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PURPOSE OF THE STUDY The authors focused on the topic of tibiotalocalcaneal arthrodesis. It is a surgical procedure used to manage severe comprehensive ankle and hindfoot pathology. The scope of surgery and the negative impact on the walking stereotype are offset by preserving a weight-bearing and pain-free limb. The purpose of the study was to evaluate the group of patients who had undergone surgery at the First Department of Orthopaedic Surgery, St. Anne s University Hospital Brno and to identify the most suitable fixation for arthrodesis. It also aimed to compare the outcomes achieved by the authors with those reported by other departments. MATERIAL AND METHODS The group included patients operated on at the authors department between 2011 and 2021. The surgery was indicated in patients with severe concomitant arthritis of the upper and lower ankle, complex hindfoot instability, Charcot arthropathy. Contraindications included acute infection, decompensated diabetes and heavy smoking. The study compares fixation using a lateral plate, a retrograde nail and a retrograde nail with fibula acting as biological plate. The patients were scored preoperatively and postoperatively using the AOFAS Ankle-Hindfoot Score. Statistical analysis of the results was also carried out. RESULTS The group included 23 patients, of whom a lateral plate was opted for in 7 patients, a retrograde nail in 8 patients and a retrograde nail with fibula used as a biological plate in 8 patients. The patients of the group were followed up for the period ranging from 0.5 to 9 years after surgery. Serious complications were observed by the authors in 6 patients of the group. The failure of osteosynthesis material was reported in 2 cases with lateral plating fixation. A stress fracture above the apex of the nail developed in 2 cases. A serious infection was observed by the authors in 1 patient. The method associated with the lowest incidence of complications was the fixation with a retrograde nail and fibula used as a biological plate. DISCUSSION The forms of fixation for tibiotalocalcaneal arthrodesis have recently advanced considerably, the methods of fixation for arthrodesis in particular. The modern implants enable to compress the individual structures, to provide stable fixation and potentially to avoid long-term plaster cast fixation. Nonetheless, these surgical procedures are associated with a high complication rate. Currently, there is no consensus in international studies on the optimal fixation for arthrodesis. Numerous papers describe complications including postoperative infections, failure of osteosynthesis material and fractures close to osteosynthesis material. The number and the type of complications observed by the authors in their group of patients were similar to those reported by other authors. CONCLUSIONS Tibiotalocalcaneal arthrodesis is a surgical procedure reserved exclusively for patients indicated based on strict criteria and should be performed by an experienced team able to cope with potential complications. In the followed-up group of patients, the optimal method of fixation for arthrodesis appeared to be the fixation with a retrograde nail and fibula used as a biological plate. [ABSTRACT FROM AUTHOR]

A hyperjerk system pertains to a dynamical system regulated by an ordinary differential equation of $n$ th order, where $n \geq 4$ . The main contribution of this work is the finding of a new autonomous hyperjerk system with a half line equilibrium. The mathematical framework of the proposed hyperjerk system contains eight terms with an absolute function nonlinearity. The essential dynamic characteristics of the model are explored, encompassing analysis of equilibrium points and their stability, depiction of the phase trajectories, illustration of bifurcation patterns, and visualization of Lyapunov exponent graphs. Our finding shows that the new 4D hyperjerk system exhibits special behavior like multistability, period doubling reversals and antimonotonocity. The proposed hyperjerk system has been implemented with an electronic circuit using MultiSim 14.0. Moreover, the FPGA implementation of the proposed hyperjerk system is performed by applying two numerical methods: Forward Euler and Trapezoidal. Experimental attractors are given from an oscilloscope by using the Zybo Z7-20 FPGA development board, which are in good agreement with the MATLAB and MultiSim 14.0 simulations. Finally, based on the chaotic dynamical behavior of the proposed chaotic hyperjerk system, a new image encryption approach is proposed. The experimental outcomes of the presented encryption algorithm prove its efficiency and security.

PURPOSE OF THE STUDY The paper focuses on the potential use of nail osteosynthesis in diaphyseal metastases of long bones. The purpose of the paper is to assess the outcomes of intramedullary osteosynthesis in pathologic and impending pathologic fractures, to evaluate patient survival and potential complications. MATERIAL AND METHODS The retrospective study evaluated a cohort of 42 patients (19 men and 23 women) in whom intramedullary osteosynthesis was performed for complete pathologic fracture (28 patients) or impending pathologic fracture (14 patients) between 2010 and 2019. Of the total number of 42 patients, 31 patients’ lower limbs were affected, namely by 17 pathologic fractures and 14 impending fractures. There were 11 humerus fractures. The mean age was 61.8 years (range 41-84 years). In the followed-up cohort, the patient survival after osteosynthesis with intramedullary nails, complications occurred and post-operative mobility of the patient were assessed. The functional outcomes were evaluated using the Musculoskeletal Tumor Society (MSTS) scoring system. The unpaired Mann-Whitney test was used to test the significance of the difference in functional outcomes and survival between the followed-up groups. Survival longer than 6 months was evaluated using Fisher’s exact test. The level of statistical significance used for the test was p 0.05. RESULTS The investigated indicator was patient survival, which was 11.3 months (range 1–50 months) on average. In the group of impending fractures, the mean survival was 13.5 months. In the group of pathologic fractures, the survival was 10 months. The functional outcome in 16 followed-up patients at three months after intramedullary osteosynthesis according to the MSTS score was 46.9% (30–66.7%). At the level of significance of p 0.05, the statistically significant difference in the functional outcomes between the group with preventive intramedullary osteosynthesis and the group with nail osteosynthesis of the pathologic fracture was not confirmed (p=0.952). When comparing the patient survival after nail osteosynthesis with impending pathologic fracture and the survival of patients with pathologic fracture, a statistically significant difference in survival between these two groups (p=0.520) was not confirmed. The patient survival of longer than 6 months was 71% in the group of impending fractures and 40% in the group of pathologic fractures. DISCUSSION The occurrence of pathologic fracture is associated with increased pain, loss of function, and according to some authors, a higher risk of death. Surgical treatment options include intramedullary osteosynthesis, plate osteosynthesis with cement filling, implantation of an intercalary spacer, and implantation of tumor endoprostheses. When deciding on a surgical procedure, an account is taken of the expected survival of the patient. In patients with an expected survival of up to 6 months, intramedullary osteosynthesis is indicated as a palliative surgical intervention. The most common complications include implant failure and metastatic progression. CONCLUSIONS Intramedullary osteosynthesis is the method of choice in treating pathologic fractures or impending pathologic diaphyseal fractures of long bones in patients with an expected predicted survival of up to 6 months. Intramedullary osteosynthesis aims to reduce pain and enable early verticalization. The study confirmed the importance of preventive intramedullary osteosynthesis and its effect on survival compared to the survival of patients with a pathologic fracture. [ABSTRACT FROM AUTHOR]

PURPOSE OF THE STUDY The preferred treatment of giant cell tumor of bone is curettage with the use of local adjuvant. If the tumor spreads beyond the bone into soft tissues, en bloc excision should be performed. Intralesional curettage allows joint preservation, but it is associated with a high recurrence rate. The purpose of the study was to identify the risk factors for local recurrence and to compare the functional outcomes after both types of surgical procedures. MATERIAL AND METHODS The group included 16 patients (5 women, 11 men) with giant cell tumor of bone in distal forearm treated at the First Department of Orthopedic Surgery, St. Anne s University Hospital Brno in 2005–2019. The mean age of patients was 38 years (22–53). The follow-up period was 6.75 years (2–15) on average. The most common location of the tumor was distal radius (14). In 6 patients denosumab treatment was indicated. Based on the obtained data, we compared the effects of gender, Campanacci grade, type of surgery and administration of denosumab on the risk of local recurrence. The functional outcomes were evaluated retrospectively based on the Musculoskeletal Tumor Society scoring system for upper limb salvage surgeries. RESULTS Resection and reconstruction using an osteocartilaginous allograft was performed in 9 patients. Seven patients were treated with tumor curettage with bone cement used to fill the cavity. The group of patients who underwent curettage showed a significantly higher mean MSTS score 89% compared to the group of patients with resection with the mean MSTS score 66% (P < 0.05). Local tumor recurrence was reported in 3 patients (18.75%). No statistically significant difference was found in gender, tumor grade, radicality of surgery or administration of targeted therapy with respect to the incidence of local recurrence. Altogether 6 complications (37.5%) were observed in the group. DISCUSSION The treatment of a giant cell tumor of bone aims to completely remove the tumor and to preserve the best possible function of the limb. The complications in distal forearm involve particularly an increase incidence of local recurrence and painful or limited range of motion of the wrist. Whereas curettage with the use of local adjuvant is burdened with a higher recurrence rate, resection with allograft reconstruction of bone defect is usually associated with poorer functional outcomes. CONCLUSIONS Tumor curettage using local adjuvant is preferred in a well-circumscribed tumor and offers an excellent functional outcome. En bloc tumor resection and reconstruction using an osteocartilaginous allograft is a suitable treatment option for a locally advanced tumor with a low risk of local recurrence. [ABSTRACT FROM AUTHOR]

PURPOSE OF THE STUDY Use of an all-polyethylene (all-poly, AP) tibial component in primary total knee arthroplasty is still an attractive option considering the durability of replacement, the elimination of backside wear and the lower cost compared to modular metalbacked tibia. The purpose of the study was to evaluate the long-term results of the total knee replacement using the P.F.C. Sigma system with a monoblock all-polyethylene tibial component implanted at the 1st Orthopedic Department of the St. Anne’s University Hospital and Masaryk University Brno in the period 1999–2010. MATERIAL AND METHODS In the monitored period, 911 total knee replacements using P.F.C. Sigma with an all-polyethylene tibial component were performed. This cohort of patients was evaluated at least 10 years after the primary replacement surgery. Altogether 323 knee replacements in 289 patients were evaluated. The clinical outcomes were assessed according to the Knee Society Clinical Rating System (KSS) and the Total Knee Arthroplasty Roentgenographic Evaluation and Scoring System. The replacement survival was evaluated using the Kaplan-Meier survival analysis. RESULTS In the evaluated group, the average KS was 82.6 points and the average functional score was 74.7 points. Excellent results were recorded in 213 cases, good results in 78 and satisfactory in 23 replacements. Poor clinical results were reported in 9 patients. The average range of motion was 105.8°. In 5 knees (1.5%) revision surgery was performed for infection complications, 3 cases were complicated due to periprosthetic fractures, 4 replacements were revised due to anterior knee pain and 8 knees showed a limited range of motion. Only 1 replacement was revised for aseptic loosening, with no need for reimplantation of the component. The survivorship of the implant was 98.5 % at the follow-up of 12.8 years, including the reasons of reimplantation. DISCUSSION Total knee replacement with an all-polyethylene tibial component is not so popular as the metal-backed modular implants. The all-polyethylene tibial component has certain advantages: lower unit costs, no backside wear, no liner dislocation, possibility of conservative bone resection. On the other hand, this type of implant is not modular and augmentations or longer stems cannot be used. Even though this type of endoprosthesis is recommended exclusively for elderly patients with a lower level of activity, the current mid- and long-term results show that indications for all-poly implants are much broader. CONCLUSIONS The total knee replacement with an all-polyethylene tibial component shows very good long-term clinical outcomes with an excellent survival rate. The all-poly design is cost-effective and may be used not only in elderly patients. [ABSTRACT FROM AUTHOR]

PURPOSE OF THE STUDY To evaluate the results of incisional open biopsies and ultrasound-guided core needle biopsies for musculoskeletal lesions in extremity and limb girdle locations. MATERIAL AND METHODS In 2019, 176 open incisional biopsies were performed at our department, 113 from bone lesions and 63 from soft tissue lesions. In the period of September 2019 to February 2020, we started performing also ultrasound-guided core needle biopsies from soft tissue lesions in limited indications, namely in 23 cases. The diagnostic accuracy, complications and pain associated with the procedure were evaluated. RESULTS Of 113 open incisional biopsies of bone, 91.1% was fully representative and 6.2% non-representative with an indication for re-biopsy. In 53 cases another surgical procedure followed, which fully confirmed the diagnosis made based on the biopsy in 79.2%. In 7.5% the diagnosis slightly changed, with no therapeutic impact, in 5.7% the histological grade was changed, and in 7.5% the diagnosis was substantially modified. Complications appeared in 9.8% of cases. The procedure was associated with pain expressed by an increase in VAS score by 2.7 points. Of 63 soft tissue open incisional biopsies, 100% was fully representative. In 30 cases another surgical procedure followed, which fully confirmed the diagnosis made based on the biopsy in 96.7%, in one case the diagnosis was changed from aggressive benign lesion to a low-grade sarcoma. Complications appeared in 6.4% of cases. The procedure was associated with pain expressed by an increase in VAS score by 1.4 points. Of 23 ultrasound-guided core needle biopsies from soft tissues in limited indications, 100% was representative. In 11 cases another surgical procedure followed, which fully confirmed the diagnosis made based on the biopsy in 81.8%, in 2 cases the diagnosis was slightly changed, with no therapeutic impact or a change of histological grade. No complications were reported. The procedure was associated with minimal pain expressed by an increase in VAS score by 0.1 points. When comparing the group of soft tissue open incisional biopsies and ultrasound-guided core needle biopsies, a statistically significant less pain associated with the procedure was found in the group of core needle biopsies. CONCLUSIONS The biopsy of musculoskeletal tumors should be performed at specialty centers for treatment of these rare conditions. In that case it produces good results and is associated with a low rate of complications. Indications for open biopsy or core needle biopsy must be assessed individually. [ABSTRACT FROM AUTHOR]

Aerodynamically generated noise affects passenger comfort in cars, high-speed trains, and airplanes, and thus, automobile manufacturers aim for its reduction. Investigation methods of noise and vibration sources can be divided into two groups, i.e. experimental research and mathematical research. Recently, owing to the increase in computing power, research in aerodynamically generated noise (aero-acoustics) is beginning to use modern methods such as computational fluid dynamics or fluid-structure interaction. The mathematical model of turbulent flow is given by the system of partial differential equations, its solution is ambiguous and thus requires verification by physical experiment. The results of numerical methods are affected by the boundary conditions of high quality gained from the actual experiment. This article describes an application of complex measurement methodology in the aerodynamic and acoustic (vibro-acoustic) fields. The first part of the paper is focused on the specification of the experimental equipment, i.e. the wind tunnel, which was significantly upgraded in order to obtain the relevant aerodynamics and vibro-acoustics data. The paper presents specific results from the measurement of the aerodynamic and vibro-acoustic fields.

The identification of cavitation is very important in technical practice for operational and especially economic reasons. The article deals with the use of another way to measure noise during cavitation. The current approach of measuring noise with an intensity probe is used in practice for identification, but it does not immediately address the position of the cavitation source for a given frequency range. Measurement by an acoustic camera is not entirely common in practice, but it allows to determine the location of the noise source for a given frequency range. To test the acoustic camera, the authors focused on the cavitating flow in a hydraulic circuit with three previously tested nozzles. Noise was measured for these nozzles using an acoustic intensity probe with two microphones. The results were evaluated by statistical methods and compared with measurements using an acoustic camera. The aim of the article is to point out the advantages of using this approach for accurate area identification of the problem. Research background: The work is focused on the issue of cavitation and its identification in the hydraulic circuit. For cavitation research, a variant of cavitation identification by noise was chosen. However, this measurement brings problems that are only revealed through more sophisticated and accurate measurements. Purpose of the article: The purpose of the article is to point out other possibilities of measuring cavitation noise using modern technologies and subsequently verify the results. Methods: Metody: A common way of measuring noise is to measure it with a suitably located acoustic intensity probe. A more modern approach is area noise measurement. Measurement methodology and benefits are described. Findings & Value added: The commonly used way of measuring noise using an acoustic intensity probe has proved to be insufficient, as it is not possible to distinguish the location of sources in the case of complex measurements. When using an acoustic camera, there are more sources of noise in a given circuit and they are detected according to the required frequencies in different places than expected. The article points out the specific identification of noise sources using the frequency spectrum of noise for selected elements.

The article deals with experimental investigation of water cavitation in the convergent-divergent nozzle of rectangular cross-section. In practice, a quick and simple determination of cavitation is essential, especially if it is basic cavitation or cavitation generated additionally by the air being sucked. Air influences the formation, development and size of the cavity area in hydraulic elements. Removal or reduction of the cavity area is possible by structural changes of the element. In case of the cavitation with the suction air, it is necessary to find the source of the air and seal it. The pressure gradient, the flow, the oxygen content in the tank, and hence the air dissolved in the water, the air flow rate, the noise intensity and the vibration velocity on the nozzle wall were measured on laboratory equipment. From the selected measurements the frequency spectrum of the variation of the water flow of the cavity with cavitation without air saturation and with air saturation was compared and evaluated.

In engineering applications the noisiness of a component or the whole device is a common problem. Currently, a lot of effort is put to eliminate noise of the already produced devices, to prevent generation of acoustic waves during the design of new components, or to specify the operating problems based on noisiness change. The experimental method and the mathematical modelling method belong to these identification methods. With the power of today’s computers the ability to identify the sources of the noise on the mathematical modelling level is a very appreciated tool for engineers. For example, the noise itself may be generated by the vibration of the solid object, combustion, shock, fluid flow around an object or cavitation at the fluid flow in an object. For the given task generating the noise using fluid flow on the selected geometry and propagation of the acoustic waves and their subsequent identification are solved and evaluated. In this paper the principle of measurement of variables describing the fluid flow field and acoustic field are described. For the solution of fluid flow a mathematical model implemented into the CFD code is used. The mathematical modelling evaluation of the flow field is compared to the experimental data.

Hand and foot osteosarcoma represents ~1% of all diagnosed cases of osteosarcoma. The rarity of osteosarcoma of the hand and foot leads to frequent misdiagnosis, delayed diagnosis or incorrect treatments, which can lead to fatal consequences. Typically, salvaging the affected limb is the treatment of choice, and with the use of chemotherapy, 60-65% of patients with osteosarcoma can be treated without amputation. Due to its rarity, misdiagnosis and treatment delays are common, yet detailed reviews and analyses of such cases are limited. The present retrospective cohort study aimed to review and analyze cases of osteosarcoma located in the hand and foot. From January 2007 to January 2019, 11 patients were treated at the Masaryk Memorial Cancer Institute Sarcoma Center (Brno, Czechia), 5 cases affected the hand and 6 affected the foot. A total of 6 male patients and 5 female patients, with a mean age of 30.9±16.74 years, were diagnosed with hand or foot osteosarcoma. The mean follow-up period was 90.36±66.14 months. The mean tumor size detected during diagnosis was 4.29±1.81 cm. Osteoblastic osteosarcoma was the most common histopathological type, accounting for 4 cases (33.4%). A majority of the osteosarcomas were identified as high grade (81.8%). A total of 5 patients experienced misdiagnoses following their initial biopsy, with 2 patients initially receiving treatment outside the Masaryk Memorial Cancer Institute Sarcoma Center. The most frequently encountered misdiagnosis was giant-cell tumor of the bone. A total of 3 patients underwent limb amputation and 2 patients developed lung metastasis and succumbed to the disease. The disease-free survival period and overall survival rate were calculated using Kaplan-Meier survival analysis. The mean disease-free survival period was 82.83±60.05 months, while the overall survival rate was 72%, with a mean survival time of 90.36±56.73 months. In summary, an examination of a case series involving 11 patients diagnosed with osteosarcoma of the hand and foot was conducted. The treatment approach, clinical characteristics and patient outcomes were described. A total of four case studies of patients with osteosarcoma in the hand or foot were presented. Misdiagnosis of this disease may result in the inappropriate treatment being administered to patients, therefore, the correct and rapid diagnosis of disease is necessary for effective treatment of hand and foot osteosarcomas., Competing Interests: The authors declare that they have no competing interests., (Copyright: © 2024 Mahdal et al.)

Background and Objectives: Curettage is the removal of a tumor from the bone while preserving the surrounding healthy cortical bone, and is associated with higher rates of local recurrence. To lower these rates, curettage should be combined with local adjuvants, although their use is associated with damage to nearby healthy bone., Objective: The purpose of this analysis is to determine the effect of local adjuvants on cortical porcine bone by using micro-computed tomography (micro-CT) along with histological and mechanical examination., Methods: Local adjuvants were applied to porcine specimens under defined conditions. To assess changes in bone mineral density (BMD), a micro-CT scan was used. The pixel gray values of the volume of interest (VOI) were evaluated per specimen and converted to BMD values. The Vickers hardness test was employed to assess bone hardness (HV). The depth of necrosis was measured histologically using hematoxylin and eosin-stained tissue sections., Results: A noticeable change in BMD was observed on the argon beam coagulation (ABC) sample. Comparable hardness values were measured on samples following electrocautery and ABC, and lowering of bone hardness was obtained in the case of liquid nitrogen. Extensive induced depth of necrosis was registered in the specimen treated with liquid nitrogen., Conclusion: This study determined the effect of local adjuvants on cortical bone by using micro-CT along with histological and mechanical examination. Phenolization and liquid nitrogen application caused a decrease in bone hardness. The bone density was affected in the range of single-digit percentage values. Liquid nitrogen induced extensive depth of necrosis with a wide variance of values., (© 2024. The Author(s).)

Myxofibrosarcoma presents an infiltrating growth pattern that results in a high tendency for local recurrence. Clear margin resection is challenging because of microscopic infiltration. The purpose of the present study was to analyze the overall and disease-free survival rates of patients with myxofibrosarcoma and the prognostic factors that determine both survival and disease recurrence. Among the 111 patients included in our study, the 5-year overall survival rate was 65.5%. An age of more than 65 years (hazard ratio [HR] 1.9 [95% confidence interval (CI) 1.4-5.6]; p < 0.001), a tumor size of more than 5 cm (HR 2.8 [95% CI 0.9-8.1]; p = 0.049) and the G3 tumor grade (HR 14.1 [95% CI 2.1-105.0]; p < 0.001) negatively affected overall survival. The 5-year recurrence-free survival rate was 49.4%. R1/R2-type resection (HR 2.4 [95% CI 1.0-5.6]; p = 0.048) had a detrimental effect on tumor recurrence. Clear margins had a positive impact on recurrence-free survival, but did not significantly affect overall patient survival, suggesting that other factors may play a more significant role in determining patient outcomes. A surgical margin of 2 mm was not sufficient to significantly influence the incidence of recurrence. Consequently, a wider surgical margin may be necessary to reduce the risk of myxofibrosarcoma recurrence., (© 2024. The Author(s).)

Background: Total knee arthroplasty (TKA) with all-polyethylene tibial (APT) components has shown comparable survivorship and clinical outcomes to that with metal-backed tibial (MBT). Although MBT is more frequently implanted, APT equivalents are considered a low-cost variant for elderly patients. A biomechanical analysis was assumed to be suitable to compare the response of the periprosthetic tibia after implantation of TKA NexGen APT and MBT equivalent., Methods: A standardised load model was used representing the highest load achieved during level walking. The geometry and material models were created using computed tomography data. In the analysis, a material model was created that represents a patient with osteopenia., Results: The equivalent strain distribution in the models of cancellous bone with an APT component showed values above 1000 με in the area below the medial tibial section, with MBT component were primarily localised in the stem tip area. For APT variants, the microstrain values in more than 80% of the volume were in the range from 300 to 1500 με, MBT only in less than 64% of the volume., Conclusion: The effect of APT implantation on the periprosthetic tibia was shown as equal or even superior to that of MBT despite maximum strain values occurring in different locations. On the basis of the strain distribution, the state of the bone tissue was analysed to determine whether bone tissue remodelling or remodelling would occur. Following clinical validation, outcomes could eventually modify the implant selection criteria and lead to more frequent implantation of APT components., (© 2024. The Author(s).)

In this study, we tackle the challenge of optimizing the design of a Brushless Direct Current (BLDC) motor. Utilizing an established analytical model, we introduced the Multi-Objective Generalized Normal Distribution Optimization (MOGNDO) method, a biomimetic approach based on Pareto optimality, dominance, and external archiving. We initially tested MOGNDO on standard multi-objective benchmark functions, where it showed strong performance. When applied to the BLDC motor design with the objectives of either maximizing operational efficiency or minimizing motor mass, the MOGNDO algorithm consistently outperformed other techniques like Ant Lion Optimizer (ALO), Ion Motion Optimization (IMO), and Sine Cosine Algorithm (SCA). Specifically, MOGNDO yielded the most optimal values across efficiency and mass metrics, providing practical solutions for real-world BLDC motor design. The MOGNDO source code is available at: https://github.com/kanak02/MOGNDO., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors. Published by Elsevier Ltd.)

Numerous studies have compared metal-backed components (MBTs) and all-polyethylene tibial components (APTs), but none of them specifically analysed the clinical results and the overall patient preference in patients who had undergone a staged bilateral knee replacement. The purpose of this study is to compare clinical results, perceived range of motion, and overall implant preference among patients who had undergone staged bilateral knee replacement with an APT and contralateral knee replacement with MBTs. A dataset of 62 patients from a single centre who underwent staged bilateral TKA between 2009 and 2022 was selected and retrospectively analysed. Tibial component removal was performed in three knees overall, all of which had MBTs. The mean measured Knee Score (KS) of knees with APTs was 78.37 and that of contralateral knees with MBTs was 77.4. The mean measured Function (FS) of knees with APTs was 78.22, and that of contralateral knees with MBs was 76.29. The mean flexion angle of knees with APTs was 103.8 and that for knees with MBTs was 101.04 degrees. A total of 54.8% of the patients preferred the knee that received APTs over contralateral MBTs. In our cohort, TKA with an APT in one knee and an MBT in the contralateral knee recorded similar clinical results and perceived ranges of motion. Patients in general preferred the knee that received an APT over contralateral knee with an MBT.

Giant cell tumour of bone (GCTB) is one of the most common local aggressive tumourous lesions with a wide variety of biological behaviour. However, there are no clear indicative criteria when choosing the type of procedure and the complication rates remain high, especially in terms of local recurrence. The purpose of the study was to (1) identify the main risk factors for local recurrence, (2) evaluate the recurrence-free survival in dependence on neoadjuvant denosumab use and the type of procedure, and (3) compare the functional outcomes after curettage and en bloc resection. The group included 102 patients with GCTB treated between 2006 and 2020. The mean age of patients was 34.4 years (15-79). The follow-up period was 8.32 years (2-16) on average. Local recurrence occurred in 14 patients (29.8%) who underwent curettage and in 5 patients (10.6%) after en bloc resection. Curettage was shown to be a factor in increasing recurrence rates (OR = 3.64 [95% CI: 1.19-11.15]; p = 0.023). Tibial location was an independent risk factor for local recurrence regardless of the type of surgery (OR = 3.22 [95% CI: 1.09-9.48]; p = 0.026). The recurrence-free survival rate of patients treated with resection and denosumab was higher compared to other treatments at five years postoperatively ( p = 0.0307). Functional ability and pain as reported by patients at the latest follow-up were superior after curettage compared to resection for upper and lower extremity (mean difference: -4.00 [95% CI: -6.81 to -1.18]; p < 0.001 and mean difference: -5.36 [95% CI: -3.74 to -6.97]; p < 0.001, respectively). Proximal tibia tumour location and curettage were shown to be major risk factors for local recurrence in GCTB regardless of neoadjuvant denosumab treatment. The recurrence-free survival rate of patients treated with resection and denosumab was higher compared to other treatments. The functional outcome of patients after curettage was better compared to en bloc resection.

The Single-Stage Grid-Connected Solar Photovoltaic (SSGC-SPV) topology has recently gained significant attention, as it offers promising advantages in terms of reducing overall losses and installation costs. We provide a comprehensive overview of the system components, which include the photovoltaic generator, the inverter, the Incremental Conductance Maximum Power Point Tracking (IC-MPPT) algorithm, and the PI regulator for DC bus voltage control. Moreover, this study presents detailed system configurations and control schemes for two types of inverters: 2L-3PVSI and 3L-3PNPC. In order to perform a comparative study between the two structures, we subjected them to the same irradiation profile using the same grid configuration. The Photovoltaic Array (PVA) irradiance is increased instantaneously, in 0.2 s, from 400 W/m 2 to 800 W/m 2 , is kept at 800 W/m 2 for 0.2 s, is then gradually decreased from 800 W/m 2 to 200 W/m 2 in 0.2 s, is then kept at 200 W/m 2 for 0.2 s, and is then finally increased to 1000 W/m 2 for 0.2 s. We explain the operational principles of these inverters and describe the various switching states involved in generating output voltages. To achieve effective control, we adopt the Finite Set-Model Predictive Control (FS-MPC) algorithm, due to the benefits of excellent dynamic responsiveness and precise current tracking abilities. This algorithm aims to minimise the cost function, while taking into account the dynamic behaviour of both the PV system and the inverter, including any associated delays. To evaluate the performance of the FS-MPC controller, we compare its application in the three-level inverter configuration with the two-level inverter setup. The DC bus voltage is maintained at 615 V using the PI controller. The objective is to achieve a Total Harmonic Distortion (THD) below 5%, with reference to the IEEE standards. The 2L-3PVSI inverter is above the threshold at an irradiance of 200 W/m 2 . The 3L-3PNPC inverter offers a great THD percentage, meaning improved quality of the power returned to the grid.

Purpose: This study aims to compare total knee replacement (TKA) with NexGen All-Poly (APT) and NexGen Metal-Backed (MBT) in terms of implant survivorship, reasons leading to implant failure and functional results of defined age categories., Methods: A single-centre, retrospective evaluation of 812 patients who underwent knee replacement with NexGen CR between 2005 and 2021, comparing a modern congruent APT component to a modular MBT equivalent component using a similar surgical technique at a notable mean follow-up duration. Implant survival, functional outcomes using the Knee Society Score and range of motion were evaluated and compared in different age categories., Results: Of the 812 NexGen CR TKAs performed at our institution, 410 (50.4%) used APT components and 402 (49.6%) MBT components. The survival rate of NexGen APT was 97.1% and that of NexGen MBT was 93.2% (p = 0.36). Removal of the implant occurred overall in 15 cases, for MBT in ten cases, and for APT in four cases. The FS was proved to be significantly higher when APT components were implanted in younger patients than for MBT (p = 0.005). A similar range of motion between the components was recorded (p = 0.1926)., Conclusion: Under defined conditions, we measured the clinical results of implants from a single manufacturer implanted in a single department using a similar surgical technique. Considering the limitations, we suggest that all-polyethylene tibial components are equal or even superior to metal-backed ones across the examined age categories., (© 2023. The Author(s).)

Wireless sensor networks (WSNs) enable communication among sensor nodes and require efficient energy management for optimal operation under various conditions. Key challenges include maximizing network lifetime, coverage area, and effective data aggregation and planning. A longer network lifetime contributes to improved data transfer durability, sensor conservation, and scalability. In this paper, an enhanced dual-selection krill herd (KH) optimization clustering scheme for resource-efficient WSNs with minimal overhead is introduced. The proposed approach increases overall energy utilization and reduces inter-node communication, addressing energy conservation challenges in node deployment and clustering for WSNs as optimization problems. A dynamic layering mechanism is employed to prevent repetitive selection of the same cluster head nodes, ensuring effective dual selection. Our algorithm is designed to identify the optimal solution through enhanced exploitation and exploration processes, leveraging a modified krill-based clustering method. Comparative analysis with benchmark approaches demonstrates that the proposed model enhances network lifetime by 23.21%, increases stable energy by 19.84%, and reduces network latency by 22.88%, offering a more efficient and reliable solution for WSN energy management., Competing Interests: The authors declare no conflicts of interest.

The cluster technique involves the creation of clusters and the selection of a cluster head (CH), which connects sensor nodes, known as cluster members (CM), to the CH. The CH receives data from the CM and collects data from sensor nodes, removing unnecessary data to conserve energy. It compresses the data and transmits them to base stations through multi-hop to reduce network load. Since CMs only communicate with their CH and have a limited range, they avoid redundant information. However, the CH's routing, compression, and aggregation functions consume power quickly compared to other protocols, like TPGF, LQEAR, MPRM, and P-LQCLR. To address energy usage in wireless sensor networks (WSNs), heterogeneous high-power nodes (HPN) are used to balance energy consumption. CHs close to the base station require effective algorithms for improvement. The cluster-based glow-worm optimization technique utilizes random clustering, distributed cluster leader selection, and link-based routing. The cluster head routes data to the next group leader, balancing energy utilization in the WSN. This algorithm reduces energy consumption through multi-hop communication, cluster construction, and cluster head election. The glow-worm optimization technique allows for faster convergence and improved multi-parameter selection. By combining these methods, a new routing scheme is proposed to extend the network's lifetime and balance energy in various environments. However, the proposed model consumes more energy than TPGF, and other protocols for packets with 0 or 1 retransmission count in a 260-node network. This is mainly due to the short INFO packets during the neighbor discovery period and the increased hop count of the proposed derived pathways. Herein, simulations are conducted to evaluate the technique's throughput and energy efficiency.

The Internet of Things (IoT) is seen as the most viable solution for real-time monitoring applications. But the faults occurring at the perception layer are prone to misleading the data driven system and consume higher bandwidth and power. Thus, the goal of this effort is to provide an edge deployable sensor-fault detection and identification algorithm to reduce the detection, identification, and repair time, save network bandwidth and decrease the computational stress over the Cloud. Towards this, an integrated algorithm is formulated to detect fault at source and to identify the root cause element(s), based on Random Forest (RF) and Fault Tree Analysis (FTA). The RF classifier is employed to detect the fault, while the FTA is utilized to identify the source. A Methane (CH4) sensing application is used as a case-study to test the proposed system in practice. We used data from a healthy CH4 sensing node, which was injected with different forms of faults, such as sensor module faults, processor module faults and communication module faults, to assess the proposed model's performance. The proposed integrated algorithm provides better algorithm-complexity, execution time and accuracy when compared to FTA or standalone classifiers such as RF, Support Vector Machine (SVM) or K-nearest Neighbor (KNN). Metrics such as Accuracy, True Positive Rate (TPR), Matthews Correlation Coefficient (MCC), False Negative Rate (FNR), Precision and F1-score are used to rank the proposed methodology. From the field experiment, RF produced 97.27% accuracy and outperformed both SVM and KNN. Also, the suggested integrated methodology's experimental findings demonstrated a 27.73% reduced execution time with correct fault-source and less computational resource, compared to traditional FTA-detection methodology.

This was a prospective cohort study of eighteen patients with large and debilitating vascular malformations with one or more major systemic complications. In all patients, we discovered activating alterations in either TEK or PIK3CA. Based on these findings, targeted treatment using the PI3K inhibitor alpelisib was started with regular check-ups, therapy duration varied from 6 to 31 months. In all patients, marked improvement in quality of life was observed. We observed radiological improvement in fourteen patients (two of them being on combination with either propranolol or sirolimus), stable disease in 2 patients. For 2 patients, an MRI scan was not available as they were shortly on treatment, however, a clinically visible response in size reduction or structure regression, together with pain relief was observed. In patients with elevated D-dimer levels before alpelisib administration, a major improvement was noted, suggesting its biomarker role. We observed overall very good tolerance of the treatment, documenting a single patient with grade 3 hyperglycemia. Patients with size reduction were offered local therapies wherever possible. Our report presents a promising approach for the treatment of VMs harboring different targetable TEK and PIK3CA gene mutations with a low toxicity profile and high efficacy., (© 2023. The Author(s).)

Underwater visible light communication (UVLC) has recently come to light as a viable wireless carrier for signal transmission in risky, uncharted, and delicate aquatic environments like seas. Despite the potential of UVLC as a green, clean, and safe alternative to conventional communication methods, it is challenged by significant signal attenuation and turbulent channel conditions compared to long-distance terrestrial communication. To address linear and nonlinear impairments in UVLC systems, this paper presents an adaptive fuzzy logic deep-learning equalizer (AFL-DLE) for 64 Quadrature Amplitude Modulation-Component minimal Amplitude Phase shift (QAM-CAP)-modulated UVLC systems. The proposed AFL-DLE is dependent on complex-valued neural networks and constellation partitioning schemes and utilizes the Enhanced Chaotic Sparrow Search Optimization Algorithm (ECSSOA) to improve overall system performance. Experimental outcomes demonstrate that the suggested equalizer achieves significant reductions in bit error rate (55%), distortion rate (45%), computational complexity (48%), and computation cost (75%) while maintaining a high transmission rate (99%). This approach enables the development of high-speed UVLC systems capable of processing data online, thereby advancing state-of-the-art underwater communication.

A compact, four-element planar MIMO (Multiple Input, Multiple Output) antenna that operates in an ultra-wideband is presented for diversity application. The orthogonal position of the unit cells replicates the single antenna thrice, thereby decreasing mutual coupling. A UWB MIMO antenna measuring 35 × 35 × 1.6 mm 3 is built using a microstrip line (50 Ω impedance) on an FR4 substrate having a thickness of 1.6 mm. The ground plane and radiator of this antenna are adjusted in several ways to bring it within its operating constraints between the frequencies of 3.1 GHz and 10.6 GHz. This technique makes the antenna small and covers the entire ultra-wideband (UWB) frequency range. The NI USRP was used to test the proposed MIMO antenna to determine its real-time performance. Based on the computed results, we conclude that this proposed antenna has outstanding characteristics in terms of performance and is suitable for wireless ultra-wideband indoor communication and diversity utilization with a small size.

To determine the appropriate treatment plan for patients, radiologists must reliably detect brain tumors. Despite the fact that manual segmentation involves a great deal of knowledge and ability, it may sometimes be inaccurate. By evaluating the size, location, structure, and grade of the tumor, automatic tumor segmentation in MRI images aids in a more thorough analysis of pathological conditions. Due to the intensity differences in MRI images, gliomas may spread out, have low contrast, and are therefore difficult to detect. As a result, segmenting brain tumors is a challenging process. In the past, several methods for segmenting brain tumors in MRI scans were created. However, because of their susceptibility to noise and distortions, the usefulness of these approaches is limited. Self-Supervised Wavele- based Attention Network (SSW-AN), a new attention module with adjustable self-supervised activation functions and dynamic weights, is what we suggest as a way to collect global context information. In particular, this network's input and labels are made up of four parameters produced by the two-dimensional (2D) Wavelet transform, which makes the training process simpler by neatly segmenting the data into low-frequency and high-frequency channels. To be more precise, we make use of the channel attention and spatial attention modules of the self-supervised attention block (SSAB). As a result, this method may more easily zero in on crucial underlying channels and spatial patterns. The suggested SSW-AN has been shown to outperform the current state-of-the-art algorithms in medical image segmentation tasks, with more accuracy, more promising dependability, and less unnecessary redundancy.

This paper proposes a solution for ensuring the security of IoT devices in the cloud environment by protecting against distributed denial-of-service (DDoS) and false data injection attacks. The proposed solution is based on the integration of simple network management protocol (SNMP), Kullback-Leibler distance (KLD), access control rules (ACL), and moving target defense (MTD) techniques. The SNMP and KLD techniques are used to detect DDoS and false data sharing attacks, while the ACL and MTD techniques are applied to mitigate these attacks by hardening the target and reducing the attack surface. The effectiveness of the proposed framework is validated through experimental simulations on the Amazon Web Service (AWS) platform, which shows a significant reduction in attack probabilities and delays. The integration of IoT and cloud technologies is a powerful combination that can deliver customized and critical solutions to major business vendors. However, ensuring the confidentiality and security of data among IoT devices, storage, and access to the cloud is crucial to maintaining trust among internet users. This paper demonstrates the importance of implementing robust security measures to protect IoT devices in the cloud environment and highlights the potential of the proposed solution in protecting against DDoS and false data injection attacks.

Social networks have greatly expanded in the last ten years the need for sharing multimedia data. However, on open networks such as the Internet, where security is frequently compromised, it is simple for eavesdroppers to approach the actual contents without much difficulty. Researchers have created a variety of encryption methods to strengthen the security of this transmission and make it difficult for eavesdroppers to get genuine data. However, these conventional approaches increase computing costs and communication overhead and do not offer protection against fresh threats. The problems with current algorithms encourage academics to further investigate the subject and suggest new algorithms that are more effective than current methods, that reduce overhead, and which are equipped with features needed by next-generation multimedia networks. In this paper, a genetic operator-based encryption method for multimedia security is proposed. It has been noted that the proposed algorithm produces improved key strength results. The investigations using attacks on data loss, differential assaults, statistical attacks, and brute force attacks show that the encryption technique suggested has improved security performance. It focuses on two techniques, bitplane slicing and followed by block segmentation and scrambling. The suggested method first divides the plaintext picture into several blocks, which is then followed by block swapping done by the genetic operator used to combine the genetic information of two different images to generate new offspring. The key stream is produced from an iterative chaotic map with infinite collapse (ICMIC). Based on a close-loop modulation coupling (CMC) approach, a three-dimensional hyperchaotic ICMIC modulation map is proposed. By using a hybrid model of multidirectional circular permutation with this map, a brand-new colour image encryption algorithm is created. In this approach, a multidirectional circular permutation is used to disrupt the image's pixel placements, and genetic operations are used to replace the pixel values. According to simulation findings and security research, the technique can fend off brute-force, statistical, differential, known-plaintext, and chosen-plaintext assaults, and has a strong key sensitivity.

A programmable logic controller (PLC) executes a ladder diagram (LD) using input and output modules. An LD also has PID controller function blocks. It contains as many PID function blocks as the number of process parameters to be controlled. Adding more process parameters slows down PLC scan time. Process parameters are measured as analog signals. The analog input module in the PLC converts these analog signals into digital signals and forwards them to the PID controller as inputs. In this research work, a field-programmable gate array (FPGA)-based multiple PID controller is proposed to retain PLC scan time at a lower value. Concurrent execution of multiple PID controllers was assured by assigning separate FPGA hardware resources for every PID controller. Digital input to the PID controller is routed by the novel idea of analog to digital conversion (ADC), performed using a digital to analog converter (DAC), comparator, and FPGA. ADC combined with dedicated PID controller logic in an FPGA for every closed-loop control system confirms concurrent execution of multiple PID controllers. The time required to execute two closed-loop controls was identified as 18.96000004 ms. This design can be used either with or without a PLC.

Background and Objective: Total knee arthroplasty (TKA) with modern all-polyethylene tibial (APT) components has shown high long-term survival rates and comparable results to those with metal-backed tibial components. Nevertheless, APT components are primarily recommended for older and low-demand patients. There are no evidence-based biomechanical guidelines for orthopaedic surgeons to determine the appropriate lower age limit for implantation of APT components. A biomechanical analysis was assumed to be suitable to evaluate the clinical results in patients under 70 years. The scope of this study was to determine biomechanically the appropriate lower age limit for implantation of APT components., Methods: To generate data of the highest possible quality, the geometry of the computational models was created based on computed tomography (CT) images of a representative patient. The cortical bone tissue model distinguishes the change in mechanical properties described in three parts from the tibial cut. The cancellous bone material model has a heterogeneous distribution of mechanical properties. The values used to determine the material properties of the tissues were obtained from measurements of a CT dataset comprising 45 patients., Results: Computational modeling showed that in the majority of the periprosthetic volume, the von Mises strain equivalent ranges from 200 to 2700 με; these strain values induce bone modeling and remodeling. The highest measured deformation value was 2910 με. There was no significant difference in the induced mechanical response between bone models of the 60-year and 70-year age groups, and there was <3% difference from the 65-year age group., Conclusions: Considering in silico limitations, we suggest that APT components could be conveniently used on a bone with mechanical properties of the examined age categories. Under defined loading conditions, implantation of TKA with APT components is expected to induce modeling and remodeling of the periprosthetic tibia. Following clinical validation, the results of our study could modify the indication criteria of the procedure, and lead to more frequent implantation of all-polyethylene TKA in younger patients., Competing Interests: Declaration of Competing Interest The authors do not have financial and personal relationships with other people or organizations that could inappropriately influence (bias) their work., (Copyright © 2022. Published by Elsevier B.V.)

Background: The purpose of this study was to evaluate the implant survival, functional score and complications of intercalary endoprostheses implanted for metastatic involvement of the femoral and humeral diaphysis., Methods: The selected group covered patients with bone metastasis who were surgically treated with an intercalary endoprosthesis between 2012 and 2021. The functional outcome was evaluated with the Musculoskeletal Tumor Society (MSTS) scoring system, and complications were evaluated by using the failure classification for prosthetics designed by Henderson., Results: The mean follow-up was 29.8 months. In our group of 25 patients with 27 intercalary endoprostheses (18 femurs, 9 humeri), there were 7 implant-related complications (25.9%), which were more common on the humerus (4 cases, 44.4%) than on the femur (3 cases, 16.7%). Only type II failure-aseptic loosening (5 cases, 18.5%)-and type III failure-structural failure (2 cases, 7.4%)-occurred. There was a significantly higher risk of aseptic loosening of the endoprosthesis in the humerus compared with that in the femur (odds ratio 13.79, 95% confidence interval 1.22-151.05, p = 0.0297). The overall cumulative implant survival was 92% 1 year after surgery and 72% 5 years after surgery. The average MSTS score was 82%. The MSTS score was significantly lower ( p = 0.008) in the humerus (75.9%) than in the femur (84.8%)., Conclusions: The resection of bone metastases and replacement with intercalary endoprosthesis has excellent immediate functional results with an acceptable level of complications in prognostically favourable patients.

Wireless Sensor Networks (WSNs) can be defined as a cluster of sensors with a restricted power supply deployed in a specific area to gather environmental data. One of the most challenging areas of research is to design energy-efficient data gathering algorithms in large-scale WSNs, as each sensor node, in general, has limited energy resources. Literature review shows that with regards to energy saving, clustering-based techniques for data gathering are quite effective. Moreover, cluster head (CH) optimization is a non-deterministic polynomial (NP) hard problem. Both the lifespan of the network and its energy efficiency are improved by choosing the optimal path in routing. The technique put forth in this paper is based on multi swarm optimization (MSO) (i.e., multi-PSO) together with Tabu search (TS) techniques. Efficient CHs are chosen by the proposed system, which increases the optimization of routing and life of the network. The obtained results show that the MSO-Tabu approach has a 14%, 5%, 11%, and 4% higher number of clusters and a 20%, 6%, 14%, and 6% lesser average packet loss rate as compared to a genetic algorithm (GA), differential evolution (DE), Tabu, and MSO based clustering, respectively. Moreover, the MSO-Tabu approach has 136%, 36%, 136%, and 38% higher lifetime computation, and 22%, 16%, 51%, and 12% higher average dissipated energy. Thus, the study's outcome shows that the proposed MSO-Tabu is efficient, as it enhances the number of clusters formed, average energy dissipated, lifetime computation, and there is a decrease in mean packet loss and end-to-end delay.

PURPOSE OF THE STUDY The paper focuses on the potential use of nail osteosynthesis in diaphyseal metastases of long bones. The purpose of the paper is to assess the outcomes of intramedullary osteosynthesis in pathologic and impending pathologic fractures, to evaluate patient survival and potential complications. MATERIAL AND METHODS The retrospective study evaluated a cohort of 42 patients (19 men and 23 women) in whom intramedullary osteosynthesis was performed for complete pathologic fracture (28 patients) or impending pathologic fracture (14 patients) between 2010 and 2019. Of the total number of 42 patients, 31 patients' lower limbs were affected, namely by 17 pathologic fractures and 14 impending fractures. There were 11 humerus fractures. The mean age was 61.8 years (range 41-84 years). In the followed-up cohort, the patient survival after osteosynthesis with intramedullary nails, complications occurred and post-operative mobility of the patient were assessed. The functional outcomes were evaluated using the Musculoskeletal Tumor Society (MSTS) scoring system. The unpaired Mann-Whitney test was used to test the significance of the difference in functional outcomes and survival between the followed-up groups. Survival longer than 6 months was evaluated using Fisher's exact test. The level of statistical significance used for the test was p 0.05. RESULTS The investigated indicator was patient survival, which was 11.3 months (range 1-50 months) on average. In the group of impending fractures, the mean survival was 13.5 months. In the group of pathologic fractures, the survival was 10 months. The functional outcome in 16 followed-up patients at three months after intramedullary osteosynthesis according to the MSTS score was 46.9% (30-66.7%). At the level of significance of p 0.05, the statistically significant difference in the functional outcomes between the group with preventive intramedullary osteosynthesis and the group with nail osteosynthesis of the pathologic fracture was not confirmed (p=0.952). When comparing the patient survival after nail osteosynthesis with impending pathologic fracture and the survival of patients with pathologic fracture, a statistically significant difference in survival between these two groups (p=0.520) was not confirmed. The patient survival of longer than 6 months was 71% in the group of impending fractures and 40% in the group of pathologic fractures. DISCUSSION The occurrence of pathologic fracture is associated with increased pain, loss of function, and according to some authors, a higher risk of death. Surgical treatment options include intramedullary osteosynthesis, plate osteosynthesis with cement filling, implantation of an intercalary spacer, and implantation of tumor endoprostheses. When deciding on a surgical procedure, an account is taken of the expected survival of the patient. In patients with an expected survival of up to 6 months, intramedullary osteosynthesis is indicated as a palliative surgical intervention. The most common complications include implant failure and metastatic progression. CONCLUSIONS Intramedullary osteosynthesis is the method of choice in treating pathologic fractures or impending pathologic diaphyseal fractures of long bones in patients with an expected predicted survival of up to 6 months. Intramedullary osteosynthesis aims to reduce pain and enable early verticalization. The study confirmed the importance of preventive intramedullary osteosynthesis and its effect on survival compared to the survival of patients with a pathologic fracture. Key words: skeletal metastases, diaphyseal metastases, intramedullary osteosynthesis, pathologic fracture, impending fracture.

PURPOSE OF THE STUDY The preferred treatment of giant cell tumor of bone is curettage with the use of local adjuvant. If the tumor spreads beyond the bone into soft tissues, en bloc excision should be performed. Intralesional curettage allows joint preservation, but it is associated with a high recurrence rate. The purpose of the study was to identify the risk factors for local recurrence and to compare the functional outcomes after both types of surgical procedures. MATERIAL AND METHODS The group included 16 patients (5 women, 11 men) with giant cell tumor of bone in distal forearm treated at the First Department of Orthopedic Surgery, St. Anne s University Hospital Brno in 2005-2019. The mean age of patients was 38 years (22-53). The follow-up period was 6.75 years (2-15) on average. The most common location of the tumor was distal radius (14). In 6 patients denosumab treatment was indicated. Based on the obtained data, we compared the effects of gender, Campanacci grade, type of surgery and administration of denosumab on the risk of local recurrence. The functional outcomes were evaluated retrospectively based on the Musculoskeletal Tumor Society scoring system for upper limb salvage surgeries. RESULTS Resection and reconstruction using an osteocartilaginous allograft was performed in 9 patients. Seven patients were treated with tumor curettage with bone cement used to fill the cavity. The group of patients who underwent curettage showed a significantly higher mean MSTS score 89% compared to the group of patients with resection with the mean MSTS score 66% (P < 0.05). Local tumor recurrence was reported in 3 patients (18.75%). No statistically significant difference was found in gender, tumor grade, radicality of surgery or administration of targeted therapy with respect to the incidence of local recurrence. Altogether 6 complications (37.5%) were observed in the group. DISCUSSION The treatment of a giant cell tumor of bone aims to completely remove the tumor and to preserve the best possible function of the limb. The complications in distal forearm involve particularly an increase incidence of local recurrence and painful or limited range of motion of the wrist. Whereas curettage with the use of local adjuvant is burdened with a higher recurrence rate, resection with allograft reconstruction of bone defect is usually associated with poorer functional outcomes. CONCLUSIONS Tumor curettage using local adjuvant is preferred in a well-circumscribed tumor and offers an excellent functional outcome. En bloc tumor resection and reconstruction using an osteocartilaginous allograft is a suitable treatment option for a locally advanced tumor with a low risk of local recurrence. Key words: giant cell tumor of bone, distal radius, distal ulna, curettage, osteocartilaginous allograft.

Giant-cell tumor of bone (GCTB) is an intermediate type of primary bone tumor characterized by locally aggressive growth with metastatic potential. The aim of this study was to identify new druggable targets among the cell signaling molecules involved in GCTB tumorigenesis. Profiles of activated signaling proteins in fresh-frozen tumor samples and tumor-derived cell lines were determined using phosphoprotein arrays. Analysis of the obtained data revealed epidermal growth factor receptor (EGFR) and platelet-derived growth factor receptor beta (PDGFRβ) as potential targets, but only the PDGFR inhibitor sunitinib caused a considerable decrease in stromal cell viability in vitro . Furthermore, in the case of a 17-year-old patient suffering from GCTB, we showed that the addition of sunitinib to the standard treatment of GCTB with the monoclonal antibody denosumab resulted in the complete depletion of multinucleated giant cells and mononuclear stromal cells in the tumor tissue. To summarize, the obtained data showed that a specific receptor tyrosine kinase (RTK) signaling pattern is activated in GCTB cells and plays an important role in the regulation of cell proliferation. Thus, activated RTKs and their downstream signaling pathways represent useful targets for precision treatment with low-molecular-weight inhibitors or with other types of modern biological therapy.

Purpose: Conventional osteosarcoma is an orphan disease. Current treatment approaches include combining a three drug chemotherapy schedule and surgery. The 3- and 5-year event-free survival (EFS) in localized disease is roughly 65 and 60%, respectively. The registration study of mifamurtide reported survival benefit, but some methodological controversies have been insufficient for FDA market authorization in contrast to EMA., Methods: prospective single centre survival analysis of a mifamurtide addition to conventional therapy in 23 patients over a 5.5 year enrolment period is reported and compared to a historical control of 26 patient with localized disease. Bias arising from observational methodology was addressed using Landmark analysis and time-dependent Cox models. Blood count dynamics were analysed during the treatment., Results: The adverse event profile was as expected with no dose limiting toxicities. There were no local relapses observed, one patient died in the first complete remission due to doxorubicin cardiotoxicity, one patient had pulmonary metastatic relapse. The observed 3- and 5-year EFS was 87.4% (CI 72.4-100%) and 87.4% (CI 72.4-100%), progression free survival (PFS) was 92.9% (CI 80.3-100%) and 92.9% (CI 80.3-100%), overall survival was 94.1% (CI 83.6-100) and 80.7% (CI 58.3-100), respectively. Comparison to the historical control showed statistically significant better PFS for mifamurtide patients (Landmark analysis; p = 0.044). Risk of progression was 5-times lower for the mifamurtide group (Cox model; HR 0.21, p = 0.136). Only subtle differences in lymphocyte counts were observed across treatment., Conclusion: the PFS benefit of mifamurtide is reported herein. The addition of mifamurtide could be considered as a best treatment option for localized osteosarcoma., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Other support: Takeda Pharmaceutical Company Limited supported post marketing analysis of usage and adverse events related to their drug mifamurtide, which in part was used in this analysis., (© 2021 The Authors. Published by Elsevier GmbH.)

PURPOSE OF THE STUDY Use of an all-polyethylene (all-poly, AP) tibial component in primary total knee arthroplasty is still an attractive option considering the durability of replacement, the elimination of backside wear and the lower cost compared to modular metalbacked tibia. The purpose of the study was to evaluate the long-term results of the total knee replacement using the P.F.C. Sigma system with a monoblock all-polyethylene tibial component implanted at the 1st Orthopedic Department of the St. Anne's University Hospital and Masaryk University Brno in the period 1999-2010. MATERIAL AND METHODS In the monitored period, 911 total knee replacements using P.F.C. Sigma with an all-polyethylene tibial component were performed. This cohort of patients was evaluated at least 10 years after the primary replacement surgery. Altogether 323 knee replacements in 289 patients were evaluated. The clinical outcomes were assessed according to the Knee Society Clinical Rating System (KSS) and the Total Knee Arthroplasty Roentgenographic Evaluation and Scoring System. The replacement survival was evaluated using the Kaplan-Meier survival analysis. RESULTS In the evaluated group, the average KS was 82.6 points and the average functional score was 74.7 points. Excellent results were recorded in 213 cases, good results in 78 and satisfactory in 23 replacements. Poor clinical results were reported in 9 patients. The average range of motion was 105.8°. In 5 knees (1.5%) revision surgery was performed for infection complications, 3 cases were complicated due to periprosthetic fractures, 4 replacements were revised due to anterior knee pain and 8 knees showed a limited range of motion. Only 1 replacement was revised for aseptic loosening, with no need for reimplantation of the component. The survivorship of the implant was 98.5 % at the follow-up of 12.8 years, including the reasons of reimplantation. DISCUSSION Total knee replacement with an all-polyethylene tibial component is not so popular as the metal-backed modular implants. The all-polyethylene tibial component has certain advantages: lower unit costs, no backside wear, no liner dislocation, possibility of conservative bone resection. On the other hand, this type of implant is not modular and augmentations or longer stems cannot be used. Even though this type of endoprosthesis is recommended exclusively for elderly patients with a lower level of activity, the current mid- and long-term results show that indications for all-poly implants are much broader. CONCLUSIONS The total knee replacement with an all-polyethylene tibial component shows very good long-term clinical outcomes with an excellent survival rate. The all-poly design is cost-effective and may be used not only in elderly patients. Key words: total knee replacement, all-polyethylene tibial component, long-term results.