Zusammenfassung Hintergrund: Ziel der vorliegenden Arbeit war es, in einer retrospektiven Untersuchung die klinischen und radiologischen Ergebnisse nach Behandlung der Daumensattelgelenksarthrose mittels Trapezium-Resektion und Implantation einer Swanson-Silikonprothese, einem Verfahren zu dem es in der deutschsprachigen Literatur kaum Informationen gibt, an einem größeren Patientenkollektiv zu ermitteln. Patienten und Methoden: Retrospektiv wurden im Durchschnitt 8,6 Jahre postoperativ die Ergebnisse von 100 Trapezium-Resektionen mit anschließender Implantation einer Swanson-Silikonprothese bei 72 Patienten (9 Männer und 63 Frauen) mit Daumensattelgelenksarthrose untersucht. Neben der Beweglichkeit des Daumenstrahles wurde die Kraft im Grob-, Spitz- und Schlüsselgriff gemessen und die Schmerzen auf der visuellen Analogskala bestimmt. Die Zufriedenheit mit dem Operationsergebnis wurde ebenso ermittelt wie der DASH-, der Mayo Modified Wrist- und der Krimmer-Score. Die bei der Nachuntersuchung gefertigten Röntgenaufnahmen wurden im Hinblick auf eine Luxation der Prothese sowie auf Vorliegen knöcherner Veränderungen ausgewertet. Ergebnisse: Das Bewegungsausmaß des Daumensattelgelenkes bei radialer Abduktion lag bei 52° und bei palmarer Abduktion bei 39°. Im Grobgriff wurden 16,5 kg Kraft gemessen. Dies entsprach 80% der gesunden Gegenseite. Beim Spitzgriff lag der Kraftwert bei 3,3 kg und beim Schlüsselgriff bei 3,5 kg, was 70% bzw. 71% der Kraft der gesunden Gegenseite entsprach. Der DASH-Score lag bei 22,5 Punkten. Die Schmerzsymptomatik lag bei 2,4 Punkten. Die Mehrzahl der Patienten zeigte sich mit dem Operationsergebnis zufrieden und sehr zufrieden. Radiologisch konnten jedoch in 54 Fällen Subluxationen und in 41 Fällen knöcherne Auffälligkeiten gefunden werden, wobei jedoch nur in 88 Fällen postoperative Röntgenaufnahmen vorlagen. Es fand sich jedoch keine Korrelation zwischen den radiologischen Ergebnissen und der aktuellen klinischen Situation. Schlussfolgerung: Die Trapezektomie mit Silikonprothesenersatz zeigt gute klinische Ergebnisse in der Behandlung der Rhizarthrose. Allerdings zeigen sich auch eine hohe Anzahl an Prothesensubluxationen und knöchernen Auffälligkeiten. Deshalb wird dieses Operationsverfahren bei uns nicht mehr eingesetzt.

BACKGROUND:Goal of the present study was the evaluation of clinical and radiological results after treatment of the first carpometacarpal joint by trapezium resection and implantation of a Swanson silicone prosthesis by means of a retrospetive study. However, up to now, only a few long-term data for this surgical technique are available. METHODS AND PATIENTS:Retrospectively the results of 100 trapezium resections in 72 patients with subsequent joint replacement by a Swanson silicone prosthesis have been followed up over 8.6 years on average. Besides the range of motion, the strengh in grip, tip pinch and key pinch were measured. The quality of pain was determined using a visual analogus pain scale from 1-10. The postoperative subjective satisfaction of patients was recorded as well as the DASH, Mayo, modified Wrist and Krimmer scores. In follow-up X-ray controls, subluxations of the silicone implants as well as bony abnormalities were evaluated. RESULTS:The postoperative range of motion of the trapeziometacarpal joint in radial abduction was measured with 52° and at palmar abduction with 39°. The average grip strength amounted to 16.5 kg. This represented 80% of the value of the contralateral side. In tip pinch the force value was 3.3 kg, corresponding to 70% of that of the opposite side and in key pinch, it was 3.5 kg, corresponding to 71% of the healthy contralateral side. The DASH score was recorded with 22.5 points. Postoperative pain symptoms on the visual analogue pain scale were recorded at 2.4 points. The majority of the patients were satisfied or very satisfied after the surgical treatment. In X-ray controls, subluxations of the silicone implants could be detected in 54 cases (61.4%) as well as bony abnormalities in 41 cases (46.6%). However, there was no correlation between the radiological findings and patient satisfaction. CONCLUSION:Trapezium resection and joint replacement with a silicone prosthesis achieves good results. However, the high number of radiographic subluxations of the prothesis and bone abnormalities as a cause of foreign body reactions limits these results. Therefore, despite the good clinical findings, this method will not been conducted any more in our patient population.

The flow rate measurement of liquid, steam, and gas is one of the most important areas of application for today’s field instrumentation. Vortex meters are used in numerous branches of industry to measure the volumetric flow by exploiting the unsteady vortex flow behind a blunt body.

BACKGROUND:The efficacy of surgical ventricular reconstruction (SVR) for ischemic cardiomyopathy has never been truly quantified. Methods to assess ventricular flow have not been applied to these patients. The objective is to develop a volume-independent technique for assessing the effects of ischemic remodeling and SVR on left ventricular blood flow dynamics. METHODS:Cardiac magnetic resonance images from a healthy volunteer and from a patient before and after SVR were segmented and transformed to generate a grid model of the heart by generating numeric grids and running third-order approximations to achieve 850 grid images per cardiac cycle. These grids formed the skeletal structure of our patient-specific time-dependent ventricular geometry model, the Karlsruhe Heart Model, used for modeling fluid dynamics. We modeled flow, ejection fraction, and blood washout from the ventricle. The model was validated using a silicone ventricle and mock circulation. RESULTS:In the healthy heart and before SVR, ejection fractions were 0.61 and 0.15 and left ventricular volumes were 166 mL and 175 mL, respectively. Surgical ventricular reconstruction decreased left ventricular volume by one fourth. Postoperative ejection fraction was 0.18 in the patient. Post-SVR shape was more spherical than preoperatively and also more spherical than the healthy heart. Ventricular flow patterns in the patient were significantly altered by SVR. However, fluid washout from the ventricle was similar before and after SVR but worse than in the healthy heart. CONCLUSIONS:Fluid dynamic modeling of the heart is possible based on cardiac magnetic resonance imaging data and enables volume-independent quantitative assessment of the surgical procedure. In the future, preoperative modeling for patients with remodeled ventricles may help to achieve optimized post-SVR flow characteristics and potentially outcomes.

A three-dimensional computational fluid dynamics (CFD) method has been developed to simulate the flow in a pumping left ventricle. The proposed method uses magnetic resonance imaging (MRI) technology to provide a patient specific, time dependent geometry of the ventricle to be simulated. Standard clinical imaging procedures were used in this study. A two-dimensional time-dependent orifice representation of the heart valves was used. The location and size of the valves is estimated based on additional long axis images through the valves. A semi-automatic grid generator was created to generate the calculation grid. Since the time resolution of the MR scans does not fit the requirements of the CFD calculations a third order bezier approximation scheme was developed to realize a smooth wall boundary and grid movement. The calculation was performed by a Navier–Stokes solver using the arbitrary Lagrange–Euler (ALE) formulation. Results show that during diastole, blood flow through the mitral valve forms an asymmetric jet, leading to an asymmetric development of the initial vortex ring. These flow features are in reasonable agreement with in vivo measurements but also show an extremely high sensitivity to the boundary conditions imposed at the inflow. Changes in the atrial representation severely alter the resulting flow field. These shortcomings will have to be addressed in further studies, possibly by inclusion of the real atrial geometry, and imply additional requirements for the clinical imaging processes.

Background. Various treatment options have been proposed for reconstruction of the scapholunate ligament. However, none of these methods prevent patients with scapholunate instability from developing wrist arthritis. This study was performed to investigate a new bone-ligament-bone autograft from the plantar plate of the toes for suitable reconstruction of the scapholunate interosseus ligament. The anatomical properties and the technical feasibility were investigated. Methods. The plantar plates of the metatarsophalangeal joints and the proximal interphalangeal joints of the 2nd-5th toes were examined in 20 cadaver feet and measurements such as length, thickness and width were recorded. Results. The average lengths of the plantar ligaments of the proximal interphalangeal joint were 0.63 cm (D3) and 0.62 cm (D4), respectively and were therefore found to be similar to that of the scapholunate ligament. Bone-ligament-bone autografts of the plantar plates were designed and intercalated between the scaphoid and lunate bones and, contrary to all previous methods, not simply superimposed upon them. Conclusions. It can be concluded from the data that this new graft of the proximal interphalangeal joint of the 3rd and 4th toes can be a suitable replacement for the scapholunate ligament.

Für die skapholunäre (SL-)Dissoziation existieren verschiedene Behandlungsmöglichkeiten. Keine kann jedoch eine sichere Verhinderung arthrotischer Spätfolgen im Handgelenk garantieren. Ziel dieser anatomischen Studie war es, ein neues Knochen-Band-Knochen-Transplantat der plantaren Platte des Zehs für eine mögliche Rekonstruktion des skapholunären (SL-)Bandes zu entwickeln.

In order to improve the diagnosis and therapy of human heart diseases, the KAHMO (KArlsruhe Heart MOdel), a patient-specific numerical model of the human heart has been developed. KAHMO consists of the left and right ventricle, the adjacent vessels and the cardiac valves.

The KAHMO (Karlsruhe Heart Model) has been developed as a framework for the patient specific numerical simulation of the intraventricular flow. The framework combines different methods from several disciplines [Oertel 2004, Oertel 2005].Based on MRI records of the patients heart, a 4 dimensional geometry of the endocardium is created. The movement of the inner ventricular wall is imposed onto the numerical model as a moving wall boundary condition in a moving grid. The heart valves are modelled using a two dimensional planar pressure drop, which is varied temporarily and spatially to create the physiological velocity profiles at the valve orifice. At the boundaries of the three dimensional simulation model a time dependent pressure boundary from a zero dimensional circulation model [Reik 2005] is used. The model includes a generic atrium and aortic tract, since these features could not be extracted from the original data set. The method has been validated by comparison with results of in vitro experiments and in vivo MRI flux measurements.With this method it is for the first time possible to simulate the asymmetric redirection in the left ventricle as observed in MRI flux measurements by Kilner and others [Kim 1995, Kilner 2000] with a numerical model using a specific human heart geometry.

The authors sought to elucidate the prognostic value of cardiac sympathetic nerve dysfunction as evaluated using iodine-123-labeled metaiodobenzylguanidine (123I-MIBG) single-photon emission computed tomography (SPECT) imaging in patients with heart failure (HF) with preserved left ventricular ejection fraction (HFpEF).Cardiac sympathetic nerve dysfunction assessed by 123I-MIBG imaging is associated with poor outcomes in chronic HF patients with reduced left ventricular ejection fraction (HFrEF). However, no information is available on the prognostic vale of cardiac 123I-MIBG SPECT imaging in patients with HFpEF.We studied 148 patients admitted for acute decompensated HF (ADHF) with nonischemic HFpEF and who underwent cardiac 123I-MIBG imaging at discharge. The cardiac 123I-MIBG heart-to-mediastinum ratio (H/M) was measured on the delayed planar image (late H/M). SPECT analysis of the delayed image was conducted, and the tracer uptake in all 17 regions on the polar map was scored on a 5-point scale by comparison with a sex-matched normal control database. The total defect score (TDS) was calculated by summing the score of each of the 17 segments. The primary endpoint was the association between TDS and cardiac events (the composite of emergent HF hospitalization and cardiac death).During a mean follow-up period of 2.4 ± 1.6 years, 61 patients experienced cardiac events. TDS was significantly associated with cardiac events after multivariate Cox adjustment (P < 0.0001). Patients with high TDS levels had a significantly greater risk of cardiac events than those with middle or low TDS levels (63% vs 40% vs 20%, respectively; P < 0.0001; HR: 4.69; 95% CI: 2.29 to 9.61; and HR: 2.46; 95% CI: 1.14 to 5.29). C-statistic of TDS was 0.730 (95% CI: 0.651 to 0.799), which was significantly higher than that of late H/M (0.607; 95% CI: 0.524 to 0.686; P = 0.0228).Cardiac 123I-MIBG SPECT imaging provided useful prognostic information in nonischemic ADHF patients with HFpEF. (Clinical Trial: Osaka Prefectural Acute Heart Failure Syndrome Registry [OPAR]: UMIN000015246)