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Purpose Clinical outcome of TKA remains unsatisfactory in 20% of the cases. Navigation has added accuracy in terms of alignment, but has improved clinical outcome only in small series with gap-balanced techniques. Reason for that could be that conventional gap balanced TKA determines gaps in extension and 90° of flexion only. Furthermore, measurement is only static. Therefore, the accuracy of a new dynamic navigation software which allows gap assessment throughout the entire range of motion was tested. The purpose of this study was to investigate the accuracy and reliability of dynamic gap testing during gap-balanced TKA. Methods In two different centres, a total of 65 TKA procedures were performed in a tibia-first, gap-balanced technique using a new CAS software. At the same and at different time points of surgery, two different surgeons performed gap measurement to provide inter-observer reliability data and repeated gap measurement to provide intra-observer reliability data. These gap measurements were performed throughout the entire ROM under dynamic stress testing to detect maximum gap values. Results CAS surgery was able to produce correct coronal alignment in 96.4% of the cases (within 3° mechanical alignment). Both inter-observer and intra-observer reliabilities were excellent for gap values throughout the entire ROM. Inter-observer bias of deviation 0.05; 95% limits of agreement of − 2.1 to + 2.21 mm. Intra-observer bias of deviation 0.09; 95% limits of agreement of − 2.27 to + 2.44 mm. Conclusions This new CAS software in combination with the presented dynamic gap measurement provides accurate gap values and therefore facilitates balancing TKA. This technique works reproducibly for different surgeons and has proven robustness also for repeated measurements of any surgeon in this study.

Purpose Aseptic loosening is a serious complication after total joint arthroplasty. Plain radiography, along with clinical signs of prosthesis loosening, is the technique of first choice to evaluate loosening of joint replacements. Nevertheless, radiographical signs of osteolysis may not be apparent until progressed stages of loosening. Thus the search for alternative diagnostic methods is of great importance. The purpose of the present study was to evaluate the potential diagnostic significance of TRAP 5b, Osteocalcin, CrossLaps and Bone ALP for aseptic loosening of total joint replacements. Methods Thirty-seven patients (25 women, 12 men, mean age 65 years, age range 54–76 years) treated with revision surgery due to clinically and radiologically confirmed late aseptic prosthesis loosening were examined prospectively. Serum levels of TRAP 5b, Osteocalcin, CrossLaps and Bone ALP were compared with a matched control group ( n  = 39). Results We found a significant decrease in TRAP 5B level in patients with aseptic loosening. Bone ALP and Osteocalcin as markers of osteoblast activity, and CrossLaps as another resorption marker did not allow any prediction of bone remodeling in this late phase of loosening. Conclusion In the „late“ phase of aseptic joint replacement loosening, no increase of TRAP 5b and therefore no increase of osteoclast number and activity was measurable. Thus, in this situation an anti-osteolytic therapy with a bisphosphonate or denosumab would not gain any further benefit.

Purpose Navigated, gap-balanced adjusted mechanical alignment (AMA) including a 0° varus tibial cut and modification of angles and resections of the femoral cuts to obtain optimal balance accepting minor axis deviations. Objectives of this study were (1) to analyse to what extent AMA achieves the goals for leg alignment and gap balance, and (2) in what percentage non-anatomical cuts are needed to achieve these goals. Methods Out of 1000 total knee arthroplasties (TKA) all varus knees (hip-knee-ankle (HKA) angle < 178°; n  = 680) were included. All surgeries were performed as computer assisted surgery (CAS) in AMA technique. CAS data at the end of surgery were analysed with respect to HKA and gap-sizes. All bone cuts were quantified. Depending on the amount of deformity, a subgroup analysis was performed. It was analysed whether the amount of deformity influences the non-anatomical cuts by correlation analysis. Results AMA reached the goals for postoperative HKA (3° corridor) in 636 cases (93.5%). While extension and flexion gap balance were achieved in more than 653 cases (96%), flexion and extension gap size were equalled in 615 knees (90.4%). The resections of the lateral tibia plateau and distal and posterior medial femoral condyle were anatomical (Tibia: 7.0 ± 1.7 mm; medial condyle distal: 7.8 ± 1.4 mm; medial posterior: 8.2 ± 1.8 mm). The number of non-anatomical resections for those cuts were low; 67 (9.9%); 24 (3.5%); 32 (4.7%). For the medial tibia plateau and the lateral posterior condyle, the cuts were non-anatomical in a high percentage of cases; Tibia: 606 (89.1%), lateral posterior condyle: 398 (58.5%). Moderate but significant correlations were found between resection differences and amount of deformity (medio-lateral: tibia: 0.399; distal femur: 0.310; posterior femur: 0.167). No correlations were found between resection differences and gap values. Conclusion AMA reaches the intended target for HKA and gap balance in over 612 (90%) of cases and maintains the medial femoral condyle anatomically. Non-anatomical tibial resection causes increased external rotation of the femoral component and by that non-anatomical cut of the posterior lateral condyle. Nonanatomical resections of AMA might be one reason for the persisting high rate of unsatisfied patients after TKA. Anatomical and individual alignment philosophies might help to reduce this rate of dissatisfaction.

Purpose The technique of adjusted mechanical alignment (AMA) in total knee arthroplasty (TKA) has been described to achieve alignment and balancing goals in varus knees in a high percentage, albeit at the price of non-anatomical bone cuts. The purpose of this study was to analyze (1) whether AMA achieves similar alignment and balancing results in different types of deformity and (2) whether they can be achieved without altering the native anatomy. Methods A series of 1000 patients with hip–knee–ankle (HKA) angles from 165° to 195° were analyzed. All patients were operated using AMA technique. According to the preoperative HKA angle, three groups of knee phenotypes (varus, straight, valgus) were defined. The bone cuts were analyzed for being anatomic (< 2 mm deviation of individual joint surface) or non-anatomic (> 4 mm deviation of individual joint surface). Results AMA reached the goals for postoperative HKA in over 93% in every group (varus: 636 cases, 94%, straight: 191 cases, 98%, valgus: 123 cases, 98%). In 0° extension, the gaps were balanced in varus knees in 654 cases (96%), in straight knees in 189 cases (97%) and in valgus knees in 117 cases (94%). A balanced flexion gap was found in a similar number of cases (varus: 657 cases, 97%, straight: 191 cases, 98%, valgus: 119 cases, 95%). In the varus group, non-anatomical cuts were performed at the medial tibia (89%) and the lateral posterior femur (59%). The straight group showed similar values and distribution for non-anatomical cuts (medial tibia: 73%; lateral posterior femur 58%). Valgus knees showed a different distribution of values, being non-anatomical at the lateral tibia (74%), distal lateral femur (67%) and posterior lateral femur (43%). Conclusion In all knee phenotypes, the AMA goals were achieved in a high percentage by altering the patients’ native anatomy. In varus knees, the alignment was corrected by non-anatomical cuts at the medial tibia, and in valgus knees at the lateral tibia and the lateral distal femur. All phenotypes showed non-anatomical resections on the posterior lateral condyle in approximately 50% of cases. Level of evidence III.

Individual alignment techniques have been introduced to restore patients’ unique anatomical variations during total knee arthroplasty. The transition from conventional mechanical alignment to individualised approaches, with the assistance of computer and/or robotic technologies, is challenging. The objective of this study was to develop a digital training platform with real patient data to educate and simulate various modern alignment philosophies. The aim was to evaluate the training effect of the tool by measuring the process quality and efficiency, as well as the post-training surgeon’s confidence with new alignment philosophies. Based on 1000 data sets, a web-based interactive TKA computer navigation simulator (Knee-CAT) was developed. Quantitative decisions on bone cuts were linked to the extension and flexion gap values. Eleven different alignment workflows were introduced. A fully automatic evaluation system for each workflow, with a comparison function for all workflows, was implemented to increase the learning effect. The results of 40 surgeons with different experience levels using the platform were assessed. Initial data were analysed regarding process quality and efficiency and compared after two training courses. Process quality measured by the percentage of correct decisions was increased by the two training courses from 45% to 87.5%. The main reasons for failure were wrong decisions on the joint line, tibia slope, femoral rotation, and gap balancing. Efficiency was obtained with a reduction in time spent per exercise from 4 min 28 s to 2 min 35 s (42%) after the training courses. All volunteers rated the training tool as helpful or extremely helpful for learning new alignment philosophies. Separating the learning experience from OR performance was mentioned as one of the main advantages. A novel digital simulation tool for the case-based learning of various alignment philosophies in TKA surgery was developed and introduced. The simulation tool, together with the training courses, improved surgeon confidence and their ability to learn new alignment techniques in a stress-free out-of-theatre environment and to become more time efficient in making correct alignment decisions.

Purpose In a prospective, consecutive study, a navigation-based technique for calculating the sliding distance of the lateral epicondyle prior to osteotomy in TKA surgery of fixed valgus deformity has been developed, and early results have been evaluated. Materials and methods Twenty-seven knees with a fixed valgus deformity undergoing TKA received this new treatment. Clinical scores and radiograph evaluation were performed preoperatively and 1-year postoperatively. Static and dynamic kinematic data were obtained from navigation at the beginning and at the end of surgery. Results The calculated amount of sliding distance varied between 5 and 16 mm. No complications regarding this technique occurred. All clinical scores showed a significant improvement, and radiological evaluation showed a correction of all parameters in 100 % of patients. Conclusion With this navigation-based technique, it is possible to calculate the amount of sliding distance prior to osteotomy and obtain excellent early results. All axes have been corrected completely, and flexion and extension gaps were balanced. No specific complications of this technique have occurred so far. Level of evidence II.

Background Plants under herbivore attack release volatiles that attract natural enemies, and herbivores in turn avoid such plants. Whilst herbivore-induced plant volatile blends appeared to reduce the attractiveness of host plants to herbivores, the volatiles that are key in this process and particularly the way in which deterrence is coded in the olfactory system are largely unknown. Here we demonstrate that herbivore-induced cotton volatiles suppress orientation of the moth Spodoptera littoralis to host plants and mates. Results We found that ( E )-4,8-dimethyl-1,3,7-nonatriene (DMNT), an induced volatile, is key in herbivore deterrence: DMNT suppressed plant odour- and pheromone-induced behaviours. We then dissected the neurophysiological basis of this interaction. DMNT-responding glomeruli were also activated by other plant compounds, suggesting that S. littoralis possesses no segregated olfactory circuit dedicated exclusively to DMNT. Instead, DMNT suppressed responses to the main pheromone component, ( Z )-9-( E )-11-tetradecenyl acetate, and primarily to ( Z )-3-hexenyl acetate, a host plant attractant. Conclusion Our study shows that olfactory sensory inhibition, which has previously been reported without reference to an animal’s ecology, can be at the core of coding of ecologically relevant odours. As DMNT attracts natural enemies and deters herbivores, it may be useful in the development or enhancement of push-pull strategies for sustainable agriculture.

In this study, we aim to report the persistent presence of anti‐SARS‐CoV‐2 immunoglobulins in pre‐immunized mare offspring. Three mares from Vital Brazil Institute were pre‐immunized with recombinant SARS‐CoV‐2 spike protein and became pregnant during this period. After parturition, the mares’ serum and colostrum/milk and foal serum were collected over 6 weeks. Our results have shown high and persistent presence of IgG and neutralizing antibodies over the weeks not only in the mares’ serum, as expected, but in mares’ colostrum/milk and foal serum as well—what were very surprising. This peculiar approach, which we were able to track specifically antibodies produced from an antigen inoculated only in the pregnant mares’, is distinct from the usual methodology applied in the current reports in this field. Thus, together, these data and our methodology could lead to new approaches to better understanding about equine passive immunization by newborn's breast‐feeding. This study investigated the total and neutralizing antibodies transferred to offspring from three mares from Vital Brazil Institute that were pre‐immunized with recombinant SARS‐CoV‐2 trimeric spike protein. They became pregnant during the immunization protocol. After parturition, the mare's serum and colostrum and foal serum showed high total and neutralizing antibodies against SARS‐CoV‐2 over 6 weeks.

OBJECTIVES We report on real-world safety and performance outcomes of minimally invasive rapid-deployment aortic valve replacement using the EDWARDS INTUITY Elite aortic valve system. METHODS The study valve system was used in a European, prospective, multicentre post-market study. Various procedural, haemodynamic and clinical outcomes were evaluated through 6 months of post-implant. RESULTS A total of 276 patients out of 280 (98.6%) enrolments were successfully implanted with the study valve using a minimally invasive approach between February 2016 and April 2017. Of these 276 patients, 240 (87%) underwent partial sternotomy and 36 (13%) patients underwent right thoracotomy. Mean cross-clamp time was 51.9 [standard deviation (SD): 16.0] min. From baseline to 6 months, the mean effective orifice area increased from 0.8 (SD: 0.3) to 1.8 (SD: 0.6) cm2 and the mean systolic gradient decreased from 46.0 (SD: 14.1) to 8.8 (SD: 3.7) mmHg. After 6 months, 70.7% and 26.4% of patients were in New York Heart Association class I and II, respectively. Freedom from death, major bleeding, major paravalvular leak, reoperation and device explant at 6 months were 96.0%, 98.5%, 98.8%, 99.2% and 99.2%, respectively. CONCLUSIONS These results demonstrate that the study valve is a safe and effective choice for patients undergoing aortic valve replacement via minimally invasive surgery. Name and registration of registry MISSION (Assessing clinical outcomes using the EDWARDS INTUITY Elite Valve System in isolated AVR using Minimally InvaSive Surgery In a EurOpean multi-ceNter, active, post-market registry). clinicaltrials.gov ID #NCT02907463.

We compared the responses of two estuarine phytoplankton communities, one from a temperate (Chubut River estuary (CH), Argentina) and one from a sub-tropical site (Babitonga Bay (BB), Brazil), in a scenario of nutrient enrichment under solar ultraviolet radiation (UVR) exposure. Seawater samples were exposed in microcosms to two nutrients, ambient vs. enriched, and two radiation conditions, with and without UVR, and exposed to solar radiation for 4 days. We evaluated the short- (PSII photochemistry, during 90 min light and 90 min dark cycles, before and after the 4 days of acclimation) and mid-term effects (growth and taxonomic changes) of the phytoplankton communities. Before acclimation, short-term UVR effects were dominant in CH, whereas in BB, nutrient effects prevailed. Such differences were related to the previous light history of the cells and to the ambient nutrient status. After acclimation, an overall improvement of the photosynthetic performance was observed at both sites, either by reducing the relative inhibition or by increasing the recovery of the effective photochemical quantum yield. Interactive effects of UVR and nutrients on growth at CH were antagonistic, while at BB, no differences were observed between the interactive and the sum of effects. Part of the differences in the mid-term observed responses can be attributed to taxonomic changes, with the CH community dominated by diatoms throughout the experiment, but with a shift from a diatom to a flagellate-dominated community in BB. Temperature differences between both sites might have favored higher growth rates and flagellates dominance in BB under the nutrient enriched conditions.