Ultrahigh molecular weight polyethylene (UHMWPE) is the most common bearing component in total joint replacements (TJR). The polymer exhibits good biocompatibility and high resistance to wear, and its properties can be further optimized. After the year 2000, a number of new commercially available UHMWPE types emerged. Their manufacturers claim that the materials exhibit longer lifetimes both in vitro and in vivo. However, each implant manufacturer promotes its own type of UHMWPE. Comparison of real benefits of the new UHMWPE types is available only from independent studies. We aim at: (i) Development of accelerated (in vitro) aging protocols and comparison of available UHMWPE liners from the point of view of their long-term stability and properties. This should show, which of the new UHMWPE’s will exhibit the best, long-term in vivo performance. (ii) Development of new stabilization/modification methods for UHMWPE as well as for new polymer materials, which should exhibit longer lifetime. This should result in modern types of TJR’s, which will be produced by local manufacturers.

Ultravysokomolekulární polyethylen (UHMWPE) je materiál, který je užíván k výrobě artikulačních komponent kloubních náhrad. Polymer má výbornou biokompatibilitu a malý otěr, jeho strukturu a vlastnosti lze modifikovat. Po roce 2000 se objevila řada nových typů UHMWPE, které in vitro i in vivo vykazují vyšší odolnosti vůči opotřebení. Každý výrobce implantátů prezentuje přednosti svého materiálu. Reálné údaje o materiálech jsou dostupné pouze z nezávislých studií. Cílem projektu je pokračovat v práci týmu: laboratorně připravené i komerční modifikované UHMWPE vystavit prostředí urychleného stárnutí vlastní metodou. Po expozici, odpovídající funkci in vivo po mnoho let, sledovat změny struktury. Výstupem bude informace, které z nyní zaváděných materiálů budou spolehlivé i v dlouhé perspektivě. Jak jsme prokázali, vlastnosti UHMWPE se průběžně zásadně mění. Druhou linií bude hledání nových typů úprav UHMWPE a dalších polymerních materiálů, které by mohly starší typy UHMWPE nahradit. Výstupem by měly být nové typy náhrad, které bude možno vyrábět v ČR a udržet krok s vývojem ve světě.

• MeSH
• artroplastiky kloubů MeSH
• biokompatibilní materiály analýza   terapeutické užití   MeSH
• polyethylen analýza   terapeutické užití   MeSH
• protézy kloubů MeSH
• selhání protézy MeSH
• testování materiálů MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• technika lékařská, zdravotnický materiál a protetika
• ortopedie
• NLK Publikační typ
• závěrečné zprávy o řešení grantu AZV MZ ČR

PURPOSE OF THE STUDY Treatment of comminuted three- and four-part displaced proximal humerus fractures continues to be discussed in daily trauma practice. In fractures with metaphyseal comminuted fractures the anatomical reconstruction is often technically unfeasible. For cases of comminuted metaphyseal proximal humerus fractures we proposed the so called non-anatomical reconstruction with simple osteosynthesis. Even today, when nailing and plating are commonly used in osteosynthesis, the non-anatomical reconstruction plays an irreplaceable role. Its application is conditioned by at least partially preserved vascular blood supply of the head fragment. This paper describes our original technique to manage these fractures and provides an evaluation of results of the group of patients in whom this procedure was performed. MATERIAL AND METHODS Our group included a total of 72 patients (who underwent surgery in the period from 1 January 1989 to 22 March 2016), of whom 57 were clinically assessed (8 patients died, 7 patients failed to be traced back). The mean age at the time of procedure was 53.61 years (range 19-81 years). The mean follow-up was 14.3 years (range 0.3-26.3 years) after the surgery. The method consists in removing the comminution zone, impacted modified diaphyseal fragment to head spongiosis and osteosynthesis of greater and lesser tubercle or their remainders to diaphyseal fragment using tensile cerclage. RESULTS The mean post-operative Constant score was 81.4 (range 30-100 points). The mean abduction was 120.4 degrees (range 60-165 degrees) and ventral flexion was 129.2 degrees (range 70-170 degrees). Excellent clinical outcome according to the Constant score was achieved in 19 patients, good outcome in 23 patients, fair in 8 patients and poor in 7 patients. DISCUSSION We have been using our original method for 27 years. Compared to osteosynthesis by locking plates, minimally invasive procedures and trauma shoulder joint replacement, our method helps achieve very good clinical outcomes. Its main advantage, however, is the fact that by this technique the specific type of fractures can be treated, otherwise manageable exclusively by arthroplasty. CONCLUSIONS At our clinic, the non-anatomical reconstruction belongs to irreplaceable methods for treating certain proximal humerus fractures. The clinical outcomes of this method can be described as very good. The method of non-anatomical reconstruction eliminates the disadvantages and risks of arthroplasty. Nonetheless, it shall be stressed that this method can be successful exclusively when applied to precisely indicated types of fractures and when performed with technical precision. Its another advantage are the minimal financial requirements. Key words: non-anatomical reconstruction, osteosynthesis, proximal humerus, cerclage.

• MeSH
• fraktury proximálního humeru * diagnóza   patofyziologie   chirurgie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• následné studie MeSH
• pooperační komplikace diagnóza   MeSH
• poranění ramene * diagnostické zobrazování   chirurgie   MeSH
• ramenní kloub patofyziologie   chirurgie   MeSH
• rozsah kloubních pohybů MeSH
• tříštivé fraktury MeSH
• vnitřní fixace fraktury * škodlivé účinky   přístrojové vybavení   metody   MeSH
• výsledek terapie MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

PURPOSE OF THE STUDY For an orthopedic surgeon it is difficult or even impossible to estimate the real quality of ultrahigh molecular weight polyethylene (UHMWPE) liners that are used in the total joint replacements (TJR) just on the basis of information given by the manufacturers. At the same time, the quality of the UHMWPE liner can impact strongly on the total lifespan of the implanted TJR. This work aims at independent, objective comparison of properties of the UHMWPE liners for total hip replacements (THR), which are most frequently used in the Czech Republic. MATERIAL AND METHODS We analyzed seventeen most frequently implanted UHMWPE cups of different manufacturers implanted in the Czech Republic between 2014 and 2015 and four control samples prepared by standard industrial-scale procedures according to our instructions, whose modification (crosslinking, thermal treatment, stabilization and sterilization) was known in detail. The UHMWPE polymer was characterized by four independent microscale methods, suitable for relatively small and irregular specimens such as THR cups: infrared microspectroscopy (IR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). RESULTS The employed methods yielded quite complete information about the investigated UHMWPE materials. IR spectra enabled us to calculate oxidation indexes (OI, measure of oxidative damage), trans-vinylene indexes (VI, measure of absorbed radiation dose during crosslinking and/or sterilization) and crystallinity indexes (CI, amount of crystalline phase that strongly influences mechanical performance). DSC curves were employed in calculation of crystallinities (wc, proportional to CI) and melting points (Tm, proportional to the average thickness of crystalline lamellae). MH measurements confirmed that the observed structure changes showed a real impact on mechanical properties. TGA experiments gave rough estimate of stabilization and, consequently, possible long-term oxidation resistance. Significant correlations among oxidative damage (OI), crystallinity (CI, wc) and microhardness (Hv) were statistically proven. The highest oxidative degradation was usually observed in samples thermally treated by annealing and/or sterilized by gamma irradiation. DISCUSSION The results confirmed our expectations that the UHMWPE liners from various manufacturers can be significantly different as far as their molecular structure, supermolecular structure, and mechanical properties are concerned. The differences among the various UHMWPE can be expected to increase after the implantation during in vivo. CONCLUSIONS From the clinical practice point of view, the results showed the following facts: (i) In the field of THR, all manufactures prefer crosslinked types of UHMWPE due to their increased wear resistance; non-crosslinked UHMWPEs are regarded as obsolete. (ii) Most of the manufacturers prefer ethylene oxide or gas plasma sterilization to gamma sterilization because the gammasterilized UHMWPEs exhibit lower long-term oxidation resistance. (iii) Modern trend is the stabilization of UHMWPEs with vitamin E. Key words: UHMWPE, hip replacements, oxidative degradation, infrared spectroscopy, microhardness.

• MeSH
• lidé MeSH
• náhrada kyčelního kloubu * MeSH
• polyethyleny * MeSH
• testování materiálů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

INTRODUCTION: The aim of this study has been to present outcomes after cementless arthroplasty for developmental dysplasia Crowe type IV of the hip, with transverse subtrochanteric shortening osteotomy and using the S-ROM stem. METHODS: We evaluated radiographs, functional scores and complications in a consecutive series of 23 patients (28 hips) with high dislocation of the hip. The average age of patients at surgery was 49.9 (range 22-68) years. The operations were performed between 2007 and 2013. Patients were assessed retrospectively-clinically and radiographically during the year 2018. RESULTS: The mean follow-up period was 94 (range 60-134) months. The average Harris hip score improved from 39.9 to 84.0. The mean leg length discrepancy decreased from 5 cm preoperatively to 1.4 cm at the final follow-up. All acetabular components were implanted into the true acetabulum, and all prostheses were stable at the latest examination. No neurovascular damage was recorded. We have identified specific complications in seven hips (25%) in total: Intraoperative femoral fracture required fixation in four hips; three hips (10.7%) needed revision: Recurrent dislocation, with the need for cup reorientation, occurred in two hips (in one of them, this was followed by the subsequent need for resection of heterotopic ossification); there was one aseptic stem loosening with the need of one-stage revision. All the osteotomies healed within 8 months. CONCLUSION: Hip arthroplasty with transverse shortening femoral osteotomy, using S-ROM stem, is an acceptable, but not complication-free treatment method in patients with Crowe type IV developmental hip dysplasia, in the midterm.

• MeSH
• dislokace kloubu etiologie   chirurgie   MeSH
• dospělí MeSH
• kyčelní kloub * diagnostické zobrazování   patofyziologie   chirurgie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• náhrada kyčelního kloubu * škodlivé účinky   metody   MeSH
• nestejná délka dolních končetin etiologie   chirurgie   MeSH
• osteotomie * škodlivé účinky   metody   MeSH
• pooperační komplikace * diagnóza   patofyziologie   chirurgie   MeSH
• rentgendiagnostika metody   MeSH
• reoperace * škodlivé účinky   metody   statistika a číselné údaje   MeSH
• retrospektivní studie MeSH
• výsledky a postupy - zhodnocení (zdravotní péče) MeSH
• vývojová kyčelní dysplazie * diagnóza   chirurgie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

PURPOSE OF THE STUDY Periprosthetic joint infection is a major complication which in most of the cases requires a long-term administration of antibiotics and often necessitates undergoing multiple challenging surgeries. Bacterial adhesion to foreign material is one of the key risk factors associated with periprosthetic joint infection. The foreign material with large adhesion area might be also the UHMWPE (Ultrahigh molecular weight polyethylene) particles released during the wear process from the surface of articulating components. The purpose of this study is to evaluate potential adhesion areas of wear particles in relation to diverse distribution of the size and shapes of wear particles in periprosthetic tissue and to assess an increase in the risk of infectious complications associated with an increase in the adhesion area of wear particles. MATERIAL AND METHODS The size and morphology of model and real UHMWPE particles were determined with the use of light microscopy and scanning electron microscopy. By determining the morphological descriptors, the surfaces of individual particles for different distributions of polyethylene particles were calculated. When measuring the model wear particles, 6 model situations were simulated, in which comparisons with the control measurement by the BET (Brunauer-Emmet-Teller) method were made. RESULTS The variability of individual morphological descriptors demonstrates the effect on the total surface of particles. The calculated coefficient defines how many times the particle surface increases when corrected to the given descriptor (elongation, flattening, roughness, porosity). The total area of real wear particles at 1 year is 4,622 cm2, at 20 years it is 92,440 cm2. Based on our calculations, the area of particles where a biofilm is actually formed (approximately 50 bacteria may adhere to a particle of 3µm in diameter) is 809.5 cm2 at 1 year and 16,190 cm2 at 20 years. DISCUSSION According to the measurements, the size of the potential adhesion area of metal parts and polyethylene particles becomes equal already after several weeks of endoprosthesis usage and after a few years it is many times larger. The question is whether the risk of bacterial adhesion, i.e. also the risk of infectious complications of TEP actually increases. The clinical practice suggests that the number of infections e.g. 10, 15 or 20 years after the primary implantation is not statistically higher, despite the confirmed growth of potential adhesion area in the form of UHMWPE particles. This fact could be explained by a partially equal regulatory pathway of infection and polyethylene disease. The immune system stimulated by wear particles might better resist the hematogenic infection. CONCLUSIONS The study outcomes clearly indicate that the area of polyethylene wear particles considerably increases over time. In spite of the fact that only approximately 10% of wear particles show parameters (also with respect to the size of particles and bacteria) for potential bacterial adhesion, this area is many times larger than the area of metal parts of the endoprosthesis. Key words: UHMWPE particle, adhesion, biofilm, wear, TJR infection.

• MeSH
• artroplastiky kloubů škodlivé účinky   přístrojové vybavení   MeSH
• infekce spojené s protézou etiologie   MeSH
• lidé MeSH
• polyethylen škodlivé účinky   MeSH
• polyethyleny škodlivé účinky   MeSH
• protézy a implantáty škodlivé účinky   MeSH
• selhání protézy * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

PURPOSE OF THE STUDY Considered to be one of the most common causes of aseptic loosening of endoprostheses is the THA failure due to the wear of articulating components, UHMWPE in particular. The purpose of this study is to verify, in terms of oxidative damage and other parameters, the differences between the UHMWPE implants made by various manufacturers explanted for aseptic loosening with the same life span in vivo. MATERIAL AND METHODS In the period 2010-2015, a total of 21 THA articulating components (cups) made of Ultrahigh molecular weight polyethylene by seven different manufacturers were explanted. For each manufacturer, three UHMWPE cups with the same life span (10-12 years after the primary implantation) were evaluated. The damage to the examined joint replacements was described in complexity using three different criteria, namely independently by three evaluators - experienced orthopaedic surgeons. The evaluated criteria were the following: degree of osteolysis determined based on the preoperative radiographs, wear rate of the explanted UHMWPE component, and extent of perioperatively detected granuloma. Oxidative damage and other structural characteristics of explanted cups were studied by means of infrared spectroscopy and microhardness testing. The correlation between the clinical orthopaedic assessment and oxidative damage were statistically processed. RESULTS Strong correlations between the oxidative damage and crystallinity, strong correlations between all types of orthopaedic assessments, negligible correlations between trans-vinylene index and all the other quantities, and moderate correlations between the oxidative damage and clinical evaluation were identified. It was confirmed by experimental measurement that the observed high oxidative damage, resulting in increased crystallinity, manifested itself also in micromechanical properties of the material at the respective site of the THA articulating component. DISCUSSION The discussion includes the comparison of correlations of individual quantities as well as potential effects on the differences in values of components made by individual manufacturers. The values are related to the data in literature and generally accepted claims. CONCLUSIONS At the time of failure almost all the components showed severe or even critical oxidative damage that strongly correlated with the overall clinical evaluation of the damage to the implant. This confirmed that the oxidative degradation is one of the main causes of THA failure. Key words: UHMWPE, oxidation index, crystallinity, THA failure, wear.

• MeSH
• kyčelní protézy * škodlivé účinky   MeSH
• lidé MeSH
• náhrada kyčelního kloubu přístrojové vybavení   MeSH
• odstranění implantátu MeSH
• polyethyleny * škodlivé účinky   MeSH
• protézy - design MeSH
• selhání protézy etiologie   MeSH
• testování materiálů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH

PURPOSE OF THE STUDY Developmental dysplasia of the hip still remains one of the most discussed topics in paediatric orthopaedics. The comprehensive care of paediatric patients with congenital developmental dysplasia of the hip at our department in the period from 1970 to 1985 included, among other things, the open reduction using Ludloff s approach in hip joints where closed reduction was not possible. This technique was supported by some of our own previous observations, such as the original classification of intraoperative findings on acetabular labrum (limbus). This study aims to evaluate the long-term results of treatment of our patients where Ludloff s open reduction was used and seeks to establish a conclusive correlation between the final result and the method of treatment of individual types of limbus, possibly confirming or ruling out that the dependence of later development of the acetabulum is dependent on correct and sparing treatment of this barrier to reduction. MATERIAL AND METHODS In the period from 1970 to 1985, the Ludloff s open reduction was performed in 70 patients. In 8 cases bilateral surgery was carried out. A total of 78 hip joints were operated on. The patients underwent the surgery at the age of 5-23 months. Postoperatively, the Hanausek biomechanical apparatus was applied to complete the treatment. In total, documentation of 21 surgeries performed in 20 patients was successfully tracked down. Two patients were removed from the group for incomplete documentation. The final group of patients included a total of 18 patients, of whom there were 13 women and 5 men. In one female patient the surgery was performed bilaterally. The shape of the femoral head, the center-edge (CE) angle and the degree of osteoarthritic changes were assessed on the pelvic radiograph of each patient. The functional result was evaluated using the Harris Hip Score (HHS). RESULTS For the purpose of assessment, the patients were divided into sub-groups based on the intraoperative finding on acetabular labrum. Type I limbus was found in a total of 5 cases. The mean HHS was 93, the mean CE angle was 22.5°. Aseptic necrosis occurred in one patient. Type II limbus was found in a total of 3 patients. The mean HHS was 84, the mean CE angle was 22°. Aseptic necrosis was observed in one patient. Type III limbus was found in 8 patients. The mean HHS was 79, the mean CE angle was 19.4°. Osteoarthritic changes of degree II-III were identified. Necrosis of the femoral head was recorded in 2 patients. Type IV limbus was found three times. The mean HHS was 73, the mean CE angle was 13.3°. Osteoarthritic changes of type III were present. Necrosis of the femoral head was recorded altogether in 2 patients. DISCUSSION The results of the Ludloff procedure reported in the available literature differ markedly as to the resulting function of the hip joint and the incidence of avascular necrosis. No author gave a description of the actual acetabular labrum deformity or showed a detailed description of individual vessel ligations. The advantage of this method is beyond any doubt its low invasiveness and when correctly performed also the minimal burden to the child. Its disadvantage is a certain degree of difficulty in performing this surgery, a worse visualisation of all barriers to reduction and a more challenging treatment of the posterior portion of the hip joint compared to techniques using the anterior approach. CONCLUSIONS Our outcomes indicate that the resulting Harris Hip Score was best in patients with the intraoperative finding of type I limbus. All the other types (ll-IV) showed worse HHS results. From the current perspective, it is in all likelihood more advantageous to use surgical approaches that enable better visualisation of the anatomical deformities and allow for better options for their treatment.

UNLABELLED: PURPOSE OF THE STUDY Ultrahigh molecular weight polyethylene (UHMWPE) is today the most frequently used bearing surface in total joint replacements (TJR) because of its properties, i.e., excellent biocompatibility, good mechanical and tribological performance and high wear resistance. UHMWPE liners are the most loaded TJR components and, therefore, their properties are decisive for TJR longevity. This study had three objectives: 1) to evaluate the oxidative degradation of explanted UHMWPE components; 2) to look for a statistically significant relationship between the extent of oxidative degradation and the durability of joint replacements; and 3) to investigate whether the durability of a TJR was related to the type of sterilisation used in manufacture. MATERIAL AND METHODS The study included 26 acetabular components obtained at revision arthroplasty between 2004 and 2013 from patients in whom a Beznoska/Poldi total hip replacement was used in the period from 1977 to 2002. The average age of the patients at the time of primary implantation was 57.9 years, the average longevity of the components removed was 18.63 years (range, 6.9 to 27.9 years). Samples of worn out and unworn areas from explanted components were processed in a three-step procedure in order to finally obtain 2-mm microtome sections. These were studied by infrared microspectroscopy. Oxidative damage to UHMWPE was determined as the oxidation index (OI); radiation damage to UHMWPE during sterilization was evaluated as the transvinylene index (VI); oxidation-induced changes in the polymer structure and its properties were characterised as the crystallinity index (CI); and local changes in mechanical properties due to oxidative degradation were assessed as microhardness (MH). Spearman's correlation coefficient and the Wilcoxon two-sample test were used for statistical analysis. RESULTS The OI values (average and maximum) in both worn out and unworn surface areas were related to component longevity. The difference between the oxidation index of ruptured components and that of the other components was statistically significant. Significant differences were also found between the average and maximum OI values of worn out areas and those of unworn surfaces. The relationship between the average oxidation index in both the unworn and worn out areas of UHMWPE components and the longevity of cracked components was statistically significant. DISCUSSION Our results show that the OI values obtained by microspectroscopy correlated with both the microscopic damage and the longevity of UHMWPE liners and the correlation was statistically significant also in relation to the longevity of total replacements. Relationships amongst OI, VI, CI and MH values as well as their relation to failure and longevity of total replacements are discussed. CONCLUSIONS It can be concluded that infrared microspectroscopic measurement of OI values is a simple and fast method to characterise UHMWPE liners. In addition, the IR spectra also show other supplementary characteristics, such as VI and CI indices. These values provide information on the quality of various UHMWPE types currently used in TJR surgery. The types of UHMWPE which exhibit high oxidative degradation should be avoided in clinical practice due to increased risk of early TJR failure. Responsible orthopedic surgeons should be aware of this fact and, if possible, collaborate with an independent, noncommercial laboratory in order to evaluate the quality of various UHMWPE liners used in their hospitals. KEY WORDS: UHMWPE, oxidation, total joint replacement, infrared spectroscopy, microhardness.

• MeSH
• biokompatibilní materiály chemie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• náhrada kyčelního kloubu přístrojové vybavení   MeSH
• oxidační stres fyziologie   MeSH
• polyethyleny chemie   MeSH
• reoperace MeSH
• selhání protézy MeSH
• senioři MeSH
• spektrofotometrie infračervená MeSH
• testování materiálů metody   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH

Zavedení umělých kloubních náhrad představuje pro miliony lidí na celém světě převratnou metodu léčby závažných kloubních postižení. Ročně narůstá počet primoimplantací a rostou nároky na životnost kloubních náhrad. S tím se ale také zvyšují nároky na odolnost artikulačních povrchů vůči opotřebení. Nejužívanějším materiálem pro jejich výrobu je stále vysokomolekulární polyetylén (UHMWPE – ultra-high molecular weight polyethylene). Ten byl zaveden do klinické praxe již v 60. letech 20. století. Fyzikálně chemické vlastnosti UHMWPE jsou předmětem mnoha výzkumů, které postupně vedou k jeho vyšší odolnosti vůči otěru při zachování stability vůči oxidativní degradaci.

The introduction of artificial joint replacement constitutes a breakthrough method of treatment for severe joint disease for millions of people worldwide. Annual increase in the number of primary replacement and also increasing demands on the longevity of joint replacements are leading to increased demands on wear resistance of articular surface. Ultra-high molecular weight polyethylene (UHMWPE) is still most commonly used material for the production of articular surface. It was introduced into clinical practice in the 60s of the 20th century. Physical-chemical properties of UHMWPE are subject of many studies. These lead gradually to its improvement in terms of higher wear resistance while maintaining the stability against oxidative degradation. The main objective of this review is to summarize the basic properties of high-molecular weight polyethylene which are important for its use in orthopaedic practice and to explain the possibilities of its modification and sterilization. Knowledge of the latest trends about this material helps to orthopaedic surgeons get oriented in the issues and then to choose for their patients implants with the highest implant longevity.

• Klíčová slova
• vysokomolekulární polyethylen, UHMWPE,
• MeSH
• ethylenoxid chemie   MeSH
• lidé MeSH
• náhrada kyčelního kloubu metody   MeSH
• polyethylen * chemie   MeSH
• protézy kloubů klasifikace   trendy   MeSH
• sterilizace metody   MeSH
• vitamin E chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH
• přehledy MeSH