Cytokine Interferon-γ suppresses the function of capsule myofibroblasts and induces cell apoptosis

Myofibroblasts (MFs), a contractile subset of fibroblasts, play a pivotal role in physiological wound healing and in the development of many fibroconnective disorders. The complex cytokine network regulating the function of MFs in joint stiffness is still poorly understood. In this in vitro study, we investigated the effect of the cytokine Interferon-gamma (IFN-γ) on MFs isolated from human joint capsules. MFs were cultivated either in the presence of increasing concentrations of IFN-γ alone or in combination with IFN-γ neutralizing antibodies. Cell viability, cytotoxicity, apoptosis, and mRNA gene expression of the MF markers alpha-smooth muscle actin (α-SMA) and collagen type I were analy…

Transsacral Bar Osteosynthesis

Uni- or bilateral sacral ala fractures in elderly persons may cause significant disability and result in non-union, if treated non-surgically. Transsacral positioning bar osteosynthesis provides the advantages of a minimally invasive approach yet reducing the risk of implant loosening. A threaded 6 mm bar is inserted through the posterior part of the ilium and the SI-joint, and advanced through the center of the S1 vertebral body towards the opposite posterior ilium. Washers and nuts are placed and tightened on both ends of the bar providing moderate compression of the vertical fracture planes in the sacrum. The stability of fixation does not depend on the bone mineral density of the sacrum…

Influence of different calcium phosphate ceramics on growth and differentiation of cells in osteoblast-endothelial co-cultures

Strategies for improvement of angiogenesis and vasculogenesis using different cells and materials are paramount aims in the field of bone tissue engineering. Thereby, the interaction between different cell types and scaffold materials is crucial for growth, differentiation, and long-term outcomes of tissue-engineered constructs. In this study, we evaluated the interaction of osteoblasts and endothelial cells in three-dimensional tissue-engineered constructs using beta tricalciumphosphate (β-TCP, [s-Ca3 (PO4 )2 ]) and calcium-deficient hydroxyapatite (CDHA, [Ca9 (PO4 )5 (HPO4 )OH]) ceramics as scaffolds. We focused on initial cell organization, cell proliferation, and differential expression…

Bioengineered human bone tissue using autogenous osteoblasts cultured on different biomatrices

Surgical treatment of critical-size posttraumatic bone defects is still a challenging problem, even in modern bone and joint surgery. Progress in cellular and molecular biology during the last decade now permits novel approaches in bone engineering. Recent conceptual and technical advances have enabled the use of mitotically expanded, bone-derived cells as a therapeutic approach for tissue repair. Using three different tissue carrier systems, we successfully cultivated human osteoblasts in a newly developed perfusion chamber. We studied cell proliferation and the expression of osteocalcin, osteopontin, bone morphogenetic protein-2A, alkaline phosphatase, and vascular endothelial growth fact…

Cell viability, osteoblast differentiation, and gene expression are altered in human osteoblasts from hypertrophic fracture non-unions

Recent studies have provided evidence that the number and proliferation capacity of bone marrow-derived mesenchymal stem cells, as well as the number of osteoprogenitor cells are reduced in patients with fracture non-unions. For fracture non-unions that do not heal after appropriate surgical intervention, the question arises as to what extent systemic cellular dysfunctions should be considered as being pathogenetic factors. For this purpose, we have examined the hypothesis that the cell function of osteoblasts isolated from patients with fracture non-unions may differ from those of normal control individuals in an identical and controlled in vitro situation. We analyzed the osteoblast cell …

The influence of bone allograft processing on osteoblast attachment and function

In order to assess the influence of eight different sterilisation and disinfection methods for bone allografts on adhesion, proliferation, and differentiation of human bone marrow stromal cells (BMSC), cells were grown in culture and then plated onto pieces of human bone allografts. Following processing methods were tested: autoclavation (AUT), low-temperature-plasma sterilisation of demineralised allografts (D-LTP), ethylene oxide sterilisation (EtO), fresh frozen bone (FFB), 80 degrees C-thermodisinfection (80 degrees C), gamma-irradiation (Gamma), chemical solvent disinfection (CSD), and Barrycidal-disinfection (BAR). The seeding efficiency was determined after one hour to detect the num…

The role of muscular trauma in the development of heterotopic ossification after hip surgery: An animal-model study in rats.

Abstract Background Heterotopic ossification (HO), the formation of bone in soft tissues, is a frequent complication after surgery of the hip and the pelvis. Although the pathophysiological entities responsible for the formation of HO remain largely unclear, muscle trauma is alleged to play a central role in the pathogenic mechanisms underlying HO. However, for this observation, made by many surgeons for decades, no objective evidence has been provided yet. Methods Fifty male Wistar rats were subjected to surgery of the right hip. The femoral canal was reamed in three steps up to 2 mm. Animals formed 2 groups: in group 1 (25 animals) every effort was taken not to injure the muscles. In cont…

Clinical pathways for fragility fractures of the pelvic ring: personal experience and review of the literature

AbstractFragility fractures of the pelvic ring (FFP) are increasing in frequency and require challenging treatment. A new comprehensive classification considers both fracture morphology and degree of instability. The classification system also provides recommendations for type and invasiveness of treatment. In this article, a literature review of treatment alternatives is presented and compared with our own experiences. Whereas FFP Type I lesions can be treated conservatively, FFP Types III and IV require surgical treatment. For FFP Type II lessions, percutaneous fixation techniques should be considered after a trial of conservative treatment. FFP Type III lesions need open reduction and in…

Osteosynthese am proximalen Humerus mittels winkelstabiler Platte oder Doppelplatte: eine vergleichende biomechanische Untersuchung / Angle-fixed plate fixation or double-plate osteosynthesis in fractures of the proximal humerus: a biomechanical study

Internal fixation of fractures of the proximal humerus needs a high stability of fixation to avoid secondary loss of fixation. This is especially important in osteoporotic bone. In an experimental study, the biomechanical properties of the angle-fixed Philos plate (internal fixator) and a double-plate osteosynthesis using two one-third tubular plates were assessed. The fracture model was an unstable three-part fracture (AO type B2). Eight pairs of human cadaveric humeri were submitted to axial load and torque. In the first part of the study, it was assessed to which degree the original stiffness of the humeri could be restored after the osteotomy by the osteosynthesis procedure. Subsequentl…

Retrograde Transpubic Screw Fixation

In the vast majority of fragility fractures of the pelvis, fractures of the posterior and anterior pelvic ring occur combined. Fractures of the pubic rami above and below the obturator foramen are much more frequent than fractures of the pubic bone and fractures at the anterior lip of the acetabulum. Retrograde transpubic screw fixation is a minimally invasive technique for stabilization of pubic rami fractures. The anterior column corridor is a straight corridor between the anterior cortex of the superior pubic ramus near to the pubic tubercle and the external cortex of the ilium above the acetabulum. The minimal canal diameter, measured in 160 Japanese, was on average 13.5 mm for men and …

Mild Heat Stress Enhances Angiogenesis in a Co-culture System Consisting of Primary Human Osteoblasts and Outgrowth Endothelial Cells

The repair and regeneration of large bone defects, including the formation of functional vasculature, represents a highly challenging task for tissue engineering and regenerative medicine. Recent studies have shown that vascularization and ossification can be stimulated by mild heat stress (MHS), which would offer the option to enhance the bone regeneration process by relatively simple means. However, the mechanisms of MHS-enhanced angiogenesis and osteogenesis, as well as potential risks for the treated cells are unclear. We have investigated the direct effect of MHS on angiogenesis and osteogenesis in a co-culture system of human outgrowth endothelial cells (OECs) and primary osteoblasts …

Microvessel-like structures from outgrowth endothelial cells from human peripheral blood in 2-dimensional and 3-dimensional co-cultures with osteoblastic lineage cells.

Tissue regeneration involves complex processes in the interaction between different cell types that control the process of neo-vascularization. In bone, osteoblasts and bone marrow stem cells provide cue elements for the proliferation of endothelial cells, differentiation of endothelial precursors, and the maturation of a vascular network. In this study, we investigated outgrowth endothelial cells (OECs), a potential source of autologous endothelial cells derived from human peripheral blood, in direct 2-dimensional (2-D) and 3-D co-culture systems with cells relevant for the regeneration of bone tissue, such as osteoblasts. In the co-cultures, OECs were evaluated in terms of their stability…

Premature termination of epidural analgesia—A prospective analysis to improve quality

Summary Background and objective Epidural analgesia (EA) is a gold-standard in post-operative pain control. Therefore, modern treatment concepts targeting early patient recovery regularly implement EA. Due to its increasing impact, EA should meet high quality standards in respect to application and maintenance. Though, daily practice often reveals EA-related problems, our investigation aimed to improve EA quality by assessing incidence and reasons of undeliberate, premature termination of post-operative EA. Methods In the first step all patients with post-operative EA were retrospectively studied covering a 6-month period (group 1). We analysed incidences and reasons of undeliberate termina…

Dynamic processes involved in the pre-vascularization of silk fibroin constructs for bone regeneration using outgrowth endothelial cells

For successful bone regeneration tissue engineered bone constructs combining both aspects, namely a high osteogenic potential and a rapid connection to the vascular network are needed. In this study we assessed the formation of pre-vascular structures by human outgrowth endothelial cells (OEC) from progenitors in the peripheral blood and the osteogenic differentiation of primary human osteoblasts (pOB) on micrometric silk fibroin scaffolds. The rational was to gain more insight into the dynamic processes involved in the differentiation and functionality of both cell types depending on culture time in vitro. Vascular tube formation by OEC was assessed quantitatively at one and 4 weeks of cul…

<p>Effects of losartan and atorvastatin on the development of early posttraumatic joint stiffness in a rat model</p>

Background After a trauma, exuberant tissue healing with fibrosis of the joint capsule can lead to posttraumatic joint stiffness (PTJS). Losartan and atorvastatin have both shown their antifibrotic effects in different organ systems. Objective The purpose of this study was the evaluation of the influence of losartan and atorvastatin on the early development of joint contracture. In addition to joint angles, the change in myofibroblast numbers and the distribution of bone sialoprotein (BSP) were assessed. Study design and methods In this randomized and blinded experimental study with 24 rats, losartan and atorvastatin were compared to a placebo. After an initial joint injury, rat knees were …

Photocrosslinkable polysaccharide hydrogel composites based on dextran or pullulan-amylose blends with cytokines for a human co-culture model of human osteoblasts and endothelial cells

Although a large body of research has been devoted to biomaterial development for bone tissue engineering and related medical disciplines in the last few years, novel and optimized materials especially for bone fractures of critical sizes demand continued development. In this respect, polysaccharide-based hydrogels demonstrate beneficial properties and fulfill the main requirements for a bone tissue scaffold as they are hydrophilic, biocompatible, and biodegradable. The aim of the present study was the development of a natural polysaccharide-based scaffold material that can integrate with the host tissue and support bone regeneration. For this purpose, we prepared and investigated two polym…

Internal Fixation of Proximal Humeral Fractures: Current Concepts

Fractures of the proximal humerus are an increasingly common type of injury. Mainly elderly patients with osteoporotic bone are affected. Whereas non-displaced and stable fractures are managed successfully with conservative treatment, there is no general agreement on the surgical strategy for displaced and unstable two- to four-part fractures. The clinical outcome is influenced by the fracture type and concomitant injury to the rotator cuff. Extensive surgical manipulation of the soft tissues, non-anatomic and/or unstable fixation as well as technical errors are important contributing factors to poor clinical results. Goals of surgical treatment are to restore anatomy, to achieve fixation t…

CD34+cells seeded in collagen scaffolds promote bone formation in a mouse calvarial defect model

Bone tissue engineering (BTE) holds promise for managing the clinical problem of large bone defects. However, clinical adoption of BTE is limited due to limited vascularization of constructs, which could be circumvented by pre-cultivation of osteogenic and endothelial derived cells in natural-based polymer scaffolds. However, until now not many studies compared the effect of mono- and cocultures pre-seeded in collagen before implantation. We utilized a mouse calvarial defect model and compared five groups of collagen scaffolds: a negative control of a collagen scaffold alone, a positive control treated with BMP-7, monocultures of either human osteoblasts (hOBs) or CD34+ cells, and a cocultu…

Do We Need a Separate Classification for Fragility Fractures of the Pelvis?

Fragility fractures of the pelvis are occurring with increasing frequency. These fractures, occurring in the geriatric patient population, are low-energy injuries and are dissimilar in many ways from those caused by high-energy trauma. For example, the mechanism of injury is different and emergency treatment is usually not necessary. Having diminished bone strength, fragility fracture lines follow areas of low bone mineral density and loss of pelvic stability may increase over time. Based on our clinical experience, we propose a comprehensive classification of pelvic fragility fractures separate from the existing pelvic ring injury classification to provide a framework for distinguishing th…

Osteoporotische Frakturen des Beckenrings

Durch die Alterung der Bevölkerung sind wir mit einer Zunahme an osteoporotischen und Ermüdungsfrakturen des Beckenrings konfrontiert. Sie werden durch niedrigenergetische Traumen verursacht. Die konventionelle Diagnostik ist weniger aufschlussreich als bei Jugendlichen und Erwachsenen, eine CT- oder MRT-Diagnostik ist erforderlich. Die Erscheinungsformen sind multipel und bieten ein ganzes Spektrum von Instabilitäten. Die konventionelle Klassifikation trifft nicht auf alle Erscheinungsformen dieser Frakturen zu. Die Behandlung umfasst sowohl konservative als auch operative Verfahren. Entscheidend dabei sind der Grad und die Lokalisation der Instabilität. Die Osteosyntheseformen unterscheid…

Osteoporotic Pelvic Fractures

Background The estimated incidence of osteoporotic pelvic fractures among persons over age 60 in Germany is 224 per 100 000 persons per year, and rising. A number of surgical treatment options are available, but clinical long-term data are lacking. Methods This review is based on pertinent publications and guidelines retrieved by a selective literature search, and on the authors' clinical experience. Results Patients often report one or more relatively trivial traumatic incidents leading up to the fracture. They complain of pain in the hip, groin, or lower lumbar region, or of low back pain and sciatica. A new classification scheme entitled Fragility Fractures of the Pelvis (FFP) takes the …

Fragility Fractures of the Pelvis.

Fragility fractures of the pelvic ring (FFP) show an increasing frequency. Trauma mechanism, fracture morphology and degree of instability are different from those in high-energy pelvic ring lesions. Little is known about the optimal treatment strategy. A new comprehensive classification system with four categories of increasing instability is presented. It is connected with recommendations for type and invasiveness of treatment. FFP Type I are anterior instabilities only and can be treated conservatively. FFP Type II are non-displaced posterior lesions which can be treated conservatively or with percutaneous fixation. FFP Type III lesions are unilateral displaced posterior lesions which re…

Iliosacral Screw Osteosynthesis

Fragility fractures of the anterior pelvic ring are very often combined with fractures of the posterior pelvic ring. The large majority of the posterior fractures is situated in the sacral ala. Non-operative therapy may be cumbersome in patients with a combination of an anterior with a posterior pelvic ring fracture. Any surgical therapy should be as less invasive as possible. Iliosacral screw fixation is a minimal invasive technique. Variations of the upper sacral anatomy make optimal iliosacral screw placement challenging. The vestibule or isthmus is the narrowest part of the bony corridor from the lateral ilium to the S1 sacral body. It always points towards anterior and superior. The wh…

Photocrosslinked Dextran-Based Hydrogels as Carrier System for the Cells and Cytokines Induce Bone Regeneration in Critical Size Defects in Mice

Modified biomaterials have for years been the focus of research into establishing new bone substitutes. In our preceding in vitro study employing different cell cultures, we developed chemically and mechanically characterized hydrogels based on photocrosslinkable dextran derivatives and demonstrated their cytocompatibility and their beneficial effects on the proliferation of osteoblasts and endothelial cells. In the present in vivo study, we investigate photocrosslinked dextran-based hydrogels in critical size defects in mice to evaluate their potential as carrier systems for cells or for a specific angiogenesis enhancing cytokine to induce bone formation. We could demonstrate that, with op…

Sind winkelstabile Plattensysteme mit elastischen Eigenschaften für die Stabilisierung der Oberarmkopffraktur vorteilhaft? / Eine in-vitro biomechanische Untersuchung

AbstractWinkelstabile Platten werden mit zunehmender Häufigkeit zur Stabilisierung von Oberarmkopfbrüchen verwendet. Rigide Implantate führen bei osteoporotischen Knochenverhältnissen u. U. aber häufiger zum Versagen. Um den Effekt der Implantatelastizität zu beurteilen wurden in einer in-vitro Studie die biomechanischen Eigenschaften eines rigiden und eines elastischen winkelstabilen Plattensystems vergleichend analysiert. An 8 Humeruspaaren wurde eine instabile subkapitale Fraktur simuliert. Die Proben wurden axial- und torsions-belastet. Analysiert wurden die Steifigkeit, das Setzverhalten unter Dauerlast und die Versagensbelastung.Das elastische Plattensystem kennzeichnete sich durch ei…

The Benefit of Multislice CT in the Emergency Room Management of Polytraumatized Patients

The early treatment of polytraumatized patients needs an effective and standardized approach. Reducing time requirements for the primary diagnostic evaluation is a major concern in the early phase of polytrauma management. Multislice-CT (MSCT) is a quick and reliable method for the initial diagnostic evaluation. Computed tomography provides more detailed and more consistent information than conventional radiography. It has the great advantage of allowing rapid examination of the head, vertebral column, chest, abdomen and pelvis during one single examination. The CT-suite needs to be adequately equipped for resuscitation and reanimation, which is done parallel to the radiological investigati…

Sonic hedgehog promotes angiogenesis and osteogenesis in a coculture system consisting of primary osteoblasts and outgrowth endothelial cells.

A number of previous studies documented the angiogenic potential of outgrowth endothelial cells in vitro and in vivo and provided evidence that therapeutic success could depend on coculture or coimplantation strategies. Thus, deeper insight into the molecular mechanisms underlying this pro-angiogenic effect of cocultures might provide new translational options for tissue engineering and regenerative medicine. One promising signaling pathway in bone repair involved in neoangiogenesis and bone formation is the sonic hedgehog (Shh) pathway. In this article, we focus on the effect of Shh on the formation of microvessel-like structures and osteoblastic differentiation in cocultures of primary os…

Molekulare, physiologische und anatomische Grundlagen der Knochenentwicklung

Radiological analysis, operative management and functional outcome of open book pelvic lesions: a 13-year cohort study.

Abstract We present the clinical and radiological outcome of a 13-year cohort study of 38 open book pelvic lesions. All patients were treated in one Level I Trauma centre. In the posterior pelvis, sacro-iliac diastasis was seen in 31 patients, sacral fracture in 7. In all patients with sacro-iliac diastasis, the pubic bone was inferiorly displaced on the primary ap pelvic overview on the side of injury. All but one patient was treated with open reduction and internal fixation of the symphysis pubis. Additional stabilization of the posterior pelvis was done in 9 patients. 32 patients were seen after a median follow up of 84 months. Majeed score and SF-36 questionnaire were used. Functional o…

Repetitive low-energy shock wave application without local anesthesia is more efficient than repetitive low-energy shock wave application with local anesthesia in the treatment of chronic plantar fasciitis

Background: It remains unclear whether application of local anesthesia (LA) interferes with clinical e!cacy of extracorporeal shock wave therapy (ESWT) for chronic plantar fasciitis. Aims: To evaluate the e"ect of local anesthesia on the clinical outcome after repetitive low-energy ESWT for chronic plantar fasciitis. Methods: Eighty-six patients with chronic plantar fasciitis were randomly assigned to receive either low-energy ESWT without LA, given weekly for three weeks (Group I, n = 45; 3 · 2000 pulses, total energy flux density per shock 0.09 mJ/mm 2 ) or identical ESWT with LA (Group II, n = 41). Primary outcome measure was: Reduction of pain from baseline to month 3 post-treatment in …

Effect of bone sialoprotein coated three-dimensional printed calcium phosphate scaffolds on primary human osteoblasts

The combination of the two techniques of rapid prototyping 3D-plotting and bioactive surface functionalization is presented, with emphasis on the in vitro effect of Bone Sialoprotein (BSP) on primary human osteoblasts (hOBs). Our primary objective was to demonstrate the BSP influence on the expression of distinctive osteoblast markers in hOBs. Secondary objectives included examinations of the scaffolds' surface and the stability of BSP-coating as well as investigations of cell viability and proliferation. 3D-plotted calcium phosphate cement (CPC) scaffolds were coated with BSP via physisorption. hOBs were seeded on the coated scaffolds, followed by cell viability measurements, gene expressi…

The effect of the pro-inflammatory cytokine tumor necrosis factor-alpha on human joint capsule myofibroblasts.

Introduction Previous studies have shown that the number of myoblastically differentiated fibroblasts known as myofibroblasts (MFs) is significantly increased in stiff joint capsules, indicating their crucial role in the pathogenesis of post-traumatic joint stiffness. Although the mode of MFs' function has been well defined for different diseases associated with tissue fibrosis, the underlying mechanisms of their regulation in the pathogenesis of post-traumatic joint capsule contracture are largely unknown. Methods In this study, we examined the impact of the pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-α) on cellular functions of human joint capsule MFs. MFs were challenged w…

Phenotypic redifferentiation and cell cluster formation of cultured human articular chondrocytes in a three-dimensional oriented gelatin scaffold in the presence of PGE2- first results of a pilot study

Modern tissue engineering strategies comprise three elemental parameters: cells, scaffolds and growth factors. Articular cartilage represents a highly specialized tissue which allows frictionless gliding of corresponding articulating surfaces. As the regenerative potential of cartilage is low, tissue engineering-based strategies for cartilage regeneration represent a huge challenge. Prostaglandins function as regulators in cartilage development and metabolism, especially in growth plate chondrocytes. In this study, it was analyzed if prostaglandin E2 (PGE2) has an effect on the phenotypic differentiation of human chondrocytes cultured in a three-dimensional (3D) gelatin-based scaffold made …

The effect of human osteoblasts on proliferation and neo-vessel formation of human umbilical vein endothelial cells in a long-term 3D co-culture on polyurethane scaffolds

Angiogenesis is a key element in early wound healing and is considered important for tissue regeneration and for directing inflammatory cells to the wound site. The improvement of vascularization by implementation of endothelial cells or angiogenic growth factors may represent a key solution for engineering bone constructs of large size. In this study, we describe a long-term culture environment that supports the survival, proliferation, and in vitro vasculogenesis of human umbilical vein endothelial cells (HUVEC). This condition can be achieved in a co-culture model of HUVEC and primary human osteoblasts (hOB) employing polyurethane scaffolds and platelet-rich plasma in a static microenvir…

Contribution of outgrowth endothelial cells from human peripheral blood on in vivo vascularization of bone tissue engineered constructs based on starch polycaprolactone scaffolds

In the present study we assessed the potential of human outgrowth endothelial cells (OEC), a subpopulation within endothelial progenitor cell cultures, to support the vascularization of a complex tissue engineered construct for bone. OEC cultured on starch polycaprolactone fiber meshes (SPCL) in monoculture retained their endothelial functionality and responded to angiogenic stimulation by VEGF (vascular endothelial growth factor) in fibrin gel-assays in vitro. Co-culture of OEC with human primary osteoblasts (pOB) on SPCL, induced an angiogenic activation of OEC towards microvessel-like structures achieved without additional supplementation with angiogenic growth factors. Effects of co-cul…

Photocrosslinkable dextran hydrogel films as substrates for osteoblast and endothelial cell growth

Functional hydrogel films on solid supports are versatile materials with large potential for cell growth and tissue engineering. Here, we report on a modular approach to generate functional hydrogel composite films for endothelial and osteoblast cell co-culture. The polymer network of the parent hydrogel was formed by a dextran derivative (BP-CMD), which contained carboxymethyl (CM) groups for further chemical functionalization and benzophenone (BP) moieties as a photocrosslinkable unit. BP-CMD could be synthesized by three different routes, first with the benzophenone unit attached via an amide bond, or second by an ether bond, or third as an ion pair between the benzophenone ammonium salt…

Retrograde nailing versus locking plate osteosynthesis of proximal humeral fractures: a biomechanical study

Background In locking plate osteosynthesis of proximal humeral fractures, secondary varus malalignment is a specific complication. Retron nails (Tantum AG, Neumunster, Germany), among others, have been designed to improve medial support of the calcar humeri. The aim of our biomechanical study was to examine whether Retron nails provide increased stiffness for axial loads and adequate stiffness for torsional loads when compared with Philos plates (Synthes AG, Umkirch, Germany). Materials and methods Twenty-two fresh-frozen paired humeri were collected. After potting the specimens, intact bones were exposed to sinusoidal axial (10-120 N) and torsional (±2.5 Nm) loading for 8 cycles to calcula…

Classification of Fragility Fractures of the Pelvis

The characteristics of fragility fractures of the pelvis are different from pelvic fractures in adolescents and adults. There are specific fracture morphologies such as U- or H-shaped fractures of the sacrum and bilateral fractures. The classification systems of AO/ASIF and Young-Burgess reflect the trauma mechanism and the type of instability in high-energy pelvic injuries. Not all types of fragility fractures of the pelvic ring fit into these classification systems. A new, comprehensive classification (FFP classification) includes all morphologies of fragility fractures of the pelvis, whether acute or chronic. It provides a framework for how to look at these lesions. The first criterion o…

Short‐term hypoxia promotes vascularization in co‐culture system consisting of primary human osteoblasts and outgrowth endothelial cells

Prevascularization of tissue constructs before implantation has been developed as a novel and promising concept for successful implantation. Since hypoxia might induce angiogenesis, we have investigated the effects of hypoxic treatment on vascularization by using co-cultures of primary human osteoblasts (POBs) and outgrowth endothelial cells. Our results show that: (a) repeated short-term hypoxia (2% O2 for 8 hr), not long-term hypoxia (2% O2 for 24 hr), over 1 or 2 weeks, significantly enhances microvessel formation in co-cultures; (b) sustained hypoxia, not short-term or long-term hypoxia, causes cytotoxicity in mono- and co-cultures; (c) the expression of some angiogenic and inflammatory…

Personality of Fragility Fractures of the Pelvis

The personality of pelvic fractures in the elderly differs in many ways from pelvic ring lesions in adults. Only high-energy trauma leads to pelvic ring disruptions. Concomitant lesions of the soft tissues occur frequently. In the elderly, low-energy falls are the rule. The most important symptom is pain, which restricts mobility. Hemodynamic instability in fragility fractures of the pelvis is rare. Emergency stabilization with pelvic binders or sheets, C-clamping or emergency external fixation are not needed. Arteriography and selective embolization is only recommended in the rare patients, who develop an active arterial bleeding due to the pelvic fracture. Especially patients, who are tre…

Influence of the anti-inflammatory cytokine interleukin-4 on human joint capsule myofibroblasts

Post-traumatic joint contracture was reported to be associated with elevated numbers of contractile myofibroblasts (MFs) in the healing capsule. During the physiological healing process, the number of MFs declines; however, in fibroconnective disorders, MFs persist. The manifold interaction of the cytokines regulating the appearance and persistence of MFs in the pathogenesis of joint contracture remains to be elucidated. The objective of our current study was to analyze the impact of the anti-inflammatory cytokine interleukin (IL)-4 on functional behavior of MFs. Cells were isolated from human joint capsule specimens and challenged with three different concentrations of IL-4 with or without…

Extracorporeal shock wave-mediated changes in proliferation, differentiation, and gene expression of human osteoblasts.

The goal of this study was to determine whether cell proliferation, differentiation, and gene expression of primary human osteoblasts (hOB) are influenced by shock wave application (SWA).Osteoblast cultures were isolated from cancellous bone fragments and treated with 500 impulses of energy flux densities of 0.06 mJ/mm, 0.18 mJ/mm, 0.36 mJ/mm, and 0.50 mJ/mm. Twenty-four hours and 96 hours after SWA cell proliferation, alkaline phosphatase activity, and mineralization were analyzed. The global gene expression profiling was determined 96 hours after SWA employing Affymetrix HG-U133A microarrays.After 24 hours, hOB showed a dose-dependent increase in cell proliferation from 68.7% (at 0.06 mJ/…

Comparative study assessing effects of sonic hedgehog and VEGF in a human co-culture model for bone vascularisation strategies.

The morphogen sonic hedgehog (Shh) seems to mediate adult repair processes in bone regeneration and vascularisation. In this study we investigated the effects of Shh on co-cultures consisting of human primary osteoblasts and outgrowth endothelial cells in terms of angiogenic activation and vessel maturation in comparison to the treatment with the commonly used proangiogenic factor, VEGF. Both, stimulation with VEGF or Shh, leads to an increase in the formation of microvessel-like structures compared to untreated controls. In contrast to VEGF, proangiogenic effects by Shh could already be observed after 24 h of treatment. Nevertheless, after 14 days the angiogenic activity of OEC was compara…