Femorale Umbauprozesse nach totaler Hüftendoprothese Finite-Elemente-Analyse 12 Jahre nach Operation

Periprothetisches stress shielding nach totaler zementierter Hüftendoprothese (TEP) ist ein durchaus bekanntes Phänomen. Viele Autoren haben die Finite-Elemente (FE) Methode genutzt, um diese Effekte an tierischen oder menschlichen Oberschenkelknochen darzustellen. Der erste Teil dieser Studie basiert auf 11 patientenspezifischen retrospektiven in vivo CT-Datensätzen 12 Jahre nach TEP-Implantaion. Um die Kontrollgruppe zur Verfügung zu stellen, wurde auf der kontralateralen, nicht operierten Seite ein im Computer generierter Prothesenschaft in das entsprehende Femur virtuell implantiert. Im Vergleich zur nicht operierten Seite fand sich eine signifikante Reduktion der strain energy density (SED) in allen ROIs, wobei der größte Effekt im distalen Prothesenschaftbereich auftrat. Alleinig in Zone 1 wurde kein klarer Trend verzeichnet, was auf die Krafteinleitung am Trochanter major und konsekutiven Spannungsspitzen zuruckgeführt werden kann. Die medianen SED-Änderungen lagen bei -31.65% (ROI 1), -25.64% (ROI 2), -30.82% (ROI 3), -12.35% (ROI 4), -40.10% (ROI 5), -30.37% (ROI 6), -43.38% (ROI 7). Der zweite Teil dieser Studie war eine prospektive Untersuchung in Bezug auf 3D-Knochendichtemessung 5 Jahre nach totaler zementierter Hüftendoprothese als unilateraler Follow-Up via CT-Daten bei 6 Studienteilnehmerinnen. In Bezug auf die postoperative Messung ergaben sich signifikante Dichtereduktionen in ROI 2 (p=0.014), ROI 3 (p=0.023), ROI 4 (p=0.023), ROI 5 (p=0.014) and ROI 6 (p=0.014). Der größte Dichteverlust wurde in ROI 2 (median: 125.5 HU) und 3 (median: 116.7 HU) beobachtet

Bone preserving level of osteotomy in short-stem total hip arthroplasty does not influence stress shielding dimensions – a comparing finite elements analysis

Background The main objective of every new development in total hip arthroplasty (THA) is the longest possible survival of the implant. Periprosthetic stress shielding is a scientifically proven phenomenon which leads to inadvertent bone loss. So far, many studies have analysed whether implanting different hip stem prostheses result in significant preservation of bone stock. The aim of this preclinical study was to investigate design- depended differences of the stress shielding effect after implantation of a selection of short-stem THA-prostheses that are currently available. Methods Based on computerised tomography (CT), a finite elements (FE) model was generated and a virtual THA was performed with different stem designs of the implant. Stems were chosen by osteotomy level at the femoral neck (collum, partial collum, trochanter sparing, trochanter harming). Analyses were performed with previously validated FE models to identify changes in the strain energy density (SED). Results In the trochanteric region, only the collum-type stem demonstrated a biomechanical behaviour similar to the native femur. In contrast, no difference in biomechanical behaviour was found between partial collum, trochanter harming and trochanter sparing models. All of the short stem-prostheses showed lower stress-shielding than a standard stem. Conclusion Based on the results of this study, we cannot confirm that the design of current short stem THA-implants leads to a different stress shielding effect with regard to the level of osteotomy. Somehow unexpected, we found a bone stock protection in metadiaphyseal bone by simulating a more distal approach for osteotomy. Further clinical and biomechanical research including long-term results is needed to understand the influence of short- stem THA on bone remodelling and to find the optimal stem-design for a reduction of the stress shielding effect

The Level of Surface Coverage of Surgical Site Disinfection Depends on the Visibility of the Antiseptic Agent—A Virtual Reality Randomized Controlled Trial

Background: Surgical site infections (SSIs) have a significant impact on outcome associated with surgical treatment. Therefore, skin antisepsis has evolved as a standard preoperative procedure in the operating room to reduce the perioperative risk of an SSI. In their “Global Guidelines for the prevention of surgical site infections”, the World Health Organization (WHO) recommend the use of an agent with remanent additives and considers colored agents as helpful. However, colored and remanent disinfectants are not available in Germany. The aim of the present study was to investigate whether using a colored antiseptic solution increases the quality of preoperative skin antisepsis. Methods: This study was designed as a randomized, double-blinded controlled trial. To examine the level of coverage of skin antisepsis, an appropriate virtual reality (VR) environment was generated. Participants could see a movable surgical clamp with a swab in their hand. When touching the skin, the participants recognized an optical change in the appearance of the skin: Using a colored antiseptic solution resulted in orange-colored skin. Using an uncolored agent, a shiny wet look was visible without a change in natural skin color. Results: Data of 141 participants (female: 61.0% (n = 86); mean age: 28 y (Range 18–58 y, SD = 7.53 y)) were included in the study. The level of disinfection coverage was higher in the group using the colored disinfectant. On average, 86.5% (sd = 10.0) of the leg skin was covered when a colored disinfectant was used, whereas only 73.9% (sd = 12.8) of the leg skin was covered when the participants had to use an uncolored agent (p [ 0.001, effect size: f = 0.56, η2 = 0.24). Conclusions: The use of an uncolored disinfectant leads to a lower surface coverage of the perioperative skin disinfection. Thus far, it is unclear whether using uncolored disinfectants is associated with higher risks for perioperative infections compared with the use of non-remanent disinfectants. Therefore, further research is necessary and current German guidelines should be re-evaluated accordingly

Femorale Umbauprozesse nach totaler Hüftendoprothese Finite-Elemente-Analyse 12 Jahre nach Operation

Periprothetisches stress shielding nach totaler zementierter Hüftendoprothese (TEP) ist ein durchaus bekanntes Phänomen. Viele Autoren haben die Finite-Elemente (FE) Methode genutzt, um diese Effekte an tierischen oder menschlichen Oberschenkelknochen darzustellen. Der erste Teil dieser Studie basiert auf 11 patientenspezifischen retrospektiven in vivo CT-Datensätzen 12 Jahre nach TEP-Implantaion. Um die Kontrollgruppe zur Verfügung zu stellen, wurde auf der kontralateralen, nicht operierten Seite ein im Computer generierter Prothesenschaft in das entsprehende Femur virtuell implantiert. Im Vergleich zur nicht operierten Seite fand sich eine signifikante Reduktion der strain energy density (SED) in allen ROIs, wobei der größte Effekt im distalen Prothesenschaftbereich auftrat. Alleinig in Zone 1 wurde kein klarer Trend verzeichnet, was auf die Krafteinleitung am Trochanter major und konsekutiven Spannungsspitzen zuruckgeführt werden kann. Die medianen SED-Änderungen lagen bei -31.65% (ROI 1), -25.64% (ROI 2), -30.82% (ROI 3), -12.35% (ROI 4), -40.10% (ROI 5), -30.37% (ROI 6), -43.38% (ROI 7). Der zweite Teil dieser Studie war eine prospektive Untersuchung in Bezug auf 3D-Knochendichtemessung 5 Jahre nach totaler zementierter Hüftendoprothese als unilateraler Follow-Up via CT-Daten bei 6 Studienteilnehmerinnen. In Bezug auf die postoperative Messung ergaben sich signifikante Dichtereduktionen in ROI 2 (p=0.014), ROI 3 (p=0.023), ROI 4 (p=0.023), ROI 5 (p=0.014) and ROI 6 (p=0.014). Der größte Dichteverlust wurde in ROI 2 (median: 125.5 HU) und 3 (median: 116.7 HU) beobachtet

Gender differences in blood transfusion strategy for patients with hip fractures - a retrospective analysis

Finanziert aus dem DFG-geförderten Open-Access-Publikationsfonds der Universität Siegen für ZeitschriftenartikelBackground: In the last decades, transfusion therapy with allogenic blood has progressively shifted to a more restrictive approach. The current study analyzed the transfusion practice and transfusion-associated factors in a regional trauma center over the course of five years. Methods: Retrospective analysis of all patients undergoing surgery for hip fractures in a level 1 trauma center of an academic teaching hospital from 2010 to 2014 (n=650). The number of transfused packed red blood cells (PRBCs), preoperative Hb concentrations, and intensive care unit (ICU) and hospital length of stay (LOS) were analyzed. A logistic regression analysis was performed to evaluate transfusion and ICU LOS-associated risk factors. (Ethical Review Board approval: 2015-497-f-S). Results: From 2010 to 2014 the average number of PRBCs transfused per patient decreased continuously despite similar preoperative Hb levels. During the same period, ICU LOS increased while hospital LOS decreased. Advanced patient age, preoperative Hb concentrations, surgical complications, and ICU LOS were associated with increased transfusion requirements. Although preoperative Hb levels were lower, females received fewer PRBCs compared to males. Conclusion: Over the course of five years, a restrictive transfusion strategy was implemented within clinical practice in patients undergoing surgery for hip fractures. In parallel, a significant reduction in the hospital LOS and an increased ICU LOS was noted. Whether there is an association between increased ICU LOS and decreasing hospital LOS and whether there is a gender effect on transfusion requirements in patients with surgery for hip fractures should be subject to further research

Risk perception of blood transfusions – a comparison of patients and allied healthcare professionals

Background: Due to an increasing demand in health care services plans to substitute selective physician-conducted medical activities have become attractive. Because administration of a blood transfusion is a highly standardized procedure, it might be evaluated if obtaining a patient’s consent for a blood transfusion can be delegated to allied healthcare professionals. Physicians and patients perceive risks of transfusions differently. However, it is unknown how allied healthcare professionals perceive risks of transfusion-associated adverse events. Methods: Patients (n = 506) and allied healthcare professionals (n = 185) of an academic teaching hospital were asked to quantify their concerns about transfusions including five predefined transfusion-associated risks and their incidences. Results: Blood transfusions were considered to be generally harmful by 10.9% of patients and 14.6% of caregivers (P = 0.180). Among all surveyed patients, 36.8% were worried about infection-transmissions (caregivers: 27.6%; P = 0.024). Compared to 5.4% of caregivers, 13.6% of patients believed infection-transmission was a frequent complication (P = 0.003). Caregivers ranked the risks of receiving an AB0-mismatch transfusion (caregivers: 29.7% vs. patients: 19.2%, P = 0.003) or a transfusion-associated allergic reaction (caregivers: 17.3% vs. patients: 11.1%, P = 0.030) significantly higher than patients and were aware of the high incidence of transfusion-associated fever (caregivers: 17.8% vs. patients: 8.3%, P < 0.001). Conclusion: A significant part of interviewees perceived transfusions as a general health hazard. Patients perceived infection-transmissions as the most frequent and greatest transfusion-associated threat while caregivers focused on fatal AB0-mismatch transfusions and allergic reactions. Understanding the patients’ main concerns about blood transfusions and considering that these concerns might differ from the view of healthcare professionals might improve the process of shared decision making. Electronic supplementary material The online version of this article (10.1186/s12913-018-2928-x) contains supplementary material, which is available to authorized users

The Level of Surface Coverage of Surgical Site Disinfection Depends on the Visibility of the Antiseptic Agent—A Virtual Reality Randomized Controlled Trial

Background: Surgical site infections (SSIs) have a significant impact on outcome associated with surgical treatment. Therefore, skin antisepsis has evolved as a standard preoperative procedure in the operating room to reduce the perioperative risk of an SSI. In their “Global Guidelines for the prevention of surgical site infections”, the World Health Organization (WHO) recommend the use of an agent with remanent additives and considers colored agents as helpful. However, colored and remanent disinfectants are not available in Germany. The aim of the present study was to investigate whether using a colored antiseptic solution increases the quality of preoperative skin antisepsis. Methods: This study was designed as a randomized, double-blinded controlled trial. To examine the level of coverage of skin antisepsis, an appropriate virtual reality (VR) environment was generated. Participants could see a movable surgical clamp with a swab in their hand. When touching the skin, the participants recognized an optical change in the appearance of the skin: Using a colored antiseptic solution resulted in orange-colored skin. Using an uncolored agent, a shiny wet look was visible without a change in natural skin color. Results: Data of 141 participants (female: 61.0% (n = 86); mean age: 28 y (Range 18–58 y, SD = 7.53 y)) were included in the study. The level of disinfection coverage was higher in the group using the colored disinfectant. On average, 86.5% (sd = 10.0) of the leg skin was covered when a colored disinfectant was used, whereas only 73.9% (sd = 12.8) of the leg skin was covered when the participants had to use an uncolored agent (p f = 0.56, η2 = 0.24). Conclusions: The use of an uncolored disinfectant leads to a lower surface coverage of the perioperative skin disinfection. Thus far, it is unclear whether using uncolored disinfectants is associated with higher risks for perioperative infections compared with the use of non-remanent disinfectants. Therefore, further research is necessary and current German guidelines should be re-evaluated accordingly

Additional file 1: of Risk perception of blood transfusions – a comparison of patients and allied healthcare professionals

Questionnaire. (PDF 55 kb