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Roach, Robert C., Peter H. Hackett, Oswald Oelz, Peter Bärtsch, Andrew M. Luks, Martin J. MacInnis, J. Kenneth Baillie, and The Lake Louise AMS Score Consensus Committee. The 2018 Lake Louise Acute Mountain Sickness Score. High Alt Med Biol 19:1–4, 2018.— The Lake Louise Acute Mountain Sickness (AMS) scoring system has been a useful research tool since first published in 1991. Recent studies have shown that disturbed sleep at altitude, one of the five symptoms scored for AMS, is more likely due to altitude hypoxia per se, and is not closely related to AMS. To address this issue, and also to evaluate the Lake Louise AMS score in light of decades of experience, experts in high altitude research undertook to revise the score. We here present an international consensus statement resulting from online discussions and meetings at the International Society of Mountain Medicine World Congress in Bolzano, Italy, in May 2014 and at the International Hypoxia Symposium in Lake Louise, Canada, in February 2015. The consensus group has revised the score to eliminate disturbed sleep as a questionnaire item, and has updated instructions for use of the score.

Stems and cups for total hip replacement (THR) must be coated with hydroxyapatite (HA), which enhances the osseo-integration of the implant. The aim of the present report was to investigate the basic influence of coating on the biomechanical situation, for example, the mechanical stress in the femur and at the femur-implant interface. Using the finite element method, three types of stems for THR were investigated: non-coated, completely HA-coated, and proximally HA-coated. All three stems were of the same design, and had identical material properties. In addition, all other conditions were identical. The results show that, in terms of the nature of the coating, the HA-coated stem is biomechanical superior to the non-coated stem, and the proximally coated stem is superior to the completely coated stem.

Using the combination ceramic on ceramic for hip prostheses, the wear rate can be reduced to less than 1 micron per million cycles. More than 20 years of experience are now available for various concepts involving alumina ceramics in THR. In the early days, monolithic ceramic cups were employed. However, since alumina ceramic has an unsatisfactory potential for bone integration, soft tissue forms at the interface, with the result that the sockets migrate and penetrate. To improve bony integration, monoblock cups surfaced with ceramic beads were introduced. For the past 10 years, there has been a trend towards the use of modular acetabular components comprising a metal shell and a liner made of Biolox forte ceramic. Two concepts for the fixation of the ceramic liners are employed: locking of the ceramic in the metal shell (CeraLock) and the sandwich concept with a polyethylene layer interposed between liner and shell. The basic design and important aspects such as diameter, range of motion, and the possibility for revision, clinical experience, and trends are discussed.

Bioceramics are used in a wide range of different clinical applications, the most important being femoral heads in total hip replacement. Because of their very attractive mechanical properties, zirconia ceramics (ZrO2) have recently been used as implant material. At the present time, two medical-grade types of zirconia are available: Mg-PSZ and Y-TZP. For the Y-TZP, an international standard (ISO) was issued. The standard is discussed, and the properties that are of importance in the field of orthopaedics are identified.

Hintergrund: Ziel der Studie war die Quantifizierung der strukturellen und funktionellen Auswirkungen akuter Höhenexposition auf die Makula. Methoden: Mittels Spektralen Domänen OCT, Fundus kontrollierter Mikroperimetrie und bester korrigierter Sehschärfe wurde die Struktur und Funktion[for full text, please go to the a.m. URL], 25. Jahrestagung der Retinologischen Gesellschaft

PURPOSE: X-linked juvenile retinoschisis (XLRS) is the most common juvenile maculopathy in men and is caused by mutations in the gene encoding retinoschisin (RS1). Evidence in the literature on the therapeutic effect of carboanhydrase inhibitors (CAIs) to treat schisis formation in the retina has remained equivocal. Here, we evaluate the effect of the CAI dorzolamide on the structural and functional disease progression in the mouse model for XLRS (Rs1h(-/y)). METHODS: Rs1h (-/y) mice were treated unilaterally with dorzolamide eye drops (Trusopt(®) 20 mg/mL) every 12 h for 2 weeks starting on postnatal day 14 (n = 27). Changes of retinal structure were monitored by confocal scanning laser ophthalmoscopy and spectral domain optical coherence tomography 12 h, 14 days, 4 weeks, 2 months, and 6 months after completion of the treatment. RESULTS: Schisis formation (peak at 3 months) preceded photoreceptor degeneration and hyper-fluorescence (peak at 7 months). Structural pathology was most severe in the superior hemi-retina with previously unreported hyper-fluorescent lesions. Quantitative analysis showed no significant differences regarding the inner or outer retinal thickness of the treated vs. untreated eyes 12 h after the completion of treatment (IRT(12 h) = -1.29 ± 1.89 μm; ORT(12 h) = 0.61 ± 2.08 μm; mean ± 95%CI) or at any later time point. CONCLUSION: Time line analysis after short-term treatment with CAI failed to show short-, intermediate-, or long-term evidence of structural improvement in Rs1h(-/y) mice. Schisis formation in the inner retina peaked at the age of 3 months and was followed by photoreceptor degeneration predominantly in the superior hemi-retina. Previously unreported hyper-fluorescent lesions co-register with structural retinal pathologies.

Seit einigen Jahren wird versucht, niedrige elektrische Ströme zur Wiederherstellung verlorener Sehfunktion oder zur Verlangsamung des Krankheitsverlaufs bei retinalen Degenerationen therapeutisch zu nutzen. Der Effekt der Elektrostimulation wird auf die Aktivierung mehrerer neuroprotektiver Faktoren[for full text, please go to the a.m. URL], 25. Jahrestagung der Retinologischen Gesellschaft

For the past 20 years, femoral heads have been successfully employed for modular total hip prostheses. To date, some 2 million ceramic femoral heads have been implanted, mainly in Europe, but also in North America and Japan. The majority of these are BIOLOX heads having a diameter of 28 mm and with the so-called European taper 12/14. The most important properties and the arguments in favour of using alumina ceramic for total hip prostheses are outlined, and safety aspects discussed. Some secondary requirements for these systems with ceramic cups or cup inserts, which are now meeting with increased interest, are considered.

Hintergrund: Stimulation mit niedrigen elektrischen Strömen hat nachgewiesenermaßen einen positiven therapeutischen Effekt bei zahlreichen Degenerationen im Tiermodell als auch beim Menschen. Ziel dieser Studie war, die Wirkung transkornealer Elektrostimulation (TES) bei Patienten mit Retinitis[for full text, please go to the a.m. URL], 24. Jahrestagung der Retinologischen Gesellschaft

Hintergrund: Gewebehypoxie spielt bei Volkskrankheiten wie Diabetes mellitus und Apoplex eine zentrale Rolle. Aber auch durch steigende Zahlen von Bergsteigern und Trekkern, die heutzutage oft in große Höhen gelangen, gewinnen die Hypoxieforschung und die Höhenphysiologie als klassische[for full text, please go to the a.m. URL], 24. Jahrestagung der Retinologischen Gesellschaft

Fretting is a problem of load-bearing implants (hip, knee) especially when modular in design and employing different materials. In contrast, fretting has not yet been observed in dental implants. In the case of ceramic femoral heads and cups (e.g. BIOLOX) no problems with fretting have so far been reported. The state-of-the-art is discussed and assessed.

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich. This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. Die Notwendigkeit künstlicher Hüftgelenke nimmt mit dem steigenden Durchschnittsalter der Bevölkerung zu. Etwa 0,1% der Bevölkerung der Welt mit „westlicher" Lebensweise benötigt ein künstliches Hüftgelenk. Die derzeit verwendeten Werkstoffe in der Hüftendoprothetik besitzen, trotz stetiger Verbesserungen, immer noch zu hohe Abriebswerte. Somit ist das Hauptziel der heutigen Forschung über Werkstoffe für die Endoprothetik, Reibungsparmer zu finden, die über einen langfristigen Zeitraum weniger Verschleiß aufweisen, bei gleichzeitiger Biokompatibilität. Derzeit ist häufig von XPE (hochvernetztes UHMW-PE) die Rede. Die sehr guten Abriebswerte von XPE geben Anlaß zu Hoffnung, ein geeignetes Material gefunden zu haben. Aber wie sieht es mit den anderen Eigenschaften aus? Unterschiedlichste Herstellungs- und Prüfmethoden erschweren den direkten Vergleich der Eigenschaften. XPE kann entweder durch Bestrahlung von UHMW-PE hergestellt werden, oder durch chemische Reaktionen mittels organischen Peroxiden. Bei der Bestrahlung können entweder Gammastrahlen oder Elektronenstrahlen zum Einsatz kommen. Die chemische Herstellung spielt im Moment noch keine große Rolle und wird deshalb im Folgenden nicht näher behandelt. In dieser Arbeit wurde versucht, aus bereits unternommenen Studien Tendenzen ableiten zu können, ob XPE den Erwartungen entspricht.