Incidence and Risk Factors of Pneumonia in Individuals With Acute Spinal Cord Injury: A Multi-national, Multi-center, Prospective Cohort Study.

OBJECTIVE: To describe the occurrence of pneumonia in individuals with acute spinal cord injury (SCI) and identify its key predictors. DESIGN: Multi-centric, longitudinal cohort study. SETTING: 10 specialized SCI rehabilitation units in Europe and Australia. PARTICIPANTS: Eligible were 902 men and women with acute SCI, aged 18 years or older, with cervical or thoracic lesions and not dependent on 24-hour mechanical ventilation; 503 participated in the study (N=503). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: We assessed demographics and lesion related parameters at study entry, and any pneumonia events throughout inpatient rehabilitation. Respiratory function, decubitus, and urinary tract infections were assessed at 1, 3, and 6 months post injury as well as at discharge from inpatient rehabilitation. Time to event (pneumonia) analyses were done using the Kaplan-Meier method, and potential predictors for pneumonia were analyzed with multivariable survival models. RESULTS: Five hundred three patients with SCI were included, with 70 experiencing at least 1 pneumonia event. 11 participants experienced 2 or more events during inpatient rehabilitation. Most events occurred very early after injury, with a median of 6 days. Pneumonia risk was associated with tetraplegia (hazard ratio [HR]=1.78; 95% confidence interval [CI] 1.00-3.17) and traumatic etiology (HR=3.75; 95% CI 1.30-10.8) American Spinal Injury Impairment Scale (AIS) A (HR=5.30; 95% CI 2.28-12.31), B (HR=4.38; 95% CI 1.77-10.83), or C (HR=4.09; 95% CI 1.71-9.81) lesions. For every 10 cmH2O increase in inspiratory muscle strength, pneumonia risk was reduced by 13% (HR=0.87; 95% CI 0.78-0.97). CONCLUSION: Pneumonia is a major complication after SCI with the highest incidence very early after injury. Individuals with traumatic or AIS A, B, or C tetraplegia are at highest risk for pneumonia.

Direct anterior versus antero-lateral approach in hip joint hemiarthroplasty.

BACKGROUND: Femoral neck fractures are common injuries in the elderly and represent a major source of morbidity and mortality. Due to the benefits, bipolar hip hemiarthroplasty (BHH) is a popular method to treat. The purpose of this study is to evaluate the functional and radiographic outcomes for BHH comparing the direct anterior approach (DAA) to the anterolateral approach (ALA) to the hip joint. METHODS: We used a prospective, randomized observational study design, where we enrolled 83 patients at a level-I-trauma center presenting with indication for BHH. We followed up the participants at defined intervals over a period of 1 year. The follow-up examinations were carried out at defined time intervals for a period of 1 year. Calculations were performed with Statistical Package for Social Sciences (SPSS) 21.0. RESULTS: Concerning postoperative pain sensation, the anterior group had statistically significantly decreased pain levels at one (p = 0.02), seven (p = 0.04) and 14 days (p = 0.02) following the intervention when compared to the ALA sample. The postoperative modified Barthel-Index showed a statistically significant difference on the first postoperative day at the anterior group. CONCLUSION: Although we compared two minimally invasive approaches, our results shows a statistically significant difference in pain intensity and mobility for the early postoperative period using the direct anterior approach.

In vitro testing of silver-containing spacer in periprosthetic infection management.

Deep infection is a serious complication in endoprosthetic surgery. In correlation to the patient local or systemic compromising factors conservative and surgical proceedings has to be evaluated. Systemic antibiotic therapy is the gold standard in infection management. Implanted silver-coated or silver-containing medical devices have been proven to their antimicrobial effectiveness since the 1990s by several investigators. The outcomes showed that long time implantation could cause damaging of the surrounding tissues, especially of adjacent nerves. The aim of our study was to evaluate the release of silver (I) ions from bone cement mixed with either nanosilver particles (AgNPs), different concentrations of silver sulfate (Ag2SO4) or from pure metallic silver strips. Therefore, we choose two methods: the first, called "static model", was chosen to evaluate the maximal accumulative concentration of silver (I) ions, with the second, called "dynamic model", we simulated a continuous reduction of the ions. In an additional test design, the different materials were evaluated for their antimicrobial activity using an agar gel diffusion assay. The outcome showed that neither the addition of 1% (w/w) nanosilver nor 0.1% silver sulfate (w/w) to polymethylmethacrylat bone cement has the ability to release silver (I) ions in a bactericidal/antifungal concentration. However, the results also showed that the addition of 0.5% (w/w) and 1% (w/w) silver sulfate (Ag2SO4) to bone cement is an effective amount of silver for use as a temporary spacer.

Online asynchronous detection of error-related potentials in participants with a spinal cord injury using a generic classifier.

For brain-computer interface (BCI) users, the awareness of an error is associated with a cortical signature known as an error-related potential (ErrP). The incorporation of ErrP detection into BCIs can improve their performance. OBJECTIVE: This work has three main aims. First, we investigate whether an ErrP classifier is transferable from able-bodied participants to participants with a spinal cord injury (SCI). Second, we test this generic ErrP classifier with SCI and control participants, in an online experiment without offline calibration. Third, we investigate the morphology of ErrPs in both groups of participants. APPROACH: We used previously recorded electroencephalographic data from able-bodied participants to train an ErrP classifier. We tested the classifier asynchronously, in an online experiment with 16 new participants: 8 participants with SCI and 8 able-bodied control participants. The experiment had no offline calibration and participants received feedback regarding the ErrP detections from the start. To increase the fluidity of the experiment, feedback regarding false positive ErrP detections was not presented to the participants, but these detections were taken into account in the evaluation of the classifier. The generic classifier was not trained with the user's brain signals. However, its performance was optimized during the online experiment by the use of personalized decision thresholds. The classifier's performance was evaluated using trial-based metrics, which considered the asynchronous detection of ErrPs during the entire trial's duration. MAIN RESULTS: Participants with SCI presented a non-homogenous ErrP morphology, and four of them did not present clear ErrP signals. The generic classifier performed better than chance in participants with clear ErrP signals, independently of the SCI (11 out of 16 participants). Three out of the five participants that obtained chance level results with the generic classifier would have not benefitted from the use of a personalized classifier. SIGNIFICANCE: This work shows the feasibility of transferring an ErrP classifier from able-bodied participants to participants with SCI, for asynchronous detection of ErrPs in an online experiment without offline calibration, which provided immediate feedback to the users.

Optimal pin position in supraacetabular external fixation.

BACKGROUND: This study focuses on (i) the length of the intraosseous part of the supraacetabular pin using the insertion technique from the spina iliaca anterior inferior to the cortical part of the incisura ischiadica major, (ii) the angle of insertion of the supraacetabular pin in the transversal plane and (iii) gender-specific differences of the measured results. METHODS: Images of uninjured pelves from 49 patients (64-line computed tomography scanner) were evaluated, and virtual external fixator pins were positioned using a three-dimensional reconstructions of computed tomography scans. The length of the pins and the insertion angle were investigated. Descriptive statistics were used, and gender-specific differences were calculated. A P-value of <0.05 was considered statistically significant. RESULTS: The results showed significant differences between male and female pelves concerning both pin length and insertion angel. For male pelves, the mean screw length was 82.7 mm (SD 5.1; range 72.9-94.3). For females, this was statistically significantly shorter (P ≤ 0.001), with an average of 74.1 mm (SD 5.0; range 63.1-81.9). In the male subgroup, the insertion angle was a mean of 22.6° (SD 3.4; range 12.4-31.8), and the female pelves had an average angle of 19.7° (SD 4.0; range 11.7-24.5). These values differed statistically significantly (P = 0.0032). CONCLUSION: Based on our measurements, we can confirm that both the length of the Schanz screws and the angle of insertion for the supraacetabular external fixator show a statistically significant difference between males and females.

Prevention of thromboembolism in spinal cord injury -S1 guideline.

INTRODUCTION: Traumatic and non-traumatic spinal cord injury bears a high risk for thromboembolism in the first few months after injury. So far, there is no consented guideline regarding diagnostic and prophylactic measures to prevent thromboembolic events in spinal cord injury. Based on a Pubmed research of related original papers and review articles, international guidelines and a survey conducted in German-speaking spinal cord injury centers about best practice prophylactic procedures at each site, a consensus process was initiated, which included spinal cord medicine experts and representatives from medical societies involved in the comprehensive care of spinal cord injury patients. The recommendations comply with the German S3 practice guidelines on prevention of venous thromboembolism. RECOMMENDATIONS: Specific clinical or instrument-based screening methods are not recommended in asymptomatic SCI patients. Based on the severity of neurological dysfunction (motor completeness, ambulatory function) low dose low molecular weight heparins are recommended to be administered up to 24 weeks after injury. Besides, mechanical methods (compression stockings, intermittent pneumatic compression) can be applied. In chronic SCI patients admitted to the hospital, thromboembolism prophylactic measures need to be based on the reason for admission and the necessity for immobilization. CONCLUSIONS: Recommendations for thromboembolism diagnostic and prophylactic measures follow best practice in most spinal cord injury centers. More research evidence needs to be generated to administer more individually tailored risk-adapted prophylactic strategies in the future, which may help to further prevent thromboembolic events without causing major side effects. The present article is a translation of the guideline recently published online (https://www.awmf.org/uploads/tx_szleitlinien/179-015l_S1_Thromboembolieprophylaxe-bei-Querschnittlaehmung_2020-09.pdf).

Respiratory function and respiratory complications in spinal cord injury: protocol for a prospective, multicentre cohort study in high-income countries.

INTRODUCTION: Pneumonia is one of the leading complications and causes of death after a spinal cord injury (SCI). After a cervical or thoracic lesion, impairment of the respiratory muscles decreases respiratory function, which increases the risk of respiratory complications. Pneumonia substantially reduces patient's quality of life, may prolong inpatient rehabilitation time, increase healthcare costs or at worse, lead to early death. Respiratory function and coughing can be improved through various interventions after SCI, but the available evidence as to which aspect of respiratory care should be optimised is inconclusive. Furthermore, ability of respiratory function parameters to predict pneumonia risk is insufficiently established. This paper details the protocol for a large-scale, multicentre research project that aims to evaluate the ability of parameters of respiratory function to predict and understand variation in inpatient risk of pneumonia in SCI. METHODS AND ANALYSIS: RESCOM, a prospective cohort study, began recruitment in October 2016 across 10 SCI rehabilitation centres from Australia, Austria, Germany, the Netherlands and Switzerland. Inpatients with acute SCI, with complete or incomplete cervical or thoracic lesions, 18 years or older and not/no more dependent on 24-hour mechanical ventilation within the first 3 months after injury are eligible for inclusion. The target sample size is 500 participants. The primary outcome is an occurrence of pneumonia; secondary outcomes include pneumonia-related mortality and quality of life. We will use the longitudinal data for prognostic models on inpatient pneumonia risk factors. ETHICS AND DISSEMINATION: The study has been reviewed and approved by all local ethics committees of all participating centres. Study results will be disseminated to the scientific community through peer-reviewed journals and conference presentations, to the SCI community, other stakeholders and via social media, newsletters and engagement activities. TRIAL REGISTRATION DETAILS: ClinicalTrials.gov NCT02891096.

Secondary Sclerosing Cholangitis in Critically Ill Patients Alters the Gut-Liver Axis: A Case Control Study.

Secondary sclerosing cholangitis in critically ill patients (SC-CIP) occurs after long-term intensive care treatment. This study aimed to assess the gut-liver axis in SC-CIP. Stool microbiome composition, gut permeability, bacterial translocation and serum bile acid profiles of 18 SC-CIP patients compared to 11 patients after critical illness without liver disease (CIP controls), 21 patients with cirrhosis and 21 healthy controls were studied. 16S rDNA was isolated from stool and sequenced using the Illumina technique. Diamine oxidase, zonulin, soluble CD14 (sCD14) and lipopolysaccharide binding protein were measured in serum and calprotectin in stool. Serum bile acids were analyzed by high-performance liquid chromatography-mass spectrometry (HPLC-MS). Reduced microbiome alpha diversity and altered beta diversity were seen in SC-CIP, CIP controls and cirrhosis compared to healthy controls. SC-CIP patients showed a shift towards pathogenic taxa and an oralization. SC-CIP, CIP controls and cirrhotic patients presented with impaired gut permeability, and biomarkers of bacterial translocation were increased in SC-CIP and cirrhosis. Total serum bile acids were elevated in SC-CIP and cirrhosis and the bile acid profile was altered in SC-CIP, CIP controls and cirrhosis. In conclusions, observed alterations of the gut-liver axis in SC-CIP cannot solely be attributed to liver disease, but may also be secondary to long-term intensive care treatment.

Attempted Arm and Hand Movements can be Decoded from Low-Frequency EEG from Persons with Spinal Cord Injury.

We show that persons with spinal cord injury (SCI) retain decodable neural correlates of attempted arm and hand movements. We investigated hand open, palmar grasp, lateral grasp, pronation, and supination in 10 persons with cervical SCI. Discriminative movement information was provided by the time-domain of low-frequency electroencephalography (EEG) signals. Based on these signals, we obtained a maximum average classification accuracy of 45% (chance level was 20%) with respect to the five investigated classes. Pattern analysis indicates central motor areas as the origin of the discriminative signals. Furthermore, we introduce a proof-of-concept to classify movement attempts online in a closed loop, and tested it on a person with cervical SCI. We achieved here a modest classification performance of 68.4% with respect to palmar grasp vs hand open (chance level 50%).

Risk of venous thromboembolism during rehabilitation of patients with spinal cord injury.

BACKGROUND: Patients with spinal cord injury (SCI) are at risk of thrombosis and bleeding. Data on the risks during rehabilitation are inconsistent, and thromboprophylactic strategies are heterogeneous. We aimed to evaluate the thrombotic risk and bleeding events of SCI patients during rehabilitation. METHODS: We retrospectively collected hospital record data of 263 consecutive SCI patients admitted at a rehabilitation clinic. 78 patients with acute venous thromboembolism (VTE) at the primary center, without acute trauma or lower extremity paresis, less than one month rehabilitation, or reasons for long-term therapeutic anticoagulation, were excluded. All patients received pharmacologic thromboprophylaxis throughout rehabilitation. Primary endpoint was objectively diagnosed VTE; secondary endpoint was bleeding. RESULTS: Of 185 patients, 162 (88%) were men; mean age was 47.8 years. 94 patients were tetraplegic, 91 paraplegic. During a mean (±SD) time of 5.1±2.1 months, VTE was diagnosed in 8 patients. After excluding five patients with VTE detected within 2 days after admission, the probability of developing VTE after 6 months of rehabilitation was 2% (95% CI 0-4.4%). Only high D-Dimer upon admission was associated with risk of VTE (adjusted HR 2.3, 95% CI 1.4-4.1). Of 24 bleedings, 14 (64%) occurred at the heparin injection site. Two patients had major bleeding and five had clinically relevant non major bleeding. CONCLUSION: SCI patients are at risk of VTE and bleeding during rehabilitation. Strategies need to be developed to identify these patients in order to initiate adequate anticoagulation. Direct oral anticoagulants, which have a favourable risk-benefit profile and are convenient, should be explored.

Outcome of type C (AO) distal humeral fractures: follow-up of 22 patients with bicolumnar plating osteosynthesis.

BACKGROUND: In the last 40 years, 220 patients with type C distal humeral fractures (AO13-C1-3) were treated at our hospital operatively. Aim of this study is to present results of patients treated by dual plating osteosynthesis in the last decade and to compare them with our previous series (A-C). MATERIALS AND METHODS: From 1999 to 2008, 48 distal humeral fractures were treated operatively by perpendicular dual plating osteosynthesis. Twenty-two patients (mean age 43.5 years) were available for follow-up. These patients were allocated on the basis of retrospective evaluation, exploration of their medical history, x-rays based on the AO-classification, and functional outcome using CASSEBAUM, JUPITER, and Quick-DASH (Disabilities of the Arm, Shoulder and Hand) scores. RESULTS: The dominant side was affecting in 42.9%. Transolecranon approach was chosen in 86.4%. Good/excellent results were found in 86.4% (CASSEBAUM) and 81.8% (JUPITER). Mean Quick-DASH was 36.1 ± 28.4. Mean range of motion (ROM) was 0/10.9°/128.2°. Mean hospitalization time was 12.9 days, 22.7% were polytrauma patients. Early mobilization was possible in 81.8%. CONCLUSION: Early mobilization was possible in the majority of cases, which may be a prerequisite for satisfying functional results. Using new locking plates, early mobilization could be maintained even in an aging population.

Lipid peroxidation product 4-hydroxynonenal as factor of oxidative homeostasis supporting bone regeneration with bioactive glasses.

Bone regeneration is a process of vital importance since fractures of long bones and large joints have a highly deleterious impact on both, individuals and society. Numerous attempts have been undertaken to alleviate this severe medical and social problem by development of novel bioactive materials, among which bioactive glass is the most attractive because of its osteoconductive and osteostimulative properties. Since lipid peroxidation is an important component of systematic stress response in patients with traumatic brain injuries and bone fractures, studies have been undertaken of the molecular mechanisms of the involvement of 4-hydroxynonenal (HNE), an end product of lipid peroxidation, in cellular growth regulation. We found that HNE generated in bone cells grown in vitro on the surfaces of bioactive glasses 45S5 and 13-93. This raises an interesting possibility of combined action of HNE and ionic bioglass dissolution products in enhanced osteogenesis probably through a mitogen-activated protein kinase (MAPK) pathway. While the proposed mechanism still has to be elucidated, the finding of HNE generation on bioglass offers a new interpretation of the osteoinducting mechanisms of bioglass and suggests the possibility of tissue engineering based on manipulations of oxidative homeostasis.

The influence of 4-hydroxy-2-nonenal on proliferation, differentiation and apoptosis of human osteosarcoma cells.

The product of lipid peroxidation, 4-hydroxy-2-nonenal (HNE) is known to cause cell death at high concentrations, while at lower concentrations it can influence cell proliferation and differentiation. In our experiments we used human osteosarcoma cells (HOS), to test the influence of HNE on cell proliferation, differentiation and induction of apoptosis. Apoptosis induction was estimated by TiterTACS TUNEL test. The cells were in parallel counted and the DAPI staining method was used to distinguish between apoptotic and necrotic cells as well as to define the proportion of cells in mitosis. To test the influence of HNE on HOS cell differentiation, cells were treated every second day with HNE. After 10 days, the cells were stained for alkaline phosphatase, a marker for osteoblast differentiation. Cell growth inhibition was caused by supraphysiological concentrations of 10 or 100 microM HNE, while apoptosis was induced with supraphysiological as well as by the physiological amount of the aldehyde (1 microM). Necrosis appeared when cells were treated with 10 or 100 microM, but not with 1 microM HNE. The proportion of cells in mitosis gradually declined with increased HNE concentration. Multiple exposures of HOS cells to 10 microM HNE prevented HOS cell differentiation. These results indicated that HNE inhibits proliferation and differentiation of HOS cells in the same concentration dependent manner as it causes apoptosis. We thus assume that HNE might be one of the important signaling molecules regulating the growth of the human osteosarcoma cells.