Bone conduction responses of middle ear structures in Thiel embalmed heads

Thiel-embalmed human whole-head specimens offer a promising alternative model for bone conduction (BC) studies of middle ear structures. In this work we present the Thiel model’s linearity and stability over time as well as its possible use in the study of a fixed ossicle chain. Using laser Doppler vibrometry (LDV), the motion of the retroauricular skull, the promontory, the stapes footplate and the round window (RW) were measured. A bone-anchored hearing aid stimulated the ears with step sinus tones logarithmically spread between 0.1 and 10 kHz. Linearity of the model was verified using input levels in steps of 10 dBV. The stability of the Thiel model over time was examined with measurements repeated after hours and weeks. The influence of a cement-fixed stapes was assessed. The middle ear elements measured responded linearly in amplitude for the applied input levels (100, 32.6, and 10 mV). The variability of measurements for both short- (2 h) and long-term (4-16 weeks) repetitions in the same ear was lower than the interindividual difference. The fixation of the stapes induced a lowered RW displacement for frequencies near 750 Hz (-4 dB) and an increased displacement for frequencies above 1 kHz (max. +3.7 dB at 4 kHz). LDV assessment of BC-induced middle ear motion in Thiel heads can be performed with stable results. The vibratory RW response is affected by the fixation of the stapes, indicating a measurable effect of ossicle chain inertia on BC response in Thiel embalmed heads.

Unfair Advantage: An Intriguing Example of Legal Transformation in the Swiss Private Law

This paper demonstrates a mixed approach to the theme of the instrumentality of law by both analysing the goal of a legal transformation and the techniques adapted to achieve it. The correct recognition of a certain practical necessity has lead the Swiss Federal Tribunal to an intriguing judgement “Fussballclub Lohn-Fall” of 1997. The legal remedies provided for cases of unfair advantage have been then creatively modified praeter legem. The adaptation was strongly influenced by foreign legal patterns. The Swiss Code of Obligations of 1911 provides a norm in art. 21 on unfair advantage (unconscionable contract), prescribing that if one party takes unjustified advantage over the weaknesses of another in order to receive an excessive benefit, such a contract is avoidable. Its wording has been shaped over a hundred years ago and still remains intact. However, over the course of the 20th century the necessity for a more efficient protection has arisen. The legal doctrine and jurisprudence were constantly pointing out the incompleteness of the remedies provided by art. 21 of the Code of Obligations. In the “Fussballclub Lohn-Fall” (BGE 123 III 292) the Swiss Federal Tribunal finally introduced the possibility to modify the contract. Its decision has been described as “a sign of the zeitgeist, spirit of the time”. It was the Swiss legal doctrine that has imposed the new measure under the influence of the German “quantitative Teilnichtigkeit” (quantitative partial nullity). The historical heritage of the Roman laesio enormis has also played its role.

Can imagined whole-body rotations improve vestibular compensation?

Unilateral damage to the labyrinth and the vestibular nerve cause rotational vertigo, postural imbalance, oculomotor disorders and spatial disorientation. Electrophysiological investigations in animals revealed that such deficits are partly due to imbalanced spontaneous activity and sensitivity to motion in neurons located in the ipsilesional and contralesional vestibular nuclei. Neurophysiological reorganizations taking place in the vestibular nuclei are the basis of the decline of the symptoms over time, a phenomenon known as vestibular compensation. Vestibular compensation is facilitated by motor activity and sensory experience, and current rehabilitation programs favor physical activity during the acute stage of a unilateral vestibular loss. Unfortunately, vestibular-defective patients tend to develop strategies in order to avoid movements causing imbalance and nausea (in particular body movements towards the lesioned side), which impedes vestibular compensation. Neuroanatomical evidence suggests a cortical control of postural and oculomotor reflexes based on corticofugal projections to the vestibular nuclei and, therefore, the possibility to manipulate vestibular functions through top-down mechanisms. Based on evidence from neuroimaging studies showing that imagined whole-body movements can activate part of the vestibular cortex, we propose that mental imagery of whole-body rotations to the lesioned and to the healthy side will help rebalancing the activity in the ipsilesional and contralesional vestibular nuclei. Whether imagined whole-body rotations can improve vestibular compensation could be tested in a randomized controlled study in such patients beneficiating, or not, from a mental imagery training. If validated, this hypothesis will help developing a method contributing to reduce postural instability and falls in vestibular-defective patients. Imagined whole-body rotations thus could provide a simple, safe, home-based and self-administered therapeutic method with the potential to overcome the inconvenience related to physical movements.

Long-Term Outcome After Monosegmental L4/5 Stabilization for Degenerative Spondylolisthesis With the Dynesys Device

STUDY DESIGN:: retrospective analysis of prospectively collected clinical data. OBJECTIVE:: To assess the long-term outcome of patients with monosegmental L4/5 degenerative spondylolisthesis treated with the dynamic Dynesys device. SUMMARY OF BACKGROUND DATA:: The Dynesys® system has been used as a semirigid, lumbar dorsal pedicular stabilization device since 1994. Good short-term results have been reported, but little is known about the long-term outcome following treatment for degenerative spondylolisthesis at the L4/5 level. METHODS:: 39 consecutive patients with symptomatic degenerative lumbar spondylolisthesis at the L4/5 level were treated with bilateral decompression and Dynesys instrumentation. At a mean follow-up of 7.2 years (range 5.0-11.2▒y) they underwent clinical and radiographic evaluation and quality of life assessment. RESULTS:: At final follow-up back pain improved in 89% and leg pain improved in 86% of patients compared to preoperative status. 83% of patients reported global subjective improvement. 92% would undergo the surgery again. 8 patients (21%) required further surgery due to symptomatic adjacent segment disease (6 cases), late onset infection (1 case), and screw breakage (1 case). In 9 cases radiological progression of spondylolisthesis at the operated segment was found. 74% of operated segments showed limited flexion-extension range of less than 4°. Adjacent segment pathology, though without clinical correlation, was diagnosed at the L5/S1 (17.9%) and L3/4 (28.2%) segments. In 4 cases asymptomatic screw loosening was observed. CONCLUSION:: Monosegmental Dynesys instrumentation of degenerative spondylolisthesis at L4/5 shows good long-term results. The rate of secondary surgeries is comparable to other dorsal instrumentation devices. Residual range of motion in the stabilized segment is reduced, and the rate of radiological and symptomatic adjacent segment degeneration is low. Patient satisfaction is high. Dynesys stabilization of symptomatic L4/5 degenerative spondylolisthesis is a possible alternative to other stabilization devices.

Influence of preoperative functional status on outcome after total hip arthroplasty

BACKGROUND: International registries with large, heterogeneous patient populations provide excellent research opportunities for studying factors that influence treatment outcomes after total hip arthroplasty. In the present study, we used a European multinational database to investigate whether there is an association between three functional variables (preoperative pain, mobility, and motion) and functional outcome. METHODS: We performed a retrospective cohort study on preoperative and follow-up clinical data that were prospectively entered into the International Documentation and Evaluation System European hip registry between 1967 and 2002. The inclusion criteria for this study were an age of more than twenty years, an underlying diagnosis of osteoarthritis, and a Charnley class-A functional designation at the time of surgery. A total of 12,925 patients (13,766 total hip arthroplasties) who met these criteria were entered into the analysis. Three functional variables (pain, mobility, and motion) that were assessed preoperatively were evaluated postoperatively at various follow-up examinations for a maximum of ten years. RESULTS: Six thousand four hundred and one patients could walk longer than ten minutes preoperatively; of these, 57.1% had a walking capacity of more than sixty minutes at the time of the most recent follow-up. In comparison, 6896 patients had a preoperative walking capacity of less than ten minutes and only 38.9% of these patients could walk more than sixty minutes at the time of the most recent follow-up. The difference was significant (p < 0.01). Similarly, 10,375 patients had a preoperative hip flexion range of >70 degrees ; of these, 74.7% had a flexion range of >90 degrees at the time of the most recent follow-up. In comparison, 2793 patients had a preoperative hip flexion range of <70 degrees and only 62.6% of these patients had a flexion range of >90 degrees at the time of the most recent follow-up. The difference was also significant (p < 0.01). Lasting, complete, or almost complete pain relief was achieved by >80% of the patients following total hip arthroplasty regardless of their preoperative categorization of pain. CONCLUSIONS: Patients with poor preoperative walking capacity and hip flexion are less likely to achieve an optimal outcome with regard to walking and motion. In contrast, there is no correlation between the preoperative pain level and pain alleviation, which is generally good and long-lasting after total hip arthroplasty.

An integrated system for 3D hip joint reconstruction from 2D X-rays: a preliminary validation study

The acquisition of conventional X-ray radiographs remains the standard imaging procedure for the diagnosis of hip-related problems. However, recent studies demonstrated the benefit of using three-dimensional (3D) surface models in the clinical routine. 3D surface models of the hip joint are useful for assessing the dynamic range of motion in order to identify possible pathologies such as femoroacetabular impingement. In this paper, we present an integrated system which consists of X-ray radiograph calibration and subsequent 2D/3D hip joint reconstruction for diagnosis and planning of hip-related problems. A mobile phantom with two different sizes of fiducials was developed for X-ray radiograph calibration, which can be robustly detected within the images. On the basis of the calibrated X-ray images, a 3D reconstruction method of the acetabulum was developed and applied together with existing techniques to reconstruct a 3D surface model of the hip joint. X-ray radiographs of dry cadaveric hip bones and one cadaveric specimen with soft tissue were used to prove the robustness of the developed fiducial detection algorithm. Computed tomography scans of the cadaveric bones were used to validate the accuracy of the integrated system. The fiducial detection sensitivity was in the same range for both sizes of fiducials. While the detection sensitivity was 97.96% for the large fiducials, it was 97.62% for the small fiducials. The acetabulum and the proximal femur were reconstructed with a mean surface distance error of 1.06 and 1.01 mm, respectively. The results for fiducial detection sensitivity and 3D surface reconstruction demonstrated the capability of the integrated system for 3D hip joint reconstruction from 2D calibrated X-ray radiographs.

Architektura a ideologie. Výchovné instituce Adolfa Hitlera v protektorátu Čechy a Morava a v Říšské župě Sudety

This article examines the architecture of the Nazi regime in two occupied cities of Czechoslovakia, Praha/Prag and Jihlava/Iglau (the latter being one of the traditionally German-speaking island in the bohemia country), and focuses specifically on the process by which Hitler youth organisations (Hitlerjugend) in case of ‘education’ and indoctrination of youth were or were not successfully established in these cities. As comparison, he takes the political-administrative centres of the Sudeten Reichsgau, Ústí/Aussig, Opava/Troppau, Karlovy Vary/Karlsbad and Liberec/Reichenberg. Drawing on Czech and German archive materials, the extensive body of modern analytical literature, and propagandist literature from the period studied, the author examines the extent to which architecture served as a projection screen for Fascist propaganda in the Occupied Eastern territories. He describes the role played by the Reichsstelle für Raumordnung and shows how the Reich’s propagandist objectives came to be reflected in a high specific typology and stylistic lexicon/configuration for the architecture of Hitler youth hostels and homes He examines the process by which these organisations were powerful implanted into the space of occupied Czechoslovakia (and Sudeten) too, a topic that has not yet been addressed in (art) history too. The building projects developed for the Protectorate (published here for the first time) and managed by the Reich’s Hitler Youth Leadership in Berlin (Kulturamt, Reichsjugendführung, RJF, Abteilung HJ) reveal the ties that existed between the construction authorities in the Reich and the Protectorate, including the Planning Committee for the City of Prague. The author asks how many German and Czech architects participated for their own profit in the Nazi system, and for future research raises the hitherto taboo question of guilt and collaboration with the Nazis and the perception of this phenomenon in art history, i.e. the measure of active cooperation of not just German but also Czech architects who contributed to the planning and implementation of projects and thereby unequivocally had a hand in consolidating the totalitarian regime and de facto in the forced „Germanification” of their own people under occupation.

Clinical primary flexor tendon repair and rehabilitation: The Bern Experience

In this chapter we present our experience with treatment of zone 2 flexor tendon repair using a six-strand repair technique combined with postoperative place-and-hold exercise. The six-strand Lim/Tsai repair technique combined with place-and-hold exercises demonstrated better digital function compared to a two-strand repair without place-and-hold exercises. Range of motion in the Lim/Tsai repair group appeared to be increased without a higher rate of ruptures but with a shorter rehabilitation period. The fact that the two groups differed in both suture techniques and rehabilitation programs made it impossible to know whether the better results in the group of Lim/Tsai were due to the six-strand repair or the place-and-hold exercises or both. Despite the obvious benefit of early active mobilization, an active motion protocol may not always be possible to apply in a substantial number of patients due to concomitant injuries, the quality of the surgical repair or patient factors (swelling, pain, limited compliance). Since August 2006 a staged rehabilitation program (“stop and go”) was introduced within our unit using early active controlled flexion (green), place-and-hold (yellow), or passive flexion exercises (red) introduced by Kleinert-Duran. Our experience using the six-strand suture repair technique and “stop and go” is outlined.

Fluid-structure interaction of an elastic pipe immersed inside a coaxial rigid pipe: a model for the Tullio phenomenon

An axisymmetric, elastic pipe is filled with an incompressible fluid and is immersed in a second, coaxial rigid pipe which contains the same fluid. A pressure pulse in the outer fluid annulus deforms the elastic pipe which invokes a fluid motion in the fluid core. It is the aim of this study to investigate streaming phenomena in the core which may originate from such a fluid-structure interaction. This work presents a numerical solver for such a configuration. It was developed in the OpenFOAM software environment and is based on the Arbitrary Lagrangian Eulerian (ALE) approach for moving meshes. The solver features a monolithic integration of the one-dimensional, coupled system between the elastic structure and the outer fluid annulus into a dynamic boundary condition for the moving surface of the fluid core. Results indicate that our configuration may serve as a mechanical model of the Tullio Phenomenon (sound-induced vertigo).