Stress shielding effect after total hip arthroplasty varies between combinations of stem design and stiffness-a comparing biomechanical finite element analysis.

PURPOSE: Total hip arthroplasty (THA) has become a highly frequent orthopaedic procedure. Multiple approaches have been made to design the femoral component for THA with a mechanical behaviour as close as possible to a natural femur. The aim of this study was to compare different combinations of design and biomechanical properties of THA prostheses and their impact on stress shielding of the periprosthetic bone. METHODS: Virtual implantation of different stem designs (straight standard stem, straight short stem, anatomical short stem) by finite element analysis based on in vivo data from computer tomography was performed. For each stem, three grades of stiffness were generated, followed by a strain analysis. RESULTS: Reduction of stem stiffness led to less stress shielding. Implantation of an anatomical short-stem prosthesis with low stiffness provided the most physiological strain-loading effect (p < 0.001). CONCLUSION: A combination of a short and an anatomically designed stem with a low stiffness might provide a more physiological strain transfer during THA. Biomechanical properties of the femoral component for THA should be considered as a multifactorial function of dimensions, design, and stiffness.

Evaluation of the Influence of Machine Tools on the Accuracy of Indoor Positioning Systems.

In recent years, the use of indoor localization techniques has increased significantly in a large number of areas, including industry and healthcare, primarily for monitoring and tracking reasons. From the field of radio frequency technologies, an ultra-wideband (UWB) system offers comparatively high accuracy and is therefore suitable for use cases with high precision requirements in position determination, for example for localizing an employee when interacting with a machine tool on the shopfloor. Indoor positioning systems with radio signals are influenced by environmental obstacles. Although the influence of building structures like walls and furniture was already analysed in the literature before, the influence of metal machine tools was not yet evaluated concerning the accuracy of the position determination. Accordingly, the research question for this article is defined: To what extent is the positioning accuracy of the UWB system influenced by a metal machine tool?The accuracy was measured in a test setup, which consists of a total of four scenarios in a production environment. For this purpose, the visual contact between the transmitter and the receiver modules, including the influence of further interfering factors of a commercially available indoor positioning system, was improved step by step from scenario 1 to 4. A laser tracker was used as the reference measuring device. The data was analysed based on the type A evaluation of standard uncertainty according to the guide to the expression of uncertainty in measurement (GUM). It was possible to show an improvement in standard deviation from 87.64cm±32.27cm to 6.07cm±2.24cm with confidence level 95% and thus provides conclusions about the setup of an indoor positioning system on the shopfloor.

Enhanced Changeover Detection in Industry 4.0 Environments with Machine Learning.

Changeover times are an important element when evaluating the Overall Equipment Effectiveness (OEE) of a production machine. The article presents a machine learning (ML) approach that is based on an external sensor setup to automatically detect changeovers in a shopfloor environment. The door statuses, coolant flow, power consumption, and operator indoor GPS data of a milling machine were used in the ML approach. As ML methods, Decision Trees, Support Vector Machines, (Balanced) Random Forest algorithms, and Neural Networks were chosen, and their performance was compared. The best results were achieved with the Random Forest ML model (97% F1 score, 99.72% AUC score). It was also carried out that model performance is optimal when only a binary classification of a changeover phase and a production phase is considered and less subphases of the changeover process are applied.

Gender differences in blood transfusion strategy for patients with hip fractures - a retrospective analysis.

Background: In the last decades, transfusion therapy with allogenic blood has progressively shifted to a more restrictive approach. The current study analyzed the transfusion practice and transfusion-associated factors in a regional trauma center over the course of five years. Methods: Retrospective analysis of all patients undergoing surgery for hip fractures in a level 1 trauma center of an academic teaching hospital from 2010 to 2014 (n=650). The number of transfused packed red blood cells (PRBCs), preoperative Hb concentrations, and intensive care unit (ICU) and hospital length of stay (LOS) were analyzed. A logistic regression analysis was performed to evaluate transfusion and ICU LOS-associated risk factors. (Ethical Review Board approval: 2015-497-f-S). Results: From 2010 to 2014 the average number of PRBCs transfused per patient decreased continuously despite similar preoperative Hb levels. During the same period, ICU LOS increased while hospital LOS decreased. Advanced patient age, preoperative Hb concentrations, surgical complications, and ICU LOS were associated with increased transfusion requirements. Although preoperative Hb levels were lower, females received fewer PRBCs compared to males. Conclusion: Over the course of five years, a restrictive transfusion strategy was implemented within clinical practice in patients undergoing surgery for hip fractures. In parallel, a significant reduction in the hospital LOS and an increased ICU LOS was noted. Whether there is an association between increased ICU LOS and decreasing hospital LOS and whether there is a gender effect on transfusion requirements in patients with surgery for hip fractures should be subject to further research.

Ten-year follow-up of a cemented tapered stem.

INTRODUCTION: This stem was cleared by the FDA in 2002 and has been implanted in cementless and cemented versions. Despite its long history, there are no long-term clinical  results available for the cemented version of this implant. The aim of this study was to provide such data. It was hypothesized that this implant delivers clinical success comparable to other tapered cemented stems. MATERIALS AND METHODS: A total of 113 hip replacements were performed in 106 patients between October 2007 and December 2009 using the cemented version of this stem. The mean age of the patients at operation was 74.8 years (range 50-91 years). The mean follow-up was 8.9 years with only two patients lost to follow-up. Implant survival was determined using the Kaplan-Meier analysis. RESULTS: Stem survival with revision for any reason as the endpoint was 96.4% after 10 years. Survival for stem aseptic loosening was 100%. There were no cases of osteolysis. Clinical outcomes, as shown by Harris Hip Scores, were in line with previous investigations and the rate of adverse events was very low. CONCLUSIONS: This is a modern cemented stem with an excellent survival rate and satisfactory functional outcomes. In this cohort, there were no failures related to the stem through the first decade.

Bone preserving level of osteotomy in short-stem total hip arthroplasty does not influence stress shielding dimensions - a comparing finite elements analysis.

BACKGROUND: The main objective of every new development in total hip arthroplasty (THA) is the longest possible survival of the implant. Periprosthetic stress shielding is a scientifically proven phenomenon which leads to inadvertent bone loss. So far, many studies have analysed whether implanting different hip stem prostheses result in significant preservation of bone stock. The aim of this preclinical study was to investigate design-depended differences of the stress shielding effect after implantation of a selection of short-stem THA-prostheses that are currently available. METHODS: Based on computerised tomography (CT), a finite elements (FE) model was generated and a virtual THA was performed with different stem designs of the implant. Stems were chosen by osteotomy level at the femoral neck (collum, partial collum, trochanter sparing, trochanter harming). Analyses were performed with previously validated FE models to identify changes in the strain energy density (SED). RESULTS: In the trochanteric region, only the collum-type stem demonstrated a biomechanical behaviour similar to the native femur. In contrast, no difference in biomechanical behaviour was found between partial collum, trochanter harming and trochanter sparing models. All of the short stem-prostheses showed lower stress-shielding than a standard stem. CONCLUSION: Based on the results of this study, we cannot confirm that the design of current short stem THA-implants leads to a different stress shielding effect with regard to the level of osteotomy. Somehow unexpected, we found a bone stock protection in metadiaphyseal bone by simulating a more distal approach for osteotomy. Further clinical and biomechanical research including long-term results is needed to understand the influence of short-stem THA on bone remodelling and to find the optimal stem-design for a reduction of the stress shielding effect.

Continuous adductor canal block versus continuous femoral nerve block after total knee arthroplasty for mobilisation capability and pain treatment: a randomised and blinded clinical trial.

INTRODUCTION: Continuous femoral nerve blocks for total knee arthroplasty can cause motor weakness of the quadriceps muscle and thus prevent early mobilisation. Perioperative falls may result as an iatrogenic complication. In this randomised and blinded trial, we tested the hypothesis that a continuous adductor canal block is superior to continuous femoral nerve block regarding mobilisation ('timed up-and-go' test and other tests) after total knee arthroplasty under general anaesthesia. METHODS: In our study, we included patients scheduled for unilateral knee arthroplasty under general anaesthesia into a blinded and randomised trial. Patients were allocated to a continuous adductor canal block (CACB) or a continuous femoral nerve block (CFNB) for three postoperative days (POD 1-3); with a bolus of 15 ml ropivacaine 0.375%, followed by continuous infusion of ropivacaine 0.2% and patient-controlled bolus administration. Both groups received an additional continuous sciatic nerve block as well as a multimodal systemic analgesic treatment. The primary outcome parameter was mobilisation capability, assessed by 'timed up-and-go' (TUG) test. Analgesic quality, need for opioid rescue and local anaesthetic consumption were also assessed. RESULTS: Forty-two patients were included and analysed (21 patients per group). No significant difference was noted in respect to mobilisation at POD 3 (TUG [s]: CACB 45, CFNB 51). It is worth saying that pain scores (numeric rating scale, NRS) were similar in both groups at POD 3 {rest [median (interquartile range)]: CACB 0 (0-3), CFNB 1 (0-3); stress: CACB 4 (2-5), CFNB 3 (2-4)}. CONCLUSIONS: Concerning the mobilisation capability, we did not actually observe a superior effect of CACB compared with CFNB technique in our patients following total knee arthroplasty. Moreover, no difference was observed concerning analgesia quality.

Immunosuppressive capabilities of mesenchymal stromal cells are maintained under hypoxic growth conditions and after gamma irradiation.

BACKGROUND AIMS: The discovery of regenerative and immunosuppressive capacities of mesenchymal stromal cells (MSCs) raises hope for patients with tissue-damaging or severe, treatment-refractory autoimmune disorders. We previously presented a method to expand human MSCs in a bioreactor under standardized Good Manufacturing Practice conditions. Now we characterized the impact of critical treatment conditions on MSCs with respect to immunosuppressive capabilities and proliferation. METHODS: MSC proliferation and survival after γ irradiation were determined by 5-carboxyfluorescein diacetate N-succinimidyl ester and annexinV/4',6-diamidino-2-phenylindole (DAPI) staining, respectively. T-cell proliferation assays were used to assess the effect of γ irradiation, passaging, cryopreservation, post-thaw equilibration time and hypoxia on T-cell suppressive capacities of MSCs. Quantitative polymerase chain reaction and ß-galactosidase staining served as tools to investigate differences between immunosuppressive and non-immunosuppressive MSCs. RESULTS: γ irradiation of MSCs abrogated their proliferation while vitality and T-cell inhibitory capacity were preserved. Passaging and long cryopreservation time decreased the T-cell suppressive function of MSCs, and postthaw equilibration time of 5 days restored this capability. Hypoxic culture markedly increased MSC proliferation without affecting their T-cell-suppressive capacity and phenotype. Furthermore, T-cell suppressive MSCs showed higher CXCL12 expression and less ß-galactosidase staining than non-suppressive MSCs. DISCUSSION: We demonstrate that γ irradiation is an effective strategy to abrogate MSC proliferation without impairing the cells' immunosuppressive function. Hypoxia significantly enhanced MSC expansion, allowing for transplantation of MSCs with low passage number. In summary, our optimized MSC expansion protocol successfully addressed the issues of safety and preservation of immunosuppressive MSC function after ex vivo expansion for therapeutic purposes.

Self-employed and stressed out? The impact of stress and stress management on entrepreneurs' mental health and performance.

Introduction: Entrepreneurs play a central role in economic and social stability, yet the start-up rate in Germany has declined in recent years, possibly due to the stress associated with entrepreneurial endeavors. Stressors such as financial uncertainty and time pressure are prevalent among entrepreneurs and negatively affect their psychological well-being. However, research on stress management strategies among self-employed individuals remains limited. Methods: This pilot study conducted a quantitative analysis with 117 self-employed participants in Germany. The study focused on typical entrepreneurial work demands and selected stress coping mechanisms. Results: The analysis revealed a significant correlation between quantitative demands and mental exhaustion. Furthermore, a high positive correlation between presenteeism and workload suggests that presenteeism may partially explain the variance in workload. These findings underscore how high job demands can lead to self-endangering behaviors that are detrimental to mental health. Discussion: Although no significant moderating effect of proactive coping on the relationship between job demands and mental exhaustion was observed, significant negative correlations between proactive coping and both job demands and mental exhaustion suggest a potential protective role of proactive coping against work-related stress. This study highlights the importance of understanding stress coping strategies among self-employed individuals and their impact on entrepreneurial success and mental well-being. Further research in this area is warranted to develop effective interventions to support the well-being and productivity of self-employed individuals in Germany.

MRI after unicondylar knee arthroplasty: rotational alignment of components.

INTRODUCTION: This pilot study used magnet resonance imaging (MRI) to analyse the rotation of medial unicondylar knee arthroplasty (UKA) components and assessed how accurately the results could be reproduced. MATERIALS AND METHODS: Knee MRI using a special protocol to reduce metal artefact was performed in ten patients who had undergone medial UKA. Two independent investigators measured the rotation angle of femoral (zirconium) and tibial (cemented full-poly or cemented modular metal-backed) components applying different reference lines for the latter. Statistical analysis comprised tests for reliability, variance between measurement techniques, standard deviations and limits of agreement. RESULTS: For all methods tested, there was sufficient inter- and intra-observer reliability. Lowest variances were, however, found for the femoral epicondyles, for both femoral and tibial components. A tangent to the dorsal epicondyles of the tibia also gave reproducible results with low variances for the tibial component. DISCUSSION: Almost all applied measurement techniques were reproducible by statistical definition, although some of them resulted in substantial differences between both, observations and observers. A variance test helps to distinguish better between clinically useful and less accurate references. CONCLUSION: MRI allows good reproducible rotation analysis via the femoral epicondyles for both femoral and tibial UKA implants. For the tibia, the tibial tuberosity, the eminentia and the tibial epicondyles in particular were shown to be less reliable. The dorsal epicondyles seem to be most suitable for the tibial component.

Rate of Complications after Hip Fractures Caused by Prolonged Time-to-Surgery Depends on the Patient's Individual Type of Fracture and Its Treatment.

INTRODUCTION: Hip fractures are common injuries in the elderly and are usually treated with timely surgery. While severe postoperative complications are reported for up to 10% of patients, many studies identified predictive factors for the occurrence of complications postoperatively. A controversially discussed factor is "time-to-surgery". The aim of the study was to examine if time-to-surgery was associated with the occurrence of complications and if the complication rate differed between the patient individual fracture types of intracapsular on the one hand and extracapsular hip fractures on the other hand. We hypothesized that time-to-surgery had less impact on complications in intracapsular hip fractures compared to extracapsular ones, and therefore, guidelines should pay attention to the patient individual case scenario. MATERIALS AND METHODS: All patients who were admitted to the Department of Trauma and Orthopaedic Surgery of an academic teaching hospital for hip fracture surgery (n = 650) over a five-year period were included in the study. After the application of the exclusion criteria, such as periprosthetic or pathologic fractures, cases needed immediate surgical treatment, and after outlier adjustment, 629 cases remained in the study. Hip fractures were classified into intracapsular fractures (treated by hip arthroplasty) and extracapsular fractures (treated by intramedullary nailing osteosynthesis). The occurrence of severe complications in patients treated within 24 h was compared with patients treated later than 24 h after injury. For statistical evaluation, a multivariate logistic regression analysis was performed to investigate the impact of time-to-surgery interval on the occurrence of complications. RESULTS: Patients with an extracapsular fracture, which was treated with intramedullary nailing (44.5%), rarely suffered a serious complication when surgery was performed within 24 h after injury. However, when the interval of the time-to-surgery was longer than 24 h, the complication rate increased significantly (8.63% vs. 25.0%, p = 0.002). In contrast to this finding in patients with intracapsular fractures (55.5%), which were treated with cemented arthroplasty, complication rates did not depend on the 24 h interval (26.17% vs. 20.83%, p = 0.567). CONCLUSIONS: The occurrence of complications after surgical treatment of hip fractures is associated with the time interval between injury and surgery. A 24 h time interval between injury and surgical procedure seems to play a major role only in extracapsular fractures treated with osteosynthesis but not in intracapsular fractures treated with arthroplasty. Therefore, guidelines should take notice of the patient individual case scenario and, in particular, the individual hip fracture type.

Fibrin glue does not improve the fixation of press-fitted cell-free collagen gel plugs in an ex vivo cartilage repair model.

PURPOSE: Adequate graft fixation over a certain time period is necessary for successful cartilage repair and permanent integration of the graft into the surrounding tissue. The aim of the present study was to test the primary stability of a new cell-free collagen gel plug (CaReS(®)-1S) with two different graft fixation techniques over a simulated early postoperative period. METHODS: Isolated chondral lesions (11 mm diameter by 6 mm deep) down to the subchondral bone plate were created on the medial femoral condyle in 40 porcine knee specimens. The collagen scaffolds were fixed in 20 knees each by press-fit only or by press-fit + fibrin glue. Each knee was then put through 2,000 cycles in an ex vivo continuous passive motion model. Before and after the 2,000 motions, standardized digital pictures of the grafts were taken. The area of worn surface as a percentage of the total collagen plug surface was evaluated using image analysis software. RESULTS: No total delamination of the scaffolds to leave an empty defect site was recorded in any of the knees. The two fixation techniques showed no significant difference in worn surface area after 2,000 cycles (P = n.s.). CONCLUSIONS: This study reveals that both the press-fit only and the press-fit + fibrin glue technique provide similar, adequate, stability of a type I collagen plug in the described porcine model. In the clinical setting, this fact may be particularly important for implantation of arthroscopic grafts.

Navigation of total knee arthroplasty: rotation of components and clinical results in a prospectively randomized study.

BACKGROUND: Navigation was introduced into total knee arthroplasty (TKA) to improve accuracy of component position, function and survival of implants. This study was designed to assess the outcome of navigated TKA in comparison with conventional implantation with the focus on rotational component position and clinical mid-term results. METHODS: In a prospectively randomized single-blinded approach, 90 patients with primary gonarthrosis were assigned to three different groups. Thirty patients each were assigned to NexGen LPS without and with navigation (groups 1 and 2), and 30 patients to navigation with the Stryker Scorpio PS (group 3). The navigation system used was the imageless Stryker KneeTrac, version 1.0. Clinical outcome was assessed by a blinded observer applying the Knee Society Score (KSS) and a visual analogue scale (VAS) for pain. CT scans and radiographs were conducted prior to and 12 weeks after index surgery. RESULTS: Seventy-nine patients were available for clinical evaluation at 3 ± 0.4 years follow-up. Four implants had to be revised for early loosening or infection (4.4%). Four patients had died and three patients were not able to follow the invitation for clinical assessment. Functional results in the KSS were significantly lower after navigated TKA. Operation time and incisions with navigation were significantly longer. Significantly less radiological outliers with navigation were found for coronal alignment of the femur, only. CONCLUSION: In this series, no beneficial effect for navigation in TKA could be shown assessing clinical data, as functional results in the presented series seemed to be lower after first generation navigated TKA. The clinical mid- to long-term value of navigation remains to be evaluated in larger patient series or meta-analyses at longer follow-up. TRIAL REGISTRATION NUMBER: DRKS 00000430.

Analyses of prosthesis stem failures in noncemented modular hip revision prostheses.

In recent years, hip prosthesis stem revision by means of modular revision systems has reached an essential role in revision prosthetics. It is an extremely successful technique. Reports about mechanical failure in nonmodular revision stems have already been published. This complication is rare, but feared. We report about mechanical failure of four non-cemented modular revision stems over a period of 28 months. All failures became clinically apparent because of severe inguinal or thigh pain and were confirmed by conventional x-ray imaging. All stem failures occurred just below the interface between prosthesis stem and neck, which is a biomechanically stressed area. Distal of the failure, all stems were still firmly fixed. In all cases, there was obvious evidence of loosening at the proximal component. Metallographic and energy-dispensive x-ray analysis of one stem showed a fatigue fracture due to dynamic stress. If new pain arises after revision surgery with modular non-cemented prosthesis systems, the possibility of an implant failure should be kept in mind. Patients should be informed accordingly about the risk of implant failure.

Minimally invasive versus conventional unicompartmental knee arthroplasty.

INTRODUCTION: Unicompartmental knee arthroplasty (UKA) has been proven to be a viable procedure in case of medial osteoarthritis of the knee joint. Minimally invasive surgery (MIS) techniques have been described to facilitate recovery after surgery. The aim of this study was to rule out major failure mechanisms and to obtain clinical data for comparison between a conventional and the MIS approach. MATERIALS AND METHODS: A consecutive series of 163 UKA (160 patients) were retrospectively included (83 conventional and 80 MIS interventions). Patients were invited for a clinical examination including clinical scores (KSS, Lequesne, UCLA, VAS, Feller- and Turba Patella Scores). Seven patients (4.3%) were lost to follow-up. RESULTS: Average follow-up was 4.6 ± 1.3 (1.5-6.8) years. Average age at operation was 67.5 ± 7.9 (45-81) years. Fifteen implants had been converted to TKA (9.2%). There were seven conversions to TKA in the MIS and 8 in the conventional group. Of the applied clinical scores there were better values for the Turba patella score in the MIS group. Differences of the other scores were not statistically significant. CONCLUSION: Comparable functional results for both UKA procedures could be shown. There were no significant differences in terms of clinical scores or revision rates. The MIS approach in medial UKA did not show any major complications. Its use seems to be safe.

Precision of preoperative digital templating in total hip arthroplasty.

The purpose of the present study was to evaluate the precision of digital templating in total hip arthroplasty (THA) and the influence of the surgeons' level of experience on the accuracy of preoperative planning. A retrospective review of digital computer planned THA's was performed on 169 hips. The preoperatively planned component sizes were compared to the sizes used in the operation. An exact agreement between planned and actually used size was achieved in 33.7% of the hips for the acetabular cups and 36% for the femoral stems. A prediction of +/- 1 size was reached in 77.5% for acetabular components and 82.3% for the femoral stem. On average, the acetabular components were planned approximately 0.9 sizes too large, the femoral stems 0.3 sizes too small. The accuracy of preoperative planning showed no differences according to the level of training of the planning surgeon. We state that the digital templating is useful to predict the implant size. However, 15 of the 169 planned components showed a difference of more than 2 sizes. Therefore, digital templating cannot fully replace intraoperative X-ray use.

Decreased Superoxide Dismutase Concentrations (SOD) in Plasma and CSF and Increased Circulating Total Antioxidant Capacity (TAC) Are Associated with Unfavorable Neurological Outcome after Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Subarachnoid hemorrhage (SAH) is a devastating disease with high morbidity and mortality. Hypoxia-induced changes and hemoglobin accumulation within the subarachnoid space are thought to lead to oxidative stress, early brain injury, and delayed vasospasm. This study aimed to evaluate the antioxidant status and its impact on neurological outcome in patients with aneurysmal SAH. METHODS: In this prospective observational study, 29 patients with aneurysmal SAH were included (mean age 54.7 ± 12.4). Blood and cerebrospinal fluid (CSF) samples were collected on days (d) 1, 3, and 7. In addition, 29 patients without intracranial hemorrhage served as controls. The antioxidant system was analyzed by glutathione peroxidase (GSH-Px; U/L) and total and free glutathione-sulfhydryl (GSH; mg/L) in the plasma. Superoxide dismutase (SOD, U/mL) and total antioxidant capacity (TAC, µmol/L) were measured in the serum and CSF. Clinical data were compiled on admission (Hunt and Hess grade, Fisher grade, and GCS). Neurological and cognitive outcome (modified Rankin scale (mRS), Glasgow Outcome Scale Extended (GOSE) and Montreal Cognitive Assessment (MoCA)) was assessed after 6 weeks (6 w) and 6 months (6 m). RESULTS: Plasma levels of SOD increased from day 1 to 7 after SAH (d1: 1.22 ± 0.36 U/L; d3: 1.25 ± 0.33 U/L, p = 0.99; d7: 1.52 ± 0.4 U/L, p = 0.019) and were significantly higher compared to controls (1.11 ± 0.27 U/L) at day 7 (p < 0.001). Concordantly, CSF levels of SOD increased from day 1 to 7 after SAH (d1: 1.22 ± 0.41 U/L; d3: 1.77 ± 0.73 U/L, p = 0.10; d7: 2.37 ± 1.29 U/L, p < 0.0001) without becoming significantly different compared to controls (1.74 ± 0.8 U/L, p = 0.09). Mean plasma TAC at day 1 (d1: 77.87 ± 49.72 µmol/L) was not statistically different compared to controls (46.74 ± 32.42 µmol/L, p = 0.25). TAC remained unchanged from day 1 to 7 (d3: 92.64 ± 68.58 µmol/L, p = 0.86; d7: 74.07 ± 54.95 µmol/L, p = 0.8) in plasma. TAC in CSF steeply declined from day 1 to 7 in patients with SAH becoming significantly different from controls at days 3 and 7 (d3: 177.3 ± 108.7 µmol/L, p = 0.0046; d7: 85.35 ± 103.9 µmol/L, p < 0.0001). Decreased SOD levels in plasma and CSF are associated with a worse neurological outcome 6 weeks (mRS: CSF p = 0.0001; plasma p = 0.027/GOSE: CSF p = 0.001; plasma p = 0.001) and 6 months (mRS: CSF p = 0.001; plasma p = 0.09/GOSE: CSF p = 0.001; plasma p = 0.001) after SAH. Increased plasma TAC correlated with a worse neurological outcome 6 weeks (mRS: p = 0.001/GOSE p = 0.001) and 6 months (mRS p = 0.001/GOSE p = 0.001) after SAH. CONCLUSION: In our study, a reduction in the antioxidative enzyme SOD and elevated TAC were associated with a poorer neurological outcome reflected by mRS and GOSE at 6 weeks and 6 months after SAH. A lower initial SOD CSF concentration was associated with the late deterioration of cognitive ability. These findings support the mounting evidence of the role of oxidative stress in early brain injury formation and unfavorable outcome after SAH.

The Influence of Oxidative Stress on Neurological Outcomes in Spontaneous Intracerebral Hemorrhage.

Spontaneous intracerebral hemorrhage (ICH) causes, besides the primary brain injury, a secondary brain injury (SBI), which is induced, amongst other things, by oxidative stress (OS) and inflammation, determining the patient's outcome. This study aims to assess the impact of OS in plasma and cerebrospinal fluid (CSF) on clinical outcomes in patients with ICH. A total of 19 ICH (volume > 30 cc) patients and 29 control patients were included. From day one until seven, blood and CSF samples were obtained, and ICH volume was calculated. OS markers, like malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione-sulfhydryl (GSH), and the total antioxidant status (TAS) were measured. Clinical data on treatment and outcome were determined. Patients with mRS ≤ 4 showed significantly elevated SOD and GSH-Px levels in plasma compared to patients with poor CO (p = 0.004; p = 0.002). Initial increased TAS in plasma and increased MDA in CSF were linked to an unfavorable outcome after six months (p = 0.06, r = 0.45; p = 0.05, r = 0.44). A higher ICH volume was associated with a worse outcome at week six (p = 0.04, r = 0.47). OS plays a significant role in SBI. Larger ICHs, elevated MDA in CSF, and TAS in plasma were associated with a detrimental outcome, whereas higher plasma-SOD and -GSH-Px were associated with a favorable outcome.

Malignant fibrous histiocytoma of the distal femur after an arthroscopic anterior cruciate ligament reconstruction: A case report and a review of the literature.

BACKGROUND: Malignant degeneration in association with orthopaedic implants is a known but rare complication. To our knowledge, no case of osseous malignant fibrous histiocytoma after anterior cruciate ligament reconstruction is reported in the literature. CASE PRESENTATION: We report a 29-year-old male Turkish patient who presented with severe pain in the operated knee joint 40 months after arthroscopic anterior cruciate ligament reconstruction. X-ray and MR imaging showed a large destructive tumor in the medial femoral condyle. Biopsy determined a malignant fibrous histiocytoma. After neoadjuvant chemotherapy, wide tumor resection and distal femur reconstruction with a silver-coated non-cemented tumor knee joint prosthesis was performed. Adjuvant chemotherapy was continued according to the EURAMOS 1 protocol. CONCLUSIONS: Though secondary malignant degeneration after orthopaedic implants or prostheses is not very likely, the attending physician should take this into consideration, especially if symptoms worsen severely over a short period of time.

Influence of nanofibers on growth and gene expression of human tendon derived fibroblast.

BACKGROUND: Rotator cuff tears are a common and frequent lesion especially in older patients. The mechanisms of tendon repair are not fully understood. Common therapy options for tendon repair include mini-open or arthroscopic surgery. The use of growth factors in experimental studies is mentioned in the literature. Nanofiber scaffolds, which provide several criteria for the healing process, might be a suitable therapy option for operative treatment. The aim of this study was to explore the effects of nanofiber scaffolds on human tendon derived fibroblasts (TDF's), as well as the gene expression and matrix deposition of these fibroblasts. METHODS: Nanofibers composed of PLLA and PLLA/Col-I were seeded with human tendon derived fibroblasts and cultivated over a period of 22 days under growth-inductive conditions, and analyzed during the course of culture, with respect to gene expression of different extra cellular matrix components such as collagens, bigylcan and decorin. Furthermore, we measured cell densities and proliferation by using fluorescence microscopy. RESULTS: PLLA nanofibers possessed a growth inhibitory effect on TDF's. Furthermore, no meaningful influence on the gene expression of collagen I, collagen III and decorin could be observed, while the expression of collagen X increased during the course of cultivation. On the other hand, PLLA/Col-I blend nanofibers had no negative influence on the growth of TDF's. Furthermore, blending PLLA nanofibers with collagen had a positive effect on the gene expression of collagen I, III, X and decorin. Here, gene expression indicated that focal adherence kinases might be involved. CONCLUSION: This study indicates that the use of nanofibers influence expression of genes associated with the extra cellular matrix formation. The composition of the nanofibers plays a critical role. While PLLA/Col-I blend nanofibers enhance the collagen I and III formation, their expression on PLLA nanofibers was more comparable to controls. However, irrespective of the chemical composition of the fibres, the collagen deposition was altered, an effect which might be associated with a decreased expression of biglycanes.