FIVE YEAR OUTCOMES OF CERAMIC-ОN-CERAMIC AND CERAMIC-ОN-POLYETHYLENE BEARINGS IN HIP JOINT REPLACEMENT

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 p<0.05.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

CUSTOMIZED ACETABULAR COMPONENTS IN REVISION HIP ARTHROPLASTY

In recent years, there is a trend of increasing demand for revision hip arthroplasty. Among these patients there are many with complex acetabular defects, including patients with pelvic discontinuity. To ensure stability for revised acetabular components in such cases becomes a challenging or unachievable task. Such defects give indications for printing customized tri-flange acetabular component. The authors analysed own experience of creating and applying custom made acetabular components in 3 patients with complex acetabular defects. Material and methods. Among the patients there were 2 women and 1 man. Average age was 60,3±19,4 years (38 to 78 years). Two patients had III B defects with pelvic discontinuity and one patient had III A defect by Paprosky classification. As the first step, the authors in collaboration with engineers printed a plaster full size pelvic 3D model, as the second step a customized tri-flange acetabular component was designed and printed. Harris Hip Score was evaluated preoperatively and 3 months postoperatively. Results. Average follow-up period was 5,3±2,5 months (3 to 8 months). The authors observed no cases of implant loosening, dislocation or deep periprosthetic infection. Average Harris Hip Score before surgery was 27,13 and after surgery – 74,1 indicating a significant improvement in 3 months postoperatively. Conclusion. Indications for use of individual acetabular components in reported patients correspond to indications formulated by Berasi et al. The authors obtained encouraging early follow-up outcomes that correspond to data of other authors. In one patient certain difficulties were reported due to insufficient pelvic distraction. Component’s flanges prevented achieving adequate pelvic distraction. Nevertheless, good primary stability was achieved. Modern software and 3D metal printers can significantly reduce the production cost of customized acetabular components. Application of this technology can be widened to various orthopaedic centres and will undoubtedly improve the quality of treatment for such patients

TOTAL HIP AND KNEE ARTHROPLASTY IN PATIENTS WITH CHRONIC KIDNEY DISEASE (REVIEW)

Chronic kidney disease is a common medical problem. It is characterized by a peculiar course leading to renal osteodystrophy resulting in increased risk of fractures and joint lesions with the concomitant need for major joints arthroplasty. Moreover, a wide spectrum of organ and metabolic deteriorations due to renal insufficiency causes a more complicated postoperative period with higher mortality and frequent infectious, cardiovascular, hemorrhagic, thrombotic and surgical complications. The highest risks are noted in patients on long lasting hemodialysis.To improve the arthroplasty outcomes an adequate correction of anemia, bone-mineral and electrolyte disorders, arterial hypertension and optimization of dialytic modalities must be ensured

Hip Arthroplasty in Patients with Hip Dysplasia by Individual Augments: Early Results

Relevance. The altered hip anatomy makes total hip arthroplasty in patients with hip dysplasia a difficult and non-standard task. The acetabulum is deformed with femoral head in subluxation or dislocation. The most important task of surgery is to restore the anatomical position of the hip center of rotation.The study purpose — to evaluate the early results of hip arthroplasty with individual augments in the patients with hip dysplasia.Materials and Methods. Since 2017, nine patients with hip dysplasia have undergone surgery using individually printed augments. All patients were women with average age 51.3±14.5 years (23 to 67). The mean follow-up was 14.3±5.2 months (8 to 20). Patients were evaluated using follow-up X-rays, a visual analogue scale (VAS), Harris Hip Score (HHS), and Western Ontario and McMaster Universities Arthritis Index (WOMAC).Results. There was no a single case of endoprosthesis dislocation, loosening of components, prosthetic infection or revision surgery in the analyzed group of patients. The planned sizes of the acetabular components were equal to the placed in 7 cases (77.8%). In two cases (22.2%), the acetabular components were 2 mm larger because the surgeon wanted a greater degree of press-fit fixation. The restoration of the anatomical position of the acetabular component was noted. Before the surgery, the femoral head was on average 22.7±11.7 mm (10 to 43 mm) higher. After the surgery, the level of the acetabular component was on average only 0.75±2.1 mm (1.7 to 5 mm), p = 0.008. Also, there were a decrease in pain and quality of life improvement by VAS from 6.78±1.39 before surgery to 2.22±1.09 at follow-up (p = 0.007), HHS increase from 30.5±18. 1 to 77.59±14.26 (p = 0.008), and WOMAC decrease from 73.3±14.1 to 18.22±8.2 (p = 0.008).Conclusion. The individually printed augments have shown high efficacy for restoration of the anatomical center of rotation and good early results in the patients with hip dysplasia undergone hip arthroplasty

Patient-specific modeling of human cardiovascular system elements

Object of study: The research is aimed at development of personalized medical treatment. Algorithm was developed for patient-specific surgical interventions of the cardiovascular system pathologies. Methods: Geometrical models of the biological objects and initial and boundary conditions were realized by medical diagnostic data of the specific patient. Mechanical and histomorphological parameters were obtained with the help mechanical experiments on universal testing machine. Computer modeling of the studied processes was conducted with the help of the finite element method. Results: Results of the numerical simulation allowed evaluating the physiological processes in the studied object in normal state, in presence of different pathologies and after different types of surgical procedures

Evaluation of Pain Syndrome in Patients after Total Knee Replacement

Total joint replacement is one the most effective methods for treatment of degenerative, systemic and posttraumatic diseases of the knee. However, up to 25% of patients remain dissatisfied with surgery outcomes. In the majority of cases the patients complain of pain in the operated joint. Identification of pain cause in the operated joint can turn to become a challenge for the surgeon.Purpose of the study — to identify the causes of pain syndrome basing on examination algorithm in patients after TKR as well as to assess the diagnostic value of each particular examination method.Materials and Methods. The authors analyzed results of comprehensive examination of 79 patients who complained of chronic knee pain after primary TKR and seeked medical help from the beginning of 2016 until December 2018. Inclusion criteria were as follows: knee prosthesis and presence of pain syndrome in the operated joint. Exclusion criteria: fistulous peri-prosthetic infection, suspected “culture-negative” infection and revisions. All patients included into the study were managed according to the standard algorithm of comprehensive examination.Results. The most likely causes of pain were identified during the examination. Infection was observed in 39 patients (49.4%), errors in three-dimensional positioning of components was considered as a probable cause of pain in 14 patients (17.7%), aseptic loosening was reported in 13 cases (16.5%), ligamentous instability — in 6 patients (7.6%), extraarticular pain origin was observed in 5 patients (6.3%) and peri-prosthetic fractures were reported in two patients (2.5%). The authors confirmed a combination of several pain causes in 17 patients (21.5%).Conclusion. Examination of patients with painfull knee joint prosthesis should be comprehensive due to potential combination of issues in each particular case. Integral and systematic approach to pain diagnostics in the operated joint is the “key to success” for planning further treatment tactics and for understanding the necessity and scope of revision procedure

Inflation Differences in the Russian Regions: an Empirical Analysis

The article addresses the difference between regional inflation rates, and criteria that determine such variations. Moreover, it examines whether inflation differences in the Russian regions significantly affect a unified monetary policy targetting a 4 per cent inflation. Using panel econometric methods with instrumental variables, we identified the factors creating regional inflation difference: a) output gap, b) inflation expectations, c) exchange rate pass-through, d) and regional price convergence. Then, we explained how these factors influence regional inflation, using the modern theoretical models that are based on the neoKeynesian logic. Additionally, we discussed the problems caused by regional inflation differences. Since the convergence of price levels to the average Russian level is the key factor influencing regional inflation differences, such differences do not constitute a problem for the unified monetary policy aimed at a 4 % inflation target. In the study, we have determined the causes of inflation differences in the Russian regions, the majority of which result from the new Keynesian Phillips curve. The obtained results can be applied for developing regional economic policies aimed at synchronizing inflation in the Russian regions, as well as for modelling the consequences of monetary policy for regional economies. © 2020 Institute of Economics, Ural Branch of the Russian Academy of Sciences. All rights reserved.Насколько различается инфляция в российских регионах, в чем причины этих различий, являются ли различия региональной инфляции проблемой для проведения единой денежно-кредитной политики, направленной на таргетирование общероссийской инфляции на уровне 4 %? Эти вопросы затрагиваются в настоящей статье. На основе эконометрических методов оценивания панельных регрессий с использованием инструментальных переменных выявлены факторы различий региональной инфляции: а) разрыв выпуска, б) инфляционные ожидания, в) эффект переноса валютного курса, г) конвергенция региональных цен. Предложено детальное объяснение механизмов влияния этих факторов на региональную инфляцию, опирающееся на современные теоретические модели, построенные в рамках неокейнсианской логики. Перечислены проблемы, к которым может приводить дифференциация региональной инфляции. Так как ключевым фактором региональной дифференциации инфляции является конвергенция общего уровня цен к среднероссийскому уровню, то различия региональной инфляции не являются проблемой при проведении единой денежно-кредитной политики и таргетирования общероссийской инфляции на уровне 4 %. Научный вклад проведенного исследования состоит в установлении причин различий инфляции в российских регионах, большая часть которых следует из неокейнсианской кривой Филлипса. Полученные результаты могут применяться при разработке мер региональной экономической политики, направленных на синхронизацию инфляционных процессов в субъектах РФ, а также при моделировании последствий единой монетарной политики Банка России для региональных экономик.Насколько различается инфляция в российских регионах, в чем причины этих различий, являются ли различия региональной инфляции проблемой для проведения единой денежно-кредитной политики, направленной на таргетирование общероссийской инфляции на уровне 4 %? Эти вопросы затрагиваются в настоящей статье. На основе эконометрических методов оценивания панельных регрессий с использованием инструментальных переменных выявлены факторы различий региональной инфляции: а) разрыв выпуска, б) инфляционные ожидания, в) эффект переноса валютного курса, г) конвергенция региональных цен. Предложено детальное объяснение механизмов влияния этих факторов на региональную инфляцию, опирающееся на современные теоретические модели, построенные в рамках неокейнсианской логики. Перечислены проблемы, к которым может приводить дифференциация региональной инфляции. Так как ключевым фактором региональной дифференциации инфляции является конвергенция общего уровня цен к среднероссийскому уровню, то различия региональной инфляции не являются проблемой при проведении единой денежно-кредитной политики и таргетирования общероссийской инфляции на уровне 4 %. Научный вклад проведенного исследования состоит в установлении причин различий инфляции в российских регионах, большая часть которых следует из неокейнсианской кривой Филлипса. Полученные результаты могут применяться при разработке мер региональной экономической политики, направленных на синхронизацию инфляционных процессов в субъектах РФ, а также при моделировании последствий единой монетарной политики Банка России для региональных экономик

The First-Stage Treatment Аlgorithm for Deep Infected Total Hip Arthroplasty

Background. Periprosthetic infection after total hip arthroplasty is a relatively common and severe complication. A two-stage revision with the temporary use of a spacer is the gold standard treatment for the deep infected total hip arthroplasty. Some authors report mechanical complications associated with spacers, which can lead to a poor functional outcome. Therefore, the aim of the study was to analyze the effectiveness of the first-stage of treatment of hip PJI with a two-stage method and to develop an spacer application algorithm in order to achieve the optimal functional result.Material and Methods. Between 2015 and 2017, 38 patients with deep periprosthetic infection received an articulation spacer as part of a two-stage protocol in Botkin Moscow City Hospital. The mean age was 60.5 (interquartile range from 5 2 to 69) years. Five different types of spacers were us ed in the study, selected individually according to theW. Paprosky acetabular defects classification. The overall frequency of complications was evaluated.Results. The overall periprosthetic infection treatment effectiveness was 92.1%. There was the recurrent infection in 3 patients (7.9%), in 2 (5.26%) cases microbial associations were founded. Mechanical complications occurred in 8 (21%) patients. Spacer dislocation occurred in 4 (10.4%) cases, spacer fracture in another 2 (5.2%). There were also 2 cases of protrusion into the pelvis (5.2%).Conclusions. The first stage a two-stage revision hip arthroplasty should be carefully plarmed. To choose the appropriate spacer we proposed an algorithm based on our data to achieve a better functional result

Importance of the Algorithm for Diagnosis of Late Deep Periprosthetic Hip Infection

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