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INTRODUCTION: Antegrade intramedullary nailing is the method of choice in most femoral shaft fractures. The trochanteric entry portal of classic femoral nails is in close proximity to the piriformis tendon, the gluteus minimus tendon, the obturator tendons, and the medial femoral circumflex artery. Nail insertion lateral to the tip of the greater trochanter may be more favorable but needs the use of a helical implant. MATERIAL AND METHODS: Measurement of the reamer pathway through an entry point lateral to the superior trochanteric border was performed with a three-dimensional motion tracking sensor in human cadaveric femurs. These results provided a scientific rationale for the design of a helical femoral nail (LFN®). In a prospective multicenter study a total of 227 femoral shaft fractures were treated by nailing with the LFN. Patients were followed at 3 months (n=193) and 12 months (n=167). RESULTS: The ease of defining the entry point and inserting the nail was rated as"very good and good" by 90% of the surgeons. Intraoperative technical complications included incomplete reduction (14%), additional iatrogenic fractures (6%), and difficulties in interlocking (3.5%). At the 1-year follow-up, delayed unions were seen in 10%, secondary loss of reduction in 3%, and deep infection in 1.8% of the patients. Angular malalignment of more than 5° was seen in 5%, mostly in valgus. A normal walking capacity was seen in 68% and normal active hip flexion in 45%. CONCLUSION: The results obtained in this study during 1 year do not provide evidence for an advantage of the LFN over conventional antegrade femoral nails.

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.

Hintergrund Die Einhaltung einer Rettungszeit

The purpose of this work is to evaluate two signal-inducing bone cements for MRI-guided spinal cementoplasty.The bone cements were made of polymethylmethacrylate (PMMA, 5 ml monomeric, 12 g polymeric) and gadoterate meglumine as a contrast agent (CA, 0-40 μl) with either saline solution (NaCl, 2-4 ml) or hydroxyapatite bone substitute (HA, 2-4 ml). The cement's signal was assessed in an open 1-Tesla MR scanner, with T1W TSE and fast interventional T1W TSE pulse sequences, and the ideal amount of each component was determined. The compressive and bending strength for different amounts of NaCl and HA were evaluated.The cement's MRI signal depended on the concentration of CA, the amount of NaCl or HA, and the pulse sequence. The signal peaks were recorded between 1 and 10 μl CA per ml NaCl or HA, and were higher in fast T1W TSE than in T1W TSE images. The NaCl-PMMA-CA cements had a greater MRI signal intensity and compressive strength; the HA-PMMA-CA cements had a superior bending strength.Concerning the MR signal and biomechanical properties, these cements would permit MRI-guided cementoplasty. Due to its higher signal and greater compressive strength, the NaCl-PMMA-CA compound appears to be superior to the HA-PMMA-CA compound.

Die Bombenanschlage von Madrid (2004) und London (2005) machen deutlich, dass es auch in Deutschland zu Terrorattacken dieser Art kommen kann. Hier sind im Krankenhaus entsprechende Alarm- und Einsatzplane sowie das Personal vorzubereiten. Es wurde ein anonymisierter Online-Fragebogen eingesetzt. Der Fragebogen wurde per E-Mail an Arztinnen und Arzte aus allen 3 Krankenhauskategorien versandt. Es wurden deskriptive statistische Verfahren angewendet. Insgesamt wurden 1204 von 7700 versandten Fragebogen ausgefullt. Das entspricht einer Quote von 15,6%; 53,3% des Gesamtkollektivs hatten in ihrer Klinik einen Katastrophenschutzplan und kannten diesen auch; 33,9% gaben an, dass in ihrer Klinik eine Ubung zum Katastrophenplan stattgefunden hat. Da nur 53,3% aller Klinikarbeiter den Katastrophenplan ihrer Klinik kennen und nur in 33,9% der Kliniken entsprechende Ubungen stattgefunden haben ist zu fordern, dass mehr Aufwand betrieben werden muss, um das Bewusstsein fur solche Schadenslagen zu steigern. Weiterhin werden standardisierte Trainingsprogramme benotigt, um Wissen und Fertigkeiten zu verbreiten, damit Schutz- und Rettungskrafte auf Terroranschlage in der BRD vorbereitet sind.

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.

The objectives of this study were to (1) establish a reproducible atrophic non-union model in rats by creation of a segmental femoral bone defect that allows, (2) in-depth characterization of impaired healing, and (3) contrast its healing patterns to the normal course. Hypothesis was that a 5-mm bone defect in male rats would deviate from uneventful healing patterns and result in an atrophic non-union. A femoral osteotomy was performed in two groups of 12-week-old male rats (1 vs. 5 mm gap) stabilized with an external fixator. Bone healing in these models was evaluated by radiology, biomechanics, and histology at 6 or 8 weeks. The evaluation of the 5-mm group revealed in some cases a delayed rather than a non-union, and therefore, a group of female counterparts was included. The creation of a 5-mm defect in female rats resulted in a reproducible atrophic non-union characterized by sealing of the medullary canal, lack of cartilage formation, and negligible mechanical properties of the callus. In both gap size models, the male subjects showed advanced healing compared to females. This study showed that even under uneventful healing conditions in terms of age and bone defect size, there is a sex-specific advanced healing in male compared to female subjects. Contrary to our initial hypothesis, only the creation of a 5-mm segmental femoral defect in female rats led to a reproducible atrophic non-union. It has been shown that an atrophic non-union exhibits different healing patterns compared to uneventful healing. A total lack of endochondral bone formation, soft tissue prolapse into the defect, and bony closure of the medullary cavity have been shown to occur in the non-union model.

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).

The institutional review board approved the use of cadaveric specimens, and informed consent was obtained from all volunteers. The authors performed and assessed a magnetic resonance (MR)-assisted navigation method for minimally invasive retrograde drilling of talar osteochondral lesions. For this method, a single imaging plane is sufficient for navigation during intervention. To accomplish this objective, a passive MR navigation device was used to evaluate 16 cadaveric ankle joints. Use of this interactive MR-assisted navigation method in combination with a passive aiming device allowed precise and rapid retrograde drilling of talar osteochondral lesions.

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.

We report on a patient who sustained a fracture of the tibial shaft during the removal of the newest type of an intramedullary nail (Expert Tibia Nail, Synthes. In this case report, we discuss the causes of this complication and possible ways to prevent this.

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.

Fractures of the distal humerus are complex injuries that can be effectively treated with open reduction and internal fixation (ORIF). The new LCP distal humerus system allows angular stable fixation of these complex fractures with anatomically preshaped plates. The aim of the study was to evaluate operative reposition, fracture healing, and pain, function and patient satisfaction after open reduction with an angular stable fixation.Fourteen patients with a mean age of 55.2 years (21-83) were treated with open reduction and angular stable internal fixation. Two patients were lost to follow up (1 died, one refused to be reevaluated). AO classification showed 12 C-fractures (1 x C 1.1; 1 x C 1.3; 4 x C 2.2; 4 x C 3.2; 2 x C 3.3) and 2 B-fracture (B 2.3 and B 3.3). 5 fractures were open fractures (4 x II degrees , 1 x I degrees ). The clinical and radiographic follow up (Mayo elbow performance score (MEPS), Dash Score, elbow anterior-posterior and lateral view X-rays, and flexion and extension force as % of contralateral side at 90 degrees flexion) were performed postoperatively. Mean follow up was 10 months.Radiographically, complete union was achieved in all patients. There were no cases of primary malposition or secondary dislocation. Complications were: (1) delayed union after olecranon osteotomy, (2) transient ulnar nerve irritation. Clinical MEPS results were good to excellent with a mean of 91 +/- 11.7 points. The mean DASH Score was 18.5 +/- 11.5 points. Mean flexion was 121 +/- 20.9, mean extension deficit was 17.9 degrees +/- 10.3. Mean flexion force was 75.3% +/- 26.7 and mean extension force was 70.7 % +/- 24.9.Treatment of supra-intercondylar fractures of the distal humerus is challenging. Anatomically preshaped angular stable implants facilitate operative reduction and stabilization of the fracture and may allow early postoperative rehabilitation. Clinical and radiological results are promising, with good range of motion and flexion and extension force.

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.

Jede vermutete Abdominalverletzung sollte schnellstmoglich in eine geeignete Klinik eingeliefert werden. Mit der notfallmedizinischen Erstuntersuchung ist eine Lebensbedrohung mit der Konsequenz einer notfallmasig blutstillenden Operation zu identifizieren. Bei penetrierenden Verletzungen mit moglicher Penetration des Peritoneums sollte bei Kreislaufstabilitat diese laparoskopisch ausgeschlossen werden. Bei vorliegender Penetration sollte eine Intestinalverletzung durch operative Exploration ausgeschlossen bzw. behandelt werden. Beim stumpfen Abdominaltrauma steht die klinische Untersuchung an erster Stelle, welche jedoch bei einer Sensitivitat bis zu 82% und einer Spezifitat von bis zu 45% alleine nicht ausreichend verlasslich ist. Fur die weitere Diagnostik hat heute die Ultraschalluntersuchung die diagnostische Peritoneallavage insbesondere im deutschsprachigen Raum vollstandig ersetzt. Diese sollte neben der Diagnostik freier intraabdomineller Flussigkeit auch Organlasionen erfassen und wiederholt durchgefuhrt werden. Damit lasst sich eine Genauigkeit von bis zu 96% mit einer Spezifitat von 99,8% und Sensitivitat von 72,1% erzielen. Die CT-Diagnostik mit und ohne i.v. Kontrastmittel stellt den Goldstandard der apparativen Diagnostik dar mit einer hohen Sensitivitat und Spezifitat von 97,2% bzw. 94,7%. Falsch-negative Befunde kommen weiterhin bei Hohlorganverletzungen vor und erfordern weitere engmaschige klinische, sonographische und ggf. computertomographische Kontrolluntersuchungen. Schlieslich kommt, insbesondere bei polytraumatisierten Patienten der intraabdominellen Druckmessung bei sich entwickelndem Organversagen eine zunehmende Bedeutung zu, mit der Konsequenz der abdominellen Dekompression ab einem Druck von 20 mmHg zu erwagen.

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.

Pin loosening is a major complication in external fixation. Biological and mechanical conditions play an important role in the maintenance and enhancement of the implant-bone interface in fracture fixation. It is thought that biodegradable coatings may be capable of preventing pin track infection and pin loosening. The goal of this study was therefore to analyze the influence of a biodegradeable coating on the osseous integration of Schanz' screws during fracture treatment. Standardized osteotomies (3-mm fracture gap) of the right tibiae were performed on 16 sheep and stabilized by an AO mono-lateral external fixator. Additional, mechanically less loaded Schanz' screws were also mounted. All screws were randomly coated with biodegradable poly(D,L-lactide). The sheep were sacrificed after 9 weeks. All screws were removed and rolled on blood agar plates for microbiological analysis. Histological sections of the pin tracks were histochemically and morphometrically analyzed. Clinically, no signs of severe infection were visible. Microbiological analysis revealed 14.8% colonization by Staphylococcus aureus in the coated and 29% in the uncoated screws. Histomorphometry of the bone surrounding the Schanz' screws revealed that significantly more osseous integration had occurred on poly(D,L-lactide)-coated screws in the absence of bacterial colonization. Significantly more bone remodeling and a higher osteoclastic activity was seen near the screw-bone interface in the uncoated screw group. Up to a threefold increase in new bone formation and more severe remodeling was observed around the screw entry compared to the pin exit in all groups. Loaded screws showed significantly more callus formation around the exit sites than their less loaded counterparts. In the present study, poly(D,L-lactide) coating of Schanz' screws was found to enhance osseous integration in the absence of bacterial colonization in sheep by causing less cortical remodeling and less osteoclastic activity in the cortices compared to uncoated screws. Additionally, the coating appeared to reduce the instances of pin track infections. Mechanical loading showed an adverse effect on bone formation and remodeling. It has been shown that both biological and mechanical factors play an important role in the maintenance of osseous integrity of the pin-bone interface. Poly(D,L-lactide) coating of Schanz' screws does not prevent osseous destruction and severe bacterial colonization along the pin tracts, but can improve osseous integration of Schanz' screws in the absence of infection.

From the perspective of trauma and orthopedic surgery interdisciplinary reconstructive surgery of the extremities encompasses different indications ranging from IIIB/Copen fractures with major segmental loss of bone and soft tissue, to arterial vessel in-jury necessitating vascular repair and to biological, plastic reconstructions following resections of musculoskeletal tumors. The interdisciplinary treatment concept including trauma-orthopedic surgery combined with vascular, plastic and neuro- as well as microsurgery has significantly decreased amputation rates and functional deficits thereby improving quality of life and long-term oncological outcome The multisdisciplinary management of both complex trauma and malignant bone/ soft tissue sarcoma of the extremity is an integral task of the surgical trauma or tumor center. Close interdisciplinary communication and expierence are the precondition for performance of a priority-adapted therapeutic strategy, low complication rates and improvement of overall prognosis.

The aim of this study was to determine the ability of the following bone turnover markers to monitor the course of callus consolidation during bone healing: Carboxy-terminal propeptide of procollagen type I (PICP), skeletal alkaline phosphatase (sALP), and amino-terminal propeptide of type III procollagen (PIlINP). Since interfragmentary movements have been proven to possess the ability to document the progression of bone healing in experimental studies, correlations between bone turnover markers and interfragmentary movements in vivo were investigated. Therefore, two different types of osteosyntheses representing different mechanical situations at the fracture site were compared in an ovine osteotomy model. Blood samples were taken preoperatively and postoperatively in weekly intervals over a nine-week healing period. At the same intervals, interfragmentary movements were measured in all sheep. After nine weeks, animals were sacrificed and the tibiae were evaluated both mechanically and histologically. Wide interindividual ranges were observed for all bone turnover markers. The systemic PICP level did not increase with callus consolidation. The bone-healing model seemed to influence the systemic level of PIIINP and sALP but no general correlation between bone turnover markers and interfragmentary movements could be detected. No differences between the different types of osteosyntheses and thus the different mechanical situations were observed. All analyzed markers failed as general predictors for the course of callus consolidation during bone healing.

Schraubenkanal-Infektionen und Schraubenlockerungen sind wesentliche Komplikationen bei der Fixateur externe-Osteosynthese. In dieser Studie wurde der Einfluss einer Poly(D,L-laktid)-Beschichtung auf die ossare Integration der Schrauben wahrend der Frakturversorgung analysiert. An 16 Schafen wurden Osteotomien der rechten Tibia mit einem monolateralen Fixateur externe stabilisiert. Zusatzlich wurden mechanisch unbelastete Schanz' Schrauben eingebracht. Die Halfte der implantierten Schrauben wurde mit Poly(D,L-laktid) beschichtet. Nach neun Wochen wurden die Schrauben entnommen, auf Blutagar-Platten ausgerollt und mikrobiologisch untersucht. Es erfolgte die histologische Aufarbeitung der Pintrakts und eine anschliesende histochemische und histomorphometrische Analyse. Obwohl klinisch keine Anzeichen fur Infektionen beobachtet wurden, zeigte die mikrobiologische Bewertung bei 15 % der beschichteten Schrauben versus 29 % der unbeschichteten Schrauben eine Kontamination durch Staphylococcus aureus. Die histologische Auswertung zeigte, dass beschichtete Schrauben eine bessere Osteointegritat (p=0,0006) als unbeschichtete Implantate aufwiesen. In der Histomorphometrie wurde in der Gruppe der unbeschichteten Schrauben ein hoheres knochernes Remodeling (p = 0,006) und eine hohere Osteoklastenaktivitat (p = 0,019) festgestellt. Belastete Schrauben zeigten mehr Kallus am Schraubenaustritt (p = 0,048). Eine Poly(D,L-laktid)-Beschichtung bei Schanz' Schrauben scheint die ossare Integration durch eine Verminderung des kortikalen Remodelings und der Osteoklastenaktivitat zu verbessern. Improvement of bony integration of Schanz’ screws by means of a Poly(D,L-laktid) coating Pin track infections and pin loosening are major complications in fracture treatment by means of external fixation. In this study, the influence of Poly(D,L-lactid)-coating on osseous integration of Schanz screws was analysed during bone healing. In sixteen sheep, osteotomies of the right tibia were stabilized by means of monolateral external fixators. In addition, mechanically unloaded Schanz' screws were inserted. One half of the implanted screws was coated with Poly(D,L-lactid). After nine weeks in vivo, the screws were extracted, rolled on blood agar plates and microbiologically analysed, followed by histological, immunhistochemical and histomorphometrical analyses of the pin tracks. Even though no clinical signs of infection were observed, micro biological evaluation indicated a contamination by Staphylococcus aureus of 15 % in the coated screws and of 29 % in the uncoated screws. The histological analyses showed an improved osseous interagtion in the coated screws (p=0,0006) compared to the uncoated implants. In histomorphometry, the group of the uncoated screws showed an increased bone remodelling (p = 0,006) and an increased osteoclast activity (p = 0,019). Mechanically loaded screws had increased callus formation at the pin exit site (p = 0,048). The poly(D,L-lactid) coating of Schanz' screws seems to enhance the osseous integration by reducing cortical remodelling and osteoclast activity.

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.

Assessing the regenerate strength in distraction osteogenesis is crucial for clinical treatment. Several methods have been used to achieve this, including plain radiography, digital radiography, quantitative computed tomography, dual energy xray absorptiometry, and ultrasound. The aim of the current study was to investigate the use of ultrasound in monitoring regenerate formation and to correlate this to biomechanical testing results. An osteotomy was done on the tibia of 30 Yucatan micropigs and an Ilizarov-type half-ring external fixator was mounted. After a 5-day latency period, the tibias were distracted for 10 days and then left to consolidate for 10 days. Seven ultrasound examinations were done during Day 15 through Day 25. After sacrifice, the bone mineral density was measured using quantitative computed tomography. Maximum load and torsional stiffness were measured and correlated with ultrasound measurements and bone mineral density. The ultrasound penetration depth and the bone mineral density correlated closely with torsional stiffness. Ultrasound can be a noninvasive predictor of bone regenerate strength in the early phase of distraction osteogenesis, which may reduce the need for radiographs.

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.

Object. Growth factors such as bone morphogenetic protein—2 (BMP-2) have been proven to promote spine fusion and to overcome the disadvantages of an autologous bone graft. The optimum method to deliver such growth factors remains a matter of discussion. The purpose of this study was to determine the safety and efficacy of a new poly(d,l-lactide) (PDLLA) carrier system for BMP-2 and to compare this carrier system with a collagen sponge carrier in a sheep cervical spine interbody fusion model. Methods. Thirty-two sheep underwent C3–4 discectomy and fusion: Group 1, titanium cage (eight animals); Group 2, titanium cage coated with a PDLLA carrier (eight animals); Group 3, titanium cage coated with a PDLLA carrier including BMP-2 (150 µg) (eight animals); and Group 4, titanium cage combined with a collagen sponge carrier including BMP-2 (150 µg) (eight animals). Blood samples, body weight, and temperature were assessed. Radiographs were obtained pre- and postoperatively and after 1, 2, 4, 8, and 12 weeks. At the same time points, disc space height, intervertebral angle, and lordosis angle were measured. After the sheep were killed 12 weeks postoperatively, flexion—extension radiography was performed to evaluate fusion sites. Quantitative computerized tomography scans were obtained to assess bone mineral density (BMD), bone mineral content (BMC), and bone callus volume (BCV). Biomechanical testing was performed in flexion, extension, axial rotation, and lateral bending. Stiffness, range of motion, neutral, and elastic zone were determined. Histomorphological and -morphometrical analyses were performed, and polychrome sequential labeling was used to determine the timeframe of new bone formation. There were no differences among the groups concerning blood counts, body weight, and temperature. Compared with the noncoated cages, all PDLLA-coated cages showed significantly higher values for BMD of the callus, as well as slightly higher values for BMC, BCV, and the bone volume/total volume ratio. In comparison with the cage-alone group, the BMP-2 groups showed significantly higher values for BMD and biomechanical stiffness. Histomorphological, -morphometrical, and polychrome sequential labeling analyses demonstrated greater progression of callus formation in the BMP-2 groups than in any other group. Compared with BMP-2 delivered using a collagen sponge carrier, BMP-2 application with a PDLLA carrier resulted in a higher BCV and a greater progression of interbody callus formation in the histomorphometrical analysis. Conclusions. The use of cervical spine interbody fusion cages coated with PDLLA as a delivery system for growth factors was effective. In this 12-week follow-up study, the PDLLA coating showed no adverse effects. The slight but not significant positive effect of the PDLLA carrier on interbody fusion might be a result of the degradation process of the biodegradable carrier. Compared with collagen sponge delivery of BMP-2, the PDLLA-coated interbody cages significantly increased the results of interbody bone matrix formation. In this new combination (implant + PDLLA + growth factor) the cage represents a “real fusion” cage, because it not only serves as a mechanical device for spinal fixation but also as a local drug delivery system.

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.

Contractile fibroblastic cells expressing the alpha-smooth muscle actin isoform, so-called myofibroblasts, have been identified to play a possible role during the healing of the medial collateral ligament by means of restoring the tissues in situ strain via extracellular matrix contraction. Recently, these cells have also been identified to be a normal part of the human anterior cruciate ligament. It has been hypothesized that myofibroblasts play a role in the wrinkling of the extracellular matrix. The goal of the present study was to identify myofibroblasts in the intact ovine anterior cruciate ligament and a free autologous tendon graft during remodeling after anterior cruciate ligament reconstruction. In 36 mature merino sheep the anterior cruciate ligament was replaced with an ipsilateral Achilles tendon split graft. Midsubstance tissue samples were immunostained for alpha-smooth muscle actin at 6, 9, 12, 24, 52, and 104 weeks. Myofibroblasts were identified in the intact ovine anterior cruciate ligament as well as in the Achilles tendon graft prior to implantation. During remodeling the first myofibroblasts were found at six weeks within newly formed fiber bundles. At 24, 52, and 104 weeks myofibroblast distribution and cell density were similar to those of the intact ovine anterior cruciate ligament. These findings indicate that alpha-smooth muscle actin containing fibroblastic cells are a regular part of the intact as well as the remodeled anterior cruciate ligament. There is evidence that myofibroblasts may be involved in maintaining tissue homeostasis in the mature ligament e.g., by means of crimp formation. The presence of these cells during the early remodeling may further indicate that alpha-smooth muscle actin containing fibroblastic cells are involved in the earliest stages of fiber bundle formation. The role and function of this special cell type for the anterior cruciate ligament needs to be further clarified.

Purpose: Tendon-to-bone healing of soft-tissue grafts has been described to progress by the development of a fibrous interzone that undergoes a maturation process leading to the development of an indirect type of ligament insertion. Previous studies used extra-articular models or fixation far away from the joint line; thus, no data are available investigating tendon-to-bone healing of a soft-tissue graft fixed anatomically. Therefore, we studied the tendon-to-bone healing of the anatomic soft-tissue graft interference fit fixation in a model of anterior cruciate ligament (ACL) reconstruction in sheep. Type of Study: Animal study. Methods: Thirty-five mature sheep underwent ACL reconstruction with an autologous Achilles tendon split graft. Grafts were directly fixed with biodegradable poly-(D,L-lactide) interference screws. Animals were euthanized after 6, 9, 12, 24, and 52 weeks and histologic evaluations were performed. Undecalcified specimens were evaluated under normal and polarized light. Additionally, animals received a polychrome sequential labeling (tetracycline, xylenol orange, and calcein green) to determine bone growth per time under fluorescent light. Results: Intratunnel histologic findings at 6 weeks showed a tendon-bone junction with only a partial fibrous interzone between the graft tissue and the surrounding bone. A mature intratunnel tendon-bone junction with a zone of fibrocartilage was found at 9 to 12 weeks. At the tunnel entrance site a wide regular ligamentous insertion site was seen in all specimens after 24 weeks. This insertion showed regular patterns such as the direct type of insertion of a normal ligament with a dense basophilic transition zone consisting of mineralized cartilage. Conclusions: A fibrous interzone between the graft tissue and the bone tunnel was only partially developed, which is in contrast to all previous studies in which nonanatomic fixation was used. Thus, it is reasonable to assume that the tendon-to-bone healing in the present study may progress partially by direct-contact healing without the development of a fibrous interzone. To our knowledge, this is the first report describing the development of a direct type of ligament insertion after ACL replacement with a soft-tissue graft. This is in contrast to previous studies reporting the development of an indirect type of insertion when using nonanatomic fixation far away from the joint line. Thus, histologic data strongly indicate that anatomic interference fit fixation is beneficial for tendon-to-bone incorporation by leading to the development of a direct type of ligament insertion. Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 18, No 2 (February), 2002: pp 124–135

In vitro and in vivo studies have demonstrated an osteoinductive effect of growth factors such as insulin-like growth factor-1 (IGF-1) and transforming growth factor-beta1 (TGF-beta1). However, for therapeutic use in fracture treatment, questions remain with regard to the local application of these proteins. A controlled, local release of growth factors from a biodegradable polylactide coating of osteosynthetic implants may have a stimulating effect on fracture healing. Such implants could stabilize the fracture and their bioactive surface could function simultaneously as a local drug-delivery system. Previous studies have demonstrated the high mechanical stability of an approximately 10-14-microm-thick poly(D,L-lactide) (PDLLA) coating on metallic implants, which can even withstand the process of intramedullary insertion. Following an initial peak, 80% of incorporated growth factors IGF-1 and TGF-beta1 were continuously released within 42 days. The effect of locally applied IGF-1 and TGF-beta1 from a biodegradable PDLLA coating of intramedullary implants on fracture healing was investigated in a rat model. Midshaft fractures of the right tibia of 5-month-old female Sprague-Dawley rats (n = 127) were stabilized with coated vs. uncoated titanium Kirschner wires. X-ray examinations and blood analyses were performed, and body weight and body temperature measurements were taken throughout the experimental period. After 28 and 42 days, respectively, tibiae were dissected for mechanical torsional testing and histomorphometrical analyses. X-rays demonstrated an almost completely consolidated fracture, biomechanical testing showed a significantly higher maximum load and torsional stiffness, and histological and histomorphometric analyses demonstrated progressed remodeling after 28 and 42 days in the group treated with growth factors as compared with controls. Interestingly, the PDLLA coating itself revealed a positive effect on fracture healing even without incorporated growth factors. No systemic changes of serum parameters, including IGF-1 and IGF binding proteins, and no differences in body weight and body temperature were observed within and between groups. These findings suggest that the local application of growth factors from a biodegradable PDLLA coating of osteosynthetic implants accelerates fracture healing significantly without systemic side effects.

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.

The newly formed regenerate bone during limb lengthening usually is assessed by observing standard plain radiographs. However, no objective data correlate the radiographic appearance with the quantitative strength of the newly formed bone. A noninvasive method was developed to assess the regenerate bone using digital radiography. The investigations were performed in a micropig animal model. The right tibia was distracted for 10 days at 2 mm per day. Digital radiography was performed after the distraction during a 10-day consolidation period. For quantitative analysis, an aluminum step wedge was placed on all images, and a region of interest was outlined in the regenerate bone. A calibration curve was calculated by measuring the corresponding gray values of the aluminum phantom. The calibration equation was used for determining the mean density in the region of interest. This method was sensitive in assessing day to day healing progress. The measurements taken the day before sacrifice were compared with torsional mechanical data using a material testing machine. The high correlation between the densimetric evaluations and the biomechanical data suggests this method is a useful tool for in vivo assessment of the regenerate bone during the consolidation period in distraction osteogenesis.

We present a newly developed torsional stiffness measurement device with the potential to quantitatively assess the in vivo torsional stiffness of bone regenerate during distraction osteogenesis. We describe the form and function of this device and its application in a model of regenerate consolidation. The device was able to produce data to assess stiffness of the regenerate with an accuracy between +/- 3 and +/- 9% for material stiffness ranging between 0.1 and 2.4 Nm/o and with a precision of +/- 3.6%. This method provides advantages over similar methods of bone fracture healing assessment with guaranteed maintenance of bone axis, minimized risk of bone misalignment during the bone healing process and a close relation to the functional loading pattern in torsion of bones such as tibia and femora.

Hintergrund Bei posttraumatischen Fehlstellungen gibt es hinsichtlich der Korrekturgrenzen wenig Evidenz. Es existieren dennoch Grenzwerte, die v. a. beim jungen Patienten spatere Beschwerden erwarten lassen.

The purpose of this study was to examine the advantages of MRI-guided ankle stress examinations in the detection of chronic ankle instability.An MRI-compatible stress device was developed and tested for MRI safety. Bilateral MRI stress examinations were performed on 50 volunteers with and without clinically evident subjective instability of the ankle joints (72 subjective stable ankle joints in 37 subjects, 28 ankles in 15 subjects with chronic ankle instability). Both the inversion test and the anterior drawer test were performed under axial, coronal, 45° paraxial, and sagittal T2-weighted fast spin-echo image control. MR images were assessed for talar tilt, subtalar tilt, anterior talus translation, anterior calcaneus translation, medial talocalcaneal translation, and the diameters of the lateral ankle ligaments (anterior talofibular ligament, calcaneofibular ligament, and posterior talofibular ligament).The MRI stress device was found suitable and safe for use in the MRI environment. The talocrural and subtalar joints could be assessed simultaneously. Significant differences between groups A and B (p≤0.05) were found in talar tilt, subtalar tilt, anterior talus translation, anterior calcaneus translation, medial talocalcaneal translation, and decrease in diameters of calcaneofibular and posterior talofibular ligaments. Also found were sex differences in talar tilt, subtalar tilt, anterior talus translation, and diameters of the anterior talofibular, calcaneofibular, and posterior talofibular ligaments. Significant relations were found between talar tilt and anterior talus translation, subtalar tilt and anterior calcaneus translation, subtalar tilt and medial talocalcaneal translation, and between anterior calcaneus translation and medial talocalcaneal translation in groups A and B.Stress examination under MRI control has advantages in the assessment of mechanical ankle instability. Additional diagnostic and clinically relevant information is obtained through direct imaging of the ligaments and assessment of additional parameters of ankle laxity (subtalar tilt, anterior calcaneus translation, medial talocalcaneal translation). The main advantages are objective imaging and measurement of abnormal looseness of the lower ankle joint and its direct simultaneous comparison with the upper ankle joint.

Die Ergebnisse bei der Versorgung von distalen Femurfrakturen waren mit einer nicht geringen Zahl von Infektionen, Pseudarthrosen und Fehlstellungen belastet. In jungerer Zeit haben sich die Losungsmoglichkeiten bei fehlgeschlagenen Osteosynthesen am distalen Femur durch die Einfuhrung minimal invasiv einzubringender winkelstabiler Implantate deutlich erweitert. Die minimal invasiven Operationstechniken, ermoglichen eine stabile Fixation der Fraktur unter grostmoglicher Schonung der ohnehin kompromittierten Weichteile. Kommt es nach primarer Versorgung einer distalen Femurfraktur mit einem „konventionellen” - nicht winkelstabilen - Implantat zum Implantatversagen oder zur Fraktur-Redislokation scheint uns daher das Umsteigen auf ein winkelstabiles Implantat (z.B. Femur Less Invasive Stabilization System - LISS) angezeigt. Ebenso konnen - falls indiziert - biologische Massnahmen wie autologe Knochentransplantation und neuerdings Applikation von Wachstumsfaktoren die Konsolidierung der Fraktur bewirken oder bei einem Implantatwechsel unterstutzen. Weitere Moglichkeiten zur Problemlosung bei fehlgeschlagenen Osteosynthesen am distalen Femur sind in Abhangigkeit der Frakturform die Verbundosteosynthese und der fruhzeitige alloarthroplastische Gelenkersatz. Unserer Erfahrung nach mussen diese Verfahren bei Anwendung der vorgenannten Techniken nur selten eingesetzt werden.

A case is reported of a 28-year-old patient with gradually developing massive swelling of the right thigh after sustaining a blunt trauma. Three and a half months after the injury, surgery was performed because of a persisting tumor at the thigh. Intraoperatively, massive bleeding occurred, the bleeding vessel was sutured. Postoperative angiography disclosed arteriovenous (av) fistulae from the internal iliacal artery to a gluteal vein as source for the bleeding. The feeding artery was closed by coiling, the patient recovered completely. To the authors’ knowledge, development of an av-fistula following blunt trauma has not been described previously. Similarly, the differential diagnosis of a posttraumatic bleeding of a congenital av-malformation was not yet reported. The authors emphasize, that prior to the surgery of inadequately behaving hematomas, an angiography should be performed.

The aim of this study was to develop a signal-inducing bone cement for magnetic resonance imaging (MRI)–guided cementoplasty of the spine. This MRI cement would allow precise and controlled injection of cement into pathologic lesions of the bone. We mixed conventional polymethylmethacrylate bone cement (PMMA; 5 ml methylmethacrylate and 12 g polymethylmethacrylate) with hydroxyapatite (HA) bone substitute (2–4 ml) and a gadolinium-based contrast agent (CA; 0–60 μl). The contrast-to-noise ratio (CNR) of different CA doses was measured in an open 1.0-Tesla scanner for fast T1W Turbo-Spin-Echo (TSE) and T1W TSE pulse sequences to determine the highest signal. We simulated MRI-guided cementoplasty in cadaveric spines. Compressive strength of the cements was tested. The highest CNR was (1) 87.3 (SD 2.9) in fast T1W TSE for cements with 4 μl CA/ml HA (4 ml) and (2) 60.8 (SD 2.4) in T1W TSE for cements with 1 μl CA/ml HA (4 ml). MRI-guided cementoplasty in cadaveric spine was feasible. Compressive strength decreased with increasing amounts of HA from 46.7 MPa (2 ml HA) to 28.0 MPa (4 ml HA). An MRI-compatible cement based on PMMA, HA, and CA is feasible and clearly visible on MRI images. MRI-guided spinal cementoplasty using this cement would permit direct visualization of the cement, the pathologic process, and the anatomical surroundings.

Bone healing is considered as a recapitulation of a developmental program initiated at the time of injury. This study tested the hypothesis that in delayed bone healing the regular cascade of healing events, including remodeling of woven to lamellar bone, would be similar compared to standard healing, although the temporal onset would be delayed. A tibial osteotomy was performed in sheep and stabilized with a rotationally unstable fixator leading to delayed healing. The sheep were sacrificed at 2, 3, 6, 9 weeks and 6 months postoperatively. The temporal and spatial tissue distributions in the calluses and the bone microstructure were examined by histology. Although histological analysis demonstrated temporal and spatial callus tissue distribution differences, delayed healing exhibited the same characteristic stages as those seen during uneventful standard healing. The delayed healing process was characterized by a prolonged presence of hematoma, a different spatial distribution of new bone and delayed and prolonged endochondral bone formation. A change in the spatial distribution of callus formation was seen by week 6 leading to bone formation and resorption of the cortical bone fragments, dependent on the degree to which the cortical bone fragments were dislocated. At 6 months, only 5 out of 8 animals showed complete bony bridging with a continuous periosteum, although lamellar bone and newly formed woven bone were present in the other 3 animals. This study demonstrates that during delayed bone healing all stages of the healing cascade likely take place, even if bony consolidation does not occur. Furthermore, the healing outcome might be related to the periosteum's regenerative capacity leading to bony union or absence of bony bridging.