The influence of different osteosynthesis configurations with locking compression plates (LCP) on stability and fracture healing after an oblique 45° angle osteotomy

Background Locking compression plates are used in various configurations with lack of detailed information on consequent bone healing. Study design In this in vivo study in sheep 5 different applications of locking compression plate (LCP) were tested using a 45° oblique osteotomy simulating simple fracture pattern. 60 Swiss Alpine sheep where assigned to 5 different groups with 12 sheep each (Group 1: interfragmentary lag screw and an LCP fixed with standard cortex screws as neutralisation plate; Group 2: interfragmentary lag screw and LCP with locking head screws; Group 3: compression plate technique (hybrid construct); Group 4: internal fixator without fracture gap; Group 5: internal fixator with 3 mm gap at the osteotomy site). One half of each group (6 sheep) was monitored for 6 weeks, and the other half (6 sheep) where followed for 12 weeks. Methods X-rays at 3, 6, 9 and 12 weeks were performed to monitor the healing process. After sacrifice operated tibiae were tested biomechanically for nondestructive torsion and compared to the tibia of the healthy opposite side. After testing specimens were processed for microradiography, histology, histomorphometry and assessment of calcium deposition by fluorescence microscopy. Results In all groups bone healing occurred without complications. Stiffness in biomechanical testing showed a tendency for higher values in G2 but results were not statistically significant. Values for G5 were significantly lower after 6 weeks, but after 12 weeks values had improved to comparable results. For all groups, except G3, stiffness values improved between 6 and 12 weeks. Histomorphometrical data demonstrate endosteal callus to be more marked in G2 at 6 weeks. Discussion and conclusion All five configurations resulted in undisturbed bone healing and are considered safe for clinical application.

Effect of Enamel Matrix Derivative Liquid on Osteoblast and Periodontal Ligament Cell Proliferation and Differentiation.

BACKGROUND Enamel matrix derivatives (EMDs) have been used clinically for more than a decade for the regeneration of periodontal tissues. The aim of the present study is to analyze the effect on cell growth of EMDs in a gel carrier in comparison to EMDs in a liquid carrier. EMDs in a liquid carrier have been shown to adsorb better to bone graft materials. METHODS Primary human osteoblasts and periodontal ligament (PDL) cells were exposed to EMDs in both gel and liquid carriers and compared for their ability to induce cell proliferation and differentiation. Alizarin red staining and real-time polymerase chain reaction for expression of genes encoding collagen 1, osteocalcin, and runt-related transcription factor 2, as well as bone morphogenetic protein 2 (BMP2), transforming growth factor (TGF)-β1, and interleukin (IL)-1β, were assessed. RESULTS EMDs in both carriers significantly increased cell proliferation of both osteoblasts and PDL cells in a similar manner. Both formulations also significantly upregulated the expression of genes encoding BMP2 and TGF-β1 as well as decreased the expression of IL-1β. EMDs in the liquid carrier further retained similar differentiation potential of both osteoblasts and PDL cells by demonstrating increased collagen and osteocalcin gene expression and significantly higher alizarin red staining. CONCLUSIONS The results from the present study indicate that the new formulation of EMDs in a liquid carrier is equally as potent as EMDs in a gel carrier in inducing osteoblast and PDL activity. Future study combining EMDs in a liquid carrier with bone grafting materials is required to further evaluate its potential for combination therapies.

Dynamic Intraligamentary Stabilization (DIS) for treatment of acute anterior cruciate ligament ruptures: case series experience of the first three years.

BACKGROUND In recent years, the scientific discussion has focused on new strategies to enable a torn anterior cruciate ligament (ACL) to heal into mechanically stable scar tissue. Dynamic intraligamentary stabilization (DIS) was first performed in a pilot study of 10 patients. The purpose of the current study was to evaluate whether DIS would lead to similarly sufficient stability and good clinical function in a larger case series. METHODS Acute ACL ruptures were treated by using an internal stabilizer, combined with anatomical repositioning of torn bundles and microfracturing to promote self-healing. Clinical assessment (Tegner, Lysholm, IKDC, and visual analogue scale [VAS] for patient satisfaction scores) and assessment of knee laxity was performed at 3, 6, 12, and 24 months. A one-sample design with a non-inferiority margin was chosen to compare the preoperative and postoperative IKDS and Lysholm scores. RESULTS 278 patients with a 6:4 male to female ratio were included. Average patient age was 31 years. Preoperative mean IKDC, Lysholm, and Tegner scores were 98.8, 99.3, and 5.1 points, respectively. The mean anteroposterior (AP) translation difference from the healthy contralateral knee was 4.7 mm preoperatively. After DIS treatment, the mean 12-month IKDC, Lysholm, and Tegner scores were 93.6, 96.2, and 4.9 points, respectively, and the mean AP translation difference was 2.3 mm. All these outcomes were significantly non-inferior to the preoperative or healthy contralateral values (p < 0.0001). Mean patient satisfaction was 8.8 (VAS 0-10). Eight ACL reruptures occurred and 3 patients reported insufficient subjective stability of the knee at the end of the study period. CONCLUSIONS Anatomical repositioning, along with DIS and microfracturing, leads to clinically stable healing of the torn ACL in the large majority of patients. Most patients exhibited almost normal knee function, reported excellent satisfaction, and were able to return to their previous levels of sporting activity. Moreover, this strategy resulted in stable healing of all sutured menisci, which could lower the rate of osteoarthritic changes in future. The present findings support the discussion of a new paradigm in ACL treatment based on preservation and self-healing of the torn ligament.

La invención de La Fonction Oblique

Un estudiante arquitecto disimula su espíritu burgués bajo una apariencia de vagabundo y enmascara su cinismo bajo la convención de la ironía. SIMULACRO Una joven arquitectura americana de California se revuelca complacida en el culto a la cabaña de madera y a la falsa granja de cubierta retorcida y pintoresca. Una arquitectura internacional politizada busca en el neorrealismo el sentido tan masoquista de la miseria del buen gusto y de la anécdota irrelevante para calmar su conciencia extraviada. Una arquitectura italiana de investigación se refugia en los más increíbles revivals de las épocas más alejadas; transformando alegremente la moda antigua en vieja decoración, influenciando al mundo y justificando su postura de anticuario con el intento vano de elevarla no solo al nivel de una tendencia más, sino al de escuela de arquitectura. SIMULACRO Una arquitectura tradicional cansada, que intenta su revitalización, disfrazándose bajo la etimología neodecorativa de “brutalismo”. Una arquitectura falaz que corrompe los lugares de placer con su exotismo y su folclore de bazar. Una arquitectura indiferente que esconde su falta de pasión bajo la coartada moderna del muro cortina y bajo la máscara de la técnica.

Thermal evolution of lower limbs during a rehabilitation process after anterior cruciate ligament surgery

Infrared thermography (IRT) is a safe and non-invasive tool used for examining physiological functions based on skin temperature (Tsk) control. The aim of this paper was to establish the probable thermal difference between the beginning and the end of the anterior cruciate ligament (ACL) rehabilitation process after surgery. For this purpose thermograms from 25 ACL surgically operated patients (2 women, 23 men) were taken on the first and last day of a six-week rehabilitation program. A FLIR infrared camera according to the protocol established by the International Academy of Clinical Thermology (IACT). The results showed significant temperature increases in the posterior thigh area between the first and the last week of the rehabilitation process probably due to a compensatory mechanism. According to this, we can conclude that temperature of the posterior area of the injured and non-injured leg has increased from the first to the last day of the rehabilitation process.

Use of infrared thermography as a tool to monitor skin temperature along the recovery process of an anterior cruciate ligament surgery

Infrared thermography (IRT) is a safe and non-invasive tool used for examining physiological functions based on skin temperature (Tsk) control. Thermograms from 25 anterior cruciate ligament (ACL) surgically operated patients (2 female, 23 male) were taken with a FLIR infrared camera according to the protocol established by the International Academy of Clinical Thermology (IACT). This work consists of 4 studies. Studies 1 and 3 were related to establish the probable thermal difference among different moments of an ACL rupture after surgery: before starting the rehabilitation (P0), at the end of rehabilitation (P1) and 18 months from the end of rehabilitation (P2). For this purpose, on the other hand, studies 2 and 4 were related to establish the skin thermal difference (Tsk) between the injured and the non-injured leg in P0, P1 and P2. Results of the first study showed significant temperature increases in the posterior thigh area between P0 and P1 probably due to a compensatory mechanism. According to this, we can conclude that temperature of the posterior area of the injured and noninjured leg has increased from the first to the last day of the rehabilitation process. In the second study we found significant temperature differences between the injured and non-injured leg in both stages of rehabilitation (p<.01). On the one hand, the temperature of the injured leg is higher in the anterior view and the temperature of the non-injured leg is higher in the posterior view. By the time the patients had recovered from the reconstruction, thermal imbalances should have not been shown between symmetrical parts, but differences seemed to be still latent.. Study 3 shows that temperatures seem to be higher after a year and a half (P2) than in P1. Study 4 shows how thermal values 18 months later seemed to be normalized between both legs. No significant differences were found between the injured leg and the noninjured leg after one year and a half of the rehabilitation process. Considering results from Study 3 and 4 we can conclude that patients seemed to have recovered from a thermal point of view. The temperature in P2 was higher but symmetrical. RESUMEN La termografía infrarroja (IRT) es una herramienta segura y no invasiva utilizada para examinar funciones fisiológicas que se basan en el control de temperatura de la piel (Tsk). Termogramas de 25 pacientes intervenidos quirúrgicamente del ligamento cruzado anterior (LCA) (2 mujeres, 23 hombres) fueron tomadas con una cámara de infrarrojos FLIR de acuerdo con el protocolo establecido por la Academia Internacional de Termología Clínica (IACT). Este trabajo consiste en 4 estudios. Los estudios 1 y 3 describen la diferencia térmica entre los diferentes momentos tras la operación del ligamento cruzado anterior: antes de comenzar la rehabilitación (P0), al final de la rehabilitación (P1) y 18 meses tras finalizar la rehabilitación (P2). Por otra parte, los estudios 2 y 4 describen la diferencia de temperatura de la piel (Tsk) entre la pierna lesionada y la pierna no lesionada en P0, P1 y P2. Los resultados del primer estudio mostraron aumentos significativos de temperatura en la zona posterior de los muslos entre P0 y P1, probablemente debido a un mecanismo de compensación. De acuerdo con esto, se puede concluir que la temperatura de la zona posterior de la pierna lesionada y no lesionada se ha incrementado desde el primero hasta el último día del proceso de rehabilitación. En el segundo estudio se encontraron diferencias significativas de temperatura entre la pierna lesionada y no lesionada en ambas etapas de la rehabilitación (p<.01). Por un lado, la temperatura de la pierna lesionada es mayor en la vista anterior. Por otro lado, la temperatura de la pierna no lesionada es mayor en la vista posterior. Una vez que los pacientes se han recuperado de todo el proceso, no deberían existir desequilibrios térmicos entre partes simétricas del cuerpo, pero las diferencias todavía estaban latentes. El tercer estudio muestra que la temperatura es más alta en P2 que en P1. El cuarto estudio muestra cómo los valores térmicos entre ambas piernas en P2 se han normalizado entre ambas piernas. No se encontraron diferencias significativas entre la pierna lesionada y la pierna no lesionada después de 18 meses tras el proceso de rehabilitación. Considerando los resultados del studio 3 y 4, podemos concluir que se ha llegado a la recuperación total desde un punto de vista térmico. La temperatura es más elevada en P2 pero simétrica.

The differential adhesion forces of anterior cruciate and medial collateral ligament fibroblasts: effects of tropomodulin, talin, vinculin, and alpha-actinin.

We have determined the effects of tropomodulin (Tmod), talin, vinculin, and alpha-actinin on ligament fibroblast adhesion. The anterior cruciate ligament (ACL), which lacks a functional healing response, and the medial collateral ligament (MCL), a functionally healing ligament, were selected for this study. The micropipette aspiration technique was used to determine the forces needed to separate ACL and MCL cells from a fibronectin-coated surface. Delivery of exogenous tropomodulin, an actin-filament capping protein, into MCL fibroblasts significantly increased adhesion, whereas its monoclonal antibody (mAb) significantly decreased cell adhesiveness. However, for ACL fibroblasts, Tmod significantly reduced adhesion, whereas its mAb had no effect. mAbs to talin, vinculin, and alpha-actinin significantly decreased the adhesion of both ACL and MCL cells with increasing concentrations of antibody, and also reduced stress fiber formation and cell spreading rate as revealed by immunofluorescence microscopy. Disruption of actin filament and microtubule assembly with cytochalasin D and colchicine, respectively, also significantly reduced adhesion in ACL and MCL cells. In conclusion, both ACL and MCL fibroblast adhesion depends on cytoskeletal assembly; however, this dependence differs between ACL and MCL fibroblasts in many ways, especially in the role of Tmod. These results add yet another possible factor in explaining the clinical differences in healing between the ACL and the MCL.

Oblique surface waves at an interface between a metal–dielectric superlattice and an isotropic dielectric

We investigate the existence and dispersion characteristics of surface waves that propagate at an interface between a metal–dielectric superlattice and an isotropic dielectric. Within the long-wavelength limit, when the effective-medium (EM) approximation is valid, the superlattice behaves like a uniaxial plasmonic crystal with the main optical axes perpendicular to the metal–dielectric interfaces. We demonstrate that if such a semi-infinite plasmonic crystal is cut normally to the layer interfaces and brought into contact with a semi-infinite dielectric, a new type of surface mode can appear. Such modes can propagate obliquely to the optical axes if favorable conditions regarding the thickness of the layers and the dielectric permittivities of the constituent materials are met. We show that losses within the metallic layers can be substantially reduced by making the layers sufficiently thin. At the same time, a dramatic enlargement of the range of angles for oblique propagation of the new surface modes is observed. This can lead, however, to field non-locality and consequently to failure of the EM approximation.

FMVSS 208 RM crash simulation support: a crash test of a 1986 Volkswagen Golf into a fixed 30 degree oblique barrier with a closing velocity of 48.4 kph. Test report.

Mode of access: Internet.

Oblique angle crash tests of loaded heavy trucks into an instrumented wall. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Tables of oblique photo scale factors and nadir point distances for 70mm photography. For unit altitude, focal lengths: 1.5, 3, 6, and 12 inches, tilts: 0 ̊to 90.̊

"Scale factor system, oblique photo, developmental. Contract NOas 59-6067-c, Aeronautics specification XPH 118 (modified)."