[How Does Affect the Type of Instability after Total Hip Arthroplasty the Outcomes? Our Experience between 1999 and 2020]. / Jak ovlivnuje typ luxace TEP kycle výsledek lécby? Analýza souboru pacientu za období 1999­2020.

PURPOSE OF THE STUDY Dislocation is one of the most common early complications of total hip arthroplasty (THA). In this manuscript, 20 years of experience with the management of this complication are presented, particularly in relation to the type of instability. MATERIAL AND METHODS In the period between January 1999 and December 2020, at least one dislocation occurred in 157 of 8 286 (1.9%) THA patients, of which 117 dislocations (1.6%) in primary and 40 (3.4%) in revision THAs. Almost all patients were operated on from the anterolateral approach during the follow-up period. The type of dislocation was evaluated using the modified Dorr classification. In the first dislocations, conservative approach was usually opted for, except for cases with a clear malposition, irreducible or unstable hips after the reduction. The minimum follow-up period was 18 months (18-240). The success rate of the chosen treatment approach was assessed by means of standard statistical methods. RESULTS The total dislocation rate in the follow-up period was 1.6% for primary THAs and 3.4% for revision THAs. The dislocation rate was slightly higher between 1999 and 2009 compared to the following decade (2.1% versus 1.3% for primary THAs; p=0.009). The most common type of dislocation was the positional dislocation (62%), followed by dislocations due to a combination of causes (17%) and component malposition (11%). Treatment of dislocation was successful in a total of 130 patients (130/157; 83%). Even though a stable hip was achieved in 21 patients (13%), the functional outcome was unsatisfactory, and in 6 patients (4%) we failed to achieve a stable hip. In the positional type of dislocation, the success rate of closed reduction following the first-time dislocation was 86.4% and a similar success rate was reported for reoperations in the first-time dislocations due to the malpositioned components (85.7%). In the second-time dislocation, the surgical therapy was significantly more reliable compared to closed reduction regardless of the type of dislocation (78.6% versus 46%). The treatment of dislocations following primary THAs showed comparable outcomes to those of the treatment of dislocations following revision THAs. Overall, the worst outcomes were achieved in patients with a combined type of dislocation. In total, the THA had to be removed in 11.5% of hips (18/157). The probability of final THA removal increased with the increasing order of dislocation. DISCUSSION In our group of patients, the dislocation rate in THA was comparable or lower than the published data. With the use of preventive measures, i.e. dual mobility cup or larger head diameters in high-risk patients, we managed to reduce the dislocation rate over time. The positional type of dislocation prevails in our group of patients just as in the previously published series, followed by instability from malposition of components. The modified Dorr classification is used to guide the treatment since it allows us not only to make good decision about the treatment modality but to some extent also to estimate the final outcome, particularly with respect to restoring a functional and stable hip. CONCLUSIONS The total dislocation rate was 1.6% for primary THAs and 3.4% for revision THAs. The first-time dislocation of the positional type shall be treated conservatively. Conversely, in the other types of dislocations and in recurrent dislocations, surgical treatment is more likely to achieve a good clinical outcome. The worst outcomes are to be expected in an instability due to combination of multiple causes, which leads to the removal of THA more often than in other types of dislocations. Also, the benefit of preventive measures in high-risk patients over time has been confirmed. Key words: total hip arthroplasty, dislocation, Dorr's classification, treatment strategy, outcomes, complications.

Final Measurement of the

This Letter reports one of the most precise measurements to date of the antineutrino spectrum from a purely ^{235}U-fueled reactor, made with the final dataset from the PROSPECT-I detector at the High Flux Isotope Reactor. By extracting information from previously unused detector segments, this analysis effectively doubles the statistics of the previous PROSPECT measurement. The reconstructed energy spectrum is unfolded into antineutrino energy and compared with both the Huber-Mueller model and a spectrum from a commercial reactor burning multiple fuel isotopes. A local excess over the model is observed in the 5-7 MeV energy region. Comparison of the PROSPECT results with those from commercial reactors provides new constraints on the origin of this excess, disfavoring at 2.0 and 3.7 standard deviations the hypotheses that antineutrinos from ^{235}U are solely responsible and noncontributors to the excess observed at commercial reactors, respectively.

Improved Measurement of the Evolution of the Reactor Antineutrino Flux and Spectrum at Daya Bay.

Reactor neutrino experiments play a crucial role in advancing our knowledge of neutrinos. In this Letter, the evolution of the flux and spectrum as a function of the reactor isotopic content is reported in terms of the inverse-beta-decay yield at Daya Bay with 1958 days of data and improved systematic uncertainties. These measurements are compared with two signature model predictions: the Huber-Mueller model based on the conversion method and the SM2018 model based on the summation method. The measured average flux and spectrum, as well as the flux evolution with the ^{239}Pu isotopic fraction, are inconsistent with the predictions of the Huber-Mueller model. In contrast, the SM2018 model is shown to agree with the average flux and its evolution but fails to describe the energy spectrum. Altering the predicted inverse-beta-decay spectrum from ^{239}Pu fission does not improve the agreement with the measurement for either model. The models can be brought into better agreement with the measurements if either the predicted spectrum due to ^{235}U fission is changed or the predicted ^{235}U, ^{238}U, ^{239}Pu, and ^{241}Pu spectra are changed in equal measure.

Precision Measurement of Reactor Antineutrino Oscillation at Kilometer-Scale Baselines by Daya Bay.

We present a new determination of the smallest neutrino mixing angle θ_{13} and the mass-squared difference Δm_{32}^{2} using a final sample of 5.55×10^{6} inverse beta-decay (IBD) candidates with the final-state neutron captured on gadolinium. This sample is selected from the complete dataset obtained by the Daya Bay reactor neutrino experiment in 3158 days of operation. Compared to the previous Daya Bay results, selection of IBD candidates has been optimized, energy calibration refined, and treatment of backgrounds further improved. The resulting oscillation parameters are sin^{2}2θ_{13}=0.0851±0.0024, Δm_{32}^{2}=(2.466±0.060)×10^{-3} eV^{2} for the normal mass ordering or Δm_{32}^{2}=-(2.571±0.060)×10^{-3} eV^{2} for the inverted mass ordering.

[Posterior Tibial Slope as a Morphological Risk Factor for Anterior Cruciate Ligament Reconstruction: a Retrospective Cohort Study]. / Zadní sklon tibie jako rizikový morfologický faktor kolena u náhrady PZV: hodnocení souboru pacientu.

PURPOSE OF THE STUDY Increased tibial slope facilitates anterior translation of tibia relative to the femur, thereby increasing the load on both the native and replaced anterior cruciate ligament. This study aims to retrospectively review the posterior tibial slope in a cohort of our patients after the ACL reconstruction and revision ACL reconstruction. Based on the results obtained by measurements, we aimed to confirm or disprove the claim that the increased posterior tibial slope is one of the risk factors of the ACL reconstruction failure. Another aim of the study was to assess whether there are any correlations between the posterior tibial slope and basic somatic parameters (height, weight, BMI) or the patient s age. MATERIAL AND METHODS The posterior tibial slope was measured retrospectively on lateral X-rays of 375 patients. There were 83 revision reconstructions and 292 primary reconstructions performed. The patient s age at the time of injury, height and weight were recorded and the BMI was calculated. The findings were then statistically analysed. RESULTS The mean posterior tibial slope in 292 primary reconstructions was 8.6 degrees, whereas the mean posterior tibial slope in 83 revision reconstructions was 12.3 degrees. The difference between the studied groups was statistically (p<0.0001) and substantively significant (d=1.35). In the breakdown into men and women, the mean tibial slope was 8.6 degrees in the group of men with primary reconstruction and 12.4 degrees in the group of men with revision reconstruction (p < 0.0001, d = 1.38). A similar result was achieved in women where in the group with primary reconstruction the mean tibial slope was 8.4 degrees, while in the group with revision reconstruction it was 12.3 degrees (p < 0.0001, d = 1.41). Furthermore, a higher age in men at the time of revision surgery (p = 0.009; d = 0.46) and a lower BMI in women at the time of revision surgery (p = 0.0342; d = 0.12) were observed. Conversely, neither height nor weight were different, both when comparing the whole groups and the groups in a breakdown by sex. DISCUSSION As regards the main aim, our results are in line with the results reported by majority of other authors, and they are substantively significant. The posterior tibial slope is a significant risk factor in anterior cruciate ligament replacements, with tibial slope above 12 degrees increasing the risk of ligament failure, namely both in men and women. On the other hand, this is obviously not the sole cause of the ACL reconstruction failure since there are also other risk parameters. It is not yet clear whether it makes sense to indicate correction osteotomy before the ACL replacement in all patients with an increased posterior tibial slope. CONCLUSIONS Our study confirmed a greater posterior tibial slope in the revision reconstruction group compared to the primary reconstruction group. Thus, we confirmed that greater posterior tibial slope may be a factor leading to the ACL reconstruction failure. Since the posterior tibial slope is easily measured on the baseline X-rays, we recommend to perform this measurement routinely before each ACL reconstruction. In the case of a high posterior tibial slope, slope correction should be considered to prevent potential ACL reconstruction failure. Key words: anterior cruciate ligament reconstruction, ACL graft failure, morphological risk factors, posterior tibial slope.

Phenotypic and functional characterisation of synovial fluid-derived neutrophils in knee osteoarthritis and knee infection.

OBJECTIVE: An increase in the number of neutrophils (NEUs) has long been associated with infections in the knee joints; however, their impact on knee osteoarthritis (KOA) pathophysiology remains largely unexplored. DESIGN: This study compared the phenotypic and functional characteristics of synovial fluid (SF)-derived NEUs in KOA and knee infection (INF). RESULTS: KOA NEUs were characterised by a lower expression of CD11b, CD54, and CD64 and higher expression of CD62L, TLR2, and TLR4 compared with INF NEUs. Except for CCL2, lower levels of inflammatory mediators and proteases were detected in KOA SF than in INF SF. Functionally, KOA NEUs displayed increased reactive oxygen species production and phagocytic activity compared with INF NEUs. Moreover, KOA and INF NEUs differed in cell sizes, histological characteristics of the surrounding synovial tissues, and their effects on the endothelial cells assessed by human umbilical vein endothelial cells. When KOA patients were subdivided based on the SF NEU abundance, patients with high NEUs (10%-60%) were characterised by i) elevated SF protein levels of TNF-α, IL-1RA, MMP-9, sTREM-1, VILIP-1 and ii) lower CD54, CD64, TLR2 and TLR4 expression compared to patients with low NEUs (<10%). Analysis of paired SF samples suggests that low or high NEU percentages, respectively, persist throughout the course of disease. CONCLUSIONS: Our findings suggest that NEU may play a significant role in KOA pathophysiology. Further studies should explore the mechanisms that contribute to the increased number of NEUs in SF and the clinical consequences of neutrophilic phenotype in KOA.

[Arthroscopic Superior Capsule Reconstruction with a Long Head of the Biceps Tendon Autograft: One-Year Follow-up Results]. / Rocní klinické výsledky artroskopické rekonstrukce horní kapsuly ramenního kloubu pomocí slachy dlouhé hlavy bicepsu.

PURPOSE OF THE STUDY: Superior Capsule Reconstruction (SCR) of the shoulder joint has recently been included in the portfolio of interventions as a solution to irreparable rotator cuff tears. One of the options is to use a long head of the biceps tendon (LHBT) autograft. This paper presents the fi rst clinical outcomes of the SCR of the shoulder joint using the LHBT autograft. MATERIAL AND METHODS It is a prospective non-randomised study in which 14 patients were included, namely 7 men and 7 women. The patients were evaluated using the pain VAS, UCLA (The University of California at Los Angeles) Shoulder Rating Scale and ASES (The American Shoulder and Elbow Surgeons) Shoulder Score. The minimum follow-up was 12 months after surgery. The measured values were analysed using the standard statistical methods. RESULTS From August 2020 to January 2022, a total of 14 SCR with biceps tendon autograph were performed at our department. The mean age of the patients was 62 years (40-72). The mean value of the UCLA Shoulder Score was 12.36 ± 2.92 points preoperatively, while after surgery the obtained values increased to the mean value of 28.86 ± 3.08 points. The ASES score was 25.48 ± 3.89 points preoperatively and 82.41 ± 7.95 points at one year after surgery. The preoperative mean VAS score was 6.14 ± 1.10 points and 1.36 ± 0.93 points at one year after surgery. The mean active shoulder fl exion measured preoperatively was 140 degrees, whereas at one year after surgery it was 171 degrees. The mean active abduction reached 123 degrees before surgery and 169 degrees after surgery. The mean active external rotation of the shoulder joint was 59 degrees preoperatively and 52 degrees postoperatively. The mean active external rotation at 90 degrees of abduction was 52 degrees preoperatively and 60 degrees postoperatively. Whereas the improvement as against the preoperative status measured by the UCLA, ASES and pain VAS was signifi cant, the differences in the range of motion were signifi cant in the case of active fl exion and abduction only. DISCUSSION Painful irreparable rotator cuff tear constitutes an indication for SCR. The reconstruction is performed using autografts, allografts and xenografts. In literature, several SCR surgical techniques using a long head of the biceps tendon have been presented. In most of these techniques the supraglenoid insertion of the LHBT was left intact. Our study showed a signifi - cant relief from problems and good functional outcomes at 1 year after surgery when the biceps tendon had been used. Similar results are reported also by other studies using the biceps tendon for SCR. When comparing this study and the other study we published earlier on SCR with xenografts, there is no signifi cant difference in the clinical outcomes between these two techniques. On the very contrary, they are slightly better in some parameters. CONCLUSIONS Arthroscopic SCR of the shoulder joint with the biceps tendon reports good clinical outcomes at one year after surgery both with regard to the relief from problems and range of motion. Due to low morbidity of graft harvesting, low cost, and easy surgical technique, it appears to be the fi rst-choice method for superior capsule reconstruction of an irreparable tear of supraspinatus or infraspinatus if the long head of the biceps tendon is preserved. A longer follow-up period and evaluation of a larger study population would be necessary to defi nitely confi rm the success rate of the described procedure. KEY WORDS: massive rotator cuff tears, irreparable rotator cuff tears, superior capsular reconstruction, autograft, long head of the biceps tendon.

Odds-ratio network for postoperative factors revealing differences in the 2-year longitudinal pattern of satisfaction between women and men after total knee arthroplasty.

Timely and accurate assessments of the factors influencing satisfaction, a key indicator of success in primary total knee arthroplasty (TKA), may help improve TKA outcomes. Here we performed the longitudinal trend analysis of relation between satisfaction and 12 postoperative factors, which positively or negatively influence the patient satisfaction 2 years after TKA. In a real-world registry cohort (women/men: 1121/650), we showed similarities and differences between women and men in the contribution of postoperative factors to satisfaction 2 years after TKA as assessed by odds-ratio-similarity network. In men, the strongest negative factors were pain and complications, followed by mechanical problems. In women, the strongest negative factors were the pain and knee instability, followed by other mechanical problems, complications and low levels of sports activity. In both sexes, physical activity and the Knee Society Score (general and functional) influenced positively satisfaction; long-distance walking was associated with satisfaction only in women. A trend analysis revealed a reduction in the strength of satisfaction-related factors over 2 years of check-ups, particularly in women. Our study demonstrates that the key check-up for assessing the evolution of satisfaction in the 2 years after TKA was at 3 months in both sexes.

Knee osteoarthritis phenotypes based on synovial fluid immune cells correlate with clinical outcome trajectories.

BACKGROUND: Knee osteoarthritis (KOA) is a highly heterogeneous disease encompassing a wide range of clinical phenotypes. Phenotypes based on immune cells and protein pattern in synovial fluid (SF) and their relationship to clinical trajectories have not been described. OBJECTIVE: To assess phenotypes based on immune cells and protein pattern of SF in KOA. DESIGN: SF-derived immune cells were investigated in 119 patients with KOA using flow cytometry. Immune-phenotypes (iPhen) were determined by multivariate patient similarity network analysis and related to clinical trajectory (3-6 months post-sampling) along with protein pattern and macrophage chemokine receptors. RESULTS: Four iPhen were detected based on the distribution of T-lymphocytes, monocyte-macrophage lineage cells and activated CD8+ T-lymphocytes. The 'activated' phenotype (n = 17) had high T-lymphocytes but low monocyte-macrophage lineage cells and neutrophils, all highly activated, and showed improved symptoms in 70% patients. The 'lymphoid progressive' phenotype (n = 31) had high neutrophils, low lymphocytes and monocyte-macrophage lineage cells, low activation and was associated with lower pain levels. The 'myeloid progressive' phenotype (n = 35) had high NK and monocyte-macrophage lineage cells but low T-lymphocytes and activation. The 'aggressive' phenotype (n = 36) had high lymphocytes, macrophages, NK cells and neutrophils and high activation, and only 39% of patients improved during follow-up. Low CXCR4 and CCR7 expression on macrophages and high CXCL10 in SF were linked to improved clinical trajectory. CONCLUSION: We identified four immune-phenotypes that were associated with different clinical trajectories in KOA patients. How these phenotypes can be targeted therapeutically deserves further investigation.

First Measurement of High-Energy Reactor Antineutrinos at Daya Bay.

This Letter reports the first measurement of high-energy reactor antineutrinos at Daya Bay, with nearly 9000 inverse beta decay candidates in the prompt energy region of 8-12 MeV observed over 1958 days of data collection. A multivariate analysis is used to separate 2500 signal events from background statistically. The hypothesis of no reactor antineutrinos with neutrino energy above 10 MeV is rejected with a significance of 6.2 standard deviations. A 29% antineutrino flux deficit in the prompt energy region of 8-11 MeV is observed compared to a recent model prediction. We provide the unfolded antineutrino spectrum above 7 MeV as a data-based reference for other experiments. This result provides the first direct observation of the production of antineutrinos from several high-Q_{ß} isotopes in commercial reactors.

A Profile and Three-Year Follow-Up of Patients with Basal Cell Carcinoma in the Western Cape, South Africa.

Background: Basal cell carcinoma (BCC) is an important malignancy in sub-Saharan Africa. There is a paucity of data regarding BCC in South Africa. Aims: To describe the clinicopathological features of patients presenting with BCC in a cohort of South African patients. Methods: This retrospective descriptive study reviewed the medical records of 149 patients with BCC who attended the dermatology clinic at Tygerberg Academic Hospital from September 2015 to August 2016. Demographic and clinical data of those patients with histologically proven BCC were retrieved from clinical records. The data included the assessment for BCC recurrence after three years (September 2016-August 2019). Results: Of 390 patients, 155 (39.7%) had histologically confirmed BCCs. Complete medical records were available for 149 of these patients, and most were male (55.7%) and white (85.9%) with a median age of 70 years. Most patients had their BCC lesions for 12 months (43.1%) before diagnosis. BCCs were mostly located on the head and neck area (58.1%). In most patients (72.0%), a diagnostic punch biopsy confirmed BCC. Plastic surgeons subsequently excised the BCC lesions in 74.0% of these patients. The most common histological subtype was nodular BCC (74.0%). The National Comprehensive Cancer Network (NCCN) risk of recurrence was approximately evenly distributed between high- (54.1%) and low-risk groups (45.9%). The major high-risk feature was the location (36.6%). Histologically confirmed BCC recurrence occurred in 9 of the 149 patients (3.7%) over three years. Conclusions: BCC represents a high burden of disease in our setting. Compared to existing studies, the BCCs in this study are clinically and histologically similar to international reports.

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.

[Glucose, Lactate, NGAL and Coefficient of Energy Balance in Synovial Fluid in Patients with Hip and Knee Prosthetic Joint Infection]. / Stanovení hladiny glukózy, laktátu, NGAL a KEB ve výpotku u infekcí TEP kolen a kyclí.

PURPOSE OF THE STUDY Laboratory methods are central to prosthetic joint infection (PJI) diagnosis. Most research teams focus on detection of specific inflammatory markers, causative pathogens, or on assessment of the tissue response. This study sought to determine the optimal cut-off values and diagnostic performance of selected synovial markers in relation to the diagnosis of hip or knee PJI. The studied markers were synovial level of glucose, lactate, coefficient of energy balance (CEB) and NGAL (neutrophil gelatinase-associated lipocalin). MATERIAL AND METHODS This prospective study includes 89 patients who underwent revision total knee or hip arthroplasty for septic or aseptic reasons in the period from 2014 to 2017. Among these 89 patients, there are 2 cases of prosthetic hip infection, 22 cases of prosthetic knee infection, 31 aseptic revision total hip arthroplasties and 34 aseptic revision total knee arthroplasties. The diagnostic characteristics of the studied methods were set in relation to the reference standard, the 2013 MSIS (Musculoskeletal Infection Society) criteria. The cut-off values were calculated using the ROC (receiver operating characteristic curve) analysis. RESULTS The synovial glucose test is considered positive if the glucose level drops below 2.65 mmol/L. The area under the curve is 0.813, sensitivity 75.0%, specificity 83.1%. The synovial lactate test is considered positive if lactate level rises above 8.87 mmol/L. The area under the curve is 0.882, sensitivity 70.8%, specificity 95.4%. Synovial NGAL is considered positive if its level exceeds 998 µg/L. The area under the curve is 1.000, sensitivity 100.0%, specificity 100.0%. CEB is considered positive if its value is lower than +4.665. The area under the curve is 0.883, sensitivity 91.7% and specificity 69.8%. Combining of these tests with other synovial markers does not improve the diagnostic performance of the studied tests. CONCLUSIONS The glucose and lactate levels and CEB undoubtedly reflect the presence of an inflammatory process in a prosthetic joint. However, the diagnostic characteristics of these tests are not better than those of other modern diagnostic techniques. As opposed to these tests, synovial NGAL shows excellent diagnostic performance. Nonetheless, the potential of this method shall be verified on larger cohorts of patients. Key words: prosthetic joint infection, periprosthetic infection, total knee arthroplasty, total hip arthroplasty, diagnosis, glucose, lactate, CEB, NGAL.

Joint Determination of Reactor Antineutrino Spectra from

A joint determination of the reactor antineutrino spectra resulting from the fission of ^{235}U and ^{239}Pu has been carried out by the Daya Bay and PROSPECT Collaborations. This Letter reports the level of consistency of ^{235}U spectrum measurements from the two experiments and presents new results from a joint analysis of both data sets. The measurements are found to be consistent. The combined analysis reduces the degeneracy between the dominant ^{235}U and ^{239}Pu isotopes and improves the uncertainty of the ^{235}U spectral shape to about 3%. The ^{235}U and ^{239}Pu antineutrino energy spectra are unfolded from the jointly deconvolved reactor spectra using the Wiener-SVD unfolding method, providing a data-based reference for other reactor antineutrino experiments and other applications. This is the first measurement of the ^{235}U and ^{239}Pu spectra based on the combination of experiments at low- and highly enriched uranium reactors.

Outcomes Following Hypofractionated Stereotactic Radiotherapy to the Cavity After Surgery for Melanoma Brain Metastases.

AIMS: Hypofractionated stereotactic radiotherapy (HSRT) to the cavity after surgical resection of brain metastases improves local control. Most reported cohorts include few patients with melanoma, a population known to have high rates of recurrence and neurological death. We aimed to assess outcomes in patients with melanoma brain metastases who received HSRT after surgery at two Australian institutions. MATERIALS AND METHODS: A retrospective analysis was carried out including patients treated between January 2012 and May 2020. HSRT was recommended for patients with melanoma brain metastases at high risk of local recurrence after surgery. Treatment was delivered using appropriately commissioned linear accelerators. Routine follow-up included surveillance magnetic resonance imaging brain every 3 months for at least 2 years. Primary outcomes were overall survival, local control, incidence of radiological radionecrosis and symptomatic radionecrosis. RESULTS: There were 63 cavities identified in 57 patients. The most common HSRT dose prescriptions were 24 Gy in three fractions and 27.5 Gy in five fractions. The median follow-up was 32 months in survivors. Local control was 90% at 1 year, 83% at 2 years and 76% at 3 years. Subtotal brain metastases resection (hazard ratio 12.5; 95% confidence interval 1.4-111; P = 0.0238) was associated with more local recurrence. Overall survival was 64% at 1 year, 45% at 2 years and 40% at 3 years. There were 10 radiological radionecrosis events (16% of cavities) during the study period, with 5% at 1 year and 8% at 2 years after HSRT. The median time to onset of radiological radionecrosis was 21 months (range 6-56). Of these events, three became symptomatic (5%) during the study period at a median time to onset of 26 months (range 21-32). CONCLUSION: Cavity HSRT is associated with high rates of local control in patients with melanoma brain metastases. Subtotal resection strongly predicts for local recurrence after HSRT. Symptomatic radionecrosis occurred in 5% of cavities but increased to 8% of longer-term survivors.

[Arthroscopic Bankart Repair with Remplissage for Anterior Instability: Functional Outcomes, Risk of Failure]. / Artroskopická Bankartova operace se soucasnou remplissage: funkcní výsledky, riziko selhání.

PURPOSE OF THE STUDY This study aimed to evaluate the clinical outcomes and the rate of recurrence in patients who had undergone arthroscopic Bankart repair with remplissage for anterior instability of the glenohumeral joint. MATERIAL AND METHODS The study included 96 arthroscopic Bankart procedures with remplissage performed between 2013 and 2019 at our department in 93 patients (81 men and 12 women; with the mean age of 33 years). We gathered and analysed preoperative data, including a 3D-CT scan of the affected shoulder. Apart from stability, the functional results were assessed postoperatively using the WOSI, SSV, Rowe score, and by measuring the strength of shoulder girdle muscles. The non-parametric MannWhitney U-test was used to identify the predisposing factors for recurrence of glenohumeral instability. RESULTS The arthroscopic Bankart repair with remplissage was indicated in 74 shoulders for primary TUBS and in 22 shoulders as a revision procedure. The recurrent instability was observed in 13 of 96 operated shoulders (13.5%). Subjective instability (positive apprehension test in the extreme positions of the shoulder joint, in abduction and external rotation in particular) was reported by 10 patients (10/13; 77%), three patients experienced a redislocation of the glenohumeral joint in the postoperative follow-up (3/13 patients; 23%). The risk of recurrence of the glenohumeral instability was not correlated with either the number of previous stabilisation procedures, or any other preoperative or intraoperative parameters. Conversely, a new postoperative injury was a factor of key importance. The patients with recurrent instability (subjective instability or glenohumeral dislocation) achieved a significantly lower Rowe score, SSV, postoperative VAS, and worse overall satisfaction with the procedure compared to the group with no recurrent instability. The remplissage induced minor limitations of external rotation at 0° abduction and internal rotation at 90° abduction. After rehabilitation, the muscle strength of the operated shoulder in both groups was comparable to that of the untreated shoulder in all planes of the shoulder range of motion. DISCUSSION Our study confirms the clinical relevance of the addition of remplissage to the arthroscopic Bankart procedure for reducing the rate of recurrent glenohumeral instability in TUBS with a clinically significant Hill-Sachs lesion. Satisfaction with the surgical outcome is high; the functional outcomes are very good, including muscle strength. Surprisingly, though, the risk of recurrent instability does not correlate with the number of implants used in the stabilisation procedure. CONCLUSIONS Addition of remplissage to the arthroscopic Bankart stabilisation in patients with a clinically significant Hill-Sachs lesion shows a low risk of recurrence of glenohumeral instability after surgery compared to the conventional arthroscopic Bankart repair alone. The remplissage does cause minor restrictions in the glenohumeral joint external rotation, but it was not reflected in the satisfaction of patients or a lower clinical score of the shoulder joint. The preoperative assessment of the HillSachs lesion using the "glenoid track" on a 3D-CT scan helps improve the preoperative planning and prediction of outcomes of the stabilisation procedure. Key words: glenohumeral instability, Bankart defect, Hill-Sachs lesion, Bankart repair, remplissage, arthroscopy.

[Effect of a Single Dose of Tranexamic Acid Administered during Anterior Cruciate Ligament Reconstruction Using Hamstrings: a Randomized Clinical Study]. / Efekt jednorázového podání kyseliny tranexamové pri rekonstrukci predního zkrízeného vazu hamstringy: randomizovaná klinická studie.

PURPOSE OF THE STUDY Anterior cruciate ligament reconstruction is one of the most common reconstruction surgeries. The unintended consequences of the surgery are hemarthrosis, blood loss, knee swelling and postoperative pain. The purpose of the study was to evaluate the effect of a single dose of intravenous tranexamic acid (TXA) on the postoperative parameters and functional status of the knee joint 3 months after surgery. MATERIAL AND METHODS It is a prospective randomised clinical study. An intravenous injection of TXA equivalent to 15 mg/kg in 100 ml of saline solution was administered to the test group during the surgery (20 minutes before the end of the surgery). The control group was administered 100 ml of saline solution without TXA. In both groups, the following parameters were evaluated preoperatively and postoperatively (on Day 1 and Day 10 and at 1 month and 3 months): thigh circumference at 1 cm above the patella, Coupens and Yates (CY) score for swelling, and pain score (VAS). At 24 hours after the surgery, the blood loss (secretion into the drain) and decrease in hemoglobin (Hb) and hematocrit (HCT) levels compared to the preoperative levels were assessed. The functional status of the knee joint was assessed based on the Lysholm knee scoring scale and the IKDC subjective knee evaluation form preoperatively, or at 1 and 3 months postoperatively. RESULTS In the test group, a significantly lower blood loss was detected 24 hours after the surgery. The mean difference of 128 ml compared to the control group was both statistically and practically significant (p < 0.001, d =1.42). The test group showed a lower decrease in Hb and HCT levels postoperatively compared to the control group, although with no statistical significance. On the first postoperative day, slightly better results of the thigh circumference at 1 cm above the patella and of the CY score were observed in the test group. However, during the follow-up check performed postoperatively on Day 10, the differences in the thigh circumference at 1 cm above the patella, CY score and pain VAS score were negligible. The differences in the functional status of the knee joint between the two groups ascertained during the check performed 1 month and 3 months after the surgery were insignificant. DISCUSSION Our study, just like other studies, confirms a significant effect of a single dose of intravenous TXA on the volume of blood loss and early postoperative swelling, which are the parameters affecting the early postoperative course. Even though the intervention does not affect the subsequent result of surgery, it can undoubtedly be of benefit perioperatively. There is a fairly limited number of randomised clinical studies on this topic in literature, with most of them published in the last 7 years. Further research should, among other things, optimise the protocol and identify a suitable candidate for TXA administration in patients undergoing an ACL reconstruction. CONCLUSIONS Our study confirmed the positive effect of a single dose of intravenous TXA during the reconstruction of anterior cruciate ligament using hamstrings on early postoperative blood loss and early postoperative swelling, which can have a positive effect on wound healing and prevent postoperative complications. Therefore, in agreement with available literature, we recom mend administering a single dose of intravenous TXA in ACL reconstruction, unless there is a contraindication to this therapy. Key words: anterior cruciate ligament reconstruction, hamstrings tranexamic acid, single intravenous administration, clinical evaluation.

[Incidence, Morphology and Clinical Significance of Hill-Sachs Lesions in Shoulder Instability - CT Scan Evaluation of the Group of Patients]. / Incidence, morfologie a klinický význam HillovýchSachsových lézí u nestabilních ramenních kloubu ­ CT hodnocení souboru pacientu.

PURPOSE OF THE STUDY Shoulder instability is often times accompanied by associated injuries caused by the humeral head displacement. These are primarily bone lesions on the head and socket of the glenohumeral joint. The purpose of this study was to evaluate the frequency, morphology and clinical significance of bone lesions in shoulder instabilities in a group of patients operated in our department for glenohumeral instability between 2012 and 2019. MATERIAL AND METHODS The ongoing evaluation included 373 patients with trauma and habitual instability who had undergone surgery in our department in the period from 2012 to 2019. All patients underwent a preoperative 3D CT scan of the shoulder joint. Subsequently, the morphology and clinical significance of individual bone lesions were evaluated based on the older Burkhart s concept of engaging/nonengaging lesions and the newer concept of glenoid track by Yamamoto and Di Giacomo of 2007, 2014 or 2020. RESULTS The frequency of Hill-Sachs lesion was 83.4% (311) in our group of patients. In nearly two thirds (211 cases) also a bone defect on glenoid was detected (59.3%). When comparing the basic types of instabilities, in the TUBS group the Hill-Sachs lesions were present up to twice as often as in the group with AMBRI instability. Clinically significant Hill-Sachs lesions according to the older concept of engaging/ nonengaging lesions of Burkhart were reported in 104 cases (34%). Clinically significant lesions according to the newer concept of Yamamoto and DiGiacomo (the so-called off-track lesions) were observed in 173 cases (55.6%). Classified as critical were the clinically insignificant lesions (the so-called on-track lesions), which by their location were near the glenoid track. These lesions were found in 80 patients. After adding up the significant (off-track) and critical on-track lesions, we arrived at 253 (81.4%) clinically significant lesions based on the updated Yamamoto concept. DISCUSSION The frequency of Hill-Sachs lesions and glenoid defects identified by us is close to the upper limit of the range described in literature (8 to 100%). Based on the recent study by Yamamoto, added to these defects were the so-called peripheral ontrack defects, the clinical significance of which is currently indisputable. The oldest classification into engaging/nonengaging lesions revealed only 34% of the significant lesions, but this concept does not evaluate the glenoid defect. The newer concept by Yamamoto/DiGiacomo resulted in detecting 55.6% of significant Hill-Sachs lesions. The latest modification of the glenoid track of 2020, which includes also the on-track lesions in the critical zone among the significant lesions, in our group of patients classified 81% of lesions as clinically significant. CONCLUSIONS Our study confirmed the very frequent occurrence of clinically significant Hill-Sachs lesions in shoulder instabilities. Therefore, for the sake of successful shoulder stabilisation surgery detailed preoperative planning with 3D CT of the shoulder joint and evaluation of the associated bone lesions are necessary. The highest detection of clinically significant lesions was achieved by the latest modification of the glenoid track concept. Future studies will have to prove the effect of this classification on the result of surgical treatment. Key words: shoulder instability, glenoid track; bone defects, Hill-Sachs lesion; bipolar lesions; 3D CT evaluation.

The effect of albumin and γ-globulin on synovial fluid lubrication: Implication for knee joint replacements.

Total knee arthroplasty has become a routine procedure for patients suffering from joint diseases. Although the number of operations continuously increases, a limited service-life of implants represents a persisting challenge for scientists. Understanding of lubrication may help to suitably explain tribological processes on the way to replacements that become durable well into the third decade of service. The aim of the present study is to assess the formation of protein lubricating film in the knee implant. A developed knee simulator was used to observe the contact of real femoral and transparent polymer tibial component using fluorescent microscopy. The contact was lubricated by various protein solutions with attention to the behaviour of albumin and γ-globulin. In order to suitably mimic a human synovial fluid, hyaluronic acid and phospholipids were subsequently added to the solutions. Further, the change in shape and the migration of the contact zone were studied. The results showed considerable appearance differences of the contact over the swing phase of the simplified gait cycle. Regarding film formation, a strong interaction of the various molecules of synovial fluid was observed. It was found that the thickness of the lubricating layer stabilizes within around 50 s. Throughout the contact zone, protein agglomerations were present and could be clearly visualised using the applied optical technique.