and the analysis of biomechanical aspects of neck trauma. For this purpose, 5 deceased persons (1 female and 4 male, mean age 49.8 years, range 20-80 years) who had suffered odontoid fractures or atlantoaxial distractions with or without medullary injuries, were studied using multislice computed tomography (MSCT), magnetic resonance imaging (MRI) and subsequent forensic autopsy. Evaluation of the findings was performed by radiologists, forensic pathologists and neuropathologists. The cause of death could be established radiologically in three of the five cases. MRI data were insufficient due to metal artefacts in one case, and in another, ascending medullary edema as the cause of delayed death was only detected by histological analysis. Regarding forensic reconstruction, the imaging methods were superior to autopsy neck exploration in all cases due to the post-processing possibilities of viewing the imaging data. In living patients who suffer medullary injury, follow-up MRI should be considered to exclude ascending medullary edema.

Chondrocyte mechanotransduction: effects of compression on deformation of intracellular organelles and relevance to cellular biosynthesis

OBJECTIVE: The effects of mechanical deformation of intact cartilage tissue on chondrocyte biosynthesis in situ have been well documented, but the mechanotransduction pathways that regulate such phenomena have not been elucidated completely. The goal of this study was to examine the effects of tissue deformation on the morphology of a range of intracellular organelles which play a major role in cell biosynthesis and metabolism. DESIGN: Using chemical fixation, high pressure freezing, and electron microscopy, we imaged chondrocytes within mechanically compressed cartilage explants at high magnification and quantitatively and qualitatively assessed changes in organelle volume and shape caused by graded levels of loading. RESULTS: Compression of the tissue caused a concomitant reduction in the volume of the extracellular matrix (ECM), chondrocyte, nucleus, rough endoplasmic reticulum, and mitochondria. Interestingly, however, the Golgi apparatus was able to resist loss of intraorganelle water and retain a portion of its volume relative to the remainder of the cell. These combined results suggest that a balance between intracellular mechanical and osmotic gradients govern the changes in shape and volume of the organelles as the tissue is compressed. CONCLUSIONS: Our results lead to the interpretive hypothesis that organelle volume changes appear to be driven mainly by osmotic interactions while shape changes are mediated by structural factors, such as cytoskeletal interactions that may be linked to extracellular matrix deformations. The observed volume and shape changes of the chondrocyte organelles and the differential behavior between organelles during tissue compression provide evidence for an important mechanotransduction pathway linking translational and post-translational events (e.g., elongation and sulfation of glycosaminoglycans (GAGs) in the Golgi) to cell deformation.

Ultrastructural quantification of cell death after injurious compression of bovine calf articular cartilage

OBJECTIVE: It has been suggested that chondrocyte death by apoptosis may play a role in the pathogenesis of cartilage destruction in osteoarthritis, but the results of in-vivo and in-vitro investigations have been conflicting. To investigate further the cell death in our in-vitro model for traumatic joint injury, we performed a quantitative analysis by electron microscopy (EM) of cell morphology after injurious compression. For comparison, the TUNEL assay was also performed. DESIGN: Articular cartilage explant disks were harvested from newborn calf femoropatellar groove. The disks were subjected to injurious compression (50% strain at a strain rate of 100%/s), incubated for 3 days, and then fixed for quantitative morphological analysis. RESULTS: By TUNEL, the cell apoptosis rate increased from 7 +/- 2% in unloaded controls to 33 +/- 6% after injury (P=0.01; N=8 animals). By EM, the apoptosis rate increased from 5 +/- 1% in unloaded controls to 62 +/- 10% in injured cartilage (P=0.02, N=5 animals). Analysis by EM also identified that of the dead cells in injured disks, 97% were apoptotic by morphology. CONCLUSIONS: These results confirm a significant increase in cell death after injurious compression and suggest that most cell death observed here was by an apoptotic process.

Incidence and clinical implications of stent fractures of the Xpert self-expanding nitinol stent in infrainguinal arteries

BACKGROUND: Different stents in infrainguinal arteries have recently been associated with stent fractures and unfavorable clinical outcome, although data is limited regarding fractures of the Xpert selfexpanding nitinol stent. Thus, purpose of the present investigation was to evaluate its incidence and clinical implications in lower limb arteries. PATIENTS AND METHODS: Fifty-three consecutive patients (53 limbs) with peripheral arterial disease underwent secondary Xpert stent implantation due to suboptimal primary balloon angioplasty (PTA). Median age was 76 years. Stent fractures were evaluated by plain X-ray at median follow-up of 16 months. Stent patency was assessed by duplex ultrasound and sustained clinical improvement was defined as improvement of the ABI of > or = 0.10 together with improvement of at least one Rutherford class above the baseline finding throughout follow-up. RESULTS: Median length of femoropopliteal and infrapopliteal lesion was 3.0 and 2.3 cm, respectively. Sixtyfive stents were implanted in 43 limbs with femoropopliteal and 10 stents in 10 limbs with infrapopliteal lesion, respectively. Stent fractures occurred in 3 of 43 limbs (7.0%) of patients with femoropopliteal lesion with stent-based fracture rate of 4.6%. All fractured stents showed multiple struts fractures and occurred in the distal and middle superficial femoral artery. No stent fracture was observed in infrapopliteal lesions. The fractured stents were not associated with any clinical deterioration. Sustained clinical improvement was 71.0% and 54.6% for femoropopliteal and infrapopliteal lesions, respectively. Stent patency assessed by duplex was 65.2 and 63.9% for femoropopliteal and infrapopliteal lesions, respectively. CONCLUSIONS: Fractures of the Xpert stent were seldom and not associated with unfavorable clinical outcome at midterm follow-up.

In search of optimal compression therapy for venous leg ulcers: a meta-analysis of studies comparing diverse [corrected] bandages with specifically designed stockings

OBJECTIVE: In search of an optimal compression therapy for venous leg ulcers, a systematic review and meta-analysis was performed of randomized controlled trials (RCT) comparing compression systems based on stockings (MCS) with divers bandages. METHODS: RCT were retrieved from six sources and reviewed independently. The primary endpoint, completion of healing within a defined time frame, and the secondary endpoints, time to healing, and pain were entered into a meta-analysis using the tools of the Cochrane Collaboration. Additional subjective endpoints were summarized. RESULTS: Eight RCT (published 1985-2008) fulfilled the predefined criteria. Data presentation was adequate and showed moderate heterogeneity. The studies included 692 patients (21-178/study, mean age 61 years, 56% women). Analyzed were 688 ulcerated legs, present for 1 week to 9 years, sizing 1 to 210 cm(2). The observation period ranged from 12 to 78 weeks. Patient and ulcer characteristics were evenly distributed in three studies, favored the stocking groups in four, and the bandage group in one. Data on the pressure exerted by stockings and bandages were reported in seven and two studies, amounting to 31-56 and 27-49 mm Hg, respectively. The proportion of ulcers healed was greater with stockings than with bandages (62.7% vs 46.6%; P < .00001). The average time to healing (seven studies, 535 patients) was 3 weeks shorter with stockings (P = .0002). In no study performed bandages better than MCS. Pain was assessed in three studies (219 patients) revealing an important advantage of stockings (P < .0001). Other subjective parameters and issues of nursing revealed an advantage of MCS as well. CONCLUSIONS: Leg compression with stockings is clearly better than compression with bandages, has a positive impact on pain, and is easier to use.

Does perioperative glucocorticosteroid treatment correlate with disturbance in surgical wound healing after treatment of facial fractures? A retrospective study

PURPOSE: To clarify whether perioperative glucocorticosteroid treatment used in association with repair of facial fractures predisposes to disturbance in surgical wound healing (DSWH). PATIENTS AND METHODS: Retrospective review of records of patients who had undergone open reduction, with or without ostheosynthesis, or had received reconstruction of orbital wall fractures during the 2-year period from 2003 to 2004. RESULTS: Steroids were administered to 100 patients (35.7%) out of a total of 280. Dexamethasone was most often used, with the most common regimen being dexamethasone 10 mg every 8 hours over 16 hours, with a total dose of 30 mg. The overall DSWH rate was 3.9%. The DSWH rate for patients who had received perioperative steroids was 6.0%, and the corresponding rate for patients who did not receive steroids was 2.8%. The difference was not statistically significant. An intraoral surgical approach remained the only significant predictor to DSWH. CONCLUSIONS: With regard to DSWH, patients undergoing operative treatment of facial fractures can safely be administered doses of 30 mg or less of perioperative glucocorticosteroids equivalent to dexamethasone.

Dental injuries in association with facial fractures

PURPOSE: The aim of the study was to investigate the association between dental injuries and facial fractures. MATERIALS AND METHODS: We performed a prospective study of 273 patients examined at a level 1 trauma center in Switzerland from September 2005 until August 2006 who had facial fractures. Medical history and clinical and radiologic examination findings were recorded to evaluate demographics, etiology, presentation, and type of facial fracture, as well as its relationship to dental injury site and type. RESULTS: In 273 patients with dentition, we recorded 339 different facial fractures. Of these patients, 130 (47.5%) sustained a fracture in the non-tooth-bearing region, 44 (16%) had a fractured maxilla, and 65 (24%) had a fractured mandible. Among 224 patients with dentition who had a facial fracture in only 1 compartment, 140 injured teeth were found in 50 patients. Of 122 patients with an injury limited to the non-tooth-bearing facial skeleton, 12 sustained dental trauma (10%). In patients with fractures limited to the maxilla (n = 41), 6 patients had dental injuries (14.5%). In patients with fractures to the mandible (n = 61), 24 sustained dental injuries (39%). When we compared the type of tooth lesion and the location, simple crown fractures prevailed in both jaws. Patients with a fracture of the mandible were most likely to have a dental injury (39.3%). The highest incidence of dental lesions was found in the maxilla in combination with fractures of the lower jaw (39%). This incidence was even higher than the incidence of dental lesions in the lower jaw in combination with fractures of the mandible (24%). CONCLUSIONS: Knowledge of the association of dental injuries and maxillofacial fractures is a basic tool for their prevention. Our study showed that in cases of trauma with mandibular fracture, the teeth in the upper jaw might be at higher risk than the teeth in the lower jaw. Further larger-scale studies on this topic could clarify this finding and may provide suggestions for the amelioration of safety devices (such as modified bicycle helmets).

Experimental folate and vitamin B12 deficiency does not alter bone quality in rats

Hyperhomocysteinemia (HHCY) has been linked to fragility fractures and osteoporosis. Folate and vitamin B(12) deficiencies are among the main causes of HHCY. However, the impact of these vitamins on bone health has been poorly studied. This study analyzed the effect of folate and vitamin B(12) deficiency on bone in rats. We used two groups of rats: a control group (Co, n = 10) and a vitamin-deficient group (VitDef, n = 10). VitDef animals were fed for 12 wk with a folate- and vitamin B(12)-free diet. Co animals received an equicaloric control diet. Tissue and plasma concentrations of homocysteine (HCY), S-adenosyl-homocysteine (SAH), and S-adenosyl-methionine (SAM) were measured. Bone quality was assessed by biomechanical testing (maximum force of an axial compression test; F(max)), histomorphometry (bone area/total area; B.Ar./T.Ar.], and the measurement of biochemical bone turnover markers (osteocalcin, collagen I C-terminal cross-laps [CTX]). VitDef animals developed significant HHCY (Co versus VitDef: 6.8 +/- 2.7 versus 61.1 +/- 12.8 microM, p < 0.001) that was accompanied by a high plasma concentration of SAH (Co versus VitDef: 24.1 +/- 5.9 versus 86.4 +/- 44.3 nM, p < 0.001). However, bone tissue concentrations of HCY, SAH, and SAM were similar in the two groups. Fmax, B.Ar./T.Ar., OC, and CTX did not differ between VitDef and Co animals, indicating that bone quality was not affected. Folate and vitamin B(12) deficiency induces distinct HHCY but has no effect on bone health in otherwise healthy adult rats. The unchanged HCY metabolism in bone is the most probable explanation for the missing effect of the vitamin-free diet on bone.

Post-mortem imaging of laryngohyoid fractures in strangulation incidents: first results

Fractures and soft-tissue injuries of the neck are of great importance in forensic pathology, as they help in assessing whether strangulation took place, and if so, how severely. In this study, we examined the usefulness of post-mortem imaging with multislice computed tomography (MSCT) in detecting lesions of the laryngohyoid structures and the surrounding soft-tissues. For this purpose, we examined MSCT images of the neck of eight deceased persons who had suffered different types of strangulation and compared the findings with those obtained at the subsequent forensic autopsy. In six of the eight cases (75%), the fracture findings at autopsy were concordant with those found with MSCT. In the two non-congruent cases, MSCT revealed fractures, which were not discovered at autopsy. Soft-tissue haemorrhages were detected by autopsy in five cases, but only in one case with MSCT. MSCT does not suffice in detecting soft-tissue injuries. These preliminary results are promising regarding the detection of fractures in strangulation cases. If these results can be confirmed in larger studies, we believe that post-mortem MSCT may serve - in combination with a thorough external examination and a profound incident-scene investigation - as a useful decision-making tool regarding the necessity of further examinations, i.e. autopsy.