Control system of storage containers filling in the uranyl nitrate crystallization process in a linear crystallizer

This article presents a model of a storage container of linear crystallizer. On the base of this model two independent control system of storage containers filling in a uranyl nitrate crystallization process were suggested. The use of the proposed control systems is necessary for the timely switching of the storage container to an empty one. For the proposed control systems, simulation results are presented in the SimSar software. The developed mathematical model and the control system could be used for optimization process during the design and adjustment of equipment

CLINICAL CASE OF INFECTION TREATMENT AFTER ARTHROSCOPIC REPAIR OF ROTATOR CUFF

Actual principles of implant associated infection treatment require determined approach already in early symptoms stage. The paper describes a clinical case of infectious complication treatment after bone-tendon repair of supraand infraspinous muscles with anchors. Following conservative treatment with no positive dynamics the authors performed two stage surgical treatment of implant associated shoulder infection. First stage included radical debridement, removal of implants and filling the defect in left humeral head with antibacterial spacer. Following infection eradication, the second stage included arthroscopy of the left shoulder, spacer removal, grafting of defect and revision left rotator cuff repair using anchors.The present clinical case demonstrates a lack of alertness in respect of possible postoperative infection, insufficient treatment experience of general orthopaedic surgeons and overall complexity of radical surgical procedure for treatment of such patients

Difficult-To-Treat Periprosthetic Hip Infection: Outcomes of Debridment

Purpose of the study — to compare management efficiency for difficult-to-treat periprosthetic hip joint infection (PJI) during resection arthroplasty with grafting by vastus lateralis pedicle island flap in comparison with insertion of an antimicrobial-loaded cement spacer. Material and Methods. 132 patients were included into the retrospective study who underwent treatment from 2012 until 2018 including removal of orthopaedic implant, radical surgical debridement of infection focus, resection arthroplasty with grafting by vastus lateralis pedicle island muscle flap (PMF group — 57 patients) or insertion of antibacterial-loaded cement spacer (AMS group — 75 patients). The authors examined medical histories, nature of infection process, infection agent type, laboratory data in respect of systemic inflammation, size of bone defects, follow up status and remission of PJI in the late period. Results. 89.4% of patients (n = 51) who underwent grafting by vastus lateralis pedicle island flap had a history of 3 and more prior surgical procedures in the same area. At the same time the share of such patients in the spacer group was only 38.6% (n = 29) (p<0.0001) while the share of patients with two and more recurrences was 78.9% (n = 45) and 25.3% (n = 19), respectively (p<0.0001). No significant variances were observed between the groups in respect of type composition of PJI microbial infection agents. The infection in a vast majority of patients in both groups was caused by microbial association: 77.2% and 72.0% in PMF and AMS groups, respectively. In the early postoperative period secondary revision of surgical site was performed in 35% and 28% of cases in PMF group (n = 20) and AMS group (n = 21), respectively, including due to recurrent infection in 15.8% and 28% of cases, respectively. Stable remission of difficult-to-treat PJI in PMF group was 96.5% and 45.3% in AMS group. Conclusion. Despite some cases that required secondary revisions in early postoperative period the resection arthroplasty in combination with pedicle muscle flap can be considered a surgery of choice for management of recurrent difficultto-treat PJI with feasible re-implantation of prosthesis against the stable remission of infection

Adverse Trends in the Etiology of Orthopedic Infection: Results of 6-Year Monitoring of the Structure and Resistance of Leading Pathogens

Osteomyelitis remains one of the most intractable diseases. The nature of the pathogen and its resistance to antibiotics significantly affect the outcome and cost of treatment.The aim of the study: to analyze the dynamics of the spectrum and antibiotic resistance of the leading pathogens of orthopedic infection for the period 2012– 2017.Material and methods. The structure of pathogens isolated from the focus of infection from 2774 patients with periprosthetic infection and chronic osteomyelitis was retrospectively analyzed. Antibiotic resistance of the leading pathogens that occupied more than 4% in the species structure was studied. Comparative analysis of changes in the spectrum of pathogens and antibiotic resistance was carried out for the periods 2012-2013, 2014–2015 and 2016-2017. Epidemiological analysis was performed in the program „microbiological monitoring system” Microbe-2. Statistical processing of the obtained data was carried out using the Z-criterion.Results. From 2774 patients with orthopedic infection have been isolated 4359 strains, in the structure of which about 73.5% were occupied by S. aureus, S. epidermidis, E. faecalis, E. faecium, P. aeruginosa, Acinetobacter sp. representatives of the family Enterobacteriacea. In 27% of the cases, microorganisms of other species were identified. Microbial associations were identified in 19.4% of cases. In the structure of the leading Gram(+) pathogens, a significant decrease in the incidence of S. aureus was detected, while the share of S. epidermidis increased significantly. Among the leading Gram(-) microorganisms, a significant increase in the proportion of representatives of the fam. Enterobacteriacea was found, against the background of a decrease in the share of Acinetobacter sp. and P. aeruginosa. The level of resistance of MSSA to the studied antibiotics ranged from 0.1 to 8.8%, for MSSE the spread was from 1.9 to 16.7%. Negative dynamics of growth of resistance of non-fermenting bacteria is established. The strains of Acinetobacter sp. demonstrated greater resistance to tested antibiotics in comparison with P. aeruginosa.Conclusion. An increase in the role of S. epidermidis and K. pneumoniae in the etiology of orthopedic infection was established. The revealed increase in the resistance of microbial pathogens to most tested and used antibiotics should be taken into account in the appointment of empirical antibiotic therapy. The extremely high frequency of resistance of gram-negative bacteria to cephalosporins and fluoroquinolones excludes the possibility of their empirical use, which requires the management of carbapenems in the starting treatment regimens. High resistance to fluoroquinolones limits the ability of oral antibiotic therapy in patients with periprosthetic infection