Twenty-Four-Hour Movement Behaviors in Adults and Older Adults before Total Knee Arthroplasty: a Study Based on Compositional Data Analysis.

PURPOSE OF THE STUDY This study aims to describe and analyze the age differences in the 24-hour movement behavior patterns among a sample of adults and older adults with end-stage knee osteoarthritis referred for total knee arthroplasty (TKA). MATERIAL AND METHODS A total of 86 patients referred for TKA were included in this study. Sleep duration, sedentary behavior (SB), light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) were assessed using multi-day 24-hour raw data from wrist-worn accelerometers. Compositional data analysis was used to analyze the differences between the age categories. RESULTS On average (SD), the adults were 59.0 (± 4.9) years; 63% female. The older adults were 72.4 (± 5.5) years; 58% female. The adults reached 23.9 milli-gravitational units (mg) as a mean acceleration over the whole day; 34% (8.1 h/day) of the time was classified as sleep, 48.9% (11.7 h/day) as SB, 12.1% (2.9 h/day) as LPA, and 5.1% (72.9 min/day) as MVPA. The older adults reached 21.3 mg; 35.2% (8.4 h/day) of the time was classified as sleep, 50.4% (12.1 h/day) as SB, 11.3% (2.7 h/day) as LPA, and 3.1% (44.9 min/day) as MVPA. Compared with the older adults, the proportion of time spent in total MVPA (P = 0.008) and MVPA bouts of ≥1 min were greater (P ≤ 0.028) in the adult group, while the proportion of time spent in total SB was lower (P = 0.045). No age difference was found for the proportion of time spent asleep. DISCUSSION Sleep, SB, and PA are exclusive and exhaustive parts of the overall 24-h day. Using accelerometer-based measures of 24-hour movement behavior to describe these behaviors more accurately is crucial for a better understanding of patients with end-stage KOA. CONCLUSIONS Our findings suggest that the adults and older adults referred for TKA are physically active despite suffering from severe knee osteoarthritis. Such a high level of physical activity may be difficult to increase by TKA postoperatively. If replicated by other studies, 24-hour movement behaviors should be implemented among the examinations required before TKA. Key words: knee osteoarthritis, accelerometer, sedentary behaviour, physical activity, sleep, 24-hour lifestyle behaviour.

Optimal Route for Tranexamic Acid in Diabetics and Obese Patients Undergoing Primary Total Knee Arthroplasty - a Data from Randomized Study.

PURPOSE OF THE STUDY To determine the optimal strategy for tranexamic acid (TXA) administration in diabetic patients, smokers and obese patients (BMI > 30 kg/m2) undergoing primary total knee arthroplasty (TKA). MATERIAL AND METHODS The total of 400 consecutive patients indicated for primary TKA were randomised into 4 basic groups with different TXA administration regimens. Group 1 (IV1) had a single intravenous dose (15 mg TXA/kg) applied prior to skin incision. Group 2 (IV2) got two intravenous doses (15 mg TXA/kg): one prior to skin incision and one subsequently 6 hours after the first dose. Group 3 (TOP) had 2 g TXA in 50 ml of saline irrigated topically at the end of the surgery. Group 4 (COMB) combined IV1 and TOP regimens. We monitored the amount of total blood loss (TBL), haemoglobin drop, use of blood transfusions (BTs), and complications in each patient. Follow-up period was one year postoperatively. RESULTS In the group of diabetic patients (n = 87; 21.7%) the lowest TBL was observed in the order: IV1, IV2 > COMB > TOP. In the obese patients (BMI > 30 kg/m2; n = 242; 60.5%), TBL was significantly lower in the intravenous regimens (IV1: p = 0.002; IV2: p = 0.005, respectively) than in the TOP regimen. In the smoking patients (n = 30; 7.5%), TBLs were significantly lower in the order: IV1 > IV2 > COMB > TOP. DISCUSSION Individualised approach to prevention and therapy is a recent trend, also because comorbidities significantly affect the result of the intervention. In the case of diabetes, obesity and smoking, there is a proven link to early post-operative infections, mainly due to poorer innate immunity. It is conceivable, though, that the occurrence of infectious complications is also contributed to by larger hematomas or hemarthroses which are largely preventable. CONCLUSIONS In the diabetic and obese patients (BMI > 30 kg/m2), the combined topical/intravenous TXA application and two intravenous doses of TXA interventions were shown to be the most effective. However, no evidence of superiority of any of the TXA administration routes was obtained in the smokers. None of the TXA protocols was associated with a higher incidence of complications or early reoperation following TKA surgery. Key words: tranexamic acid, topical application, intravenous application, combined administration, diabetes, obesity, BMI, smoking, blood loss, hidden blood loss, total knee arthroplasty, complications.

[Smoking, Preoperative Activity, and Waiting Time for the Surgery Could Predict the Risk of Early Reoperation in Total Knee Arthroplastyy]. / Kourení, predoperacní aktivita a cekání na operaci by mohlo predikovat cetnost casných reoperací u pacientu s TEP kolena.

PURPOSE OF THE STUDY Information that would help physicians make decisions and improve the likelihood of achieving the desired results of medical interventions is sought as part of the concept of the individualized approach to patients. The primary purpose of our study was to identify which features determine the higher/lower likelihood of the need for early reoperation after a TKA (total knee arthroplasty). The successful preoperative identification of high risk patients could lead to the adjustment of the surgical procedure and thus lower the percentage of revision surgeries. MATERIAL AND METHODS In total, 826 patients (296 men and 530 women) were included in our prospective study; these patients underwent TKA implantation at our department between September 2010 and March 2015. The average age of the patients at the time of primary TKA implantation was 68.9 years. Over 60 preoperative and perioperative parameters were tracked and continuously recorded in our arthroplasty register. First, conventional analysis of individual parameters was carried out and odd ratios for their relationship with revision surgeries were set. Subsequently, the data were transformed into a graph and methods of complex network analysis were applied to identify such combinations of features (parameters) that would significantly separate the operated patients into homogeneous subgroups. The observed patient subgroups were then reanalyzed for parameters related to reoperations. RESULTS Thirty-three patients (4% of those studied) required early TKA revision (within 3 years of primary implantation). The most frequent reason for revision surgery was an early postoperative infection. The analysis of observed characteristics proved that the likelihood of revision surgery was by 80% lower in women in comparison with men. Other parameters associated with a higher frequency of reoperations were the level of preoperative activity, smoking and the waiting time for the first operation. Patients waiting for primary TKA implantation for more than 3 months showed a 2.7 times greater likelihood of revision surgery when compared to those who were operated within 3 months after the indication to surgery. Patients declaring medium or high activity levels (assessed by means of the UCLA scale) had a 2.1 times higher likelihood of revision surgery in comparison to patients with low physical activity levels. Smoking meant up to 3.2 times greater likelihood of revision in comparison with nonsmokers. Conversely, no correlation between a greater risk of reoperation and age, BMI (body mass index) or the level of comorbidities evaluated by means of the Charlson scale was confirmed. No correlation between the risk of revision and primary diagnosis was found either. DISCUSSION The frequency of early TKA revision surgeries (within 3 years after the primary surgery) in the evaluated sample is relatively high (4%). On the contrary, the reasons for early revisions correspond with recent publications. The risks of TKA infection overlap with the predictors of wound healing disorders to a great extent. Smoking, obesity and comorbidities decreasing the efficiency of the immune system are mentioned most frequently. Patients waiting for TKA implantation longer were more inclined to require early revision surgery too. Awareness of this fact is reflected in the tendency to shorten the waiting time for TKA surgery. A number of studies have pointed out the negative influence of longer waiting times on postoperative results. In our study, it was men who required revision most frequently, specifically the group of those having smoking and higher physical activity in their case histories. The influence of smoking on early postoperative morbidity is also well known. A significant finding is that stopping smoking can decrease the probability of early reoperation. However, we failed to explain the influence of higher physical activity. The influence of patients' age, BMI, level of comorbidities or primary diagnosis on the frequency of revision surgeries were not demonstrated. CONCLUSIONS We proved that women definitely show a lower risk of early TKA revision surgeries in comparison with men. A higher frequency of reoperations was related to modifiable factors such as smoking, longer waiting times for the primary operation, and a higher preoperative level of physical activity. A significant finding is that stopping smoking could decrease the probability of early TKA revision. Nonetheless, we do not recommend decreasing preoperative physical activity at this point; it will require further studies and verification of this finding. Also, the potential mechanism of the influence of greater preoperative load on the particular reason for revision is yet to be explained. Key words: total knee arthroplasty, complication, early reoperation, risk factors, multivariate analysis, smoking, preoperative activity, waiting times for surgery.

[Local Application of Tranexamic Acid in Total Hip Arthroplasty Decreases Blood Loss and Consumption of Blood Transfusion]. / Lokální aplikace kyseliny tranexamové u TEP kycle snizuje krevní ztráty a spotrebu krevních transfuzí.

PURPOSE OF THE STUDY The primary aim of our study was to identify the effects of local application of tranexamic acid (TXA, Exacyl) on the amount of postoperative blood loss and blood transfusion requirement in primary total hip arthroplasty. We also recorded the levels of postoperative haemoglobin and its drop in early period after surgery. In each patient, we monitored in detail the incidence of early complications (haematoma, wound exudate). Lastly, the economic aspect of TXA administration was also taken into account. MATERIAL AND METHODS The prospective study included a total of 312 patients (122 men and 190 women) undergoing primary total hip arthroplasty (THA) at our department between January 2012 and November 2015. The patients enrolled in the study were divided into the intervention group with local (intra-articular) application of TXA and the control group without using TXA. Each group had 156 patients. The mean age of patients in the group with TXA was 65.6 years and the most frequent indication for THA surgery was primary osteoarthritis (59.0 %). The groups did not show any differences in basic characteristics, which was statistically verified. In each patient the volume of postoperative drainage, total blood loss, including the hidden loss, was recorded. In postoperative period, we monitored the haemoglobin levels and haematocrit. On discharge of each patient from the hospital, the size and site of a haematoma, wound exudate if still present even after postoperative day 4 and early surgical revision were evaluated. RESULTS In the group with TXA the blood losses from drains were significantly lower compared to the control group (493.4 ± 357.1 ml vs. 777.3 ± 382.5 ml; p < 0.0001). The median value for total blood loss (i.e. drainage volume and hidden loss) in the group with TXA was by 29.5 % lower than the median in the group without TXA (689.2 vs. 977.1 ml). The mean total blood loss (intraoperative + postoperative) was 783.8 ± 478.6 ml (mean ± standard deviation) in the patients with TXA and 1079.7 ± 487.1 ml in the second group without TXA. The difference in the total blood loss volume was significant (p < 0.0001). In the group with TXA the consumption of blood transfusion was significantly lower by 50 % (20 vs. 40 units), (p = 0.0004). The patients with TXA also reported a significantly lower consumption of allogeneic blood (p = 0.004), a higher level of postoperative haemoglobin (p < 0.0001) and a lower mean drop of haemoglobin (p < 0.0001). We did not observe any significant differences in the incidence of haematomas (p = 0.644). No higher volume of wound drainage and joint swelling after postoperative day 4 in patients with TXA was found (p = 0.565; p = 0.242). The TXA group did not show a higher rate of surgical revision (p = 1.000). The total economic costs of blood transfusion requirements were significantly lower in the TXA group than in the control group (p = 0.004), including consumption of autologous transfusions and blood salvage (p < 0.0001). DISCUSSION The main effect of the local application of TXA is to reduce bleeding which should result in lower postoperative blood loss and consumption of allogenic blood transfusion. The advantage of the local application of TXA is its easy application and maximum concentration of TXA at the surgical site. In addition, a potential harm associated with a systemic administration of a higher TXA dose is reduced because of only minimal TXA resorption into the circulation. According to a number of recent studies, the local application of TXA achieves comparable results to its intravenous application. The economic benefit of TXA intervention is also worth considering. CONCLUSIONS The local application of TXA is an effective and, simultaneously, safe method to reduce perioperative blood loss and consumption of blood transfusions and also to decrease the costs of hospital stay in the patients after THA. Another advantage of the local application is the need to administer one dose only, whereas at least two doses need to be administered intravenously in order to achieve the same effect. No significant complications were observed in the patients with TXA. According to the recent literature, it is therefore appropriate to include the local application of TXA among the recommended procedures for THA, as is the case in total knee arthroplasty. Key words: tranexamic acid, local application, blood loss, hidden blood loss, THA, total hip arthroplasty, complications.

[Influence of Enhanced Recovery Regime on Early Outcomes of Total Knee Arthroplasty]. / Vliv intenzifikovaného pooperacního rezimu na casné výsledky TEP kolena.

PURPOSE OF THE STUDY Our study compared early outcomes of total knee arthroplasty performed in conventional and enhanced perioperative care regimes, i.e. without the use of Redon drain, with intensified perioperative analgesia and more frequent and intensive rehabilitation regime in the latter. MATERIAL AND METHODS The prospective study included 194 patients (76 men and 118 women) implanted with primary knee endoprosthesis. The mean age was 68.8 (44.7 - 88.0 years). The patients were divided into two groups - the "enhanced" and "conventional" procedures. In the first group, Redon suction drain was not inserted at the end of the surgery, and the patients commenced passive knee mobility exercise of the operated knee immediately after being brought back from the operating theatre. The general anaesthesia was supplemented by a combined femoral nerve block and wound infiltration with local anaesthetics. The second group comprised the patients who underwent conventional surgery, i.e. with the use of drain, without femoral nerve block, with no wound infiltration with local anaesthetics, and without immediate post-operative mobilization of the joint. The evaluation was carried out using regular clinical tools (subjective evaluation, objective examination, questionnaire and Knee Society Score (KSS)). Standard statistical methods were applied to data processing. RESULTS The patients under the "conventional regime" showed a significantly sharper drop in haemoglobin and haematocrit levels, higher consumption of blood transfusion and analgesics during the first three days after the surgery. The patients under the "enhanced regime" showed a better range of joint motion at hospital discharge, flexion in particular (p = 0.001). During the hospital stay no frequent swelling, secretion or wound reddening was reported in any of the monitored groups. In the "conventional" group, however, haematomas were more frequently present. The postoperative checks did not reveal any differences in satisfaction of the patients with the surgery. At the first follow-up examination at the outpatient department the "conventional" group patients more often reported knee pain and a feeling of a swollen knee. Nonetheless, their statements did not correspond with the VAS score. In the period between the 6th and 12th months following the surgery, the differences in the range of motion disappeared. The KSS showed a noticeable improvement in both the groups as against the preoperative values. In the "enhanced" group patients, the score increased dramatically at the beginning, whereas in the "conventional" group, the score was growing slowly and gradually until the last follow-up check after the surgery. The "conventional" group patients more frequently reported infectious complications (surface and deep wound infections: 4 vs. 2 patients) requiring a revision surgery (p = 0.024). DISCUSSION Recently, attention has been drawn to the rapid recovery approach, which eliminated postoperative immobilization and enabled the patient to start exercising already on the day of the surgery, with some patients even walking independently. The individual enhanced recovery regimes differ in details but mostly result in achieving the aim much sooner when compared to the conventional approaches. The patients under the enhanced recovery regimes can accomplish better functional outcomes in the first few months after the surgery than the patients undergoing the surgery under the conventional regime. The routine use of Redon drains in TKA is obviously unnecessary; it tends to be associated with a higher blood loss and a higher risk of prosthetic joint infection. CONCLUSIONS The TKA implant without suction drains combined with intensified perioperative analgesia and intensive postoperative rehabilitation is a safe way to earlier recovery of the function of the operated knee, or, by extension, the lower limb. The described approach is not associated with a higher risk of perioperative complications (bleeding, healing disorders or early infections). Patients also benefit from lower blood losses. Based on the results of our study, we recommend performing the TKA surgeries routinely without drains, with perioperative analgesia and immediate postoperative joint mobilization. Key words: total knee arthroplasty; perioperative care; rapid recovery; drainage; active movement; postoperative outcomes; pain; infection.

[Intra-Articular Application of Tranexamic Acid Significantly Reduces Blood Loss and Transfusion Requirement in Primary Total Knee Arthroplasty]. / Lokální aplikace kyseliny tranexamové významne snizuje mnozství krevních ztrát a spotrebu krevních transfuzí po primární TEP kolena.

PURPOSE OF THE STUDY The aim of this prospective study was to investigate the effect of topical application of tranexamic acid (TXA, Exacyl) on the amount of post-operative blood loss, and blood transfusion requirement in patients undergoing primary total knee arthroplasty (TKA). Attention was paid to early complications potentially associated with TXA administration, such as haematoma, wound exudate, or knee swelling. In addition, the economic benefit of TXA treatment was also taken into account. MATERIAL AND METHODS The study included 238 patients (85 men and 153 women) who underwent primary total knee arthroplasty (TKA) at our department between January 2013 and November 2015. A group of 119 patients (41 men and 78 women) received intraarticular TXA injections according to the treatment protocol (TXA group). A control group matched in basic characteristics to the TXA group also consisted of 119 patients. The average age in the TXA group was 69.8 years, and the most frequent indication for TKA surgery was primary knee osteoarthritis (81.5%). In each patient, post-operative volume of blood lost from drains and total blood loss including hidden blood loss were recorded, as well as post-operative haemoglobin and haematocrit levels. On discharge of each patient from hospital, the size and site of a haematoma; wound exudate, if present after post-operative day 4; joint swelling; range of motion and early revision surgery, if performed, were evaluated. Requirements of analgesic drugs after surgery were also recorded. RESULTS In the TXA group, blood losses from drains were significantly lower than in the control group (456.7 ± 270.8 vs 640.5 ±448.2; p = 0.004). The median value for blood losses from drains was lower by 22% and the average value for total blood loss, including hidden losses, was also lower than in the control group (762.4 ± 345.2 ml vs 995.5 ± 457.3 ml). The difference in the total amount of blood loss between the two groups was significant (p = 0.0001), including hidden blood loss (p = 0.030). The TXA patients had significantly fewer requirements for allogeneic blood transfusion (p < 0.0004), higher post-operative haemoglobin levels (p = 0.014), lower incidence of haematomas (p = 0.0003), and a significantly higher flexion degree on discharge from hospital (p < 0.0001). No higher volume of wound drainage was found (p = 1.000). Only one patient of the TXA group underwent revision surgery due to wound healing disturbance. The total costs of blood transfusion requirements were significantly lower in the TXA group than in the control group (p = 0.0004). DISCUSSION Topical administration allows the antifibrinolytic effect of TXA to act directly at a bleeding site. Its advantages involve easy application, maximum TXA concentration at the site of application, no danger associated with administration of a higher TXA dose and minimal TXA resorption into the circulation. On the other hand, there are no exact instructions for an effective and safe topical application of TXA and some authors are concerned that a coagulum arising after TXA application might affect soft tissue behaviour (healing, swelling, rehabilitation) or result in infection. CONCLUSIONS The study showed the efficacy and safety of topical TXA administration resulting in lower peri-operative bleeding, fewer blood transfusion requirements and higher haemoglobin levels after TKA. The patients treated with TXA had less knee swelling, lower incidence of haematomas and used fewer analgesic drugs in the early post-operative period. The economic benefit is also worth considering. In agreement with the recent literature, it is suggested to add topical TXA application to the recommended procedures for TKA surgery. Key words: tranexamic acid, Exacyl, topical application, intra-articular application, blood loss, hidden blood loss, total knee arthroplasty, complications.

[Patient Satisfaction after Total Knee Arthroplasty. Analysis of Pre-Operative and Peri-Operative Parameters Influencing Results in 826 Patients]. / Spokojenost s náhradou kolena: analýza predoperacních a perioperacních parametru u 826 pacientu.

UNLABELLED: PURPOSE OF THE STUDY The aim of the study was, first, to assess satisfaction of our patients after primary total knee arthroplasty (TKA) at various intervals of follow-up. Second, a list of pre- and peri-operative factors with potential effects on patient satisfaction was analysed. The third objective was to identify conditions under which a result of replacement could be considered definite with a little probability of further unexpected development. A more detailed knowledge of unsatisfied patients may provide valuable information for use in pre-operative evaluation, indication for surgery, as well as in the surgery itself. MATERIAL AND METHODS This prospective study consisted of 826 patients who underwent primary TKA between September 2010 and March 2015 and had at least one complete post-operative examination. Our group included 296 men and 530 women. The average age at primary TKA was 68.9 (45-87). Primary osteoarthritis was the most frequent indication to surgery (82.6 %). The followup period ranged from 1 month to 3 years. On each follow-up examination, every patient received an original questionnaire with 24 questions concerning the course of their post-operative period (between the discharge from hospital and the planned follow-up). The patients assessed the degree of satisfaction with surgery outcomes on a scale ranging from "fully satisfied" to "dissatisfied" and expressed their overall satisfaction in percents. RESULTS At the final follow-up, 6.5% of the patients were not satisfied with the outcome. The patients' overall satisfaction was 90.2 % (i.e., responses to the question of how you were satisfied with surgery). Significantly more satisfied patients were among those with primary osteoarthritis. Their satisfaction was related to the level of the UCLA activity rating, feelings of uncertainty when walking and to the functional ability component of the KSS system. On the other hand, more dissatisfied patients were found among those with several previous operations, a higher ASA score or a higher number of risk factors (Charlson comorbidity score etc.). The duration of pre-operative complaints had no relation to post-operative satisfaction. Similarly, there was no relation between VAS-evaluated pain intensity before TKA and patient satisfaction after arthroplasty. Obesity and satisfaction were not inter-related either. DISCUSSION Assessment of satisfaction is one of the Patient Reported Outcome Measures (PROMs) used by patients to evaluate the effect of a therapeutic method. These instruments aid in assessing the degree to which the method has met the needs and expectations of patients. It is relevant to emphasise that subjective factors, such as expectation or satisfaction, do not depend on the therapeutic procedure only. Recent reports have shown that, in 10% to 30% of the patients, the TKA outcome has not met their expectations. More detailed studies draw attention to the fact that there are more dissatisfied patients after TKA than those after THA. When satisfaction with pain relief is considered, the number of dissatisfied patients is even lower (72%-86%). CONCLUSIONS An analysis of the patients' responses shows that the rate of satisfaction is high shortly after surgery but declines gradually thereafter. The overall satisfaction is stable about 12 months after the surgery. The number of dissatisfied patients or those reporting pain after TKA in our study is in agreement with the results reported in relevant literature. The associations found here will be used in preparing a tool for clinical outcome prediction. KEY WORDS: total knee arthroplasty, outcome evaluation, patient-reported outcome measures, satisfaction, dissatisfaction, pain after total knee arthroplasty, function after total knee arthroplasty.

[Validity of the Morawietz classification for evaluation of periprosthetic tissue]. / Prínos Morawietzovy klasifikace k hodnocení periprotetických tkání.

PURPOSE OF THE STUDY A consensual classification of the periprosthetic interface membrane obtained at revision total joint arthroplasty was published by Morawietz et al. in 2006. Based on histomorphological criteria, four types of periprosthetic membrane were proposed: type I, aseptic failure; type II, septic failure; type III, combined type (carrying signs of both type I and II); and type IV, indeterminate type. The aim of this study was to find out whether and to what extent the Morawietz system would be suitable for use at an independent institution involved in the evaluation of periprosthetic membranes for a long time. Should it appear that the institution achieved an equally good or even better agreement between the clinical diagnosis and the histopathological finding, this consensus classification could be recommended for routine use. MATERIAL AND METHODS The samples of periprosthetic tissue evaluated in this study were obtained during surgery from the following groups of patients: 66 patients with aseptic loosening of total hip (THA) or knee arthroplasty, 15 patients with infection of THA, 16 patients with THA without any signs of aseptic loosening, osteolysis or infection; 8 patients with hip osteoarthritis and 8 patients with knee osteoarthritis. Sample collection and processing (for purposes of histomorphological evaluation and immunohistochemical staining) was performed according to the established protocol. The tissue samples evaluation was made by an experienced pathologist hand in hand with the method described in the original paper by Morawietz et al. For a more detailed tissue analysis, selected antibodies (CD4, CD8, CD20, IFN-γ and Hsp-60) were visualized by immunohistochemistry. RESULTS The majority of samples from aseptic reoperations were classified as membranes of the type I (79%) and III (16%). Specimens retrieved from septic cases were mostly classified as membranes of type II and III (60% together). The septic membranes showed a significantly higher expression of CD20 protein when compared with both the aseptic (p < 0.0001) and control THA samples (p = 0.003). The membranes retrieved from the surroundings of a stable THA without osteolysis and infection had lower expression levels of Hsp60 and IFN-γ, when compared with those from both aseptic and septic loosening. Finally, Hsp-60 expression was significantly higher in osteoarthritic tissue than in samples from stable THA (p = 0.041). DISCUSSION Morawietz et al. proposed a standardized classification system for evaluation of periprosthetic tissue. As any attempt at generalization of a complex issue, this proposal has certain shortcomings. One of these is poor detection of chronic and low-grade infections. A method that would improve the conventional counting of polymorphonuclear leukocytes is still being sought. In this connection, immunostaining for CD20 combined with an assessment of antimicrobial peptides may be a promising option. The supplementary specimen staining showed that pseudosynovial tissue is much more active in patients carrying infection and the least active in samples from stable THA in which certain tolerance and thus tissue homeostasis might be expected. CONCLUSIONS 1. In this study the distribution of findings classified according to the Morawietz system was similar to the results published in the original study from 2006. 2. The definition of an aseptic membrane (type I) in the Morawietz system meets the requirements of clinical practice (agreement, about 80%). 3. An increased sensitivity for infectious membrane detection can be achieved by using supplementary immunohistochemical staining effective particularly in chronic and low-grade infections. 4. Painless and stable THAs typically have very low expression levels of CD4, CD20 and Hsp-60 proteins, and interferon- -gamma (IFN-γ) as well. Key words: total hip arthroplasty, total knee arthroplasty, aseptic loosening, prosthetic joint infection, tissue analysis, membranes, CD receptors, Hsp-60 protein, IFN-γ.

[Multivariate analysis of blood loss during primary total hip or knee arthroplasty]. / Analýza krevních ztrát po primární TEP kycle a kolena.

PURPOSE OF THE STUDY: The primary aim of the study was to identify characteristics predicting the blood loss associated with primary total hip (THA) and knee (TKA) arthroplasty surgery. The other objective was to find out which characteristics were important for peri-operative allogeneic blood transfusion in the same group of patients. MATERIAL AND METHODS: This prospective study comprised 210 consecutive patients who underwent primary THA (n = 115) or primary TKA (n = 95) at our department. In each patient, 21 pre-operative and peri-operative characteristics were recorded. Of them, the following characteristics were selected for statistical evaluation: age, gender, BMI, primary diagnosis, Charlson co-morbidity score, type of prophylaxis for deep-vein thrombosis, type of implant fixation (in THA), pre-operative INR value, haematocrit, haemoglobin (Hb) and platelet levels, amount of autologous blood donated by the patient, ASA score, operative time, use of tourniquet (in TKA), type of anaesthesia used, blood recuperation and patient's smoking habits. Multivariate analysis was used as the statistical method. For hypothesis testing, a statistical significance level of 0.05 was stated and, for enclosing (removing) characteristics to (from) multivariate models, the significance level was set at 0.11. RESULTS: The group included 81 men and 129 women; the mean age at the time of surgery was 65.5 ± 11.97 years (mean±SD) in the THA patients and 68.5 ± 8.52 years in the TKA patients. Primary osteoarthritis was the most frequent surgical diagnosis (THA, 64.35%; TKA, 82.1%). The mean amount of blood loss was 1258 ± 402.6 ml in THA and 1580 ± 475.5 ml in TKA. The mean amount of allogeneic blood required was 130 ± 202 ml when all THA patients were considered, and 371.95 ± 159.3 ml when only those who received it were involved. For the TKA patients, the corresponding values were 160.1 ± 278.8 ml for all patients and 507 ± 264.5 ml for blood recipients only. The characteristics that affected the amount of blood loss in THA included BMI, ASA score, blood recuperation, type of anaesthesia, and smoking habits; in TKA these were BMI, pre-operative platelet count, INR and type of anaesthesia. High pre-operative Hb levels made the probability of allogeneic blood requirement lower in both THA and TKA. Autotransfusion decreased the probability of allogeneic blood requirements only in THA. DISCUSSION That the pre-operative Hb level is the strongest predictor for the probability of allogeneic blood transfusion during both THA and TKA is a logical and well-known fact. What remains to be established is the optimal protocol for pre-operative preparation of the patients with low Hb levels undergoing elective replacement (hip and knee) surgery. This study clearly showed that, in THA patients, pre-operative autologous blood donation decreased the probability of allogeneic blood transfusion. Other results of our multivariate analyses were not clinically unambiguous and therefore further research on a larger patient group is warranted. Such studies will also require the development of a more exact method for the assessment of blood loss at the operating theatre. CONCLUSION: The patients with low pre-operative Hb levels have a high probability that they will require allogeneic blood transfusion during primary THA and TKA. Autologous blood donation can decrease this probability significantly (here proved only for THA patients). The multivariate model of blood loss published here could assist in estimation of peri-operative blood loss and potential risk of blood transfusion requirements.

[Microbial and pharmacological characteristics of VancogenX]. / Mikrobiologické a farmakologické vlastnosti kostního cementu VancogenX.

PURPOSE OF THE STUDY: Prosthetic joint infection is a feared complication in total hip arthroplasty. The use of antibiotic-impregnated bone cement is the important part of preventive and therapeutic strategies. At present a number of commercial bone cements are available and support of their use by the results of experimental trials and clinical studies has varied. In relation to this issue we studied essential microbiological and pharmacological characteristics of VancogenX in comparison with gentamicin-loaded bone cement used conventionally. MATERIAL AND METHODS: Based on a previously described protocol, we tested pellets of four commercial bone cements, namely, Hi-Fatigue G, Palacos R+G, VancogenX, and Palacos R as a control. Bone cement was prepared in a vacuum-mixing system. The strains used for bacterial load included Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Pseudomonas aeruginosa and Escherichia coli. Each cement was tested for its antimicrobial and antibiofilm activities and the results were evaluated by standard methods. In addition, we investigated time-related release of gentamicin and vancomycin from the bone cements tested. RESULTS: All antibiotic-loaded cement pellets were able to prevent growth of the bacterial strains tested. The bactericidal effect lasted for several days in relation to the bacterial species and cement used, with the exception of S. epidermidis whose growth was inhibited by gentamicin-loaded cement only for one day. The antibiotic-loaded pellets also prevented the formation of a biofilm for 24 hours at least. The major amount of vancomycin (32.915 mg/l) was released from VancogenX to MH medium within 24 hours and the last measureable amount (4.327 mg/l) was recorded at 48 hours after the start of the experiment. In physiological saline the highest level of vancomycin was 139.852 mg/ml measured at 24 hours, and the antibiotic was detectable at a level of 2.334 mg/ml as late as 8 days after the experiment started. Release of gentamicin from VancogenX was as follows: the 24-hour level was higher in MH medium than physiological saline (178 versus 131.4 mg/ml); however, gentamicin was still detectable in physiological saline at 192 hours after the start of the experiment while no gentamicin was found in MH medium after 72 hours. DISCUSSION: The antimicrobial effect of VancogenX bone cement was not an unexpected finding since both gentamicin and vancomycin have been used with bone cement for a long time and their combination is optimal in terms of preventing prosthetic joint infection. However, there is a disputable issue of poor release of vancomycin from bone cement. In MH medium we were able to detect the vancomycin released from VancogenX only for two days after the initial rapid elution while its release into physiological saline seemed to be slower but much longer. It is possible that more vancomycin is released from bone cement, but this amount is immediately bound to proteins in the cement vicinity and this process is not detectable by any analytical method. CONCLUSIONS: The bone cement VancogenX showed excellent antimicrobial and antibiofilm properties and can be recommended for use in orthopaedic practice. Therapy of prosthetic joint infection is the main indication. Extension of the indication to the prevention of prosthetic joint infection in high-risk patients should be preceded by biomechanical studies demonstrating that the cement is appropriate for long-term implant fixation.

MBL2 gene variation affecting serum MBL is associated with prosthetic joint infection in Czech patients after total joint arthroplasty.

Prosthetic joint infection (PJI) is a serious complication of the total joint arthroplasty (TJA). Serum mannose-binding lectin (MBL), a pattern recognition receptor, is involved in antibacterial immune response. This study investigated whether functional variants of the MBL2 gene may be associated with the risk of PJI. MBL2 -550 (H/L, rs11003125), MBL2 -221 (Y/X, rs7096206) and MBL2 +54 (G/A, rs1800450) single nucleotide polymorphisms (SNP) were genotyped in 112 PJI patients and two control groups: 245 patients with aseptic TJA and 196 Czech population controls without TJA. Serum MBL concentration was assessed in PJI patients (n = 92) and aseptic TJA controls (n = 56). The distribution of MBL2 genotypes complied with the Hardy-Weinberg equilibrium in all investigated groups. Importantly, MBL2 -550 L allele (allelic frequency, 0.72) and LL genotype (genotype frequency, 0.51) were more frequent among PJI patients compared to aseptic TJA controls (L allele: 0.63, P = 0.016, P(c) = 0.048; LL genotype: 0.39, P = 0.037, P(c) > 0.05) and to Czech population controls (L allele: 0.61, P = 0.010, P(c) = 0.030; LL genotype: 0.35, P = 0.006, P(c) = 0.018), respectively. Regarding MBL protein, the MBL2 -550 L carriers presented with lower serum MBL concentrations than non-carriers (median; 593 vs 1876 ng/ml; P < 0.01). Similarly, the carriage of MBL2 -221 X and 54 A alleles was associated with lower serum MBL concentrations (P < 0.01). In conclusion, MBL2 -550 genetic variant(s) associated with low serum concentration of MBL protein can increase the risk of PJI.