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The aim of this study was to present clinical experience and outcomes of intramedullary nailing of proximal, midshaft and distal tibia fractures with the Expert Tibia Nail (ETN; Synthes GmbH, Switzerland), an implant offering a wide range of proximal and distal locking options in multiple planes to increase stability of the implant and bone construct.180 patients with 185 tibia fractures were enclosed between July 2004 and May 2005 from ten trauma units (Levels I, II and III) and treated with intramedullary reamed and unreamed nailing with the ETN. Patients attended examinations at 12 weeks and 1 year. The occurrence of postoperative complications was documented as well as the outcomes of fracture healing, primary and secondary malalignment, implant failure, rate of infection and the need for reoperation.The 1-year follow-up rate was 81 %. At 1 year, the prevalence of delayed union was 12.2 % and higher for open fractures (18.2 %) compared to closed fractures (9.7 %). According to the fracture location, the percentage of delayed union was 5.9, 16.7 and 10.5 % in proximal third, midshaft and distal third cases, respectively. Patients with a plated fibula fracture had an eightfold higher risk of delayed union. The rate of malalignment5° in any plane 1 year after surgery was 5.5 %. Proximal third fractures were at a higher risk of postoperative malalignment (17.6 %). The rate of secondary malalignment was 1.4 %. The risk of unplanned reoperation was 9.2 %.Intramedullary ETN fixation of tibia fractures results in low rates of delayed union, primary and secondary malalignment, implant-related complications, and secondary surgery. Fibula plating had a negative effect on the healing of the tibia.

This paper seeks to outline the development of disaster medicine services in Germany and the preparedness of the security and rescue forces for mass casualty incidents after an accident, a natural disaster or a terrorist attack.The method used was review of articles and interview with experts.The plane crash at the 1988 Ramstein air show highlighted problems in the approach to incident management. Following this event, Germany improved the medical management of major incidents. At the railway accident in Eschede in 1998, a "proof of concept" was evident. The newest increases of terrorist threats were also turning points in the further development of disaster medicine in Germany.Emergency medical training must be adapted to the increase in disasters, mass casualty incidents, and terrorist threats.

Muskuloskeletale Verletzungen stellen eine haufige Notarzteinsatzindikation dar. Meist steht die Schmerztherapie, Reposition und Schienung der Verletzungen mit Transport in eine geeignete Klinik im Vordergrund. Einfache, jedoch zwingend notwendige Masnahmen, wie die Reposition einer dislozierten Fraktur mit peripherer Durchblutungsstorung haben fur den weiteren Krankheitsverlauf, die Rehabilitation und Lebensqualitat des Patienten wesentlichen Einfluss. Hier sind die Vermeidung von Sekundarschaden und Schonung der Weichteile hervorzuheben. Beim mehrfachverletzten Patienten ist eine vitale Gefahrdung, vor allem durch Volumenmangelschock, auszuschliesen. Hier hat die Blutstillung oberste Prioritat. Nach Stabilisierung sollte der Patient in ein Zentrum der Schwerstverletztenversorgung transportiert werden. In diesem Beitrag werden grundlegende Begriffe erklart und praklinisch relevante Masnahmen beschrieben.

Relevant changes have occurred in disaster management in Germany due to legal alterations and the introduction of the diagnosis-related groups (DRG) system. This has resulted in a reduction in bed capacities and an increase in bed utilization. In addition to the preclinical deployment strategy the provisional aspects of disaster medicine with the problem of the emergency service/hospital interface will be described. A suggestion for a solution for optimization of patient allocation in mass disasters or catastrophes will be demonstrated with the catastrophe network of the German Society for Trauma Surgery (DGU).

Blood vessel formation is a prerequisite for bone healing. In this study, we tested the hypothesis that a delay in bone healing is associated with an altered regulation of blood vessel formation. A tibial osteotomy was performed in two groups of sheep and stabilized with either a rigid external fixator leading to standard healing or with a highly rotationally unstable one leading to delayed healing. At days 4, 7, 9, 11, 14, 21, and 42 after surgery, total RNA was extracted from the callus. Gene expressions of vWF, an endothelial cell marker, and of several molecules related to blood vessel formation were studied by qPCR. Furthermore, histology was performed on fracture hematoma and callus sections. Histologically, the first blood vessels were detected at day 7 in both groups. mRNA expression levels of vWF, Ang1, Ang2, VEGF, CYR61, FGF2, MMP2, and TIMP1 were distinctly lower in the delayed compared to the standard healing group at several time points. Based on differential expression patterns, days 7 and 21 postoperatively were revealed to be essential time points for vascularization of the ovine fracture callus. This work demonstrates for the first time a differential regulation of blood vessel formation between standard and mechanically induced delayed healing in a sheep osteotomy model.

Der Begriff „Fast Track“ ist in der Unfallchirurgie bisher nicht dezidiert eingefuhrt. Fast-Track-Prinzipien, wie sie in der Abdominalchirurgie ublich sind, werden in der Unfallchirurgie seit langem angewandt. Durch fruhzeitige operative Versorgung, eine stabile Osteosynthese und, wenn die Weichteile es zulassen, fruhen Beginn der Mobilisierung unter optimaler Schmerzmedikation sind die besten Ergebnisse zu erzielen. Durch die Anwendung neuer Prinzipien in der Osteosynthesetechnik (v.a. winkelstabile Verfahren) lasst sich dieses Fast-Track-Vorgehen nun auch bei der Therapie fragiler (osteoporotischer) und komplexer oder Defektfrakturen anwenden.

A new small animal model of bone atrophic nonunion was established for investigating the process of bone regeneration by performing cauterization of the periosteum, removal of the local bone marrow, and stabilization with external fixation. The model allows the creation of an atrophic nonunion without the need for a critical size defect. Furthermore, it provides reproducible, well-defined mechanical conditions and minimized physical interference of the implant with the biological processes in the healing zone. Eighty adult Sprague-Dawley rats received an osteotomy of the left femur, stabilized with an external fixator. In half of the animals, the periosteum proximal and distal to the osteotomy was destroyed by cauterization and the adjacent bone marrow was removed (nonunion group). At 2 and 8 weeks after surgery, radiological, biomechanical, histological, and histomorphometrical analyses showed a typical physiological healing in the control group, while the nonunion group was characterized by resorption of the bone ends with some callus formation distant to the osteotomy. At both time points, the callus was composed of significantly less bone and significantly more connective tissue (p < 0.001). In addition, the torsional strength of the osteotomized femur was significantly less in the nonunion group than in the control group, which was comparable to that of the intact femur (p < 0.001). In conclusion, the present model allows the induction of an atrophic nonunion without the need of a critical size defect. It is reproducible, provides standardized biomechanical conditions, and allows minimized interaction of the implant with the healing zone.

Unser Fall zeigt erstmals die Diagnostik eines akuten Myokardinfarkts als Unfallursache in der Polytrauma-Computertomographie im Rahmen des Schockraummanagements. Dabei stellt die Kontrastmittel (KM)-CT das wichtigste Instrumentarium zur Diagnosefindung dar. Neben dem Fallbericht werden die Differenzialdiagnosen wie die Herzkontusion, die direkte Verletzung oder Dissektion der Koronararterien und der versicherungsrechtliche Aspekt der Klarung des Myokardinfarkts als Unfallursache beschrieben. In unserem Fall war die Demarkierung der Hinterwand in der KM-CT fur die Diagnosefindung des Myokardinfarkts als Unfallursache wegweisend. Trotzdem ist die Abgrenzung zwischen Myokardinfarkt als Ursache oder Folge eines Unfalls schwierig. Gemeinsam mit der Lokalisation der Verletzung haben hier die Anamnese und der Unfallmechanismus Schlusselfunktionen. Nur in der Zusammenschau kann der primare Myokardinfarkt im Rahmen der Polytraumaversorgung fruhzeitig diagnostiziert und von anderen Differenzialdiagnosen abgegrenzt werden.

Distale Humerusfrakturen sind komplexe Verletzungen, die in der Regel mittels Plattenosteosynthese behandelt werden. Das neu entwickelte „Distale Humerussystem“ erlaubt die winkelstabile Fixierung mit anatomisch vorgeformten Platten. Das Ziel dieser Studie war die Untersuchung der Reposition, Frakturheilung, Funktion und Patientenzufriedenheit nach operativer Versorgung mit diesem System. 18 Patienten mit einem mittleren Alter von 55 Jahren (21–83) wurden bei supra-diakondylaren Humerusfrakturen mittels offener Reposition und winkelstabiler Plattenosteosynthese versorgt. 2 Patienten konnten nicht nachuntersucht werden (ein Patient lehnte die Nachuntersuchung ab, ein Todesfall). In der AO Klassifikation zeigten sich 16 C-Frakturen (1× C 1.1; 1× C 1.3; 5× C 2.2; 6× C 3.2; 3× C 3.3) und 2 B-Frakturen (B 2.3 und B 3.3). Die Nachuntersuchung beinhaltete die Erhebung des Mayo Elbow Performance Scores (MEPS), Dash Scores, Rontgen des Ellenbogens in 2 Ebenen (ap und seitlich) und die Messung der Beuge- und Streckkraft in % der kontralateralen Seite. Die mittlere Nachuntersuchungszeit war 11 Monate. Bei allen Patienten zeigte sich radiologisch eine komplette Frakturkonsolidierung. Es zeigten sich keine Falle mit primarer Fehlposition oder sekundarer Dislokation. Die klinische Untersuchung zeigte im MEPS gute bis sehr gute Ergebnisse mit einem mittleren MEPS von 90,3 (± 11,7) von 100 Punkten. Der mittlere Dash Score war 23,8 (± 11,5.) Punkte. Die mittlere Ellenbogenflexion betrug 127° (± 21°) und das mittlere Extensionsdefizit war 16° (± 10°). Es zeigte sich weiterhin eine mittlere Flexionskraft von 72,2 % (± 25,0) und eine mittlere Extensionskraft von 71,6 % (± 23,6) in % der unverletzten Seite. Die Behandlung von Supra-diakondylaren Frakturen des distalen Humerus wird durch die Anwendung anatomisch vorgeformter, winkelstabiler Implantate optimiert. Die stabile Fixierung erlaubt die fruhzeitige postoperative Mobilisation und vermindert das Risiko eines sekundaren Repositionsverlustes. Die klinischen und radiologischen Ergebnisse sind bisher viel versprechend bei gutem Bewegungsumfang und Flexions- und Extensionskraft.

Der weltweite Anstieg von Katastrophen und die Zunahme der terroristischen Bedrohungslage lasst die Katastrophenmedizin auch in Deutschland zunehmend in den Fokus einer breiten Offentlichkeit rucken. Nach dem 11.09.2001 wurden zwar bundesweite Einrichtungen als Warn- und Fuhrungsinstitutionen gegrundet, die Strukturierung der Vorbereitung auf den Katastrophenfall bleibt jedoch weiterhin Landersache. Im Fall einer Katastrophe wird den Krankenhausern eine Schlusselfunktion zufallen. Einschlagige Analysen ergaben jedoch, dass zwar Krankenhauskatastrophenplane verfugbar sind, deren Umsetzungsgrad jedoch dringend verbesserungsbedurftig erscheint. Aufbauend auf die Initiative TraumaNetzwerkD DGU soll in Zusammenarbeit mit dem Bundesamt fur Bevolkerungsschutz und Katastrophenhilfe (BBK) ein landerubergreifendes so genanntes „Katastrophennetzwerk“ erstellt werden. Es soll die Versorgungskapazitaten der darin eingebundenen Kliniken den vorbereitenden Planungen zur Verfugung stellen und den Kliniken die Vorbereitung auf das Grosschadensereignis erleichtern.

Die Akut- und Primarphase der klinischen Behandlung des Schwerverletzten sind die entscheidenden Phasen fur die Festlegung und Durchfuhrung einer prioritatenorientierten (operativen) Behandlungsstrategie unter Berucksichtigung des entstandenen Verletzungsmusters sowie des Zustandes des Patienten. Die Akutphase dient der Behandlung von Massenblutungen und der Entlastung von Korperhohlen („lebensrettende Eingriffe“). In der Primarphase („day 1 surgery“) werden definierte Verletzungen mit entsprechender Dringlichkeit versorgt. Konzeptionell werden die „damage control surgery“ und das „early total care“ unterschieden. Das „Damage-control-Vorgehen“ sollte bei Patienten mit bestimmten Instabilitats- oder Risikokriterien erfolgen, um eine weitere Belastung ihres Zustandes zu vermeiden.

In major trauma patients, multiple organ failure (MOF) is considered a leading cause of death. Acute lung injury is deemed a "pacemaker" of MOF. The purpose of this study was to determine if incidence of organ failure and mortality in multiple trauma patients can be reduced by implementation of lung-protective strategies.All critically ill multiple trauma patients admitted to the ICU of a major trauma center in Berlin, Germany from January 1999 to December 2002 were analyzed retrospectively. Patients were ventilated pressure controlled with low tidal volumes and adequate PEEP.n=287 patients were included. The most frequent injuries were traumatic brain injury (TBI-68%), chest trauma (68%), and lung contusions (55%). Injury severity score (ISS) was 32+/-19 (mean+/-standard deviation), polytraumaschluessel (PTS) 34+/-19, and APACHE II 14+/-7. During their ICU-stay 16 patients died, 9 (56%) from TBI. Single-organ-failure occurred in n=69 patients (24%, mortality 5%), two-organ-failure in n=22 (8%, mortality 14%), and MOF in n=9 (3%, mortality 13%); one patient died from MOF 14 days after trauma. The number of days on mechanical ventilation increased depending on the number of organs failed (R=0.618, p0.001). Seven patients (2%) fulfilled ARDS criteria for longer than 24h despite optimized ventilatory settings, one died of irreversible shock. Patients with MOF had a significantly increased ICU-LOS (35+/-15 days) compared to patients without organ failure (11+/-11 days; p0.001).The low incidence of MOF in our series of trauma patients suggests that MOF may be prevented in some patients by implementation of lung-protective strategies. The improved outcome was associated with an increased ICU-LOS.

The formation of new blood vessels is a prerequisite for bone healing. CYR61 (CCN1), an extracellular matrix-associated signaling protein, is a potent stimulator of angiogenesis and mesenchymal stem cell expansion and differentiation. A recent study showed that CYR61 is expressed during fracture healing and suggested that CYR61 plays a significant role in cartilage and bone formation. The hypothesis of the present study was that decreased fixation stability, which leads to a delay in healing, would lead to reduced CYR61 protein expression in fracture callus. The aim of the study was to quantitatively analyze CYR61 protein expression, vascularization, and tissue differentiation in the osteotomy gap and relate to the mechanical fixation stability during the course of healing. A mid-shaft osteotomy of the tibia was performed in two groups of sheep and stabilized with either a rigid or semirigid external fixator, each allowing different amounts of interfragmentary movement. The sheep were sacrificed at 2, 3, 6, and 9 weeks postoperatively. The tibiae were tested biomechanically and histological sections from the callus were analyzed immunohistochemically with regard to CYR61 protein expression and vascularization. Expression of CYR61 protein was upregulated at the early phase of fracture healing (2 weeks), decreasing over the healing time. Decreased fixation stability was associated with a reduced upregulation of the CYR61 protein expression and a reduced vascularization at 2 weeks leading to a slower healing. The maximum cartilage callus fraction in both groups was reached at 3 weeks. However, the semirigid fixator group showed a significantly lower CYR61 immunoreactivity in cartilage than the rigid fixator group at this time point. The fraction of cartilage in the semirigid fixator group was not replaced by bone as quickly as in the rigid fixator group leading to an inferior histological and mechanical callus quality at 6 weeks and therefore to a slower healing. The results supply further evidence that CYR61 may serve as an important regulator of bone healing.

Fracture healing requires a certain degree of mechanical stability and an adequate blood supply. The hypothesis of the present study was that increased interfragmentary shear leads to a reduced initial vascularization and prolonged healing. The aim of the study was to quantitatively analyze the histological appearance of vascularization and tissue differentiation with regard to fracture stability during the course of healing. A mid-shaft osteotomy of the tibia was performed in two groups of sheep and stabilized with either a rigid or semirigid external fixator, differing in bending stiffness. Interfragmentary movements and ground reaction forces were evaluated in vivo during a 9-week period. The sheep were sacrificed at 2, 3, 6, and 9 weeks postoperatively. The tibiae were tested biomechanically and histological sections from the callus were prepared for analysis of tissue differentiation and vascularization. Larger interfragmentary shear movements in the semirigid fixator group were associated with a reduced initial blood supply. At 6 weeks the semirigid fixator group showed a significantly lower percentage of mineralized bone and a higher amount of fibrous tissue leading to a significantly lower stiffness of the callus than the rigid fixator group. This initial delay in healing was compensated for in the later stages with the production of greater volumes of callus tissue so that both groups showed the same callus stiffness at 9 weeks. However, the rigid fixator group showed signs of the beginning of callus remodeling at the latest time points suggesting a faster bone healing. The results indicate the important role of the initial mechanical stability specifically in the vascularization of an osteosynthesis. Further studies should illustrate the precise role of mechanical conditions on the regulation of angiogenesis during early bone healing.

The purpose of this study was to prove whether homologous growth hormone has a beneficial effect in the early phase of bone healing. Therefore the left tibias of 24 Yucatan micropigs were osteotomized and stabilized by plate fixation. The treatment group (12 animals) received 100 microg of recombinant porcine growth hormone (rpGH)/kg body w/day sc, whereas the control pigs (12 animals) received 1 ml sodium chloride as placebo. After a healing period of 4 weeks the animals were sacrificed and destructive torsional testing was performed. For histological evaluation 6 microm serial slices of the tibiae were stained with von Kossa. The total area of callus formation (CA) and the mineralized bone area (BA) were quantified by image analysis. The fraction of mineralized bone tissue within the callus area, the bone density (BD), was calculated as follows: BD = (BA/CA) x 100. Torsional failure load was 91% higher and torsional stiffness 61% higher in the treatment group than in the control group (P0.05). The histomorphometric measurements revealed an advance for the CA (GH: 127.6 +/- 38.9 mm(2); placebo: 75.9 +/- 50.7 mm(2); P0.005) as well as for the BA (GH: 89.3 +/- 25.8 mm(2); placebo: 55.9 +/- 38.5 mm(2); P0.001) for the GH-treated animals in comparison to the control animals. The BD was similar in both groups (GH: 70.6 +/- 8.4%; placebo: 74.0 +/- 6.24%; P = 0.28). These data indicate that administration of homologous GH stimulates callus formation and ossification in the early phase of bone healing, which consequently results in an increased mechanical strength and stiffness.

The indications for surgical treatment of benign bone tumors and tumor-like lesions depend on the biological activity, clinical symptoms and anatomic location of the the lesion. Clinically silent lesions ("leave me alone Lesions") lacking any scintigraphic enhancement and without danger of pathologic fracture or malign transformation only need surveillance and do not require surgery.However, tumors becoming symptomatic, displaying progression after termination of skeletal growth or radiographic signs of malignancy should be scheduled for surgical intervention. For most benign tumors intralesional curettage and subsequent bone grafting is the treatment of choice, maintaining structural integrity and functional stability of the bone and adjacent joint. In case of uncertain histopathological diagnosis an open biopsy should be performed followed by definitive either marginal or en-bloc resection, preferably at a single procedure. Depending on the tumor-specific risk of recurrence, adjuvant measures as phenol instillation or cryotherapy using liquid nitrogen may additionally be applied. As for the unicameral juvenile bone cyst or osteoid osteoma alternative minimal invasive techniques like corticoid injection and CT-guided percutaneous eradication of the nidus have been successfully introduced into clinical practice. Depending on the activity of the tumor recurrent lesions are recommended to be treated by marginal or enbloc resection. The radical and aggressive mode of surgical therapy has to be balanced with the treatment-related morbidity, i.e. complication rate, possibilities for reconstructive stabilizations and resultant functional deficits,making the decision a responsible challenge to the orthopedic surgeon.

Einleitung. Die intervertebrale Spondylodese mit Spongiosa-augmentierten intervertebralen Cages findet zunehmende klinische Verbreitung, obwohl experimentelle Daten weitgehend fehlen. Ziel dieser Studie war es daher, in einem zervikalen Schafsmodell den Effekt von Designparametern (Auflageflache, maximale Pore) auf das Einheilungsverhalten von Cages zu untersuchen.

Fracture healing is influenced by numerous hormones, growth factors, and cytokines. The systemic administration of growth hormone (GH) has shown to accelerate bone regeneration. Local application of growth factors, such as insulin-like growth factor-1 (IGF-1) and transforming growth factor-beta-1 (TGF-beta1), are known to stimulate bone metabolism. Until now, the exact local and systemic mechanisms that lead to improved bone regeneration remain unclear. In addition, the effect of systemic administration of GH as compared with locally delivered growth factors on fracture healing in rats is not known. A midshaft fracture of the right tibia of 5-month-old female Sprague-Dawley rats (n = 80) was intramedullary stabilized with IGF-1 and TGF-beta1 coated vs. uncoated titanium K-wires. The growth factors were incorporated in a poly(D,L-lactide) (PDLLA) coating and released continuously throughout the experiment. Recombinant species-specific (rat) GH was applied systemically (2 mg/kg body weight) by daily subcutaneous injection and compared with a placebo group. The healing process was radiologically monitored. Twenty-eight days after fracture biomechanical torsional testing was performed. The consolidation and callus composition, including quantification of cartilage and mineralized tissue, was traced in histomorphometrical investigations using an image analysis system. Both methods, the systemic administration of GH and the local application of growth factors, showed significant biomechanical and histological effects on fracture healing. The local growth factor application showed a stronger effect on fracture healing than the systemic GH injection. The combined application of both methods did not accelerate the effect on bone healing compared with the single application. It is therefore concluded that combining local and systemic stimulating methods does not provide further additive effects with regard to fracture healing.

In vitro and in vivo studies have demonstrated an osteoinductive effect of growth factors like IGF-I and TGF-beta 1. However, for therapeutic use in fracture treatment, the local application of these bioactive molecules is still an unsolved problem. The controlled release of growth factors from a biodegradable coating of osteosynthetic implants could stimulate fracture healing locally. Coated implants could stabilise the fracture and work as a local drug delivery system. Previous studies demonstrated a high mechanical stability of a thin 10 microns poly(D,L-lactide) (PDLLA) coating on metallic implants that withstands even an intramedullary insertion process. After an initial peak, 80% of incorporated growth factors IGF-I and TGF-beta 1 were continuously released within 42 days. The effect of locally applied IGF-I and TGF-beta 1 from a biodegradable PDLLA coating of intramedullary implants on fracture healing were investigated in a rat model. A fracture of the right tibia of 5-month-old female Sprague-Dawley rats was stabilised with coated versus uncoated titanium K-wires. X-ray examinations and blood analysis were performed, body weight and body temperature monitored throughout the experimental period. After 42 days both tibiae were dissected for mechanical torsional testing and histomorphometric analyses. The results demonstrate a nearly completely consolidated fracture in the X-ray examinations, a significant higher maximum load and torsional stiffness in the biomechanical tests and a progressed remodeling in the histological and histomorphometric analyses after 42 days in the group treated with growth factors compared to the controls. Interestingly, the PDLLA coating itself had a positive effect on fracture healing even without incorporated growth factors. No systemic change of serum parameters including IGF-I and IGF binding proteins and no differences in body weight and body temperature were seen in any group. These findings suggest that the local application of growth factors from a biodegradable poly(D,L-lactide) coating of osteosynthetic implants accelerates fracture healing significantly without systemic side effects.

Das Ziel der vorliegenden Untersuchung war es zu uberprufen, ob systemisch appliziertes spezies-spezifisches rekombinantes Wachstumshormon (GH) die Knochenheilung stimulieren kann. Hierfur wurde die linke Tibia von 30 Yucatan Minischweinen osteotomiert, uber einen Halbringfixateur stabilisiert und 2 mm/Tag fur 10 Tage distrahiert. Daran schlos sich eine 10tagige Konsolidierungsphase an. Die eine Halfte der Tiere erhielt taglich subcutan rekombinantes porcines Wachstumshormon (r-pGH) 100 μg/kg KG, die andere Halfte NaCl als Placebo injiziert. Mittels einer eigens entwickelten Mesvorrichtung konnte in-vivo im Zeitverlauf wiederholt die torsionale Steifigkeit der Regenerate bestimmt werden. Nach Totung der Tiere wurde von den distrahierten Tibiae und den jeweiligen gesunden kontralateralen Tibiae die torsionale Bruchkraft in einer Materialprufmaschine ermittelt. Um die endokrine Antwort der r-pGH-Applikation zu uberprufen, wurden die Serumspiegel von Insulin-like growth factor I (IGF-I) bestimmt. Wahrend der gesamten Konsolidierungsphase zeigte die Versuchsgruppe signifikant hohere in-vivo Steifigkeitswerte als die Kontrollgruppe. Dabei lagen die Unterschiede zwischen 61 % (Tag 1), 101 % (Tag 4) und 81 % am Versuchsende (Tag 10 der Konsolidierungsphase). Die postmortale torsionale Bruchkraft im Vergleich zur gesunden kontralateralen Seite wies 64 ± 22,4 % in der hormonbehandelten Gruppe im Gegensatz zu 26 ± 12,9 % in der Kontrollgruppe auf. Die IGF-I Serumspiegel waren in der behandelten Gruppe um mehr als das 4 fache erhoht, wahrend in der Kontrollgruppe keine signifikante Veranderung zu sehen war. Unsere Ergebnisse zeigen, das die systemische Gabe von r-pGH eine starke Beschleunigung der Regeneratkonsolidierung bei der Callusdistraktion am Minischwein bewirkt. Diese knochenanabole Wirkung von GH konnte in der Zukunft eine Behandlungsoption bei der Distraktionsosteogenese darstellen und dazu beitragen, die Behandlungsdauer zu Gunsten des Patienten zu verkurzen.

Purpose: To develop a signal-inducing bone cement for musculoskeletal procedures in magnetic resonance imaging (MRI). Materials and Methods: Acrylic resins were mixed with contrast agents (CAs) and water. We determined the ideal concentration of the components and assessed feasibility in cadaveric bones in an open high-field MR scanner. The contrast-to-noise ratio (CNR) in air and bone was evaluated and mechanical tests were achieved. We determined the amount of water that was not incorporated and measured the amount of CA released with photometric analysis. The cement was analyzed microscopically. Results: Preparation and application of the CA-water-cement compound was feasible and its differentiation in MRI was clear. The maximal CNRair had a value of 157.5 (SD 18.3) in an interventional fast T1W turbo-spin echo (TSE) sequence. The compressive strength decreased with the amount of water added. Although nearly 50% of the water added was not incorporated in the cement, the CNR was sufficient for cement detection. The threshold for systemic toxicity of delivered CA was not reached and the microscopic analysis showed water bubbles in the cement. Conclusion: A signal-inducing bone cement is feasible for the use in MRI. J. Magn. Reson. Imaging 2010;31:636–644. © 2010 Wiley-Liss, Inc.

We have established a new small animal model to investigate the process of bone regeneration. A total of 42 male Sprague-Dawley rats received an osteotomy of the left femur, stabilized with a custom-made external fixator. The fixation method was chosen to create an easily reproducible, biomechanically well-defined model with minimized interference of the implant with the healing zone. At 14 or 56 days post-operation, the animals were sacrificed and examined biomechanically, histologically and radiologically. Radiologically, the femurs of all animals were anatomically positioned directly post-operation and remained in that position throughout the examination period. At 14 days post-operation, a typical periosteal callus formation could be observed both histologically and radiologically. At 56 days post-operation, the osteotomy was almost completely bridged by periosteal callus and the biomechanical competence of the bones was fully restored. Relative to the intact contralateral femur, the torsional stiffness median was 130.3% (interquartile range 118.9-157.7%) and the maximum torsional failure moment median was 135.6% (interquartile range 69.5-208.7%). As this model provides standardized conditions, it is suitable for a wide range of investigations and is particularly valuable for investigations of locally applied therapies, such as osteoconductive materials or osteoinductive factors.