Antimicrobial efficacy and activity perseverance in arthroplasty of calcium sulfate beads containing vancomycin prepared ahead of time and stored in ready-to-use formula.

The use of local therapy with antibiotics in a suitable carrier is essential in the treatment and prevention of infections in orthopedic surgery and traumatology. In our orthopedic surgery department, a synthetic calcium sulfate hemihydrate (CaSO4·½H2O) is used as an antibiotic carrier, enabling the application of most types of intravenous antibiotics in the form of powder and liquid. This type of carrier with antibiotics is prepared in the theater during the procedure. During a surgical procedure, a small dead space is created (hand and foot area), which must be filled with an antibiotic carrier, and the situations arise where a large amount of the carrier is not used and thrown away. Therefore, we verified the efficacy of vancomycin in the pre-prepared carrier by an orientation microbiological method and by measuring the concentrations of the vancomycin released in active form and its two crystalline degradation products. Based on the agar diffusion test, we did not measure any difference in the effectiveness of the antibiotic in the carrier after its 12-day storage. Although vancomycin concentrations decreased by approximately 32% at the end of 12 days of storage, the concentrations of the released active form of vancomycin are many times higher than the minimum inhibitory concentrations for resistant strains of Staphylococcus aureus. Thus, the calcium sulfate carrier with vancomycin can be prepared several days in advance before its application, certainly up to 12 days.

[Revision of Infected Total Knee Arthroplasties with DAIR Method - Factors Affecting the Two-Year Survival Rate]. / Revize infektu totální náhrady kolenního kloubu metodou DAIR ­ faktory ovlivnující dvouleté prezití.

PURPOSE OF THE STUDY Periprosthetic joint infections in total knee arthroplasty (TKA) represent one of the most limiting factors of implantation. Frequency of this complication is up to 2.5% in primary implantation. Revision TKA with the use of DAIR (Debridement, Antibiotics and Implant Retention) procedure is a widely accepted method in treating infection, but the indication criteria have not been clearly defined as yet. The lack of uniformity prevails also with respect to the surgical technique and the importance of respective techniques for successful treatment. The purpose of this study was to evaluate the factors affecting the twoyear survival of TKA after treating the infection by DAIR. MATERIAL AND METHODS We conducted a monocentric retrospective analysis involving 52 cases of infected TKA managed with DAIR in the period between 2007 and 2016. The evaluation took into account such factors as the sex, age, history of revision surgery for aseptic or septic reasons, and pathogens. The patients were divided into groups based on the McPherson criteria. As to the procedure, we monitored the effect of administered antibiotics, time interval between the manifestation of symptoms of TKA infection and surgery, exchange of modular parts, and use of pulse lavage, continual lavage, local antibiotic carrier, or combination of these techniques. Treatment failure was defined as persistent infection and transition to chronic suppressive antibiotic therapy or need for revision surgery of the respective joint due to recurrent infection of TKA, or death directly associated with the treatment of infected TKA in the follow-up period of 2 years after DAIR. The R software (Team Development Core, 2017) was used to carry out the statistical analysis. The target variable was the failure at two years after surgery. The Generalized Linear Model (GLM) was used for the binary dependent variable - the socalled logistic model with a logit link function. RESULTS 32 of 52 patients (61.5%) were successfully treated, of whom 18 women (62.1%) and 14 men (60.9%). The effect of causative agent, administered antibiotics, polyethylene insert exchange, McPherson score or history of revision surgery of the respective joint for aseptic reasons was not confirmed. The history of revision surgery for infection of the affected joint had a strong negative impact on treatment success, 10 of 13 (76.9%) implants failed as against 10 of 39 (25.6%) implants with negative history of infection. The mean time from surgery to the manifestation of infection was 5.9 weeks (0.5-47.5). When surgery was performed within 2 weeks from the manifestation of infection, 1 of 15 (6.7%) cases failed. In case of a later surgery, 19 of 37 (51.4%) cases failed. As concerns the used surgical technique, 60% (9/15) failure was reported in case of the combination of pulse lavage and continual lavage, 36.4% (4/11) in case of the combination of pulse lavage and local antibiotic carrier, 25% (4/16) in case of separate continual lavage, and 66.7% (2/3) in case of continual lavage with local antibiotic carrier. DISCUSSION The importance of individual factors in revision surgery of periprosthetic joint infections of TKA remains unclear. The world literature indicates as a major negative effect the time factor, the positive history of infection of the affected implant, or other previous revision surgery for aseptic reasons. Ambiguous results are achieved in assessing the effect of the pathogen, administered antibiotics or presence of fistula, the statistical significance of which has not been confirmed in our study. Questionable is also the importance of individual surgical techniques. CONCLUSIONS DAIR is a suitable method in treating infections of stable TKA without the history of revision surgery for infection. The surgery should be performed within 2 weeks from the manifestation of symptoms. Key words: debridement, antibiotics, infection, implant retention, total knee arthroplasty.

[Economic Analysis of the Costs of Hospital Stay of Patients with Infection as a Complication of Total Replacements - Part 2: Total Hip Arthroplasty]. / Ekonomická analýza nákladu na hospitalizaci pacientu s infekcní komplikací totální náhrady - 2. cást: totální náhrada kycelního kloubu.

PURPOSE OF THE STUDY The study aims to quantify the costs of a hospital stay of patients with periprosthetic joint infection after total hip arthroplasty throughout the period of treatment. MATERIAL AND METHODS The group included patients who have been treated at our department for infection as a complication of total hip replacement since 1 January 2011, who have been provided with treatment (including complications) exclusively at the departments of Nemocnice Ceské Budejovice, a.s. and whose treatment can be considered completed in 2019. The patients were included in the study regardless of the type of infection and method of treatment. The group consisted of 36 patients (16 men and 20 women). There were 3 cases of early postoperative infection, 14 cases of late postoperative infection and 19 cases of hematogenous infection. The group includes 8 patients treated by a one-stage reimplantation, 19 patients managed by a two-stage reimplantation, 6 patients treated by a revision surgery with implant retention, and 3 patients in whom only the implant removal was possible. In selected patients, all the reported points for all the hospital stays and costs incurred on a separately charged material were ascertained and the final sum was compared with the reimbursement obtained by the hospital in the DRG system valid for the respective year of treatment. The total costs were analysed and also an analysis by type of infection and method of treatment was carried out. RESULTS The average costs of managing infection as a complication of total hip arthroplasty at our department amounted to CZK 320 065 (CZK 56 995 - CZK 953 614), the reimbursement in respect of the monitored cases in the DRG system equalled CZK 220 503 (CZK 89 149 - CZK 589 974). The aforementioned suggests that the average loss per treated patient is CZK 99 562 (CZK + 63 372 - CZK -428 499). DISCUSION Care associated with infections as a complication of total hip arthroplasty is very costly and these costs are not fully covered by the reimbursement from the health insurance companies. In the Czech Republic, these costs have not been quantified as yet, therefore it is only possible to compare the costs with international publications arriving at similar conclusions and with own monitoring of the costs of periprosthetic joint infections after total hip arthroplasty. The most economically efficient is the one-stage replacement which, however, is not suitable for all the patients, and the two-stage reimplantation continues to be the gold standard. In our study, the most expensive was found to be the treatment of periprosthetic joint infection after total hip arthroplasty, in which also the highest financial loss is reported. CONCLUSIONS Due to the very high costs of treatment for periprosthetic joint infections after total hip arthroplasty, it is necessary to exert maximum efforts to prevent periprosthetic joint infections and to consider a change in the method of financing, particularly in centres to which patients are referred from other centres in order to make this treatment economically viable. Key words:total hip arthroplasty, PJI - periprosthetic joint infection, economic analysis.

[Economic Analysis of the Costs of Hospital Stay of Patients with Infection as a Complication of Total Replacements - Part 1: Total Knee Arthroplasty]. / 1. cást: totální náhrada kolenního kloubu - 1. cást: totální náhrada kolenního kloubu.

PURPOSE OF THE STUDY The study aims to quantify the costs of a hospital stay of patients with total knee periprosthetic joint infection throughout the period of treatment. MATERIAL AND METHODS The group included patients who have been treated at our department for infection as a complication of total knee replacement since 1 January 2011, who have been provided with treatment (including complications) exclusively at the departments of Nemocnice Ceské Budejovice, a.s. and whose treatment can be considered completed in 2018. The patients were included in the study regardless of the type of infection and method of treatment. The group consisted of 24 patients (11 men and 13 women). There were 2 cases of early postoperative infection, 6 cases of late postoperative infection and 16 cases of hematogenous infection. The group includes 17 patients treated by a two-stage reimplantation, 6 patients treated by a revision surgery with implant retention, and 1 patient treated by a one-stage replacement. In selected patients, all the reported points for all the hospital stays and costs incurred on a separately charged material were ascertained and the final sum was compared with the reimbursement obtained by the hospital in the DRG system valid for the respective year of treatment. The total costs were analysed and moreover, an analysis by type of infection and method of treatment was carried out. RESULTS The average costs of managing infection as a complication of TKA in our department amounted to CZK 405 864 (CZK 66 768-CZK 181 17). The average cost of a two-stage revision was CZK 497 487, the cost of a revision surgery with original implant retention was CZK 175 312. The reimbursement in respect of the monitored cases in the DRG system equalled CZK 276 230 (CZK 40 943-CZK 848 401). The aforementioned suggests that the average loss per a treated patient is CZK 129 635 (CZK + 26 066Kc-CZK -332 774). DISCUSION Our study is in agreement with recent literature, when confirming that the care associated with infections as a complication of TKA is very costly (especially in case of a two-stage reimplantation) and also that this care is not fully covered by the health insurance company. The reimbursement made by the health insurance companies does not cover on average 1/3 of the costs of care for an infectious patient. Theoretically, the reasons behind the reduced reimbursement may be sanctions which, however, cannot be accepted in case of late hematogenous infections which constituted more than 50% in our group. CONCLUSIONS Our study presented the actual costs associated with the care of TKA infection. It makes sense that the most expensive is the two-stage reimplantation, which is nevertheless still considered to be the gold standard procedure in chronic TKA infection. High costs of therapy together with the requirement of expert care would justify the introduction of care provided by specialised centres. In this case, centralisation could result in a more efficient use of funds and improvement of the quality of provided care. Key words:total knee arthroplasty, PJI - periprostetic joint infection, economic analysis. ÚVOD.

The use of broad-range bacterial PCR in the diagnosis of infectious diseases: a prospective cohort study.

OBJECTIVES: Broad-range PCR has the potential to detect virtually any bacterial species via amplification and nucleotide sequencing of a DNA region common to all bacteria. We aimed to evaluate its usefulness and clinical relevance when applied to a wide variety of primary sterile materials. METHODS: A prospective study including 1370 samples (75 heart valves, 151 joint tissue samples, 230 joint aspirates, 848 whole blood samples and 66 culture-negative cerebrospinal fluid samples) were studied by using a commercial PCR system for detecting 16S rDNA (Molzym). The PCR results were compared with culture and were considered to provide added diagnostic value only if the PCR approach revealed new pathogens that were missed by culture. RESULTS: The added value of PCR was evident in 173 of 555 PCR-positive samples (0.126; 0.109-0.144 (proportion from all tested samples; 95% confidence interval)), most frequently in examinations of heart valves (0.56; 0.448-0.672) and joint tissue samples (0.219; 0.153-0.284). In contrast, the lowest rate of PCR with added value was noted for blood samples, regardless of the patient cohort they had been drawn from (nononcologic patients from intensive care: 0.065; 0.043-0.087, haematooncologic children: 0.048; 0.027-0.070). Moreover, PCR missed up to 7.1% of blood culture findings (0.071; 0.048-0.095) regarded as clinically relevant, which was the second highest failure rate after joint tissue samples (0.099; 0.052-0.147). CONCLUSIONS: Broad-range PCR substantially increases detection rate of pathogens, especially from heart valves and joint samples. However, a concurrent risk of false-negative PCR results justifies the need for parallel culture.

[The Risk of Total Joint Replacement Infectious Complications in Relation to the UHMWPE Particle Adhesion Area]. / Riziko infekcních komplikací po náhrade nosného kloubu ve vztahu k adhezní plose UHMWPE cástic.

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.

Rare case of osteomyelitis of tibial shaft caused by Nocardia cyriacigeorgica.

Nocardiosis is a rare infection caused by the aerobic actinomycete of the Nocardia genus. In most cases, nocardiosis manifests as a lung infection or a bone lesion. Due to the nonspecific and mild clinical manifestations of nocardiosis, the establishment of definite diagnosis can be difficult. When antibiotic therapy is incorrectly targeted, only the symptoms of the disease are suppressed. The mainstay in the treatment of Nocardia osteomyelitis has so far been the combined surgical debridement with long-term, initially intravenous, antibiotic administration. We present the successful conservative treatment of a nocardiosis osteomyelitis of the tibia caused by the Nocardia cyriacigeorgica species in an 81-year-old female patient that manifested itself as a secondary affection on top of a primary nocardiosis infection of the lung. From microbiological examination, N. cyriacigeorgica was discovered; the identification was made using matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) with an identification score of 1.9. The sensitivity was evaluated using E test. Sensitivity to trimethoprim/sulfamethoxazole, amikacin, imipenem, and linezolid was demonstrated. The bacteria were shown to be resistant to ciprofloxacin. For treatment, trimethoprim/sulfamethoxazole was used due to the value of minimum inhibitory concentration, which was 0.25 mg/L. The initial dose of 960 mg of trimethoprim/sulfamethoxazole every 8 h was reduced to 960 mg every 12 h after 3 months. The total duration of treatment was 7.5 months. Under the established treatment, the bone and lung lesions healed. Nocardiosis of the long bone is considered a rare disease and its precise diagnosis has not yet been standardized. We used the MALDI-TOF MS method for the identification of the causal organism which is a fast and reliable method according to current world literature even when compared with the rRNA genetic sequencing reference method. Our case study presents a rare case of osteomyelitis of tibial shaft caused by N. cyriacigeorgica and its successful conservative treatment.

[Endoprosthesis Infections - Guidelines for Antibiotic Therapy Common Guidelines of the Czech Society for Orthopaedics and Traumatology and the Society for Infectious Diseases of the Czech Medical Association of J. E. Purkyne]. / Infekce endoprotéz ­ doporucení antibiotické lécby Spolecné doporucení Ceské spolecnosti pro ortopedii a traumatologii a Spolecnosti infekcního lékarství Ceské lékarské spolecnosti J. E. Purkyne.

PURPOSE OF THE STUDY This study aims to articulate regional guidelines for curative and suppressive antibiotic therapy of total joint replacement infections. MATERIAL AND METHODS When developing the standard, used as source materials were the published foreign guidelines for antibiotic therapy of prosthetic joint infections, the analysis of resistance of bacterial strains conducted in the Hospital in Ceské Budejovice, a.s. and the assessment of strain resistance for the Czech Republic published by the European Antimicrobial Resistance Surveillance Network (EARS-Net). Considered was also the availability of individual antibiotics in the Czech Republic and restricted prescription according to the Summary of Product Characteristics as specified in the State Institute for Drug Control marketing authorisation. The expert group composed of orthopaedists, microbiologists and infectious disease specialists elaborated the basic antibiotic guideline for choosing an appropriate antibiotic/antifungal drug based on the usual susceptibility, its dose and dosage interval for initial and continuation therapy. The comments of individual specialists were gradually incorporated therein and in case of doubts majority rule was applied. The drafted document was sent for peer reviews to clinical orthopaedic, infectious disease and microbiological centres, whose comments were also incorporated and the finalised document was submitted for evaluation to specialised medical societies. RESULTS The outcome is the submitted guideline for antibiotic curative and suppressive therapy suitable for managing the prosthetic joint infections, which was approved by the committee of the Czech Society for Orthopaedics and Traumatology andthe Society for Infectious Diseases of the Czech Medical Association of J. E. Purkyne. DISCUSION Curative therapy of total joint replacement infections consists primarily in surgical treatment and has to be accompanied by adequate antibiotic therapy administered initially intravenously and later orally over a sufficient period of time. Bearing in mind the wide spectrum of pathogens that can cause infections of a joint replacement and their capacity to form a biofilm on foreign materials, the correct choice of an antibiotic, its dose and dosage interval are essential for successful treatment. Such standard should respect regional availability of antibiotics, regional pathogen resistance/susceptibility and ensure the achievement of sufficiently high concentrations at the requested location including anti-biofilm activity. CONCLUSIONS The submitted guideline is not the only treatment option for joint total replacement infections, but it makes the decisionmaking easier when treating these complications in the form of infections. The final choice of an antibiotic, its dose and duration of therapy shall be based on a critical assessment of results of microbiological (blood culture and molecular genetic) tests and reflect the patient s clinical condition. Since these are multidisciplinary issues, we consider useful for this guideline to be commented upon and approved by the committee of both the Society for Orthopaedics and Infectious Diseases so that it can become the starting point for treatment. Key words: total joint replacement infection, TEP, ATB, antibiotic therapy, consensus meeting, guideline.

[Alloplastic Materials and their Propensity to Bacterial Colonisation]. / Aloplastické materiály z pohledu jejich citlivosti ke kolonizaci bakteriemi.

UNLABELLED: PURPOSE OF THE STUDY The alloplastic materials currently used for protective surface layers on implants were tested in vitro under microbiological laboratory conditions by contamination with microbial agents most frequently found in deep infection of total joint replacements. The objective was to find out how the resistance to bacterial colonisation was related to different surface finishes. MATERIAL AND METHODS Each of 14 samples of alloplastic material currently used in the manufacture of orthopaedic implants was inoculated with each of the group of microorganisms most frequently infecting joint replacements; these were Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Enterococcus faecalis and Escherichia coli. At 24 hours of incubation, biofilms produced on sample surfaces were collected, stained with crystalline violet and assessed by spectrophotometry. The average value of biofilm absorbances (AV595) for the group of microorganism tested was taken as a basic characteristic of each material sample indicating its sensitivity to bacterial. RESULTS Of the metal materials with smooth surface finish, Vitalium (AV595, 0.368) showed the lowest affinity to microbial colonisation; next was titanium (AV595, 0.459) and steel (AV595, 0.505). A significant increase in sensitivity to bacterial colonisation was recorded in all types of surface finish of steel (AV595, 0.571) and in titanium alloy with a rough surface texture (AV595, 0.737 to 1.676); p < 0.05. Porous titanium surfaces significantly increased material affinity to colonisation. DISCUSSION Our study had certain limitations concerning in vitro evaluation of porous surfaces that have high affinity to bacterial colonisation. Porous titanium, and its hydroxyapatite layer in particular, considerably promotes osteoblast colonisation of the surface as well as implant osseointegration in the bone bed. Microorganisms therefore have no room for surface colonisation. Problematic may remain the surface parts outside contact with bone that keep their affinity to bacterial colonisation. CONCLUSIONS The material of choice for cemented implants is Vitalium which, of all metal surfaces, has the lowest sensitivity to bacterial colonisation. The materials of choice for cementless implants are titanium alloys. However, an osteoactive surface not in contact with bone remains a problem. On the one hand, its roughness and porosity are crucial to good osseointegration, on the other hand, its affinity to bacterial colonisation is high. KEY WORDS: alloplastic material, biofilm, joint replacement infection.

[Eleven-Year Experience with Total Ankle Arthroplasty]. / Jedenáctileté zkusenosti s náhradou hlezna.

UNLABELLED: PURPOSE OF THE STUDY Total joint replacement is one of the options in surgical treatment of advanced ankle arthritis. It allows the ankle to remain mobile but, unfortunately, it does not provide the same longevity as total knee or hip replacements. Therefore, decisions concerning the kind of treatment are very individual and depend on the clinical status and opinion of each patient. MATERIAL AND METHODS A total of 132 total ankle replacements were carried out in the period from 2004 to 2015. The prostheses used included the Ankle Evolutive System (AES) in 52 patients, Mobility Total Ankle System (DePuy) in 24 patients and, recently, Rebalance Total Ankle Replacement implant in 53 patients. Three patients allergic to metal received the Taric prosthesis. Revision arthroplasty using the Hintegra prosthesis was carried out in four patients. The outcome of arthroplasty was evaluated on the American Orthopaedic Foot and Ankle Society (AOFAS) scoring scale. Indications for total ankle arthroplasty included post-traumatic arthritis in 83 patients, rheumatoid arthritis in 37 and primary arthritis in 12 patients. There were 78 women and 54 men, with an average age of 55.6 years at the time of surgery. RESULTS The average follow-up was 6.1 years (1-11 years). The average AOFAS score of the whole group increased from 33.2 before surgery to 82.5 after it. The primary indication had an important role. Arthroplasty outcomes were poorer in patients with post-traumatic arthritis than in those with rheumatoid arthritis or primary arthritis. In patients with post-traumatic arthritis, the average AOFAS score rose to 78.6 due to restricted motion of the ankle, and some patients continued to have pain when walking. The average AOFAS score in a total of 49 patients who had rheumatoid arthritis or primary arthritis reached a value of 86.4. Post-operative complications were recorded in ten patients (7.6%) in whom part of the wound was healing by second intention. Ossification was also a frequent complication and had to be removed in six patients (4.5%). No early infection was recorded and late infection was treated in three patients. The prosthesis had to be removed and ankle arthrodesis performed in seven patients (5.3%). All had necrosis of the talus with ankle instability. In five, the retrograde nail Medin was used and extensive defects remaining after talar necrosis were filled with massive bone grafts obtained from a bone bank. One patient required tibio-calcaneal arthrodesis with external fixator; surgery in one case involved the use of a Zimmer Trabecular Metal Ankle Fusion Spacer with retrograde nail fixation. The development of cystic radiolucencies adjacent to tibial or talar components presents another post-operative complication. It was recorded mostly in the patients after AES implantation, in whom eight of 52 (15.3%) had these findings. DISCUSSION Total ankle arthroplasty is a complicated surgical procedure potentially associated with various technical problems. The occurrence of complications is indirectly related to the experience of the orthopaedist performing surgery; literature data show that the number of complication decreases with an increased frequency of ankle replacements done. CONCLUSIONS Total ankle arthroplasty, as every orthopaedic surgery, has its advantages and disadvantages. The positive aspects are pain relief and improved mobility of the ankle allowing for physiological gait. However, it shows a lower survivorship rate that the other large joint replacements. A successful outcome depends on the correct indication. The ankle should be stable, the talus without signs of necrosis and valgus or varus deviations of the ankle should not exceed 10 to 15 degrees. KEY WORDS: total ankle arthroplasty, re-implantation, aseptic loosening, retrograde nail, Trabecular Metal spacer, revision arthroplasty.

PCR diagnostic system in the treatment of prosthetic joint infections.

In our prospective study, we examined whether a multiplex PCR diagnostic method is suitable for the primary detection of pathogens. We also examined the possibility and sensitivity of detecting genes responsible for biofilm production and methicillin resistance. From 2007 to 2009, 94 patients were included in the study. A UNB (universal detection of 16S ribosomal bacterial DNA) and UNF (universal detection of pathogenic fungi) were used in the primary detection. A multiplex assay for biofilm production, methicillin resistance allowed us to distinguish between Gram positivity and negativity and to detect Staphylococci. From all the samples, the culture was positive in 53.2 % of cases, and by using the UNB method, we detected bacteria in 79.8 % of cases-the UNF detection of fungi was positive in 10.6 % of cases. In 75 % of positive findings, we detected a Gram-negative bacterium in 65.3 % of cases. In 47.2 % of Staphylococci detected, the ability to produce biofilm was confirmed. 61.1 % of the Staphylococci exhibited a methicillin resistance. Our multiplex scheme cannot yet fully replace microbial cultivation but can be a rational guide when choosing an appropriate antibiotic therapy in cases where the microbial culture is negative.

The effect of Vancomycin degradation products in the topical treatment of osteomyelitis.

BACKGROUND: The topical application of Vancomycin is increasingly being used in orthopedics because of the development of methicillin resistant bacteria. Consequently, resistance to Vancomycin has recently been on the rise. One possible explanation for this phenomenon could be the thermal degradation of Vancomycin to antibacterially inactive crystalline degradation products (CDP-1s). The aim of our in vitro experiment was to compare the creation and elution characteristics of CDP-1s and the active form of Vancomycin (factor B) released from bone grafts. METHODS: CDP-1s and the factor B released from bone grafts into the buffer solution were measured using the high-performance liquid chromatography method at progressive intervals. RESULTS: The factor B was released from bone grafts at the highest levels, typically on the first day (618.8 mg/L). CDP-1 levels kept increasing until the end of measurement on day 15, when the concentration of CDP-1s (1280.7 mg/L) was much higher compared to that of factor B (217.5 mg/L). CONCLUSIONS: We confirmed the tendency of Vancomycin to convert to antimicrobially ineffective CDP-1s. Although Vancomycin is decomposed into crystalline degradation products, its active forms are released from bone grafts in sufficient concentration for more than two keks (Tab. 3, Fig. 1, Ref. 15).

Bone grafts as vancomycin carriers in local therapy of resistant infections.

The level of an antibiotic capable of inhibiting the etiological agent at the site of infection is an essential prerequisite for successful antibiotic therapy. In some cases, locally applied antibiotics may compensate for limitations of systemic administration and shorten systemic therapy. We aimed at verifying to what extent vancomycin (Van) bound to ground bone grafts is usable in the treatment of serious infections. The levels of released Van significantly exceeded the Van minimum inhibitory concentration, which can suppress Van-sensitive staphylococci and Van intermediate Staphylococcus aureus, for the whole period of a 16-day measurement. Our results indicate that bone grafts can be used as Van carriers in therapy of osteomyelitis caused by Van-sensitive Staphylococcus strains.

[Cement-within-cement femoral stem reimplantation technique]. / Reimplantace náhrady kycelního kloubu metodou docementování dríku do puvodního cementového luzka.

PURPOSE OF THE STUDY: The reimplantation of a cemented femoral component at revision is always a challenge for the orthopaedic surgeon, particularly when the cement mantle is intact. The aim of this study was to provide evidence that the recementing of a femoral stem into the original cement mantle can be included in routine surgical procedures. MATERIAL AND METHODS: A group of 104 patients with femoral stem revision, followed-up for an average of 50.2 months, were retrospectively reviewed. The outcome evaluation was focused, in the first place, on survivorship of the femoral component, acetabular migration, and dislocation and infection after revision arthroplasty. Hip function evaluation was based on the Harris hip scores before surgery and at the latest follow-up. On radiographs Gruen zones were assessed pre-operatively and at the latest follow-up. The results were statistically evaluated using the Kaplan-Meier survival analysis (Statistica 8.0). RESULTS: Of the 104 patients, only three (2.9 %) had stem re-revision due to its loosening. Further 16 patients underwent revision for other post-operative complications. The success rate of reimplantation in our group including all post-operative complications was 81.7 %. The average Harris scores were 56 before surgery and 87 at the latest follow-up. Radiolucent lines in Gruen zones were on average 0.45 mm in width before revision and 0.15 mm at the latest follow-up. Fourteen patients had second revision within 20 months of the first and only five were revised after a long period. DISCUSSION: The cement-within-cement exchange of a femoral component is a relatively frequent orthopaedic procedure. Despite this frequency, however, there have not been enough literature reports based on large patient groups to give support to its routine use. The aim of this study was to demonstrate on a large patient group that recementing a femoral stem into the original intact cement mantle can be considered an established operative technique. Our results suggest that the list of indications for this technique, as described by Lieberman and Nelson, can be extended by the following: broken stem with an intact distal cement mantle, replacement of a monoblock femoral component due to severe head damage, loosening of the femoral component without impairment of the distal cement mantle, conversion of a cervico-capital to a total hip replacement and the need of removing all bone cement. No risk is associated with reimplantation of the original component if there is no need for a different implant to correct angle or length stability. A new implant is always used when any part of the femoral component has been damaged mechanically. If only the proximal stem requires recementing, the use of the original component is preferred because of absolute cement/stem cohesion. The number of our patients in which the technique failed was generally in agreement with the results of other authors. CONCLUSIONS: Utilisation of the original cement mantle of a femoral component is one of the options at revision arthroplasty. It requires rational considerations based on the type of surgery, state of the cement mantle, and type of material used for the femoral stem. The method is indicated preferably in the hips with an intact cement mantle treated for loosening of the acetabular component, recurrent dislocation or unequal leg-length in monoblock femoral components. In such situations the removal of well-fixed cement would also involve a considerable loss of bone tissue. The follow-up outcomes showed that the involvement of the cement-within-cement technique in routinely used surgical procedures is fully justified.

[Anatomical study of flexor hallucis brevis insertion: Implications for clinical practice]. / Anatomická studie úponové cásti m. flexor hallucis brevis pro klinickou praxi.

PURPOSE OF THE STUDY: The flexor hallucis brevis (FHB) is one of the short muscles of the foot. It divides in front into two portions, which are inserted into the medial and lateral sides of the base of the first phalanx of the great toe. The detailed knowledge of its insertion into the proximal phalangeal base is decisive in any surgery involving the first metatarsophalangeal (MTP) joint, such as implant arthroplasty, resection arthroplasty or amputation. Complications resulting from injury to this insertion are commonly known. The aim of this study was to describe in detail the morphology of FHB insertion sites and to determine a safe extent of resection to be done at the base of the proximal phalanx. MATERIAL AND METHODS: In 36 cadaver specimens we measured FHB insertion length from the plantar side of the proximal phalangeal base and from the plane perpendicular to the long axis of the phalanx and passing through the base of the concave articular surface of the phalanx. RESULTS: Measured from the plantar base of the proximal phalanx, the mean length of the medial insertion site was 11.5 ± 0.9 mm (range, 9.5 to 13.0 mm) and that of the lateral insertion site was 9.5 ± 1.1 mm (range, 8.0 to 11.5 mm). After resection, the mean values for medial and lateral FBH insertion sites were 8.5 ± 1.7 mm (range, 6.5 to 11.0 mm) and 7.1 ± 1.4 mm (ran- ge, 5.5 to 9.5 mm), respectively. The mean total proximal phalangeal length was 33.1 ± 2.2 mm (range, 28.5 to 37.0 mm), reduced after resection to 30.5 ± 2.1 mm (range, 26.0 to 34.5 mm). DISCUSSION: Our results show that the medial insertion site, where the medial FHB tendon and distal part of the abductor hallucis muscle are joining, is longer than the lateral site. Therefore the length of the lateral site is decisive for preserving FHB function. Since the plane perpendicular to the long axis of the phalanx and passing through the base of the concave articular surface of the phalanx is almost identical with the beginnings of FHB insertions, it seems optimal for clinical practice to perform the initial resection along this plane. CONCLUSIONS: To preserve at least one third of the FHB insertion, the final resection should not exceed 4 mm or 13 % of the proximal phalangeal length, as measured from the reference plane defined above.

[Long-term results of the SVL total knee arthroplasty]. / Dlouhodobé výsledky náhrady kolenního kloubu SVL.

PURPOSE OF THE STUDY: The aim of the study was to evaluate the long-term results of the total knee replacement Beznoska SVL implanted at the 1st Department of Orthopaedic Surgery, 1st Faculty of Medicine, Charles University and Motol University Hospital Prague, in the 1997/2009 period. MATERIAL AND METHODS: The SVL implant is a non-constrained knee replacement, anatomically similar to the bone it replaces, which preserves the posterior cruciate ligament. A total of 1101 knee joint replacements were evaluated in 973 patients, of whom 128 underwent bilateral arthroplasty. Kaplan-Meier curves were used to estimate the cumulative survival of implants. Clinical outcomes were assessed using the Knee Society clinical rating system (KS score) and radiographic data evaluation was also included. RESULTS: Using KS scores, the results were excellent in 997, good in 75, satisfactory in 19 and poor in 10 knees. The average range of motion was 0.16 to 106.31 degrees. The complications included flexion contracture, as the most frequent problem (13 knees), 10 knees were infected, aseptic loosening due to polyethylene granuloma was found in eight knees and anterior knee pain was experienced in six cases. At follow-up of 12.5 years implant survivorship was 98 %, as evaluated by the Kaplan-Meier analysis. DISCUSSION: A comparison of SVL implant survivorship with other knee replacement designs is discussed. It should be emphasized that the clinical outcome depends not only on implant quality, but also on the operative technique used and the surgeon's experience and skills. It is the SVL system that allows for the balancing of knee joint stability and thus enables even less experienced surgeons to make use of a more sophisticated implantation technique. CONCLUSIONS: Total knee replacement using the SVL Beznoska implant is a safe, reliable and economic treatment with excellent clinical outcomes.

[In vitro assessment of vancomycin released from bone grafts]. / Monitoring vankomycinu uvolnovaného z kostních stepu v pokuse in vitro.

PURPOSE OF THE STUDY: Infections of the musculoskeletal system present a serious problem in orthopaedic and trauma medicine because, typically, they are often recurrent and associated with the development of resistance to antibiotics. The aim of this study was to ascertain whether the local concentration of vancomycin released from cancellous bone grafts exceeded the minimum inhibitory concentration (MIC) for vancomycin-resistant Staphylococcus aureus (VRSA ≥ 16 mg/L) during a 16-day in vitro experiment. MATERIAL AND METHODS: Morselised grafts of spongy bone were selected as ideal local carriers of antibiotic. They were impregnated with vancomycin (Edicin®). Its concentration was assessed by Agilent 1200 high performance liquid chromatography coupled with a diode array detector (Agilent Technologies, USA). Morselised bone was impregnated with vancomycin at 0.1 g antibiotic per 10 g bone, and 20 samples each weighing 1 g were prepared. They were placed in test tubes with phosphate buffer at pH = 7.4 and maintained in a thermostat at 37°C. During the 16-day period, buffer samples were taken at intervals and examined for vancomycin concentration by the above-described method. RESULTS: During the whole experimental period, the level of released vancomycin was high above the MIC for VRSA. The maxi- mum average concentration was obtained between day 2 and day 4 and it reached 507.68 mg/L. At this interval the vancomycin level was stable, because there was no significant difference (p >.0.005) between the values of the 2nd and the 4th day. Then a gradual decrease in antibiotic levels was detected, with an average concentration of 332.29 mg/L recorded at 16 days. DISCUSSION: Recently, the occurrence of methicilin-resistant Staphylococcus aureus (MRSA) infections has been increasing as well as the risk of VRSA infections, and therefore our experiment was set up to assess the releasing properties of bone grafts impregnated with vancomycin The levels of released vancomycin were much higher than the MIC for VRSA for the whole period of measurement. This finding is different from the results of an in vitro study by Witso et al., in which the vancomycin level dropped below the MIC after 2 weeks. The decrease in vancomycin levels following its maximum values was greater than it had been expected although the samples were diluted only minimally..There are several explanations for this finding. However, from the clinical point of view it is important that, for a sufficiently long period, vancomycin is maintained at a level exceeding the MIC for VRSA. CONCLUSIONS: In an in vitro experiment under conditions simulating a human internal environment, the elution of antibiotic from vancomycin-impregnated cancellous bone grafts was investigated. The local vancomycin concentrations much exceeded the MIC for VRSA for more than 2 weeks. The highest levels, i.e. the total vancomycin amount, were recorded at 2 to 4 days after carrier application. Based on the experimental results, vancomycin-loaded bone grafts can be recommended for local treatment of the musculoskeletal system infected with antibiotic-sensitive staphylococci, MRSA strains or possibly also for VRSA infections.

[ToeFit-Plus system for replacement of the first metatarsophalangeal joint]. / Nase zkusenosti s náhradou I. MTP kloubu palce implantátem ToeFit Plus.

PURPOSE OF THE STUDY: Hallux rigidus is a frequent disease of the first metatarsophalangeal (MTP) joint. It is a painful condition markedly reducing joint motion. For grade-3 and grade-4 disease, as classified by Coughlin, first MTP joint replacement is another option of surgical treatment, in addition to resection arthroplasty or arthrodesis. MATERIAL AND METHODS: In a group of 27 patients with symptomatic hallux rigidus, 28 MTP joint replacements using a TOEFIT-PLUS implant were carried out in the 2005-2009 period. There were 24 women and three men, with an average age of 56.3 years. The average follow-up was 24 months (range, 4 to 48). Indication for surgery included hallux rigidus in 20, conditions following Keller's arthroplasty in five, necrosis of the first metatarsus head in two cases and a condition after the Austin procedure in one patient. Pain, assessed by the Kitaoka score, and the range of joint motion; were evaluated before the surgery and at the final follow-up visit this also included the radiographic assessment of implant position and its integration. RESULTS: Of the 28 implants used, nine were hemiprosthetic and 19 total joint replacements. The average time between surgery and full weight-bearing was 6.6 weeks (range, 5 to 8) in both groups. The post-operative Kitaoka score was 87.1 (68-100) as compared with the preoperative value of 36.3 (24-52), and this difference was statistically significant.The range of motion at the first MTP improved from 14.7 degrees pre-operatively to 38.5 degrees post-operatively. There was no statistically significant difference in joint function, as assessed by the Kitaoka score and range of motion, between the two groups (hemiprosthetic vs. total joint replacements). The complications included prolonged skin healing with minor dehiscence in four cases. Revision surgery was required in three cases because of restricted joint motion associated with pain. In three cases of the total joint replacement group, there was radiographic evidence of asymptomatic osteolysis around both the phalangeal and the metatarsal component. In the hemiarthroplasty group, no osteolysis was recorded. DISCUSSION: Up to now several types of implants have been developed to alleviate pain and restore and maintain the first MTP motion in patients with hallux rigidus.The TOEFIT-PLUS implant belongs to the most recent ones. Our results are in agreement with those of other currently used replacements in terms of clinical and functional evaluation. The complications recorded in our study are also similar to those reported in the literature, which include aseptic loosening, dislocation and mechanical failure of the implant. There is no consistent approach to their treatment. Arthrodesis with tricortical graft seems to be an option, but it carries a considerable risk of failure. Since in our patients aseptic loosening was recorded only in the total joint replacement group, hemiarthroplasty has recently been preferred, because it has clinical and functional outcomes as good as total joint replacement. CONCLUSIONS: Our results with the use of TOEFIT-PLUS replacement show that this implant is effective in the treatment of hallux rigidus advanced stages and has good clinical outcomes, i.e., maintenance of motion at the MTP joint of the big toe, pain alleviation and early weight bearing. Since hemiarthroplasty is associated with fewer complications whose potential treatment is easier, this approach seems to have a better prospect than total joint replacement.

[Distribution of UHMWPE wear particles in periprosthetic tissues of total hip replacements]. / Distribuce oterových cástic UHMWPE v periprotetických tkáních u TEP kycelního kloubu.

INTRODUCTION: Information on the distribution of UHMWPE wear particles around joint replacements is essential for the understanding of aseptic loosening of implants. MATERIAL AND METHODS: Samples of soft tissue from around total hip arthroplasty (THA), which had a typical appearance of polyethylene granuloma, were collected from the places corresponding to the radiological zones of Gruen and DeLee. The samples were taken from 45 patients (group N1). Since the samples varied in macroscopic appearance and/or the technique of processing, a sub-group of 15 more uniform samples (group N2) were collected by the first author in order to ensure the maxi- mum reliability. The samples were examined for the extent of tissue damage and the amount of particles in each zone. The comprehensive orthopaedic evaluation of tissue damage was carried out as follows: the first author studied the joint replacement revision protocol and pre-operative radiograph in each patient. He evaluated the degree of damage in each zone and wrote down the results in the form of an ordered series according to increasing damage (relational statement). This ordered series was called orthopaedist's statement (OS). The amount of particles in each zone around THA was assessed by the IRc method developed in the laboratory of the second author. IRc method yielded numbers that were proportional to the volume of biologically active particles with size 0.1-10 microm in given zones. The set of numbers from IRc method for each individual case of THA was ordered in a series (relational statement). This ordered series was called a measurement statement (MS) and could be directly compared with orthopaedist's statement (OS). The OS's and MS's for each patient were statistically evaluated, independently for each group (N1=45, N2=15), and two hypotheses were tested: a) distribution of particles in various zones around THA is uniform, b) there is an agreement between OS and MS. RESULTS: The number of UHMWPE wear particles in different periprosthetic zones within each patient was significantly different in both groups (N1 and N2) at the significance level of P=0.001. The OS's and MS's were identical at the significance level P=0.05. Moreover, maximum amount of particles was found in zones III and 7 in 40 patients out of 45. DISCUSSION: Polyethylene wear debris is considered one of the major causes of THR failures. However, neither national nor international literature has provided a study that would show a statistically significant relationship between the numbers of wear particles in individual zones and the extent of tissue damage in these zones. This is most probably due to the fact that four independent methods had to be developed in order to compare OS's and MS's: 1) accurate technique of tissue sampling during THA revisions, 2) accurate method of isolating wear particles from the tissues collected, 3) efficient, reliable and reproducible quantification of UHMWPE particles and 4) correct method of statistical analysis for comparison of the orthopaedist's statements and the measurement statements for all patients involved. CONCLUSION: The distribution of wear particles in the periprosthetic tissues of THA is not uniform, i.e. the amount of wear particles of each patient varies from zone to zone. The extent of tissue damage in each zone, as assessed by the orthopaedic surgeon (OS), was in a good agreement with the volume of 0.1-10 microm particles obtained by IRc measurement (MS) of the zone. We have provided conclusive evidence that the highest number of particles is accumulated in zone III and zone 7. As the number of particles the zones varies and the greatest damage is repeatedly found in areas with the highest particle numbers, it can be concluded with certainly that wear particles are one of the main causes of aseptic joint implant failure.

[Polyetheretherketone (PEEK). Part I: prospects for use in orthopaedics and traumatology]. / Polyetheretherketon (PEEK) - I. cást: Perspektivní materiál pro ortopedickou a traumatologickou praxi.

On the basis of current studies, polyaryletherketone (PAEK) polymers appear to be materials with great prospects for medical application. The most important member of this family of semi-crystalline thermoplastics is polyetheretherketone (PEEK) with its composites. The excellent properties of this material find their use in the treatment of various disorders of the skeletal system. At present they are used with advantage to construct spinal implants, and replacements for other orthopaedic applications and for dental and trauma medicine are at advanced stages of clinical testing.