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O aumento da expectativa de vida permite a mulher viver muitos anos após a menopausa. Além disso, a mudança nos hábitos alimentares da sociedade moderna tem determinado o aumento da incidência de obesidade e sobrepeso na população. Essas duas situações têm despertado o interesse da comunidade científica, visto as repercussões deletérias que podem ocorrer com o organismo. O objetivo deste estudo foi avaliar o efeito da deficiência de estrogênio associado à dieta hiperlipídica sobre a integridade óssea da mandíbula de ratas. Para tal, ratas Wistar jovens foram avaliadas por citologia vaginal e aos 90 dias de idade, divididas em 4 grupos: Controle (C4%), Controle hiperlipídica19% (C19%), Ovariectomizada 4% (OVX4%) e Ovariectomizada19% (OVX19%). O período experimental começou com a castração (90 d de idade), seguido da alimentação com dieta hiperlipídica, por 30 dias. Ao final desse período, após anestesia, o sangue foi coletado para análise sérica de cálcio, fósforo, fosfatase alcalina e estradiol. Mandíbulas, vértebras L4 e fêmures foram removidos e preparados para análise das propriedades físicas e biomecânicas. Não foram observadas diferenças na ingestão alimentar, no comprimento corporal nem nas medidas ósseas dos grupos. O cálcio sérico diminuiu significativamente nos grupos castrados. O fósforo diminuiu enquanto, a fosfatase alcalina aumentou em todos os grupos, quando comparados ao C4%. Dentre os parâmetros físicos avaliados alguns apresentaram diferenças entre os grupos. Nas vértebras L4, os pesos imersos e úmidos aumentaram com a castração e com a dieta hiperlipídica, enquanto, os percentuais de material orgânico e mineral diminuíram. Nas mandíbulas, os pesos imersos e úmidos e a densidade óssea aumentaram com a castração, mas diminuem com a associação castração/dieta hiperlipídica. O volume ósseo e o percentual de água diminuíram com a ingestão de dieta hiperlipídica. Nenhuma alteração foi observada nos fêmures. Nas cinzas das mandíbulas os percentuais de magnésio apresentaram-se significativamente aumentados em todos os grupos. Mas, os de cálcio e fósforo não variaram. Nos testes biomecânicos de vértebra L4 e fêmur não foram encontradas diferenças entre os grupos. No entanto, na mandíbula os grupos alimentados com dieta hiperlipídica apresentaram menor resistência à tensão aplicada, em relação aos grupos de dieta normolipídica. Ficou evidenciado nessas ratas que a deficiência de esteróides sexuais associada à dieta hiperlipídica influencia de forma negativa a integridade óssea mandibular. / Increased life expectancy of women allows her to live many years after menopause. On the other hand, the western way of life has brought about an increased incidence of obesity and overweight to people. These two situations have attracted the interest of the scientific community, given the deleterious consequences that may occur with the body. The aim of this study was to evaluate the effect of estrogen deficiency associated with high-fat diet on the mandibular bone integrity of rats. Wistar young rats were previously evaluated by vaginal cytology and at 90 days old were divided into 4 groups: control (C4%), Control 19% fat diet (C19%), ovariectomized 4% (OVX4%), ovariectomized and 19% fat diet (OVX 19%). The experimental period started with castration (90 days old) followed by the implementation of high-fat diet for 30 days. At the end of this period, after anesthesia blood was collected for later analysis of serum concentrations of calcium, phosphorus, alkaline phosphatase and estradiol. Mandibular bone, lumbar column L4 and femurs were removed and prepared for physical and biomechanical analysis. There were no differences in food intake, body length or in bone measurements of all groups. Serum calcium decreased significantly in ovariectomized groups. Phosphorus concentrations decreased and alkaline phosphatase increased in all experimental groups, compared to C4%. Among the physical parameters evaluated some differences were showed between the groups. At L4 vertebrae, the immersed and wet weights increased with castration and the high-fat diet, while the percentage of organic material and mineral decreased. In mnadibles, the immersed and wet weights and bone density increased with castration, but decrease with the combination of castration/fat diet. The bone volume and the percentage of water decreased with the intake of fat diet. No changes were observed in the femurs. In the ashes of mandibular bones the percentage of magnesium were significantly increased in all groups. But the calcium and phosphorus did not change. The biomechanical test of the L4 vertebra and femur were not significant differences between the groups. However, in mandibular bone, groups fed with high-fat diet had lower resistance to the applied voltage, compared to normal-fat diet groups. It was evident in these rats that the deficiency of sex steroids associated with high-fat diet negatively influences mandibular bone integrity.

O aumento da expectativa de vida permite a mulher viver muitos anos após a menopausa. Além disso, a mudança nos hábitos alimentares da sociedade moderna tem determinado o aumento da incidência de obesidade e sobrepeso na população. Essas duas situações têm despertado o interesse da comunidade científica, visto as repercussões deletérias que podem ocorrer com o organismo. O objetivo deste estudo foi avaliar o efeito da deficiência de estrogênio associado à dieta hiperlipídica sobre a integridade óssea da mandíbula de ratas. Para tal, ratas Wistar jovens foram avaliadas por citologia vaginal e aos 90 dias de idade, divididas em 4 grupos: Controle (C4%), Controle hiperlipídica19% (C19%), Ovariectomizada 4% (OVX4%) e Ovariectomizada19% (OVX19%). O período experimental começou com a castração (90 d de idade), seguido da alimentação com dieta hiperlipídica, por 30 dias. Ao final desse período, após anestesia, o sangue foi coletado para análise sérica de cálcio, fósforo, fosfatase alcalina e estradiol. Mandíbulas, vértebras L4 e fêmures foram removidos e preparados para análise das propriedades físicas e biomecânicas. Não foram observadas diferenças na ingestão alimentar, no comprimento corporal nem nas medidas ósseas dos grupos. O cálcio sérico diminuiu significativamente nos grupos castrados. O fósforo diminuiu enquanto, a fosfatase alcalina aumentou em todos os grupos, quando comparados ao C4%. Dentre os parâmetros físicos avaliados alguns apresentaram diferenças entre os grupos. Nas vértebras L4, os pesos imersos e úmidos aumentaram com a castração e com a dieta hiperlipídica, enquanto, os percentuais de material orgânico e mineral diminuíram. Nas mandíbulas, os pesos imersos e úmidos e a densidade óssea aumentaram com a castração, mas diminuem com a associação castração/dieta hiperlipídica. O volume ósseo e o percentual de água diminuíram com a ingestão de dieta hiperlipídica. Nenhuma alteração foi observada nos fêmures. Nas cinzas das mandíbulas os percentuais de magnésio apresentaram-se significativamente aumentados em todos os grupos. Mas, os de cálcio e fósforo não variaram. Nos testes biomecânicos de vértebra L4 e fêmur não foram encontradas diferenças entre os grupos. No entanto, na mandíbula os grupos alimentados com dieta hiperlipídica apresentaram menor resistência à tensão aplicada, em relação aos grupos de dieta normolipídica. Ficou evidenciado nessas ratas que a deficiência de esteróides sexuais associada à dieta hiperlipídica influencia de forma negativa a integridade óssea mandibular. / Increased life expectancy of women allows her to live many years after menopause. On the other hand, the western way of life has brought about an increased incidence of obesity and overweight to people. These two situations have attracted the interest of the scientific community, given the deleterious consequences that may occur with the body. The aim of this study was to evaluate the effect of estrogen deficiency associated with high-fat diet on the mandibular bone integrity of rats. Wistar young rats were previously evaluated by vaginal cytology and at 90 days old were divided into 4 groups: control (C4%), Control 19% fat diet (C19%), ovariectomized 4% (OVX4%), ovariectomized and 19% fat diet (OVX 19%). The experimental period started with castration (90 days old) followed by the implementation of high-fat diet for 30 days. At the end of this period, after anesthesia blood was collected for later analysis of serum concentrations of calcium, phosphorus, alkaline phosphatase and estradiol. Mandibular bone, lumbar column L4 and femurs were removed and prepared for physical and biomechanical analysis. There were no differences in food intake, body length or in bone measurements of all groups. Serum calcium decreased significantly in ovariectomized groups. Phosphorus concentrations decreased and alkaline phosphatase increased in all experimental groups, compared to C4%. Among the physical parameters evaluated some differences were showed between the groups. At L4 vertebrae, the immersed and wet weights increased with castration and the high-fat diet, while the percentage of organic material and mineral decreased. In mnadibles, the immersed and wet weights and bone density increased with castration, but decrease with the combination of castration/fat diet. The bone volume and the percentage of water decreased with the intake of fat diet. No changes were observed in the femurs. In the ashes of mandibular bones the percentage of magnesium were significantly increased in all groups. But the calcium and phosphorus did not change. The biomechanical test of the L4 vertebra and femur were not significant differences between the groups. However, in mandibular bone, groups fed with high-fat diet had lower resistance to the applied voltage, compared to normal-fat diet groups. It was evident in these rats that the deficiency of sex steroids associated with high-fat diet negatively influences mandibular bone integrity.

Background: Open reduction and internal fixation with a plate is deemed to represent the gold standard of surgical treatment for displaced intra-articular calcaneal fractures. Standard plate fixation is usually placed through an extended lateral approach with high risk for wound complications. Minimally invasive techniques might avoid wound complications but provide limited construct stability. Therefore, 2 different types of locking nails were developed to allow for minimally invasive technique with sufficient stability. The aim of this study was to quantify primary stability of minimally invasive calcaneal interlocking nail systems in comparison to a variable-angle interlocking plate. Material and Methods: After quantitative CT analysis, a standardized Sanders type IIB fracture model was created in 21 fresh-frozen cadavers. For osteosynthesis, 2 different interlocking nail systems (C-Nail; Medin, Nov. Město n. Moravě, Czech Republic; Calcanail; FH Orthopedics SAS; Heimsbrunn, France) as well as a polyaxial interlocking plate (Rimbus; Intercus GmbH; Rudolstadt, Germany) were used. Biomechanical testing consisted of a dynamic load sequence (preload 20 N, 1000 N up to 2500 N, stepwise increase of 100 N every 100 cycles, 0.5 mm/s) and a load to failure sequence (max. load 5000 N, 0.5 mm/s). Interfragmentary movement was detected via a 3-D optical measurement system. Boehler angle was measured after osteosynthesis and after failure occurred. Results: No significant difference regarding load to failure, stiffness, Boehler angle, or interfragmentary motion was found between the different fixation systems. A ignificant difference was found with the dynamic failure testing sequence where 87.5% of the Calcanail implants failed in contrast to 14% of the C-Nail group (P < .01) and 66% of the Rimbus plate. The highest load to failure was observed for the C-Nail. Boehler angle showed physiologic range with all implants before and after the biomechanical tests. Conclusion: Both minimally invasive interlocking nail systems displayed a high primary stability that was not inferior to an interlocking plate. Clinical relevance: Based on our results, both interlocking nails appear to represent a viable option for treating displaced intra-articular calcaneal fractures.

Es erfolgt eine Knochenstrukturanalyse der proximalen Tibia unter Berücksichtigung verschiedenster radiologischer, biomechanischer und histomorphometrischer Aspekte. Die regionen-, alters- und geschlechtsspezifischen Aspekte dieser Problemregion werden herausgearbeitet. Der eindeutige Nachweis einer regionen-abhängigen Verteilung der Knochendichte und der biomechanischen Eigenschaften in der proximalen Tibia ist eines der Hauptergebnisse der vorliegenden Studie. In der proximalen Tibia besteht eine signifikante Abnahme der Knochendichte von proximal nach distal. Im zentralen Bereich der proximalen Tibia besteht in allen Sektionen im Vergleich zu den anterior/posterior und medial/lateral liegenden Gebieten die niedrigste Knochendichte. In der vorliegenden Studie wurde die proximale Tibia in 3 Etagen (von proximal nach distal) unterteilt. Beim Vergleich der auf diesen Etagen aufgebrachten ROIs (region of interest,jeweils 5 in den beiden proximalen Etagen und 4 im distalen Abschnitt) zeigte sich in den beiden proximalen Etagen lateral (Ebene I anterolateral/ Ebene II posterolateral) die höchste Knochendichte. Im Gegensatz dazu zeigte sich in der distalen Etage anteromedial die höchste Knochendichte. Weiterhin wurden die 3 gängigen Stabilisierungsverfahren für diese Region einer umfangreichen biomechanischen Testung unterzogen. Es zeigte sich, dass der Ilizarov Fixateur bei den verschiedensten Lastfällen meist das instabilste Implantat war. Trotz der biomechanischen Defizite konnten die in der klinischen Studie mit Composite Fixateur versorgten Frakturen trotz erheblichem Weichteilschaden und instabiler Fraktursituation zur Ausheilung gebracht werden. Das LIS-System erwies sich gegenüber der konventionellen Abstützplatte hinsichtlich der biomechanischen Steifigkeit sowohl in der statischen als auch in der zyklischen Testung als gleichwertiges oder sogar biomechanisch günstigeres Implantat. Diese positiven klinischen wie biomechanischen Erfahrungen führen auch zur Förderung der Entwicklung anderer winkelstabiler Fixateur interne-Systeme in den verschiedensten Problemregionen (Pilon tibiale, proximaler und distaler Humerus, distaler Radius). Als wesentliche neue Therapieansätze für das operative Vorgehen in der Problemregion der proximalen Tibia lassen sich die folgenden Gesichtspunkte herausarbeiten: 1) Knochendichteadaptierte Implantat- und Schraubenpositionierung bei der konventionellen Osteosynthese, 2) Knochendichteadaptierte Pin- und Olivendrahtpositionierung bei externen Fixationsverfahren (Ilizarovringfixateur, Fixateur externe) im Bereich der proximalen Tibia, 3) Implantatverbesserungen (LISS-Schraubenkonfiguration und -positionierung, Plattendesign, Umstellungsplatte, Verriegelungsbolzen bei Marknägeln wie UTN, PTN), 4) Prothesenverbesserung (knochendichteadaptiertes Zapfendesign mit 3 Zapfen für die tibiale Komponente). / In this study an analysis of the bone structure of the proximal tibia was performed with special attention paid to the different radiological, biomechanical and histomorphometrical aspects. Region-, age- and gender-specific attributes of the localised bone were also examined. Evidence of a region related variation of bone density and biomechanical behaviour is one of the main results of this study. In the proximal tibia, a significant reduction in the bone density exists from proximal to distal. In comparison to the anterior/posterior or medial/lateral areas, the lowest bone mineral densities were found in the central region. In this study the proximal tibia was divided into 3 different levels (from proximal to distal). When comparing the different regions of interest (ROIs) 5 each in the two proximal levels and 4 in the most distal level), the lateral regions (level 1 anterolateral/ level 2 posterolateral) presented the highest bone mineral density. In contrast, the highest bone density in the distal- level was detected in the anteromedial region. Furthermore, complex biomechanical testing of- 3 common fixation techniques for fracture situations of the proximal tibia was performed. It was shown that the Ilizarov fixator was the most unstable implant in several load tests. Despite this biomechanical deficit fractures treated by composite- fixators in different clinical trails healed uneventfully, even with severe soft tissue damage or an unstable fracture situation. In comparison to the conventional buttress plate, the LIS-System was an equal or superior implant, both in static and cyclic stiffness testing. These clinical and biomechanical experiences lead to the development of other angle stable internal fixator systems for different problematic regions (tibial plafond, proximal and distal humerus, distal radius). The following new therapeutic aspects were developed for the surgical treatment of the proximal tibia: 1) Bone mineral density adapted implant-and screw placement in conventional plating. 2) Bone density adapted pin- and olive wire placement during external fixation (ilizarov ring fixator, external fixator) techniques of the proximal tibia. 3) Improvement of implant design (LISS screw configuration and- placement, plate design, locking bolt configuration in nails). 4) Improvement of prosthetic design (bone density adapted design of the tibial components)