Background:Careful preoperative planning in revision cases with complex acetabular defects is crucial for optimal surgery outcome. However, in many cases, computed tomography (CT) scans cannot give a clear understanding of the pelvic destruction. Three-dimensional (3D) models-based on CT data can help surgeon in planning of complex acetabular reconstruction.Materials and Methods:We used 3D plaster pelvic models in 17 revision cases. There were 5 patients with Paprosky II C acetabular defects, 2 patients with Paprosky IIIA defects, and 10 patients with Paprosky IIIB defects (3 patients among them with pelvic discontinuity). We used 3D printer and digital 3D models based on CT scan data for 3D models printing. In 3 cases with Paprosky IIIB defects, we implanted custom-made acetabular components with the porous coating, also printed on the 3D printer.Results:In 14 cases, we used trabecular metal (TM) augments with TM cups. In 100% of cases, number and type of planned and used augments were same. In 9 (64.3%) cases, size of planned and used cups was same. In other cases, the difference was not >2 mm.Conclusions:Use of 3D plaster models for the revision hip arthroplasty planning with complex acetabular defects has shown high accuracy in the clear understanding of acetabular bone deficiency.

BACKGROUND: Osteoarthritis of the knee joint leads to a decrease in the volume of movements, a violation of the sliding of articular surfaces, and a change in the axis of the limb under load, which affects the biomechanics of walking. AIM: This study aims to compare the results of robot-assisted total knee arthroplasty (TKA) and manual techniques, their influence on the biomechanical and podometric parameters of the patient’s walk. METHODS: A prospective randomized study of 68 patients was carried out in the period from 2020 to 2021. Our follow-up period was 1 year. All patients were performed arthroplasty of one knee joint. The main Group “A” included 33 patients TKA with the use of an active robotic setting “TSolution-One” (“THINK Surgical, Inc.” [Fremont, California, USA]); the comparison Group “B” consisted of 35 patients with manual technic of TKA. We studied pain syndrome on the visual analog scale, functional state on the Oxford Knee Score (OKS) and Western Ontario and McMaster Universities Arthritis Index (WOMAC), the volume of ROM movements, and the deviation of the mechanical axis by teleroentgenography of the lower limb. Objective analysis of limb function was performed on the «Alter-G» and the «C-mill». RESULTS: Post-operative pain syndrome on the 1st day after surgery in Group A is stronger by 7.9%, but by the 5th day after surgery in Group A, the pain syndrome is lower by 14.3%. ROM in Group A is better by 16% by 3 months after surgery, after 1 year by 10%. The positioning accuracy of the implant in Group A is 30% better. There are no statistically significant differences in the OKS and WOMAC scales between the groups. The results of restoring normal step in Group A are 13.5% better than in Group B. CONCLUSIONS: Robot-assisted TKA gives more accurate alignment of the mechanical axis, which improves the biomechanics of walking.

Реферат С ростом количества первичного эндопротезирования возрастает и потребность в ревизионном эндопротезировании тазобедренного сустава. увеличивается число пациентов с тяжелыми разрушениями вертлужной впадины, у которых достижение стабильности эндопротеза становится трудной или недостижимой задачей. В таких случаях возникают показания к печати индивидуального трехфланцевого вертлужного компонента. Среди наших пациентов было 2 женщины и 1 мужчина, их средний возраст составил 60,3±19,4 лет (от 38 до 78 лет). у двух пациентов был дефект типа IIIB по классификации Paprosky с диссоциацией тазового кольца, а у одной пациентки-дефект IIIA (эта больная имела 14 операций на пораженном суставе в анамнезе). В тесном сотрудничестве с инженерами сначала распечатывали гипсовую 3D-модель таза в натуральную величину, потом проектировали имплантат с последующей его печатью из титанового порошка на 3D-принтере. Средний срок наблюдения составил 5,3±2,5 месяца (от 3 до 8 месяцев). На момент написания статьи в данной серии пациентов не было ни одного случая расшатывания импланта, вывиха или глубокой перипротезной инфекции. Средний балл по шкале Харриса у 3 пациентов перед операцией составил 27,13, а после операции 74,1, что свидетельствует о значительном улучшении уже через 3 месяца после имплантации индивидуальных вертлужных компонентов. В ранние сроки получены обнадеживающие результаты применения таких конструкций. у одной пациентки имелись сложности с имплантацией индивидуального компонента, поскольку фланцы помешали обеспечить достаточную дистракцию таза. Несмотря на это, достигнута хорошая первичная стабильность компонента. Современное программное обеспечение и 3D-принтеры позволяют значительно удешевить производство индивидуальных вертлужных компонентов. учитывая увеличение количества пациентов с тяжелыми разрушениями вертлужной впадины, 3D-технологии изготовления индивидуальных вертлужных компонентов заслуживают широкого применения, что улучшит качество лечения таких больных. Ключевые слова: диссоциация тазового кольца, ревизионное эндопротезирование тазобедренного сустава, индивидуальный вертлужный компонент, 3D-принтеры в ортопедии.

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Titanium dioxide (TiO2) nanocrystals are one of the most promising materials for modern photocatalysis applications, having unique properties such as a huge specific surface area and affordability of synthesis. However, the facile fabrication of TiO2-based photocatalysts active in regular daylight remains a major challenge. In this work, aiming to create such a nanocrystalline material by a very simple technology, we provide a detailed analysis of the paramagnetic centers (PCs) and their photoinduced reactions in N- and Nb-codoped TiO2 nanocrystals. The resulting powders show a surface area up to 170 m2/g and an intense visible-light photocatalysis of rhodamine 6G with reaction rate k = 0.087 min–1. Ti3+, N•, and O2 – PCs are observed and studied using electron paramagnetic resonance spectroscopy. We also present a new approach to the study of photoinduced processes in nanocrystalline photocatalystsa simple theoretical model of kinetics of these PCs, which well predicts their behavior and variations of their concentration under illumination. Our results indicate that the obtained Nb–N–TiO2 nanocrystals with a high concentration of PCs on the sample surface can be used in cutting-edge industries, paving the way for the most advanced photocatalytic systems operating in sunlight.

In view of the increasing number of hip joint replacement volume there remains the key issue of improving prosthesis survivorship which directly depends on the friction couple. Material and methods. The authors have analyzed five year outcomes of two bearing types (head and insert) used in hip replacement: ceramic-on-ceramic (CoC) in 324 patients and ceramic-on-polyethylene (CoP) in 300 patients. Totally 550 patients were operated in the period starting 2010 till 2014, including 74 patients underwent bilateral hip replacement. The authors divided patients based on gender and also into three age groups: 20-40, 41-60 and 61-80 years old. The largest group comprised 156 women aged 41-60 years (28.4%). Additional grouping of patients was made based on gender, age and bearing diameter.36 mm diameter bearing was characterized of the most frequent use. Functional outcomes were assessed by Harris Hip Score. Statistical analysis was made with Statistica 10 software. Statistical significant was observed at p0.05.Results.28 mm diameter bearing were rarely (19.5%) applied and mainly in women which is related to need for use of smaller acetabulum components and inability to implant a larger insert.36 mm diameter bearing were used most frequently, CoC articulation of36 mm was used in men in 34% of cases and in women – in 18.12% of cases.40 mm articulations were implanted in women two times less than in men which is related to a smaller diameter of acetabulum in women. Generally, CoC bearings were implanted more often in men which can be explained by a bigger social demand as well as a higher anti-luxation stability of large diameter bearings. Dislocations of implants occurred in 5 (0.91%) patients: in 4 patients with CoP bearingand in one patient with CoC articulation. Four revision procedures (0.64%) were made due to deep periprosthetic infection: two surgeries in each group. Harris Hip Score evaluation in CoC group demonstrated excellent and good outcomes in 99.2% of cases, and in CoP group – in 97.5% of cases.Conclusion. The authors observed no ceramic fractures or acoustic effects during 60 months follow up. It’s reasonable to increase CoC bearing diameter to achieve a better anti-luxation effect. CoC bearing selection should depend on patient’s activity and social demands but not only on the age. Based on study observations the authors forecast a higher survivorship of CoC couple within 15-20 years and expect to prove this conclusion in further studies.

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Relevance. Late deep periprosthetic infection (PJI) of the hip joint is a serious complication after arthroplasty which takes the lead among the world reasons for revision. Accurate diagnostics allows to achieve good results and select a proper treatment tactics. Purpose of the study — to evaluate the efficiency of diagnostics algorithm for late deep PJI and impact of the microbial landscape on the risk of infection recurrence. Materials and methods. The authors evaluated two groups of patients who underwent revision in the period from 2002 to 2014 and from 2015 to 2018. The first (retrospective) group included 144 patients who were not diagnosed for late deep PJI. The second (prospective) group included 157 patients who underwent detailed diagnostics for late deep PJI based on the algorithm including the analysis of x-rays, pelvic CT, triple evaluation of ESR and CRP, puncturing of affected joint and microbiology examination. The authors assessed the microbial landscape in 51 patients with late deep hip PJI. Results. In the first group 12 patients (8.3%) underwent sanation and spacer insertion during first stage of treatment, 46 patients (59.7%) after revision demonstrated positive intraoperative cultures confirming septic etiology of implant loosening, 19 patients (24.67%) had no flora growth, and no intraoperative microbiological examination was done for remaining 67 patients (46.52%). In the second group after detailed diagnostics 51 patients (32.4%) underwent removal of prosthesis and spacer insertion in the first stage, other 13 patients (8.2%) featured flora growth after revision, remaining 93 patients (59.2%) had no flora growth after revision. Recurrent PJI was observed in 21 patients (14.5%) in the first group, and in 10 patients (6.3%) in the second group. In the second group recurrent PJI was reported in 40% of patients due to microbial associations, in 30% — due to MRSA, in 20% — due to culture negative bacteria and in 10% — due to S. aureus. Conclusion. Triple examination allows to obtain an accurate diagnosis and isolate the pathogen for deep PJI. Application of such diagnostics algorithm allows to reduce 2.1 times the risk of recurrent deep PJI and to scale down 4 times the detection of type IV infection by Coventry–Tsukayama classification.