Single-bundle anterior cruciate ligament reconstruction: a biomechanical cadaveric study of a rectangular quadriceps and bone--patellar tendon--bone graft configuration versus a round hamstring graft.

Purpose: The purposes of this study were to investigate anterior tibial translation under loading conditions after single-bundle (SB) anterior cruciate ligament (ACL) reconstruction using a rectangular tunnel placement strategy with quadriceps and bone--patellar tendon--bone (BPTB) graft and to compare these data with a SB hamstring reconstruction with a round tunnel design.

Methods: In 9 human cadaveric knees, the knee kinematics were examined with robotic/universal force-moment sensor testing. Within the same specimen, the knee kinematics under simulated pivot-shift and KT-1000 arthrometer (MEDmetric, San Diego, CA) testing were determined at 0°, 15°, 30°, 60°, and 90° of flexion under different conditions: intact knee, ACL-deficient knee, and SB ACL-reconstructed knee.

Grasping multiple sclerosis: do quantitative motor assessments provide a link between structure and function?

Motor disability in MS is commonly assessed by the Expanded Disability Status Scale (EDSS). Categorical rating scales are limited by subjective error and inter-rater variability. Therefore, objective and quantitative measures of motor disability may be useful to supplement the EDSS in the setting of clinical trials.

Accidental perforation of the lateral femoral cortex in ACL reconstruction: an investigation of mechanical properties of different fixation techniques.

Purpose: The aim of this study was to evaluate the mechanical properties of anterior cruciate ligament (ACL) reconstruction using the medial portal technique with cortical fixation and hybrid fixation after penetration of the lateral cortex by use of different drill sizes.

Methods: In this biomechanical study a porcine in vitro model was used. The testing protocol consisted of a cyclic loading protocol (1,000 cycles, 50 and 250 N) and subsequent ultimate failure testing.

Arthroscopic fixation of matrix-associated autologous chondrocyte implantation: importance of fixation pin angle on joint compression forces.

Purpose: The aim of the study was to investigate the effect of pin fixation perpendicular and 30° tilted to the matrix surface on the joint compression forces.

Methods: In a porcine knee model, joint compression forces were recorded with a digital pressure sensor above the medial meniscus and with axial compression of 100 N by use of a material testing machine. The forces were recorded for an intact femoral condyle, as well as a standardized cartilage defect of 25 × 20 mm, after matrix-associated autologous chondrocyte implantation (m-ACI) (BioSeed C; Biotissue Technologies, Freiburg, Germany), fixed by use of a conventional suture technique and pin fixation with a biodegradable pin perpendicular and 30° tilted to the matrix surface.

Zwitterionic and cationic P(5)-clusters from four-membered phosphorus-nitrogen-metal heterocycles.

A general route for the functionalization of P(4) mediated by four-membered phosphorus-nitrogen-metal heterocycles is introduced yielding novel phosphorus-rich clusters.

Two pore domain potassium channels in cerebral ischemia: a focus on K2P9.1 (TASK3, KCNK9).

Background: Recently, members of the two-pore domain potassium channel family (K2P channels) could be shown to be involved in mechanisms contributing to neuronal damage after cerebral ischemia. K2P3.1-/- animals showed larger infarct volumes and a worse functional outcome following experimentally induced ischemic stroke.

High level expression of the anti-retroviral protein APOBEC3G is induced by influenza A virus but does not confer antiviral activity.

Human APOBEC3G is an antiretroviral protein that was described to act via deamination of retroviral cDNA. However, it was suggested that APOBEC proteins might act with antiviral activity by yet other mechanisms and may also possess RNA deamination activity. As a consequence there is an ongoing debate whether APOBEC proteins might also act with antiviral activity on other RNA viruses.

Proprioception with bicondylar sledge prostheses retaining cruciate ligaments.

The current study was designed to evaluate the proprioceptive performance of the knee after implantation of bicondylar sledge prostheses in comparison with contralateral knees and knees of healthy control subjects. After implantation of a sledge prosthesis in the medial and lateral condyles of a knee retaining all ligaments, 15 patients were evaluated clinically and by proprioceptive testing. Clinical examination was done using common scoring systems.

Proprioceptive function, clinical results, and quality of life after unicondylar sledge prostheses.

Objective: Evaluation of proprioceptive performance and quality of life after implantation of unicondylar sledge knee prostheses in comparison with normal control subjects.

Design: A total of 17 patients were examined after implantation of unicondylar sledge prostheses. Clinical examination was performed, quality of life was assessed, and proprioceptive performance was examined.

An epicardial cyst in a child.

An 8-year-old girl, without any previous medical history, presented with a first short syncope. Physical examination was unremarkable. Transthoracic echocardiography revealed a thin-walled, echo-free cystic structure adjacent to the posterior wall of the left ventricle, and compressing it moderately.

A new clamping technique for biomechanical testing of tendons in small animals. aprobst@uni-muenster.de.

When biomechanical properties of tendons are studied, the technique of clamping the tendons in the testing machine presents a methodological challenge, especially when murine tendons are examined. These short tendons tend to rupture at the transition line to the fixation, leading to false interpretations. Therefore a new clamping technique for investigation of healthy murine Achilles tendons (n = 50) was developed, in which the intramuscular tendon fibers were fixed between two paper strips and the calcaneus was wedged into a conical slot in a wooden block and then mounted in the testing machine (n = 20).

Liver bridging techniques in the treatment of acute liver failure.

The introduction of orthotopic liver transplantation in the management of acute liver failure has dramatically increased the survival rates of patients at the cost of removing the patient's native liver and life-long dependence on immunosuppression. However, it is well known that in many patients with acute liver failure the diseased liver has the potential to recover. Death in these patients is often due to increased intra-cranial pressure or infection.

Which stabilization technique corrects anatomy best in patients with AC-separation? An experimental study.

In ten human cadaveric shoulder specimens four different parameters were documented prior to, and after, dissecting all passive stabilizers. These included the vertical, horizontal and mediolateral acromioclavicular distance, as well as the clavicular rotation. In addition, the same parameters were documented after acromioclavicular (AC) reconstruction using eight different techniques.

Hepatic vein catheterization: a new technique in rats.

Blood samples taken directly from the hepatic veins are often required for evaluation of liver function or ischemia/reperfusion injury and for direct determination of metabolic products of the liver. In the rat, blood samples are usually obtained by direct puncture of the hepatic veins. Successful catheterization of these small vessels is only possible under direct vision because great dexterity is needed to persuade the catheter to enter the hepatic vein.

Reduction of hepatic reperfusion injury by indomethacin-mediated vasoconstriction: a rat model with temporary splenocaval shunt.

For reduction of radical formation during reperfusion, a lower oxygen supply by limiting the reperfusion flow rate should be beneficial for the organ. Thus, indomethacin was given prior to reperfusion for induction of temporary postischemic vasoconstriction. In an in vivo model (female Wistar rats, 200-250 g, n = 16) with portal decompression by a splenocaval shunt, hepatic ischemia was induced for 30 min by cross-clamping of the hepatoduodenal ligament followed by portal intravenous injection of indomethacin (2 mg/kg body wt) at the end of ischemia.

Monitoring of liver oxygenation during neuroleptanalgesia in the dog.

In an animal study (7 mongrel dogs) the effects of neuroleptanalgesia (NLA) and combinations of NLA with nitrous oxide (N2O) and isoflurane on the macro- and microcirculation of the liver were investigated. Measurements were made in three steps. After NLA alone the dogs were supplementarily ventilated with nitrous oxide/oxygen at a ratio of 2:1.