Outcome nach Gelenkersatz bei Patienten mit rheumatoider Grunderkrankung

Hintergrund Der künstliche Gelenkersatz ist für Patienten mit fortgeschrittenen rheumatisch degenerativen Gelenkveränderungen eine sinnvolle Therapieoption. Ziel dieser Studie war es, den Einfluss rheumatischer Grunderkrankungen auf postoperative Komplikationen und „patient-reported outcome“ (PRO) nach elektivem Gelenkersatz („total joint replacement“ [TJR]) zu untersuchen. Materialien und Methoden In einer retrospektiven Analyse von 9149 Patienten nach elektiver Knie- oder Hüfttotalendoprothesenimplantation (TKR und THR) wurden Komplikationsraten und PRO von Patienten mit und ohne rheumatische Grunderkrankung („rheumatic disease“ [RD]) verglichen. Multivariate logistische Regressionsmodelle wurden verwendet, um festzustellen, ob rheumatische Grunderkrankungen einen unabhängigen Risikofaktor für verschiedene Komplikationen darstellen. Ergebnisse RD-Patienten hatten nach TJR in den univariaten Analysen ein erhöhtes Risiko für internistische Komplikationen (7,1 % vs. 5,2 %, p = 0,028) und Clavien-Dindo-Grad-IV-Komplikationen (2,8 % vs. 1,8 %, p = 0,048). Dies konnte in multivariaten statistischen Analysen bestätigt werden (p = 0,034). Die Raten für operative Revisionen und chirurgische Komplikationen waren vergleichbar (2,5 % vs. 2,4 %, p = 0,485). Die Analyse des PRO ergab eine höhere Responderrate bei Patienten mit RD nach TKR (91,9 % vs. 84,5 %, p = 0,039). Die Responderrate nach THR war hingegen vergleichbar (93,4 % vs. 93,2 %, p = 0,584). Schlussfolgerung Trotz teilweise erhöhter postoperativer Komplikationsraten zeigen Patienten mit rheumatischer Grunderkrankung 1 Jahr nach Operation ein vergleichbares Outcome nach TJR. RD-Patienten nach TKR zeigen sogar höhere Responderraten. RD-Patienten sind zwar eine vulnerable Patientengruppe, können aber dennoch von einem Gelenkersatz profitieren

Large-area deposition of protective (Ti,Al)N coatings onto polycarbonate

Polycarbonate (PC) and protective (Ti,Al)N coatings exhibit extremely different material properties, specifically crystal structure, thermal stability, elastic and plastic behavior as well as thermal expansion coefficients. These differences present formidable challenges for the deposition process development as low-temperature synthesis routes have to be explored to avoid a thermal overload of the polymer substrate. Here, a large-area sputtering process is developed to address the challenges by systematically adjusting target peak power density and duty cycle. Adhering (Ti,Al)N coatings with a critical residual tensile stress of 2.2 +/- 0.2 GPa are obtained in the pulsed direct current magnetron sputtering range, whereas depositions at higher target peak power densities, realized by high power pulsed magnetron sputtering, lead to stress-induced adhesive and/or cohesive failure. The stress-optimized (Ti,Al)N coatings deposited onto PC with a target peak power density of 0.036 kW cm-2 and a duty cycle of 5.3% were investigated by cross-cut test confirming adhesion. By investigating the bond formation at the PC | (Ti,Al)N interface, mostly interfacial CNx bonds and a small fraction of (C-O)-(Ti,Al) bonds are identified by X-ray photoelectron spectroscopy, indicating reactions at the hydrocarbon and the carbonate groups during deposition. Nanoindentation reveals an elastic modulus of 296 +/- 18 GPa for the (Ti,Al)N coating, while a Ti-Al-O layer is formed during electrochemical impedance spectroscopy in a borate buffer solution, indicating protective passivation. This work demonstrates that the challenge posed by the extremely different material properties at the interface of soft polymer substrates and hard coatings can be addressed by systematical variation of the pulsing parameters to reduce the residual film stress

Caloric vestibular stimulation as a treatment for conversion disorder: a case report and medical hypothesis

Conversion disorder is a medical condition in which a person has paralysis, blindness, or other neurological symptoms that cannot be clearly explained physiologically. To date, there is neither specific nor conclusive treatment. In this paper, we draw together a number of disparate pieces of knowledge to propose a novel intervention to provide transient alleviation for this condition. As caloric vestibular stimulation has been demonstrated to modulate a variety of cognitive functions associated with brain activations, especially in the temporal–parietal cortex, anterior cingulate cortex, and insular cortex, there is evidence to assume an effect in specific mental disorders. Therefore, we go on to hypothesize that lateralized cold vestibular caloric stimulation will be effective in treating conversion disorder and we present provisional evidence from one patient that supports this conclusion. If our hypothesis is correct, this will be the first time in psychiatry and neurology that a clinically well-known mental disorder, long considered difficult to understand and to treat, is relieved by a simple or common, non-invasive medical procedure