Development and evaluation of new cementless revision acetabular components for total hip arthroplasty / type TC /

Development and evaluation of new cementless revision acetabular components for total hip arthroplasty / type TC / Objective: The aim of the clinical part of the study was to introduce a new revision oval cup type TC, and evaluate its reliability and utility in revision endoprosthesis. Due to the different structure of the implant, we aimed to objectively demonstrate the remodeling of bone tissue in its vicinity. In the experimental part of the work we verified the hypothesis that the use of locking screws has an effect on the bond strength of the implant with bone tissue, and therefore on the primary stability of the acetabular component. Method: We evaluated 31 patients that underwent revision hip surgery between 2004 and 2008. The mean follow-up was 7.1 years (range 5.3 to 9.3 years, minimum 5 years after surgery). Osteointegration of the implant and remodeling of bone tissue around the implant and its ribs were evaluated by digital radiography and computed tomography, and clinical results according to Harris. The experiment was based on the execution of pull-out tests after the implantation of TC cups in cadaveric bovine pelves. We evaluated the dependence of tensile forces in the axis of the implant on extraction of the metal cup from the bone bed. Four tests were conducted with the cup fixed..

Maternal Exposure Results in Long-Term Deoxynivalenol Persistence in Piglets’ Plasma and Modulates the Immune System

Deoxynivalenol (DON)-contaminated feed represents a serious problem for pigs due to their high sensitivity to its toxicological effects. The aim of the present study was to evaluate the impact of intrauterine DON exposure on the immune system of piglets. Pure DON was intravenously administered to sows at the end of gestation (during the last 2–3 days of gestation, one dose of 300 µg per day). The plasma concentration of DON was analyzed using liquid chromatography combined with high-resolution Orbitrap-based mass spectrometry (LC–MS/MS (HR)) and selected immune parameters were monitored six times in piglets from birth to 18 weeks. DON was found in the plasma of 90% of newborn piglets at a mean concentration of 6.28 ng/mL and subsequently, at one, three, and seven weeks after birth with decreasing concentrations. Trace amounts were still present in the plasma 14 weeks after birth. Flow cytometry revealed a significant impact of DON on T lymphocyte subpopulations during the early postnatal period. Lower percentages of regulatory T cells, T helper lymphocytes, and their double positive CD4+CD8+ subset were followed by increased percentages of cytotoxic T lymphocytes and γδ T cells. The capacity to produce pro-inflammatory cytokines was also significantly lower after intrauterine DON exposure. In conclusion, this study revealed a long-term persistence of DON in the plasma of the piglets as a consequence of short-term intrauterine exposure, leading to altered immune parameters

Magnification of digital hip radiographs differs between clinical workplaces

<div><p>Preoperative planning for total hip arthroplasty includes templating on anteroposterior radiographs. It is necessary to consider radiographic magnification in order to scale templates accurately. Studies dealing with hip templating report different values of radiographic magnification. It is not clear if the observed difference in magnification between the studies is caused by variability in studied groups, methodology or instrumentation. We hypothesize that there is a difference in magnification between clinical workplaces. Within this study, radiographic magnification was estimated on 337 radiographs of patients after total hip surgery from five orthopaedic departments in the Czech Republic. Magnification was determined for each patient as a ratio between diameter of implanted femoral head measured on radiogram and its true size. One-way ANOVA revealed significant differences in magnification between workplaces (F(4,332) = 132, p≤0.001). These results suggest that radiographic magnification depends on the workplace where it is taken or more precisely on radiographic device. It indicates potential limits in generalizability of results of studies dealing with preoperative planning accuracy to other institutions.</p></div

Radiographic magnification determined in clinical studies.

<p>Femoral head after THA is used as a magnification reference.</p

Boxplot of radiographic magnification.

<p>Hip radiographic magnification measured from radiographs of patients after total hip replacement at five hospitals.</p

Radiographic magnification obtained at five workplaces.

<p>Radiographic magnification obtained at five workplaces.</p

Clinics, X-ray devices and patients included in the study.

<p>Clinics, X-ray devices and patients included in the study.</p

Schematic diagram showing radiological magnification.

<p>(A and B) various positions of hip joint over the table, (A vs. B) various radiological setups.</p