PURPOSE OF STUDY: Total joint replacements (TJR) have become the cornerstone of modern orthopedic surgery. A great majority of TJR employs ultrahigh molecular weight polyethylene (UHMWPE) liners. TJR manufacturers use many different types of UHMWPE, which are modified by various combinations of crosslinking, thermal treatment, sterilization and/or addition of biocompatible stabilizers. The UHMWPE modifications are expected to improve the polymer's resistance to oxidative degradation and wear (release of microparticles from the polymer surface). This manuscript provides an objective, non-commercial comparison of current UHMWPE formulations currently employed in total knee replacements. MATERIALS AND METHODS: UHMWPE liners from 21 total knee replacements (TKR) were collected which represent the most implanted liners in the Czech Republic in the period 2020-2021. The UHMWPEs were characterized using several methods: infrared microspectroscopy (IR), non-instrumented and instrumented microindentation hardness testing (MH and MHI), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and solubility measurements. The above-listed methods yielded quite complete information about the structure and properties of each UHMWPE type, including its potential long-term oxidation resistance. RESULTS: For each UHMWPE liner, IR yielded information about immediate oxidative degradation (in the form of oxidation index, OI), level of crosslinking (trans-vinylene index, VI) and crystallinity (CI). The MH and MHI testing gave information about the impact of structure changes on mechanical properties. The remaining methods (DSC, TGA, and solubility measurements) provided additional information regarding the structure changes and resistance to long-term oxidative degradation. Statistical evaluation showed significant differences among the samples as well as interesting correlations among the UHMWPE modifications, structural changes, and mechanical performance. DISCUSSION: Surprisingly enough, UHMWPE materials from different manufacturers showed quite different properties, including the resistance against the long-term oxidative degradation, which is regarded as one of the main reasons of TJR failures. The most promising UHMWPE types were crosslinked materials with biocompatible stabilizers. CONCLUSIONS: Current UHMWPE liners from different manufactures used in total knee replacements exhibit significantly different structure and properties. From the point of view of clinical practice, the traditional UHMWPE types, which contained residual radicals from irradiation and/or gamma sterilization, showed inferior resistance to oxidative degradation and should be avoided. The best properties were observed in modern UHMWPE types, which combined crosslinking, biocompatible stabilizers, and sterilization by ethylenoxide or gas plasma. KEY WORDS: UHMWPE; knee replacements; oxidative degradation; infrared spectroscopy; microhardness.
- MeSH
- biokompatibilní materiály chemie MeSH
- diferenciální skenovací kalorimetrie MeSH
- lidé MeSH
- polyethyleny * chemie MeSH
- protézy - design MeSH
- protézy kolene * MeSH
- termogravimetrie MeSH
- testování materiálů * metody MeSH
- totální endoprotéza kolene * přístrojové vybavení metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- srovnávací studie MeSH
xiv, 471 stran : ilustrace (některé barevné), portréty ; 28 cm
Vysokoškolská učebnice, která se zaměřuje na základy ortopedie a traumatologie.
- MeSH
- ortopedie MeSH
- traumatologie MeSH
- Konspekt
- Ortopedie. Chirurgie. Oftalmologie
- Učební osnovy. Vyučovací předměty. Učebnice
- NLK Obory
- ortopedie
- traumatologie
- NLK Publikační typ
- učebnice vysokých škol
- kolektivní monografie
- Publikační typ
- abstrakt z konference MeSH
BACKGROUND: Despite the fact that many synovial fluid biomarkers have found application in the routine diagnosis of periprosthetic joint infection (PJI), this process still remains a challenge for orthopaedic surgeons. To simplify this process, fast point-of-care (POC) tests can be used during ambulatory visits and in operating room conditions. However, before such tests can be routinely used in clinical practice, they require validation. The purpose of the present study was to evaluate the diagnostic accuracy of different fast POC tests for detecting C-reactive protein (CRP) in synovial fluid for the diagnosis of PJI. METHODS: Synovial fluid samples were collected from 120 consecutive patients who underwent revision total joint arthroplasty (TJA). The patients were divided into 2 groups. The first group included 76 patients who underwent revision for reasons other than infection (the aseptic revision TJA [arTJA] group), and the second group included 44 patients who underwent revision because of periprosthetic joint infection (PJI). The diagnosis of infection was made according to the International Consensus Meeting (ICM) 2018 criteria. All patients were operatively treated at a single orthopaedic center from January 2022 to February 2023. Four fast CRP tests with different cutoff values (1 and 3 mg/L, ≥8 mg/L, ≥10 mg/L [cassette], ≥10 mg/L [strip]) were used off-label for synovial fluid testing. Tests were performed on the same synovial fluid samples, and the results of these tests were compared with those obtained with the laboratory method. RESULTS: The cassette test with a minimum cutoff value of ≥8 mg/L demonstrated the best accuracy for the diagnosis of chronic PJI, with a sensitivity and specificity of 90.9% and 90.8%, respectively. For the cassette test with a cutoff value of >3 mg/L, the sensitivity and specificity were 68.2% and 77.6%, respectively. For the tests with a minimum cutoff value of ≥10 mg/L, the sensitivity and specificity were 77.3% and 94.7%, respectively, for the cassette test and 77.3% and 96.1%, respectively, for the strip test. The laboratory method with the statistically calculated threshold (2.7 mg/L) revealed the highest AUC (area under the receiver operating characteristic curve) value (0.95), with 90.9% sensitivity and 94.7% specificity. CONCLUSIONS: The cassette POC test with the minimum cutoff value of ≥8 mg/L had very good accuracy for the diagnosis of chronic PJI. This test had comparable sensitivity and slightly lower specificity in comparison with the laboratory method with the calculated threshold of 2.7 mg/L. LEVEL OF EVIDENCE: Diagnostic Level III . See Instructions for Authors for a complete description of levels of evidence.
- MeSH
- biologické markery MeSH
- C-reaktivní protein analýza MeSH
- infekce spojené s protézou * etiologie MeSH
- infekční artritida * chirurgie MeSH
- lidé MeSH
- náhrada kyčelního kloubu * škodlivé účinky MeSH
- senzitivita a specificita MeSH
- synoviální tekutina chemie MeSH
- totální endoprotéza kolene * škodlivé účinky MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
PURPOSE OF THE STUDY Infections of joint replacements represent one of the most serious problems in contemporary orthopedics. The joint infections treatment is usually multimodal and involves various combinations of drug delivery and surgical procedures. The aim of this study was to evaluate and compare the bacteriostatic and bactericidal properties of the most common antibiotic carriers used in orthopedic surgery: bone cements mixed with antibiotic and porous calcium sulfate mixed with antibiotic. MATERIAL AND METHODS Three commercial bone cements (Palacos®, Palacos® R+G, Vancogenx®) and commercial porous sulfate (Stimulan®) were prepared with a known concentration of vancomycin (a glycopeptide antibiotic). Specifically, for the purpose of our study, the testing specimens were prepared to release 0, 1, 2, 4, 8, 16, 32, 64, 128, 256, and 512 mg of vancomycin into 1 liter of solution. The specimens with increasing amount of antibiotic were placed in a separate tubes containing 5 mL of Mueller-Hinton broth inoculated with a suspension (0.1 m, McFarland 1) of the reference strain CCM 4223 Staphylococcus aureus to evaluate their bacteriostatic properties (broth dilution method). After this initial incubation and evaluation of the broth dilution method, an inoculum from each tube was transferred onto blood agar plates. After another 24-hour incubation under the same conditions, we evaluated the bactericidal properties (agar plate method). As many as 132 of independent experiments were performed (4 specimens × 11 concentrations × 3 repetitions = 132). RESULTS The bacteriostatic properties of all investigated samples were excellent, perhaps with the exception of the first bone cement (Palacos®). The sample Palacos® started to exhibit bacteriostatic properties at concentrations ≥ 8 mg/mL, while all other samples (Palacos R+G®, Vancogenx®, and Stimulan®) were bacteriostatic in the whole concentration range starting from 1 mg/mL. The bacteriocidic properties did not show such clear trends, but correlated quite well with different properties of the investigated samples during mixing - the most homogeneous samples seemed to exhibit the best and the most reproducible results. DISCUSSION The reliable and reproducible comparison of ATB carriers is a difficult task. The situation is complicated by high numbers of local antibiotic carriers on the market, numerous antibiotics used, and differences in clinical trials at different laboratories. Simple in vitro testing of bacteriostatic and bacteriocidic properties represents a simple and efficient approach to the problem. CONCLUSIONS The study confirmed that the two most common commercial systems used in the orthopedic surgery (bone cements and porous calcium sulfate) prevent bacterial growth (bacteriostatic effect), but they may not be 100% efficient in complete elimination of bacteria (bacteriocidic effect). The scattered results in the case of bacteriocidic tests seemed to be connected with the homogeneity of ATB dispersion in the systems and with the lower reproducibility of the employed agar plate method. Key words: local release of antibiotics; bone cements; calcium sulfate; antimicrobial susceptibility.
- MeSH
- agar MeSH
- antibakteriální látky farmakologie terapeutické užití MeSH
- kostní cementy farmakologie terapeutické užití MeSH
- lidé MeSH
- ortopedické výkony * MeSH
- ortopedie * MeSH
- polymethylmethakrylát chemie MeSH
- reprodukovatelnost výsledků MeSH
- síran vápenatý MeSH
- vankomycin farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
OBJECTIVE: To investigate the relationship between osseous variations of the glenoid fossa and thinning of the overlaying articular cartilage. MATERIALS AND METHODS: In total, 360 dry scapulae, comprising adult, children and fetal specimens, were observed for potential presence of osseous variants inside the glenoid fossa. Subsequently, the appearance of the observed variants was evaluated using CT and MRI (each 300 scans), and in-time arthroscopic findings (20 procedures). New terminology of the observed variants was proposed by an expert panel formed by orthopaedic surgeons, anatomists and radiologists. RESULTS: Tubercle of Assaky was observed in 140 (46.7%) adult scapulae, and an innominate osseous depression was identified in 27 (9.0%) adult scapulae. Upon radiological imaging, the tubercle of Assaky was found in 128 (42.7%) CTs and 118 (39.3%) MRIs, while the depression was identified in 12 (4.0%) CTs and 14 (4.7%) MRIs. Articular cartilage above the osseous variations appeared relatively thinner and in several young individuals was found completely absent. Moreover, the tubercle of Assaky featured an increasing prevalence with aging, while the osseous depression develops in the second decade. Macroscopic articular cartilage thinning was identified in 11 (55.0%) arthroscopies. Consequently, four new terms were invented to describe the presented findings. CONCLUSION: Physiological articular cartilage thinning occurs due to the presence of the intraglenoid tubercle or the glenoid fovea. In teenagers, the cartilage above the glenoid fovea may be naturally absent. Screening for these variations increases the diagnostic accuracy of glenoid defects. In addition, implementing the proposed terminological updates would optimize communication accuracy.
- MeSH
- dítě MeSH
- dospělí MeSH
- kloubní chrupavka * diagnostické zobrazování MeSH
- kloubní jamka lopatky * diagnostické zobrazování MeSH
- lidé MeSH
- lopatka MeSH
- magnetická rezonanční tomografie MeSH
- mladiství MeSH
- počítačová rentgenová tomografie MeSH
- ramenní kloub * MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé MeSH
- mladiství MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: The aim of this study was to analyze the treatment results of fungal periprosthetic joint infections (PJI) caused by Candida species from a single orthopedic center and to compare them with reports from other institutions. METHODS: Eight patients operated on from January 2014 to December 2021 met the inclusion criteria and were analyzed in terms of clinical outcomes. A systematic review of the literature identified 153 patients with Candida PJIs extracted from 12 studies according to the PRISMA (Preferred Reporting Item for Systematic Reviews and Meta-Analyses) guidelines. RESULTS: The success rate of the treatment in the case series was 50%. The most frequent pathogens were Candida albicans (three cases; 37.5%) and Candida parapsilosis (three cases; 37.5%). In one patient (12.5%), bacterial co-infection was noted, and in five patients (62.5%) significant risk factors of PJI were confirmed. The overall success rate on the basis of data collected for systematic review was 65.5%. A sub-analysis of 127 patients revealed statistically significant differences (p = 0.02) with a higher success rate for the knees (77.6%) than for the hips (58%). In 10 studies the analysis of risk factors was performed and among 106 patients in 77 (72.6%) comorbidities predispose to fungal PJI were confirmed. Bacterial co-infection was noted in 84 patients (54.9%). In 93 patients (60.7%) Candida albicans was the culprit pathogen, and in 39 patients (25.5%) Candida parapsilosis was the culprit pathogen. Based on these two most frequent Candida species causing PJI, the success rate of the treatment was statistically different (p = 0.03), and was 60.3% and 83.3%, respectively. The two-stage strategy was more favorable for patients with Candida parapsilosis infections (94.4% success rate) than the one-stage protocol (50% success rate; p = 0.02); as well as in comparison to the two-stage treatment of Candida albicans (65% success rate; p = 0.04). CONCLUSIONS: The analysis of the literature showed no differences in the overall success rate between one- and two-stage surgical strategies for all Candida species, but differed significantly comparing the two most frequent strains and concerning PJI localization. The frequent presence of bacterial co-infections makes it necessary to consider the additional administration of antibiotics in the case of fungal PJI.
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
