One major complication of external fixation is pin track infection that may result in devastating osteomyelitis for the patient. The broad antimicrobial effect of silver is well known and this study was conducted to investigate the antibacterial activity of pins coated with colloidal silver. A total of 96 pins were inserted into one tibia of 24 sheep. Four pins of either stainless steel, titanium, silver-coated, or stainless steel pins coated with a polyurethane-argentum sleeve were inserted in six sheep, respectively. After pin insertion S. aureus was inoculated into the insertion channel between skin and bone and the animals were sacrificed after four weeks. Clinical assessment, radiological evaluation, microbiological and biomechanical testing, and histological methods were used. All animals developed clinical signs of infection after three to six days. The inoculated S. aureus was identified in all animals as an infection-causing strain by the DNA-fingerprinting technique. None of the different pin types, including silver-coated pins, showed a significant reduction of infection rates. Significant differences between the groups were rare and limited to few specific tests. Colloidal silver showed no significant reduction of pin track infections. Nanoparticulate silver with a higher active surface and a more homogenous distribution within biomaterials might be able to exhibit a better antimicrobial activity in coated pins.

This study analyzes the qualification of biochemical markers in the diagnosis of osteoporosis and evaluates the potential of a multiparametric classification of premenopausal and non-osteoporotic as well as osteoporotic postmenopausal women, which is based on biochemical marker profiles. For this evaluation data of 29 women in the age between 28-74 years were used. The classification of osteoporosis was done by the trabecular density of the lumbar spine using qCT-measurements. The biochemical markers of formation and resorption AP, bAP, OC, ucOC, PICP, PYD, DPD, NTX, BSP and vitamin K were analyzed on day 1 and 42 in all patients. For vitamin K we found significant distribution differences between non-osteoporotic and osteoporotic women (p<0.005). The crosslinks PYD and DPD showed weakly significant differences. All other parameters exhibited non-significant results. Vitamin K acted with a sensitivity of 64% and a specificity of 82%. The used multiparameter classification process improved sensitivity and specificity considerably. The parameter profiles of OC/PYD, vitamin K/PYD and vitamin K/bAP revealed the highest sensitivities with specificities of more than 82%.

In trauma surgery gluing is an attractive method of bonding fractured bone, which is rapid and does not require the use of screws and plates. The purpose of this study was to analyze in vitro the properties of a new bioresorbable bone glue, and in vivo its structure and degradation. The newly developed bone glue is based on alkylenbis(oligolactoyl)methacrylates and employs a two-component initiator system. Starting components for synthesis are ethylene glycol, lactic acid and methacrylic acid. In vitro the solidified glue is degraded via hydrolysis of ester bonds. Degradation products are ethylene glycol, lactic acid and oligomeres of methacrylic acid. After the first week polymer pellets (MMA, HEMALA, ELAMA) showed a weight loss of 12%. From week 2-20 a linear weight loss of 1.5% per week, that is 40% after 20 weeks, was observed. The in vivo investigations of the ultrastructure of the glue revealed a transparent and homogeneous mass with large electron-tight vacuoles. Differences in structure and degradation were not observed. Degradation of glue by hydrolysis and phagocytosis, with good biocompatibility was demonstrated.

Die Deckung von Weichteildefekten bei offenen Sprunggelenkfrakturen oder bei Wundheilungsstörungen nach operativer Versorgung im Bereich des Innen- oder des Außenknöchels ist häufig eine schwierige operative Herausforderung. Neurovaskuläre Lappenplastiken werden in den letzten Jahren zunehmend angewand.

Über die ideale Operationsmethode der Bennett-Fraktur besteht bislang kein Konsens. Neben verschiedensten konservativen Behandlungsmethoden, publizierte z.B. Lambotte bereits 1913 über die Drahtfixierung der Fragmente untereinander. Als weiteres OP-Verfahren steht neuerdings die minimalinvasive Schraubenosteosynthese mittels kanü-lierter Titanschraube zur Verfügung. Material/Methodik/Ergebnisse: An technischen Vorraussetzungen zu dieser Operation sind ein hochauflösender Bildwandler und als Osteosyn-thesematerial eine 3,0 mm Hohlschraube mit kurzem Gewinde erforderlich.

Tierexperimentelle Infektmodelle sind häufig mit dem Problem behaftet, daß durch Kontaminationen und Superinfektionen das Versuchsergebnis in Frage gestellt wird. Die Problematik, daß die Übertragbarkeit der Erkenntnisse vom Tier auf den Mensch sehr kritisch zu hinterfragen ist, wird hierdurch zusätzlich verstärkt.

Obwohl die Knochengefäße bereits seit langer Zeit im wissenschaftlichen Interesse stehen, wird ihnen gerade in den letzten Jahren im Rahmen der Frakturbehandlung eine immer größere Bedeutung zugemessen. Etablierte und klinisch bewährte Operationsverfahren, wie zum Beispiel die Plattenosteosynthese, wurden unter dem Aspekt der Fragmentdurchblutung kritisch betrachtet und teilweise modifiziert.

The operative exposure of a fracture causes disturbances in the blood supply, which may lead to a prolonged healing process or even to bone necrosis, especially when using the complex and complicated methods of osteosynthesis at the ankle. In order to damage the supplying vessels as little as possible, position, direction and penetration of the bone arteries of the talocrural joint were examined by corrosion preparation. The tibial nutrient artery arises from the posterior tibial artery or from the popliteal artery and penetrates constantly from posterior at the level of the proximal third. The fibular nutrient artery, coming from the peroneal artery, penetrates more distaly from medial into the middle third of the diaphysis. In one specimen it did not exist at all. Distal tibia and fibula are supplied by the perimalleolar arterial ring, which is connected with the three arteries of the leg. The talus is supplied by numerous very small vessels, which are provided with extraosseous anastomoses and penetrate the whole non-articular surface. Implications for the operation will be explained.

The operative exposure of a fracture in an osteosynthesis causes disturbances in the blood supply, which often leads to a prolonged process of healing or even to healing problems, a fracture non-union, which is frequently located at the forearm. In order to damage the supplying vessels as little as possible, the position, direction and penetration of the arteries of radius and ulna are demonstrated and systematised in this study. Near the elbow arteries, coming from large adjoining vessels, penetrate the area of the capsular insertion. The nutrient arteries enter both bones in the second proximal quarter of diaphysis, at the radius from anterior to medial, at the ulna from anterior to anteroradial. Small vessels, which penetrate closely proximal to the articular surface in order to supply the distal forearm bones, come from an anastomosis between the radial, the interosseous and the ulnar arteries. In this study access vessels, choice and position of implants will be discussed.