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The aim of this study was to compare two variants of a novel polycarbonate polyurethane prosthesis with polyethylene terephthalate (Dacron) prosthesis in an established sheep model of carotid patch angioplasty. Two variants of the polycarbonate polyurethane prosthesis were used: (1) Polycarbonate polyurethane equal (PCU-e) prosthesis consisted of a multilayered porous structure with equal internal and external layers; (2) Polycarbonate polyurethane with more porous inner layers (PCU-mp) prosthesis had more porous inner layers than external layers. Carotid patch angioplasty was performed in 12 sheep: in six sheep, the PCU-e variant and in the other six sheep, the PCU-mp variant was implanted. Dacron patches were implanted in the contralateral carotid artery of all sheep as a control. Half of the animals with each polycarbonate polyurethane variant were euthanized after two weeks and the other half after eight weeks. Cellular infiltration, endothelialization, and neointimal hyperplasia were examined. All grafts were patent, and no thrombus was seen in any of the harvested arteries. The pores of all the three patch materials allowed infiltration of inflammatory cells, capillaries, and connective tissue. After eight weeks, a nearly complete endothelialization was visible in all patch groups without an obvious difference between the three patch materials. The neointima was thinner in the PCU patches (PCU-e: 56 +/- 13 mu m, PCU-mp: 119 +/- 60 mu m) when compared to Dacron patches (156 +/- 64 mu m) after two weeks. After 8 weeks, a further neointimal growth was detectable, without any significant difference of neointimal thickness between the three patch materials (Dacron: 274 +/- 82 mu m, PCU-e: 324 +/- 98 mu m, PCU-mp: 235 +/- 59 mu m). With the novel polycarbonate polyurethane patch materials, we achieved promising functional and morphological results with 100% patency and nearly complete endothelialization. Our findings showed at least a non-inferiority of the novel polycarbonate polyurethane patch material compared to Dacron. There were no significant differences detected between the two polycarbonate polyurethane patch variants.

Objectives: Among the different graft materials being applied in sinus elevation surgery autogenous bone, especially from the iliac crest, is considered to be the graft of choice. The goal of this prospective study was to investigate whether purely cancellous transplants of this donor site lead to significantly better results regarding bone quantity and quality when compared to corticocancellous iliac bone grafts. Material and methods: Fifteen patients suffering from extreme maxillary atrophy underwent bilateral sinus floor augmentation with grafts from the iliac crest consisting of purely cancellous bone (PCB) for the right side and a mixture of 50% cancellous and 50% cortical bone for the left side, respectively. Bone samples that were taken during implant insertion were examined histologically for semiquantitative assessment. In addition, bone density was measured histomorphometrically. Data were statistically analyzed by a repeated measures analysis of covariance model and post hoc paired t-tests as well as Pearson's correlation analysis. Results: Semiquantitative analysis of bone quality resulted in comparable results for both graft preparations while bone density was significantly higher in the PCB group. Without consideration of the different transplant groups, there was neither a significant correlation between patients' age and bone density nor bone quality. Differences between the genders could not be observed either. Conclusions: Because of better bone density, the PCB graft from the iliac crest remains our gold standard. Even in elderly patients, autogenous grafts can be utilized without losses in the properties of the resulting bone.

Congenital aplasia or hypoplasia of the fibula (FAH) is a rare malformation that is defined by a partial or complete absence of the fibular bone. Etiology and pathogenesis are unknown and the precise morphology of the tissue cord replacing the malformed fibula has not been well described. Therefore, tissue cord was examined in 8 patients with FAH. Light microscopic, immunohistochemical, and electron microscopic investigations showed a core of embryonic cartilage with collagen II and VI expressions surrounded by connective tissue. Although collagen II expression is typical for chondroid differentiation, collagen VI reactivity is normally seen in articular cartilage and tendon-like fibrocartilaginous tissue but is absent in hyaline cartilage. Further ultra-structural analyses by electron microscopy supported these findings. The histomorphologic changes correspond to the histologic findings of Papenbrock et al. (2000, Mech Dev 92:113–123) who produced a congenital malformation in transgenic mice that resembled FAH by overexpression of Hox c11.

The etiology and the pathogenesis of congenital pseudarthrosis of the tibia (CPT) are still unknown. The affected tibia exhibits insufficient mechanical strength and osteogenetic capability. CPT is frequently associated with neurofibromatosis type 1 (NF1; von Recklinghausen's disease); however, both diseases have not yet been linked pathogenetically. This study presents the pathomorphologic findings of CPT under special consideration of NF1. Therefore, samples from patients operated on for CPT (n = 4) with (n = 3) and without (n = 1) neurofibromatosis were investigated by light microscopy, immunohistochemistry, and electron microscopy. The most striking finding in all patients was thickened periosteum with accumulation of nerval cells surrounding small arteries, causing subtotal or complete obliteration. In conclusion, impaired vascularization can result in decreased osteogenic capabilities. The similarity of ultrastructural findings in the abnormal periosteum and in skin neurofibromas of neurofibromatosis patients may indicate a pathogenetic association of both diseases.

Devices constantly tracking the blood pressure (BP) of hypertensive patients are highly desired to facilitate effective patient management and to reduce hospitalization. We report on experiences gathered in a pilot study that was designed to evaluate the prototype of a newly developed, minimally invasive implantable sensor system for long-term BP monitoring. The device was implanted in the femoral artery (FA) of 12 sheep via standard FA catheterization under fluoroscopic control. Accuracy of the recorded blood pressure was determined by comparison with a reference catheter, which was positioned in the contralateral FA immediately after implantation. Regular follow-up included angiography, computed tomography (CT), and control of functionality and position of the BP sensor. Animals were euthanized after 6 months. FA segments with in situ pressure sensor underwent macroscopic and histopathologic examinations. All implantations of the novel sensor device in the FA were successful and uneventful. High-quality BP recordings were documented. Bland–Altman plots indicate very good agreement. Comparison with measurements taken from the reference sensor revealed mean differences and standard deviations of −0.56 ± 0.85, 0.29 ± 1.44, and 0.85 ± 2.27 mmHg (diastolic, systolic, and pulse pressure, respectively) after exclusion of one outlier. CT uncovered deficiencies in cable stability that were addressed in a redesign. No thrombus formation, necrosis, or apoptosis were detected. The pilot study proved the technical feasibility of wireless BP measurement in the FA via a novel miniature sensor device.

Platelet-rich plasma (PRP) is a potent agent that improves soft tissue and bone healing. By the release of growth factors and cytokines, PRP is believed to locally boost physiologic healing processes. Recently, antimicrobial activity of PRP has been demonstrated against S. aureus strains. Major scientific effort is being put into the understanding and prevention of infections i.e. by delivery of antimicrobial substances. In previous studies we showed the ideal antibacterial activity-profile of the human beta-defensin 2 (hBD-2) for orthopaedic infections and therefore hypothesized that hBD-2 may be the effector of antimicrobial platelet action. Platelet concentrates were produced from human platelet phresis obtained from a hospital blood bank. They were screened by immunohistochemistry, Western Blot and ELISA for the human beta defensin-2. In vitro susceptibility to PRP was investigated by a standard disc diffusion test with or without pre-incubation of PRP with anti-hBD-2 antibody. SPSS statistical software was used for statistical analysis. PRP contains hBD-2 470 pg/10(9) platelets or 1786 pg/ml, respectively, (ELISA), which was confirmed by immunohistochemistry and Western Blot. In antimicrobial testing, PRP demonstrates effective inhibition of E. coli, B. megaterium, P. aeruginosa, E. faecalis and P. mirabilis. With this study we confirm the previously reported antimicrobial action of platelet concentrates i.e. PRP. In opposition to previously reported effects against gram positive bacteria our study focuses on gram negative and less common gram positive bacteria that do frequently cause clinical complications. We provide a possible molecular mechanism at least for E. coli and P. mirabilis for this effect by the detection of an antimicrobial peptide (hBD-2). This study may advocate the clinical use of PRP by highlighting a new aspect of platelet action.

Mesh implants as standard treatment for tissue defects can be adapted to patient’s needs by specific bioactive coatings. The biophysical interaction with the surrounding tissue must be understood to describe the influence of coatings qualitatively and quantitatively. This study investigates the use of meshes to repair diaphragmatic defects. The physical stress in this tissue is high in comparison to other applications. Therefore, knowledge gained from this experimental model can be applied to other locations. Meshes were implanted on surgically created diaphragmatic defects in growing rabbits. A standardized load model was used to investigate 33 rabbits. The commercial products Ultrapro®, Surgisis®, and Proceed ® were implanted. The adhesive properties of the meshes as well as the defect size were determined macroscopically at explantation after 4 months. Sections of the explanted meshes and diaphragms were examined histologically and immunohistochemically. The median defect size for all mesh groups decreased from the initial size of 10 mm down to 4.5 mm at explantation. No statistically significant differences were seen between the three mesh groups. Surgisis ® was found to be completely disintegrated after 4 months. Ultrapro ® and Proceed® showed no macroscopic differences compared to their original appearance. Both sealed the original diaphragmatic defect as tightly as at time of implantation. Histological and immunohistochemical analyses showed significant differences between the three mesh groups. Proceed ® caused stronger inflammatory reaction in the surrounding tissue and inferior connective tissue formation. Regarding the composition of the newly generated tissue within the defect area, Ultrapro® and Surgisis® were found superior. This can sufficiently be explained by the different gradient of inflammatory reaction in the surrounding tissue. Because Surgisis® offers no sufficiently lasting support for the diaphragmatic defect, our future main focus for mesh modification is laid on Ultrapro®.

Ziel der prospektiven Studie war die Identifikation von Befundmustern in der Positronenemissionstomographie (PET) mit 18F-Fluordeoxyglucose (18F-FDG) zur diagnostischen Differenzierung schmerzhafter Knieprothesen in aseptische Knieprothesenlockerung und Protheseninfekt fur die tibiale und femorale Komponente. Patienten, Material, Methode: 20 Patienten mit klinischem Verdacht auf aseptische Prothesenlockerung bzw. einen Infekt zementierter Knieprothesen wurden praoperativ mittels FDG-PET untersucht. Die Grenzflache zwischen Prothese und angrenzendem Knochen wurde dabei in 3 Segmente fur das Femur und 3 Segmente fur die Tibia sowie 4 Segmente fur das periprothetische Weichteilgewebe unterteilt. Fur jedes dieser Segmente wurde durch zwei unabhangige Untersucher ein visueller Uptake-Score (0–3) erhoben. Die endgultige Diagnosesicherung erfolgte in allen Fallen durch die klinische und operative Befunderhebung mit histologischer und mikrobiologischer Gewebeaufarbeitung. Ergebnisse: Intraoperativ fanden sich 6 aseptische Lockerungen der femoralen und 5 aseptische Lockerungen der tibialen Prothesenkomponenten und 9 Protheseninfekte. 8 der 9 infizierten Prothesen wiesen sowohl eine Lockerung der femoralen als auch der tibialen Prothesenkomponenten auf. Eine statistisch signifikante Korrelation zwischen dem semiquantitativen Uptake der einzelnen Segmente und der Diagnose einer aseptischen Lockerung oder eines Protheseninfektes konnte nicht nachgewiesen werden. Eine differenzierte Befundinterpretation des qualitativen und semiquantitativen Glukosemetabolismus hingegen zeigte eine diagnostische Treffsicherheit (Spezifitat / Sensitivitat / pos. Vorhersagewert (PVW) / neg. Vorhersagewert (NVW)) von 93% / 83% / 83% / 93% fur eine aseptische Lockerung der femoralen Komponente, von 87% / 80% / 67% / 93% fur eine aseptische Lockerung der tibialen Komponente und von 82% / 89% / 80% / 90% fur eine Protheseninfektion. Schlussfolgerung: Die differenzierte Interpretation des regionalen Glukosemetabolismus bietet, gesichert durch Ubereinstimmung der FDG-PET Befunde mit den intraoperativen und histologisch / mikrobiologischen Befunden, eine vielversprechende diagnostische Moglichkeit zur Differenzierung zwischen aseptischer Knieprothesenlockerung und Protheseninfekt. Der tatsachliche Nutzen der erarbeiteten Befundinterpretation muss an groseren Patientenkollektiven evaluiert werden.

The aim of the present study was to analyze the osteogenic potential of a biphasic calcium composite material (BCC) with a negative surface charge for maxillary sinus floor augmentation. In a 61 year old patient, the BCC material was used in a bilateral sinus floor augmentation procedure. Six months postoperative, a bone sample was taken from the augmented regions before two titanium implants were inserted at each side. We analyzed bone neoformation by histology, bone density by computed tomography, and measured the activity of voltage-activated calcium currents of osteoblasts and surface charge effects. Control orthopantomograms were carried out five months after implant insertion. The BCC was biocompatible and replaced by new mineralized bone after being resorbed completely. The material demonstrated a negative surface charge (negative Zeta potential) which was found to be favorable for bone regeneration and osseointegration of dental implants.

Objective We give the first account of failure of extracorporeal membrane oxygenation therapy secondary to congenital cystic malformation of the lung (CCAM) type 0. Design Case report. Setting Pediatric intensive care unit. Patient A female neonate, appropriate for gestational age, with respiratory failure immediately after delivery. Interventions : Cardiopulmonary support with venoarterial extracorporeal membrane oxygenation. Results There was no improvement of pulmonary function, and the patient died. CCAM type 0 was diagnosed postmortem. Conclusions CCAM type 0 should be considered as a rare differential diagnosis of irreversible lung pathologies leading to failure of extracorporeal membrane oxygenation therapy for neonatal respiratory failure.

As a clinical pilot study using the skeletonized, periodontally/miniscrew-anchored Distal Jet appliance, this study aimed to verify the positional stability of the palatally-inserted paramedian miniscrews when subjected to loading for several months, hence to assess the efficacy of the supporting anchorage design.Sixteen miniscrews (8-9 mm in length, 1.6 mm in diameter, polished surface) were inserted in the anterior region of the palate at paramedian locations. Once they had been in place for 1 week, skeletonized Distal Jets for bilateral molar distalization were anchored to the first premolars and necks of the miniscrews using composite. The appliances' coil spring systems were activated to a distalization force of 200-240 cN. The miniscrews were processed histologically after minimally-invasive explantation.Forces acting reciprocally on the anchorage unit result in significant anchorage loss in the palatally-inserted titanium miniscrews used for added anchorage support: we observed ventral movement in the vicinity of the miniscrew heads of 0.95+/-0.82 mm (the mean; p = 0.005), and extrusion of 0.21+/-0.28 mm (p = 0.040). In the process they tipped 2.65 degrees +/-6.23 degrees in relation to the palatal plane and 2.15 degrees +/-5.76 degrees in relation to the anterior cranial base. We observed no evidence of direct screw-to-bone contact in any of the explanted miniscrews.Titanium miniscrews with a polished surface, 1.6 mm in diameter and 8-9 mm long, do not provide stationary anchorage in molar distalization with the periodontally/miniscrew-anchored Distal Jet. When subjected for several months to load from forces that act in reciprocity to the force systems occurring during molar distalization, they fail to remain completely stationary in position in the palatal locations in which they were inserted. However, the combined anchorage setup is sufficient, intraorally and regardless of patient compliance, to largely compensate for the mesially-acting forces that occur reciprocal to molar distalization.

Even following the introduction of the “third generation” cementing technique, an improvement of the fixation of the acetabular component similar to that of the femoral has not been shown in clinical studies. The goal of the present study was to achieve a better stability with the use of an amphiphilic bonder while preserving the mechanically important subchondral sclerosis. In a total of 20 sheep, a cemented total hip replacement was implanted. In the treatment group (n = 10), the implantation was carried out following surface conditioning of the acetabular bed with an amphiphilic bonder. All the sheep were followed for 9 months. To assess the biocompatibility, the osseous ingrowth at the cement–bone interface was depicted with the help of an in vivo fluorescent marking of the osteoblasts. Additionally, conventional radiographs were obtained over the course of treatment. Finally, the ovine pelvic regions were split following a standardized technique allowing for histological evaluation of the cement–bone interfaces. The acetabular components of the treatment group revealed a stable cement–bone compound. In the control group, the implants were easily dislodged from their beds. This finding was consistent with the radiological and histological results, which had revealed increased, progressive lytic radiolucent lines and the interposition of fibrous tissue at the cement–bone interface in the control group compared to the treatment group. The bonder was biocompatible. Following the application of the bonder, the cemented acetabular components revealed an improved stability without signs of inflammation or neoplasia in a viable acetabular osseous bed. With the help of this technique, the in vivo longevities of cemented acetabular components can be increased in the clinical setting without sacrificing the biomechanical relevant subchondral sclerosis.