Computation of the Spatial Distribution of Charge-Carrier Density in Disordered Media

The space- and temperature-dependent electron distribution n(r,T) determines optoelectronic properties of disordered semiconductors. It is a challenging task to get access to n(r,T) in random potentials, while avoiding the time-consuming numerical solution of the Schrödinger equation. We present several numerical techniques targeted to fulfill this task. For a degenerate system with Fermi statistics, a numerical approach based on a matrix inversion and one based on a system of linear equations are developed. For a non-degenerate system with Boltzmann statistics, a numerical technique based on a universal low-pass filter and one based on random wave functions are introduced. The high accuracy of the approximate calculations are checked by comparison with the exact quantum-mechanical solutions.

Trauma-associated extracellular histones mediate inflammation via a MYD88-IRAK1-ERK signaling axis and induce lytic cell death in human adipocytes

Despite advances in the treatment and care of severe physical injuries, trauma remains one of the main reasons for disability-adjusted life years worldwide. Trauma patients often suffer from disturbances in energy utilization and metabolic dysfunction, including hyperglycemia and increased insulin resistance. White adipose tissue plays an essential role in the regulation of energy homeostasis and is frequently implicated in traumatic injury due to its ubiquitous body distribution but remains poorly studied. Initial triggers of the trauma response are mainly damage-associated molecular patterns (DAMPs) such as histones. We hypothesized that DAMP-induced adipose tissue inflammation contributes to metabolic dysfunction in trauma patients. Therefore, we investigated whether histone release during traumatic injury affects adipose tissue. Making use of a murine polytrauma model with hemorrhagic shock, we found increased serum levels of histones accompanied by an inflammatory response in white adipose tissue. In vitro, extracellular histones induced an inflammatory response in human adipocytes. On the molecular level, this inflammatory response was mediated via a MYD88-IRAK1-ERK signaling axis as demonstrated by pharmacological and genetic inhibition. Histones also induced lytic cell death executed independently of caspases and RIPK1 activity. Importantly, we detected increased histone levels in the bloodstream of patients after polytrauma. Such patients might benefit from a therapy consisting of activated protein C and the FDA-approved ERK inhibitor trametinib, as this combination effectively prevented histone-mediated effects on both, inflammatory gene activation and cell death in adipocytes. Preventing adipose tissue inflammation and adipocyte death in patients with polytrauma could help minimize posttraumatic metabolic dysfunction.

[Augmentation techniques for the treatment of osteoporosis-associated fractures of the extremities]

The current demographic development is leading to an increasing number of cases of osteoporosis-related fractures. Affected individuals are typically part of a vulnerable, predominantly geriatric patient group with limited physical resources. Additionally, the pathophysiological characteristics of osteoporotic bones with reduced bone quality and quantity, pose a significant challenge to the osteosynthesis techniques used. Achieving rapid postoperative mobilization and stable weight-bearing osteosynthesis to prevent postoperative medical complications are the main goals of the surgical management. In recent years augmentation techniques have gained in importance in the treatment of osteoporosis-related fractures by significantly enhancing the stability of osteosyntheses and reducing mechanical complication rates. The main options available are polymethyl methacrylate (PMMA) augmentation and various bioresorbable bone substitute materials with different properties. Implant augmentations can be applied at various locations in the extremity bones and standardized procedures are now available, such as for the proximal humerus and femur. When used correctly, low complication rates and promising clinical outcomes are observed. This article aims to provide an overview of available techniques and applications based on the current literature. Guidelines and substantial scientific evidence are still limited.

Primary Radial Nerve Lesions in Humerus Shaft Fractures-Revision or Wait and See

Background: This study investigates the surgical state-of-the-art procedure for humeral shaft fractures with primary radial nerve palsy based on its own case series in relation to the current and established literature. Methods: Retrospective review of treated cases between January 2018 and December 2022 describing radial nerve palsy after humerus shaft fractures, radiological fracture classification, intraoperative findings, surgical procedure, patient follow-up and functional outcome. Results: A total of 804 patients (463 women and 341 men) with humerus shaft fractures were identified. A total of 33 patients showed symptomatic lesions of the radial nerve (4.1%). The primary lesion was identified in 17 patients (2.1%). A broad and inhomogeneous distribution of fractures according to the AO classification was found. According to the operative reports, the distraction of the radial nerve was found eleven times, bony interposed three times and soft tissue constricted/compressed three times. In every case the radial nerve was surgically explored, there was no case of complete traumatic nerve transection. Four intramedullary nails and thirteen locking plates were used for osteosynthesis. Complete recovery of nerve function was seen in 12 cases within 1 to 36 months. Three patients still showed mild hypesthesia in the thumb area after 18 months. Two patients were lost during follow-up. Conclusions: With this study, we support the strategy of early nerve exploration and plate osteosynthesis in humeral fractures with primary radial nerve palsy when there is a clear indication for surgical fracture stabilisation. In addition, early exploration appears sensible in the case of palsies in open fractures and secondary palsy following surgery without nerve exposure as well as in the case of diagnostically recognisable nerve damage. Late nerve exploration is recommended if there are no definite signs of recovery after 6 months. An initial wait-and-see strategy with clinical observation seems reasonable for primary radial nerve palsies without indication for surgical fracture stabilisation.

Isotachophoresis with Oscillating Sample Zones to Control the Spatial Overlap of Co-focused Species

Microfluidic isotachophoresis (ITP) is a powerful technique that can significantly increase the reaction rate of homogeneous chemical reactions by cofocusing reactants in a narrow sample zone. Correspondingly, ITP has been utilized to reduce the reaction time in various bioanalytical assays. However, in conventional ITP, it is hardly possible to control the reaction rate in real time, i.e., speeding up or slowing down a reaction on demand. Here, we experimentally demonstrate a new mode of ITP that allows the spatial overlap of two ITP zones to be precisely controlled over time, which is a crucial first step toward controlling reaction rates. Two nonreactive samples are initially focused and separated by a spacer using a DC electric field. By superimposing an oscillating field component with sufficiently high amplitude on the DC field, the spatial overlap of their concentration profiles is temporarily increased due to electromigration dispersion. The time-average of this overlap can be precisely controlled by varying the frequency and amplitude of the oscillation. We suggest that this scheme can be transferred to chemical reactions between ionic species with sufficiently different electrophoretic mobilities. Tuning the parameters of the oscillatory electric field should allow direct control of the corresponding reaction rate.

3D C-arm navigated acromioclavicular joint stabilization

INTRODUCTION

Surgical treatment options for acromioclavicular joint separations are varied. Frequently, suspension devices (SD) are inserted for stabilization under arthroscopic view. This study investigates the feasibility and accuracy of three-dimensional (3D) digital-volume-tomography (DVT) C-arm navigated implantation with regard to the general trend toward increasingly minimally invasive procedures.

MATERIALS AND METHODS

The implantation of a TightRope® suture button system (SD) via a navigated vertical drill channel through the clavicle and coracoid was investigated in 10 synthetic shoulder models with a mobile isocentric C-arm image intensifier setup in the usual parasagittal position. Thereby, in addition the placement of an additive horizontal suture cerclage via a navigated drill channel through the acromion was assessed.

RESULTS

All vertical drill channels in the Coracoclavicular (CC) direction could be placed in a line centrally through the clavicle and the coracoid base. The horizontal drill channels in the Acromioclavicular (AC) direction ran strictly in the acromion, without affecting the AC joint or lateral clavicle. All SD could be well inserted and anchored. After tensioning and knotting of the system, the application of the horizontal AC cerclage was easily possible. The image quality was good and all relevant structures could be assessed well.

CONCLUSION

Intraoperative 3D DVT imaging of the shoulder joint using a mobile isocentric C-arm in the usual parasagittal position to the patient is possible. Likewise, DVT navigated SD implantation at the AC joint in CC and AC direction on a synthetic shoulder model. By combining both methods, the application in vivo could be possible. Further clinical studies on feasibility and comparison with established methods should be performed.

Sacroiliac versus transiliac-transsacral screw osteosynthesis in osteoporotic pelvic fractures: a biomechanical comparison

INTRODUCTION

Pelvic fractures were often associated with high-energy trauma in young patients, but data show a significant increase in osteoporotic pelvic fractures in old age due to the progressive demographic change. There is an ongoing discussion about the best fixation techniques, which are ranging from lumbopelvic fixation to sacral bars or long transiliac-transsacral (TITS) screws. This study analyzes TITS screw osteosynthesis and sacroiliac screw osteosynthesis (SI), according to biomechanical criteria of fracture stability in osteoporotic human pelvic cadavers ex vivo.

METHODS

Ten osteoporotic cadaveric pelvises were randomized into two groups of 5 pelvises each. An FFP-IIc fracture was initially placed unilaterally and subsequently surgically treated with a navigated SI screw or a TITS screw. The fractured side was loaded in a one-leg stance test setup until failure. Interfragmentary movements were assessed by means of optical motion tracking.

RESULTS

No significant difference in axial stiffness were found between the SI and the TITS screws (21.2 ± 4.9 N and 18.4 ± 4.1 N, p = 0.662). However, there was a significantly higher stability of the fracture treatment in the cohort with TITS-screws for gap angle, flexion, vertical movement and overall stability. The most significant difference in the cycle interval was between 6.000 and 10.000 for the gap angle (1.62 ± 0.25° versus 4.60 ± 0.65°, p = 0.0001), for flexion (4.15 ± 0.39 mm versus 7.60 ± 0.81 mm, p = 0.0016), interval 11.000-15.000 for vertical shear movement (7.34 ± 0.51 mm versus 13.99 ± 0.97 mm, p < 0.0001) and total displacement (8.28 ± 0.66 mm versus 15.53 ± 1.07 mm, p < 0.0001) for the TITS and the SI screws.

CONCLUSIONS

The results of this biomechanical study suggest a clear trend towards greater fracture stability of the TITS screw with significantly reduced interfragmentary movement. The application of a TITS screw for the treatment of the osteoporotic pelvic ring fracture may be prioritized to ensure the best possible patient care.

Orthogeriatric care-outcome of different fragility fractures

INTRODUCTION

Fragility fractures (FF) are associated with increased morbidity and mortality and reflect a dramatic turning point in the life of older adults. The scientific discourse is dominated by proximal femoral fractures, but FF affect multiple parts of the body and often precede hip fractures. Orthogeriatric co-management has multiple shown to improve patient's outcome. We hypothesize that all geriatric patients with FF benefit from orthogeriatric co-management.

MATERIALS AND METHODS

We retrospectively evaluated all patients over 70 years with FF (hip joint, periprosthetic, spine, pelvic ring, and humerus) of our geriatric trauma center for the years 2019-2021, who received orthogeriatric co-management. Demographic data, fracture type, complications, discharge modality and in-hospital mortality were recorded. For patients transferred to geriatrics, the Barthel Index (BI) and the discharge modality were recorded. Primary outcome parameters were discharge modality and BI difference. Secondary outcome parameters were complication rates and in-hospital mortality. Logistic regression analysis was performed.

RESULTS

555 patients (83.8 ± 6.5 years, 182 males, 373 females) were evaluated. 245 (44.1%) patients were referred to geriatrics for further orthogeriatric treatment. Positive predictors were age, surgery, and a high Charlson Comorbidity Index. The overall in-hospital mortality was 8.6% (n = 48) (5.8% (n = 32) during acute trauma care and 6.5% (n = 16) during stay in geriatrics). The mortality rate of nursing home residents was significantly higher compared to patients living at home (10.4% vs. 5.6%). The rate of non-surgical complications was 44.5%. 26.9% of patients living at home were discharged to a nursing home, while 51.3% were able to return home. The risk of admission to a nursing home was reduced for thoracolumbar fractures (OR = 0.22) and increased markedly for periprosthetic fractures (OR = 3.95). During orthogeriatric treatment, all fractures showed a significant increase in BI. Patients living at home benefited more than nursing home residents (20.5 ± 19.5 vs. 8.7 ± 18.0 points). The chance of a BI increase (> 19 points) was increased for hip and pelvic ring fractures. Devastating results showed patients with dementia. In comparison, mentally healthy patients had a 4.5-fold increased chance of increasing their BI (> 19 points).

CONCLUSIONS

Presented data shows that all patients with FF are at high risk for complications and could benefit from standardized orthogeriatric management. Modern patient care requires a holistic orthogeriatric approach to improve patient's outcome.

Influence of Weight Bearing on Postoperative Complications after Surgical Treatment of the Lower Extremity

PURPOSE

In order to prevent implant failure and secondary fracture dislocation, it is often recommended that patients perform partial weight-bearing after surgery of the lower extremity. Previous examinations showed that patients are often not able to follow these instructions. In this study, patients who had undergone surgery of the lower extremity were studied in order to analyze whether incorrect loading influenced the number and severity of complications.

METHODS

Fifty-one patients were equipped with electronic shoe insoles, which measure loading and other parameters. The measurement period was 24 to 102 hours. Median duration of follow-up was 490 days. The primary outcome parameter was postoperative complications leading to revision surgery. Statistical analysis was performed using the chi-square and Fisher exact tests with significance set at a p < 0.05.

RESULTS

Seven out of fifty-one patients had postoperative complications. Four wound complications, one implant failure, chronic instability after fracture of the tibia, and one implant loosening of a hip prosthesis were recorded. In total, 26 of 39 patients were not able to follow the postoperative instructions. Five of the twenty-six patients with difficulties in partial weight-bearing suffered a postoperative complication. In comparison, only 2 of the other 25 patients were affected. There was no statistically significant correlation between high weight-bearing and occurrence of complications (p = 0.29).

CONCLUSION

Most of the patients were unable to follow the surgeon's instructions for partial weight-bearing. Excessive loading did not seem to influence the number and severity of postoperative complications, especially regarding implant failure. Therefore, we should continue with measurements and reevaluate the "partial weight-bearing doctrine".

[Keeping the big picture in Terror-MASCAL-A new hospital concept]

BACKGROUND

Two key positions have been defined for the in-house management of patients in the context of a terrorism-related mass casualty incident (Terror-MASCAL). The senior triage coordinator (LArS) categorizes the injured according to injury severity using algorithms. The central operational and medical coordinator (ZONK) disposes and prioritizes the injured for treatment measures, considering the injury severity and the available treatment capacities. The dynamics and complexity of a Terror-MASCAL combined with the high number of patients requires comprehensible documentation.

MATERIAL AND METHODS

The evaluation of an incident exercise of a Terror-MASCAL revealed deficits in its documentation. Based on the deficits identified, requirements have been defined. The article presents the management and documentation aids of a German national trauma center.

RESULTS

The hospital with its currently available resources is abstractly represented via the Trauma Tactics Board (TTB). Patients with their individual injuries are represented by identification cards on the TTB. The ZONK can prioritize and dispose further treatment based on the information about the available resources and the patient-specific injury pattern. The patient registry continues to document the patient's other medical findings. Important external and internal information is noted in an event register. The entire documentation process on the TTB is documented by camera.

CONCLUSION

Documentation aids are required to fulfil the core tasks of the ZONK. By using the documentation aids, a hospital can prepare for a Terror-MASCAL within a short time. Lack of daily practical application of the documentation aids should be compensated for by regular practice and interdisciplinary exchange of experience.

Clinical performance of the Femoral Neck System within 1 year in 125 patients with acute femoral neck fractures, a prospective observational case series

INTRODUCTION

Osteosynthesis of femoral neck fractures (FNFs) is an important treatment option, especially for younger patients. We aimed to assess the rate of early implant-related complications in FNF osteosynthesis using the Femoral Neck System (FNS).

PATIENTS AND METHODS

Consecutive patients diagnosed with displaced or nondisplaced FNFs were treated with FNS in this prospective, observational, multicenter investigation. Patients were followed up for minimally 3 months and up to 12 months if radiologic bone union and no pain was not achieved beforehand. Predefined treatment-related adverse events (AEs, defined as implant failure, loss of reduction, iatrogenic fractures, deep infection, and surgical revision), radiologic bone union, and patient-reported Harris hip score (HHS) and EQ-5D-5L index score were assessed.

RESULTS

One hundred and twenty-five patients were included in the study. Thirty-eight (30.4%) fractures were displaced (Garden III and IV), and 37 (29.6%) were vertical fractures (Pauwels type III). Predefined treatment-related AE rate at 3 months was 8 patients, 6.4% (95% CI, 2.8-12.2), and at 12 months, 11 patients, 8.8% (95% CI, 4.5-15.2). Cumulative incidences of bone union were 68% at 3 months, 90% at 6 months, and 98% at 12 months. The mean changes of HHS and EQ-5D-5L index score between preinjury and at 12 months were -7.5 (95% CI, [ - 21.1] to [6.2]) and  - 0.03 (95% CI, [ - 0.21] to [0.15]), respectively; neither were statistically significant.

CONCLUSION

The current study on osteosynthesis of FNFs with the FNS resulted in treatment-related complication rates of 6.4% (95% CI, 2.8-12.2) at 3 months and 8.8% (95% CI, 4.5-15.2) at 12 months. On average, patients returned to preinjury function and quality of life. The current study may also indicate that the conventional wisdom of treating stable FNF in patients aged between 60 and 80 years with osteosynthesis may need to be reconsidered.

REGISTRATION

The study is registered with ClinicalTrials.gov (registration number: NCT02422355).

Supporting SURgery with GEriatric Co-Management and AI (SURGE-Ahead): A study protocol for the development of a digital geriatrician

INTRODUCTION

Geriatric co-management is known to improve treatment of older adults in various clinical settings, however, widespread application of the concept is limited due to restricted resources. Digitalization may offer options to overcome these shortages by providing structured, relevant information and decision support tools for medical professionals. We present the SURGE-Ahead project (Supporting SURgery with GEriatric co-management and Artificial Intelligence) addressing this challenge.

METHODS

A digital application with a dashboard-style user interface will be developed, displaying 1) evidence-based recommendations for geriatric co-management and 2) artificial intelligence-enhanced suggestions for continuity of care (COC) decisions. The development and implementation of the SURGE-Ahead application (SAA) will follow the Medical research council framework for complex medical interventions. In the development phase a minimum geriatric data set (MGDS) will be defined that combines parametrized information from the hospital information system with a concise assessment battery and sensor data. Two literature reviews will be conducted to create an evidence base for co-management and COC suggestions that will be used to display guideline-compliant recommendations. Principles of machine learning will be used for further data processing and COC proposals for the postoperative course. In an observational and AI-development study, data will be collected in three surgical departments of a University Hospital (trauma surgery, general and visceral surgery, urology) for AI-training, feasibility testing of the MGDS and identification of co-management needs. Usability will be tested in a workshop with potential users. During a subsequent project phase, the SAA will be tested and evaluated in clinical routine, allowing its further improvement through an iterative process.

DISCUSSION

The outline offers insights into a novel and comprehensive project that combines geriatric co-management with digital support tools to improve inpatient surgical care and continuity of care of older adults.

TRIAL REGISTRATION

German clinical trials registry (Deutsches Register für klinische Studien, DRKS00030684), registered on 21st November 2022.

Neutrophil-derived catecholamines mediate negative stress effects on bone

Mental traumatization is associated with long-bone growth retardation, osteoporosis and increased fracture risk. We revealed earlier that mental trauma disturbs cartilage-to-bone transition during bone growth and repair in mice. Trauma increased tyrosine hydroxylase-expressing neutrophils in bone marrow and fracture callus. Here we show that tyrosine hydroxylase expression in the fracture hematoma of patients correlates positively with acknowledged stress, depression, and pain scores as well as individual ratings of healing-impairment and pain-perception post-fracture. Moreover, mice lacking tyrosine hydroxylase in myeloid cells are protected from chronic psychosocial stress-induced disturbance of bone growth and healing. Chondrocyte-specific β2-adrenoceptor-deficient mice are also protected from stress-induced bone growth retardation. In summary, our preclinical data identify locally secreted catecholamines in concert with β2-adrenoceptor signalling in chondrocytes as mediators of negative stress effects on bone growth and repair. Given our clinical data, these mechanistic insights seem to be of strong translational relevance.

Is new always better: comparison of the femoral neck system and the dynamic hip screw in the treatment of femoral neck fractures

BACKGROUND

Hip fractures in the elderly population are common and the number of patients is rising. For young and geriatric patients with undisplaced fractures osteosynthesis is the primary type of treatment. The dynamic hip screw (DHS) is around for many years and proved its value especially in displaced fractures. Since 2018 the femoral neck system (FNS) is available as an alternative showing promising biomechanical results. The aim of this study is to evaluate clinical results of the FNS and compare it to the DHS.

MATERIALS AND METHODS

Patients older than 18 years with Garden I-IV fractures that were treated with osteosynthesis in a level 1 trauma center were included in the study. Between January 2015 and March 2021, all patients treated with FNS (1-hole plate, DePuy-Synthes, Zuchwil, Switzerland) or DHS (2-hole plate, DePuy-Synthes, Zuchwil, Switzerland) for proximal femur fractures were included in the study. Closed reduction was achieved using a traction table. All operations were carried out by experienced orthopedic trauma surgeons. Primary outcome measures were rate of implant failure (cut out) and surgical complications (hematoma, infection). Secondary outcome measures were Hb-difference, length of hospital stay and mortality.

RESULTS

Overall, 221 patients were included in the study. 113 were treated with FNS, 108 with DHS. Mean age was 69 ± 14 years. There were 17.2% Garden I, 47.5% Garden II, 26.7% Garden III and 8.6% Garden IV fractures. No difference between the groups for age, body mass index (BMI), Charlson comorbidity index (CCI), time to surgery, Pauwels and Garden classification, rate of optimal blade position or tip apex distance was found. FNS showed lower pre- to postoperative Hb-difference (1.4 ± 1.1 g/l vs. 2.1 ± 1.4 g/l; p < 0.05), shorter operating time (36.3 ± 11.6 min vs. 54.7 ± 17.4 min; p < 0.05) and hospital stay (8.8 ± 4.3 d vs. 11.2 ± 6.8 d; p < 0.05). Surgical complications (FNS 13.3% vs. DHS 18.4%, p > 0.05), rate of cut out (FNS 12.4% vs. DHS 10.2%, p > 0.05) and mortality (FNS 3.5%; DHS 0.9%; p > 0.05) showed no difference between the groups. Logistic regression showed that poor blade position was the only significant predictor for cut out and increased the risk by factor 7. Implant related infection (n = 3) and hematoma/seroma (n = 6) that needed revision was only seen in DHS group.

CONCLUSION

FNS proved to be as reliable as DHS in all patients with hip fractures. Not the type of implant but blade positioning is still key to prevent implant failure. Still due to minimal invasive approach implant related infections and postoperative hematomas might have been prevented using the FNS.

Computer-Based Mechanobiological Fracture Healing Model Predicts Non-Union of Surgically Treated Diaphyseal Femur Fractures

As non-unions are still common, a predictive assessment of healing complications could enable immediate intervention before negative impacts for the patient occur. The aim of this pilot study was to predict consolidation with the help of a numerical simulation model. A total of 32 simulations of patients with closed diaphyseal femoral shaft fractures treated by intramedullary nailing (PFNA long, FRN, LFN, and DePuy Synthes) were performed by creating 3D volume models based on biplanar postoperative radiographs. An established fracture healing model, which describes the changes in tissue distribution at the fracture site, was used to predict the individual healing process based on the surgical treatment performed and full weight bearing. The assumed consolidation as well as the bridging dates were retrospectively correlated with the clinical and radiological healing processes. The simulation correctly predicted 23 uncomplicated healing fractures. Three patients showed healing potential according to the simulation, but clinically turned out to be non-unions. Four out of six non-unions were correctly detected as non-unions by the simulation, and two simulations were wrongfully diagnosed as non-unions. Further adjustments of the simulation algorithm for human fracture healing and a larger cohort are necessary. However, these first results show a promising approach towards an individualized prognosis of fracture healing based on biomechanical factors.

Detecting Isotachophoresis Zones Hidden in Noise Using Signal Processing

Lowering the limit of detection in chemical or biochemical analysis is key to extending the application scope of sensing schemes. Usually, this is related to an increased instrumentation effort, which in turn precludes many commercial applications. We demonstrate that the signal-to-noise ratio of isotachophoresis-based microfluidic sensing schemes can be substantially increased merely by postprocessing of recorded signals. This becomes possible by exploiting knowledge about the physics of the underlying measurement process. The implementation of our method is based on microfluidic isotachophoresis and fluorescence detection, for which we take advantage of the physics of electrophoretic sample transport and the structure of noise in the imaging process. We demonstrate that by processing only 200 images, the detectable concentration, compared to the detection from a single image, is already lowered by 2 orders of magnitude without any additional instrumentation effort. Furthermore, we show that the signal-to-noise ratio is proportional to the square root of the number of fluorescence images, which leaves room for further lowering of the detection limit. In the future, our results could be relevant for various applications where the detection of minute sample amounts plays a role.

Road Traffic Accidents, Climbing Frames, or Trampolines: What Harms Children in the 2020s?

Background In the modern Western world, activities and the daily routine of children have changed over time. Detailed analyses of the mechanisms of injuries and current fracture patterns in children are rare. The aim of the study was to elicit and investigate the most dangerous leisure and sporting activities leading to fractures in children today. Materials and methods This is a retrospective study focusing on children that were treated in a level-one trauma center in Germany between 2015 and 2020. All children who were 14 years of age or younger and suffered a traumatic injury treated in our emergency department were included in this study. From the database, mechanisms of injury, type of injury, age, and gender were analyzed. Results The study included 12508 patients, including 7302 males and 5206 females. Among the 10 most common mechanisms of injury were collisions (8.6%), falls (7.7%), injuries while playing (6.1%) or while running or walking (5.9%), soccer (5.9%), bicycle accidents (3.8%), and trampoline falls (3.4%). Road traffic accidents involving passengers or pedestrians caused 3.3% of the injuries but were the most common cause of death. The most common mechanisms of injury causing a fracture were falls, playing soccer, and bicycle accidents. Sorting the mechanisms of injury by the percentage that caused a fracture, the most dangerous activities were falling from heights above 2 meters, skiing and snowboarding, climbing and bouldering, skateboarding, and horseback riding. In the five-year study period, four out of six children died due to road traffic accidents. Conclusion Injured children must be provided with the best quality of care 24/7 in orthopedic trauma departments and have to be kept as a focus in the training of orthopedic trauma surgeons. Road traffic accidents are still the main cause of death in children, but they are overall less common. Falls and sports activities are the most likely to cause a fracture.

Epidemiology, patterns, and mechanisms of pediatric trauma: a review of 12,508 patients

BACKGROUND

Pediatric traumas are common and remain a unique challenge for trauma surgeons. Demographic data provide a crucial source of information to better understand mechanisms and patterns of injury. The aim of this study was to provide this information to improve treatment strategies of potentially preventable morbidity and mortality in children.

MATERIAL AND METHODS

A retrospective review of every pediatric trauma treated in the emergency department (ED) between 2015 and 2019 was performed. Inclusion criteria were the age between 0 and 14 years and admission to the ED after trauma. Demographic data, time of presentation, mechanism of injury and pattern of injury, treatment, and outcome were analyzed. Different injury patterns were assessed in relation to age group, sex, mechanism of injury and treatment.

RESULTS

A total of 12,508 patients were included in this study. All patients were stratified into five age groups: babies under the age of 1 (8.8%), toddlers between 1 and 3 (16.8%), preschool children between 4 and 6 (19.3%), young school children between 7 and 10 (27.1%), and young adolescents between 11 and 14 (27.9%). The predominant sex in all age groups was male. 47.7% of patients were admitted between 4 and 10 pm; 14.8% of the patients arrived between 10 pm and 8 am. Peak months of admissions were May to July. Overall, 2703 fractures, 2924 lacerations and superficial tissue injury, 5151 bruises, 320 joint dislocations, 1284 distortions, 76 burns, and 50 other injuries were treated. Most common mechanisms for fractures were leisure activities, falls, and sports-related activities. Forearm fractures were the most common fractures (39.5%) followed by humerus fractures (14%) and fractures of the hand (12.5%). A total of 700 patients with fractures (25.9%) needed surgery. 8.8% of all patients were hospitalized for at least one day. 4 patients died in the hospital (0.03%).

CONCLUSION

Despite of higher risk, severe injuries in children are rare. Minor injuries and single fractures are common. Treatment should be managed in specialized centers to ensure an interdisciplinary care and fast recovery. Peak times in the late afternoon and evening and summer months should be taken into consideration of personnel planning.

Energy Scales of Compositional Disorder in Alloy Semiconductors

The study of semiconductor alloys is currently experiencing a renaissance. Alloying is often used to tune the material properties desired for device applications. It allows, for instance, to vary in broad ranges the band gaps responsible for the light absorption and light emission spectra of the materials. The price for this tunability is the extra disorder caused by alloying. In this mini-review, we address the features of the unavoidable disorder caused by statistical fluctuations of the alloy composition along the device. Combinations of material parameters responsible for the alloy disorder are revealed, based solely on the physical dimensions of the input parameters. Theoretical estimates for the energy scales of the disorder landscape are given separately for several kinds of alloys desired for applications in modern optoelectronics. Among these are perovskites, transition-metal dichalcogenide monolayers, and organic semiconductor blends. While theoretical estimates for perovskites and inorganic monolayers are compatible with experimental data, such a comparison is rather controversial for organic blends, indicating that more research is needed in the latter case.

No Excess Mortality in Geriatric Patients With Femoral Neck Fractures Due to Shorter Intensive Care Caused by COVID-19

Background

Since March 2020, increasing numbers of hospitalized patients with coronavirus disease-2019 (COVID-19) infections have been registered. The first and the second waves necessitated the extensive restructuring of hospital infrastructure with prioritization of intensive care capacity. Elective surgeries in all surgical disciplines were postponed to preserve intensive care capacity for COVID-19 patients. However, emergency care for trauma patients had to be maintained. Especially, geriatric patients with hip fractures often require intensive care.

This study sought to investigate the possible excess mortality of geriatric patients with femoral neck fractures due to shorter intensive care unit stays because of COVID-19.

Material and methods

All patients over the age of 70 between March 2019 and February 2020 who underwent surgical treatment for femoral neck fractures were included. This cohort (group 1) was compared with all patients over 70 who received surgical treatment for hip fractures during the period of the pandemic between March 2020 and February 2021 with attention to potential excess mortality due to low intensive care capacity (group 2). Demographic data, American Society of Anesthesiologists (ASA) score, surgical modality, ICU stay, complications, and mortality were analyzed and compared.

Results

A total of 356 patients with 178 in each cohort with a mean age of 82.7 in group 1 and 84.8 in group 2 (p<0.05) were included. No significant difference was seen in sex and ASA scores. During the pandemic, patients with hip fractures had a significantly shorter stay in ICU (0.4 ± 0.9 vs 1.2 ± 2.8 days; p<0.05), shorter time to surgery (29.9 ± 8.2 vs 16.8 ± 5.3 h; p<0.05) and operations were significantly more often performed out-of-hour (4 pm-12 am 47.8% vs 56.7%; 12 am-8 am 7.9% vs 13.5%, p<0.05). Interestingly, mortality was lower during the pandemic, but the difference did not reach significance (6.7% vs 12.4%, p=0.102).

Conclusion

During the pandemic, ICU capacity was reserved for COVID patients. Due to a change in the law of the Joint Federal Committee with effect from January 1, 2021, all patients with proximal femur fractures had to be operated on within the first 24 hours, which is why a significantly shorter time to surgery was observed during the pandemic period. As a consequence, a lower mortality rate was observed, although no significance could be reached.

ESIN in femur fractures in children under 3: is it safe?

BACKGROUND

Pediatric femur fractures are a major trauma in children. Different treatment algorithms have been developed but indications for surgical treatment, especially in very young patients, are still controversial. Literature recommends surgical stabilization with elastic-stable intramedullary nailing (ESIN) starting at the age of 3 and non-operative treatment in younger patients. This study sought to present the outcome of patients younger than 3 years of age treated with ESIN for femur fractures.

MATERIALS AND METHODS

Inclusion criteria were patients younger than 3 treated with ESIN in femur fractures. Patient demographics, fracture characteristics, mechanism of injury, outcomes and complications were recorded using charts and X-rays. Primary outcome measures were time to mobility, fracture consolidation and surgical-related complications.

RESULTS

Between 2010 and 2020, 159 patients were treated with ESIN in femur fractures in our institution. A total of 30 patients met the criteria. The mean age was 2.1 ± 0.7 years (13 months-2.9 years). Most common mechanism was fall from standing height (60%). Other mechanisms were motor vehicle accidents as a pedestrian (10%) or as a passenger (10%) as well as direct blow trauma (20%). Femoral shaft fracture was the most common injury (80%). 5 subtrochanteric and one distal metaphyseal femur fractures were found. Mean length of stay was 2.0 ± 1.3 days. Radiographic controls were performed on day 1, 14 and 6 weeks after surgery if not otherwise specified or if complications occurred. 4.6 ± 1.2 (n 2-7) X-rays were performed on average after surgery. First radiographic consolidation signs were seen after 2.4 ± 0.6 weeks. Only one child showed surgical-related complication with a leg length discrepancy of 1 cm. In 10% of the patients, shortening after surgery of 1.7 ± 1.4 mm (0.3-3.1 mm) occurred. One child initially treated with traction therapy showed skin irritations and was operated with ESIN. No non-union or ESIN-related complications were found. Mean follow-up was 5.1 ± 4.4 months (4-24 months). First independent mobilization was seen at an average of 3.4 ± 1.1 weeks (2-6 weeks) after surgery. Implant removal was performed after 3.2 ± 1.3 months (2-8 months). No refracture after implant removal occurred.

CONCLUSION

Early results with ESIN show a reasonable and safe treatment option for femur fractures in toddlers and young children under the age of 3 with easy postoperative care, fast fracture union and early independent mobilization.

How Safe and Time Consuming is the Surgical Training of Young Orthopaedic Surgeons? A Retrospective Analysis of Proximal Femur Fractures

BACKGROUND

Fractures of the proximal femur in the elderly population are rising. Teaching the appropriate surgical treatment of these fractures is of paramount importance. The aim of the study was to evaluate differences in outcome of surgical procedures between supervised trainees and senior surgeons.

OBJECTIVE

Are there more surgical complications, poorer quality or an increased operating time if the procedure (in this case: fixation of proximal femur fractures) is performed by trainees under supervision in comparison to experienced surgeons.

MATERIAL AND METHODS

All patients treated with the proximal femur nail antirotation (PFNA) between 2015 and 2016 at a level one trauma centre were included in this study. The retrospective review of the 299 patients compared supervised surgical trainees and senior surgeons. Parameters included operating time, tip apex distance, position of the blade, Hb-difference, transfusion rate, surgical complications as well as mortality, and were compared between the groups.

RESULTS

153 of 299 procedures were performed by supervised surgical trainees. In comparison to senior surgeons, there was no significant difference in operating time (WA 54.48 min; OA 60.47 min; p > 0,05), Hb-difference (WA 2.8 g/dl; OA 2.6 g/dl; p > 0.05), tip-apex distance (WA 21.2 mm; OA 20.5 mm, p = 0.37) or rate of surgical complications. There was no difference in the rate of optimal blade positions between the groups (WA 87.5%; OA 89.0%; p = 0.366). Furthermore, mortality showed no difference between the groups, but was greater in older patients or high ASA grade.

CONCLUSION

Supervised surgical training during treatment of proximal femur fractures shows no increase in operating time, complications or mortality and no difference in quality. With the fast growth of the elderly population, surgical training of fragility fractures should receive more attention in the future.

Mast Cells Trigger Disturbed Bone Healing in Osteoporotic Mice

Mast cells are important tissue-resident sensor and effector immune cells but also play a major role in osteoporosis development. Mast cells are increased in numbers in the bone marrow of postmenopausal osteoporotic patients, and mast cell-deficient mice are protected from ovariectomy (OVX)-induced bone loss. In this study, we showed that mast cell-deficient Mcpt5-Cre R-DTA mice were protected from OVX-induced disturbed fracture healing, indicating a critical role for mast cells in the pathomechanisms of impaired bone repair under estrogen-deficient conditions. We revealed that mast cells trigger the fracture-induced inflammatory response by releasing inflammatory mediators, including interleukin-6, midkine (Mdk), and C-X-C motif chemokine ligand 10 (CXCL10), and promote neutrophil infiltration into the fracture site in OVX mice. Furthermore, mast cells were responsible for reduced osteoblast and increased osteoclast activities in OVX mice callus, as well as increased receptor activator of NF-κB ligand serum levels in OVX mice. Additional in vitro studies with human cells showed that mast cells stimulate osteoclastogenesis by releasing the osteoclastogenic mediators Mdk and CXCL10 in an estrogen-dependent manner, which was mediated via the estrogen receptor alpha on mast cells. In conclusion, mast cells negatively affect the healing of bone fractures under estrogen-deficient conditions. Hence, targeting mast cells might provide a therapeutic strategy to improve disturbed bone repair in postmenopausal osteoporosis. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

A complex intervention to promote prevention of delirium in older adults by targeting caregiver's participation during and after hospital discharge - study protocol of the TRAnsport and DElirium in older people (TRADE) project

Background

Among potentially modifiable risk factors for delirium, transfers between wards, hospitals and other facilities have been mentioned with low evidence. TRADE (TRAnsport and DElirium in older people) was set up to investigate i) the impact of transfer and/or discharge on the onset of delirium in older adults and ii) feasibility and acceptance of a developed complex intervention targeting caregiver’s participation during and after hospital discharge or transfer on cognition and the onset of delirium in older adults.

Methods

The study is designed according to the guidelines of the UK Medical Research Council (MRC) for development and evaluation of complex interventions and comprises two steps: development and feasibility/piloting. The development phase includes i) a multicenter observational prospective cohort study to assess delirium incidence and cognitive decline associated with transfer and discharge, ii) a systematic review of the literature, iii) stakeholder focus group interviews and iv) an expert workshop followed by a Delphi survey. Based on this information, a complex intervention to better and systematically involve family caregivers in discharge and transport was developed. The intervention will be tested in a pilot study using a stepped wedge design with a detailed process and health economic evaluation. The study is conducted at four acute care hospitals in southwest Germany. Primary endpoints are the delirium incidence and cognitive function. Secondary endpoints include prevalence of caregiver companionship, functional decline, cost and cost effectiveness, quality of discharge management and quality of admission management in admitting hospitals or nursing homes. Data will be collected prior to discharge as well as after 3, 7 and 90 days.

Discussion

TRADE will help to evaluate transfer and discharge as a possible risk factor for delirium. In addition, TRADE evaluates the impact and modifiability of caregiver’s participation during patient’s transfer or discharge on delirium incidence and cognitive decline providing the foundation for a confirmatory implementation study.

Trial registration

DRKS (Deutsches Register für klinische Studien) DRKS00017828. Registered on 17th September 2019. Retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02585-0.

Early Results in Non-Displaced Femoral Neck Fractures Using the Femoral Neck System

Introduction

Femoral neck fractures in the elderly are a major event and are rising in incidence over the last decade. Advancing age and numerous comorbidities largely account for high mortality rate and require geriatric expertise. Treatment options are total hip arthroplasty (THA), hemiarthroplasty (HA) or osteosynthesis. Literature suggests THA or HA for better outcomes, although no clear guidelines exist.

Material and methods

A retrospective chart review was performed of 63 patients (80 ± 11 years; 32 women, 31 men) with Garden one femoral neck fractures treated between June 2018 and June 2020 with either HA or internal fixation with the Femoral Neck System (FNS). Primary outcome measures were surgical and non-surgical complication rates and best achievable mobilization during the hospital stay.

Results

Thirty four patients were treated with HA, and 29 with the FNS. Mobilization was measured using the Charité Mobility Index (CHARMI). No difference between age, ASA, CCI or preoperative CHARMI was found. The CHARMI was significantly lower in the HA group. No difference in surgical complications was found. The HA cohort showed more non-surgical complications, a longer ICU stay and more blood transfusions. Hospitalization was significant longer in the HA than the FNS cohort (15.1 ± 5.1 vs 9.8 ± 3.8 days). Radiographic controls were performed after 6 and 12 weeks. The FNS group showed a mean shortening of 3.3 mm. 4 of 21 patient had shortening >5 mm. 20 of 21 patients showed radiographic signs of bone healing after 3 months.

Conclusion

Early results with the FNS show faster recovery than patient with hemiarthroplasty. Internal fixation with the FNS may be an option in non-displaced femoral neck fractures. Further studies should be performed to better evaluate the FNS compared to traditional internal fixation methods and arthroplasty.

Accuracy of screw stabilization of the dorsal pelvic ring using a hybrid operating room: 5 Year experience in a level 1 trauma center

INTRODUCTION

Accuracy for screw placement in the dorsal pelvic ring can be enhanced using intraoperative 3D navigation. Advances in intraoperative imaging lead to benefits for pelvic surgery. New c-arms are equipped with flat panel detectors, which have a larger detector and assure higher image quality with accompanying dose reduction. A hybrid OR is defined by a fixed imaging system in an operating room providing the benefit of the surgical environment in combination with advanced intraoperative imaging. Aim of our investigation was to analyze the accuracy of navigated sacroiliac (SI) and transsacral transiliac (TSTI) screws in the dorsal pelvic ring, which were implanted with a hybrid OR in the first five years of use.

MATERIAL AND METHODS

All percutaneous SI or TSTI screws implanted in the hybrid OR using intraoperative navigation in the first 5 years of utilization (between June 2012 to June 2017) were included. Intraoperative 3D-scans and postoperative computed tomography were examined for screw perforation.

RESULTS

210 SI and TSTI screws were implanted in 187 patients using intraoperative navigation in the hybrid-OR. 90.6 % of SI screws showed no cortical perforation. 6,3 % had a grade 1, 2.4 % a grade 2 and 0.8 % a grade 3 perforation. In 80.7 % of TSTI screws no perforation and in 13.3 % a grade 1 perforation was detected. 3.6 % showed a grade 2 and 2.4 % a grade 3 perforation. No significant difference between both screw types regarding the grade of cortical perforation could be seen. No significant relation between perforation rate and year of operation could be detected.

CONCLUSION

Intraoperative navigation in a hybrid OR ensures a high accuracy for SI screws. Due to the large field of view and high image quality TSTI screws can be safely implanted in S1 and S2. Utilization of a hybrid-OR is accompanied with a steep learning curve.

[Surgical treatment strategies and their radiological potential for correction of proximal radius fractures in children and adolescents]

BACKGROUND AND OBJECTIVE

The isolated proximal radius fracture in children is a quite rare injury. In difference to adults a conservative treatment is often possible. But in case of increasing dislocation the indication for surgery is given. Options for an operative treatment are "closed reduction", "percutaneous reduction", "intramedullary nailing", "open reduction" with and without fixation. Aim of this study is to compare these procedures with each other.

STUDY DESIGN AND METHODS

This was a retrospective investigation and 82 patients who underwent surgery after an isolated proximal radius fracture were included. Fracture types were classified according to the AO (working group for osteosynthesis questions)/OTA (Orthopedic Trauma Association) classification. The preoperative and postoperative degrees of axis deviation were compared and were considered to be a measure of the quality of treatment.

RESULTS

The lowest degree of axis deviation resulted by open reduction and implantation of K‑wires (15,8°) and implantation of headless compression screws (HCS, 16°). Closed reduction without any fixation resulted in 19°, with implantation of an TEN (titan elastic nail) in 20° and the open reduction without any fixation resulted in 21° of axis deviation. No correlation was observed concerning the fracture type and the postoperative axis deviation.

CONCLUSION

The study shows that the postoperative result does not depend on the fracture type (according to the AO/OTA classification) but on the surgical procedure. Despite the good radiological results in open reduction and internal fixation this procedure should be reserved for difficult situations in which less invasive surgical procedures fail, to avoid aseptic bone necrosis.

Complement Factor C5a Inhibits Apoptosis of Neutrophils-A Mechanism in Polytrauma?

Life-threatening polytrauma results in early activation of the complement and apoptotic system, as well as leukocytes, ultimately leading to the clearance of damaged cells. However, little is known about interactions between the complement and apoptotic systems in PMN (polymorphonuclear neutrophils) after multiple injuries. PMN from polytrauma patients and healthy volunteers were obtained and assessed for apoptotic events along the post-traumatic time course. In vitro studies simulated complement activation by the exposure of PMN to C3a or C5a and addressed both the intrinsic and extrinsic apoptotic pathway. Specific blockade of the C5a-receptor 1 (C5aR1) on PMN was evaluated for efficacy to reverse complement-driven alterations. PMN from polytrauma patients exhibited significantly reduced apoptotic rates up to 10 days post trauma compared to healthy controls. Polytrauma-induced resistance was associated with significantly reduced Fas-ligand (FasL) and Fas-receptor (FasR) on PMN and in contrast, significantly enhanced FasL and FasR in serum. Simulation of systemic complement activation revealed for C5a, but not for C3a, a dose-dependent abrogation of PMN apoptosis in both intrinsic and extrinsic pathways. Furthermore, specific blockade of the C5aR1 reversed C5a-induced PMN resistance to apoptosis. The data suggest an important regulatory and putative mechanistic and therapeutic role of the C5a/C5aR1 interaction on PMN apoptosis after polytrauma.

Tunneling current modulation in atomically precise graphene nanoribbon heterojunctions

Lateral heterojunctions of atomically precise graphene nanoribbons (GNRs) hold promise for applications in nanotechnology, yet their charge transport and most of the spectroscopic properties have not been investigated. Here, we synthesize a monolayer of multiple aligned heterojunctions consisting of quasi-metallic and wide-bandgap GNRs, and report characterization by scanning tunneling microscopy, angle-resolved photoemission, Raman spectroscopy, and charge transport. Comprehensive transport measurements as a function of bias and gate voltages, channel length, and temperature reveal that charge transport is dictated by tunneling through the potential barriers formed by wide-bandgap GNR segments. The current-voltage characteristics are in agreement with calculations of tunneling conductance through asymmetric barriers. We fabricate a GNR heterojunctions based sensor and demonstrate greatly improved sensitivity to adsorbates compared to graphene based sensors. This is achieved via modulation of the GNR heterojunction tunneling barriers by adsorbates.

Cement augmentation of the proximal femur nail antirotation: is it safe?

BACKGROUND

Cement augmentation of the proximal femur nail antirotation (PFNA; Fa. DePuy Synthes) showed good biomechanical and clinical results regarding increased stability and functional outcome [Linden et al. in J Orthop Res 24:2230-2237, 2006;Kammerlander et al. in Injury 49:1436-1444, 2018;]. Cement-associated complications are well known in orthopedic procedures like hip arthroplasty, vertebra- and kyphoplasty. This study investigates outcome and safety of augmentation of the proximal femur nail blade.

MATERIALS AND METHODS

The retrospective review of the 299 patients (mean age 80 ± 13 years; 205 women and 94 men) focused on perioperative complications after augmentation which was performed with Traumacem V+ Cement (Fa. DePuy Synthes) in 152 cases. The decision for augmentation of the blade was made by the attending surgeon and based on the factors age, bone quality, and fracture pattern. Primary outcome measures were changes in blood pressure, heart rate or oxygen saturation, and the number of needed vasoactive drugs during augmentation. Secondary outcome measures where the rate of cement leakage into the joint, mechanical failure, and perioperative complications like pulmonary embolism, stroke, or heart attack.

RESULTS

In 152 augmented cases, no leakage of cement into the joint could be detected. No signs of mechanical failure like cut-out of the blade were seen after 6 weeks and 3 months. Also, augmentation did not show a higher rate of mortality or postoperative complications like stroke, heart attack, embolism, or infection. 57 of 152 augmented cases received an intraoperative intervention with vasoactive medication at the time of augmentation either prophylactically or because of a blood pressure fall. Out of the non-augmented cases, 21 of 147 needed vasoactive medication in the second half of the operation. The difference between these groups was significant (p < 0.05). In the cases without an intervention, there was a significant blood pressure fall of about 8 ± 7.4 mmHg during the augmentation (p < 0.001). Still, none of the augmented cases showed a change in heart rate or oxygen saturation.

CONCLUSION

The augmentation of the PFNA blade proved to be a safe procedure. Cement augmentation will not increase postoperative complications or mortality. The risk for leakage of cement into the joint is low and mechanical cut-out might be prevented. The decision for augmentation should be made carefully and always be declared loud and in advance to allow the anesthetist to prepare, because blood pressure changes can occur.

Interaction of proteins with phase boundaries in aqueous two-phase systems under electric fields

The electric-field driven transport of proteins across the liquid-liquid interface in an aqueous two-phase system (ATPS) is studied in a microfluidic device using fluorescence microscopy. An ATPS containing polyethylene glycol (PEG) and dextran is employed, and bovine serum albumin (BSA) and bovine γ-globulins (BγG) are considered as model proteins. It is shown that both proteins, initially in the dextran-rich phase, accumulate at the liquid-liquid interface, preferably close to the three-phase contact line between the two liquid phases and the microchannel wall. It is in these regions where the proteins penetrate into the PEG-rich phase. The transport resistance of the liquid-liquid interface is higher for BγG than for BSA, such that a much larger molar flux of BSA into the PEG phase is observed. This opens up the opportunity of separating different protein species by utilizing differences in the transport resistance at the interface. A mathematical model is developed, accounting for adsorption and desorption processes at the liquid-liquid interface. The underlying theoretical concept is that of an electrostatic potential minimum formed by superposing the applied electric field and the field due to the Donnan potential at the interface. A fit of the model parameters to the experimental data results in good agreement between theory and experiments, thereby corroborating the underlying picture.

Increased Presence of Complement Factors and Mast Cells in Alveolar Bone and Tooth Resorption

Periodontitis is the inflammatory destruction of the tooth-surrounding and -supporting tissue, resulting at worst in tooth loss. Another locally aggressive disease of the oral cavity is tooth resorption (TR). This is associated with the destruction of the dental mineralized tissue. However, the underlying pathomechanisms remain unknown. The complement system, as well as mast cells (MCs), are known to be involved in osteoclastogenesis and bone loss. The complement factors C3 and C5 were previously identified as key players in periodontal disease. Therefore, we hypothesize that complement factors and MCs might play a role in alveolar bone and tooth resorption. To investigate this, we used the cat as a model because of the naturally occurring high prevalence of both these disorders in this species. Teeth, gingiva samples and serum were collected from domestic cats, which had an appointment for dental treatment under anesthesia, as well as from healthy cats. Histological analyses, immunohistochemical staining and the CH-50 and AH-50 assays revealed increased numbers of osteoclasts and MCs, as well as complement activity in cats with TR. Calcifications score in the gingiva was highest in animals that suffer from TR. This indicates that MCs and the complement system are involved in the destruction of the mineralized tissue in this condition.

Systemic and local cardiac inflammation after experimental long bone fracture, traumatic brain injury and combined trauma in mice

Background

Trauma is the leading cause of death and disability worldwide, especially in the young population. Cardiac injuries are an independent predictor for a poor overall outcome after trauma. The aim of the present study was to analyze systemic inflammation as well as local cardiac inflammation after experimental limb-, neuro- and combined trauma in mice.

Methods

Male C57BL/6 mice received either a closed tibia fracture (Fx), isolated traumatic brain injury (TBI) or a combination of both (Fx ​+ ​TBI). Control animals underwent sham procedure. After 6 and 24 ​h, systemic levels of inflammatory mediators were analyzed, respectively. Locally, cardiac inflammation and cardiac structural alterations were investigated in left ventricular tissue of mice 6 and 24 ​h after trauma.

Results

Mice showed enhanced systemic inflammation after combined trauma, which was manifested by increased levels of KC, MCP-1 and G-CSF. Locally, mice exhibited increased expression of inflammatory cytokines (IL-1β, TNF) in heart tissue, which was probably mediated via toll-like receptor (TLR) signaling. Furthermore, mice demonstrated a redistribution of connexin 43 in cardiac tissue, which appeared predominantly after combined trauma. Besides inflammation and structural cardiac alterations, expression of glucose transporter 4 (GLUT4) mRNA was increased in the heart early after TBI and after combination of TBI and limb fracture, indicating a modification of energy metabolism. Early after combination of TBI and tibia fracture, nitrosative stress was increased, manifested by elevation of nitrotyrosine in cardiac tissue. Finally, mice showed a trend of increased systemic levels of cardiac troponin I and heart-fatty acid binding protein (HFABP) after combined trauma, which was associated with a significant decrease of troponin I and HFABP mRNA expression in cardiac tissue after TBI and combination of TBI and limb fracture.

Conclusion

Mice exhibited early cardiac alterations as well as alterations in cardiac glucose transporter expression, indicating a modification of energy metabolism, which might be linked to increased systemic- and local cardiac inflammation after limb-, neuro- and combined trauma. These cardiac alterations might predispose individuals for secondary cardiac damage after trauma that might compromise cardiac function after TBI and long bone fracture.

Translational potential statement

Injuries to the head and extremities frequently occur after severe trauma. In our study, we analyzed the effects of closed tibia fracture, isolated TBI, and the combination of both injuries with regard to the development of post-traumatic secondary cardiac injuries.

Trauma, a Matter of the Heart-Molecular Mechanism of Post-Traumatic Cardiac Dysfunction

Trauma remains a leading global cause of mortality, particularly in the young population. In the United States, approximately 30,000 patients with blunt cardiac trauma were recorded annually. Cardiac damage is a predictor for poor outcome after multiple trauma, with a poor prognosis and prolonged in-hospitalization. Systemic elevation of cardiac troponins was correlated with survival, injury severity score, and catecholamine consumption of patients after multiple trauma. The clinical features of the so-called "commotio cordis" are dysrhythmias, including ventricular fibrillation and sudden cardiac arrest as well as wall motion disorders. In trauma patients with inappropriate hypotension and inadequate response to fluid resuscitation, cardiac injury should be considered. Therefore, a combination of echocardiography (ECG) measurements, echocardiography, and systemic appearance of cardiomyocyte damage markers such as troponin appears to be an appropriate diagnostic approach to detect cardiac dysfunction after trauma. However, the mechanisms of post-traumatic cardiac dysfunction are still actively being investigated. This review aims to discuss cardiac damage following trauma, focusing on mechanisms of post-traumatic cardiac dysfunction associated with inflammation and complement activation. Herein, a causal relationship of cardiac dysfunction to traumatic brain injury, blunt chest trauma, multiple trauma, burn injury, psychosocial stress, fracture, and hemorrhagic shock are illustrated and therapeutic options are discussed.

Reaming of femoral fractures with different reaming irrigator aspirator systems shows distinct effects on cardiac function after experimental polytrauma

Cardiac injuries are recorded after multiple trauma and are associated with a poor patient outcome. Reaming prior to locked intramedullary nailing is a frequently used technique to stabilize femoral diaphysis fractures. However, in polytraumatized patients, complications such as fat emboli and acute respiratory distress syndrome have been associated with reaming. The reaming irrigator aspirator (RIA) system provides concomitant irrigation and suction of the intramedullary contents, and should, therefore, reduce reaming-associated complications. The aim of the study was to investigate cardiac function after multiple trauma with regard to two different RIA devices (RIAI vs RIAII). 15 male pigs were included in the study. Pigs received either sham treatment or multiple trauma (chest trauma, femur fracture, liver laceration, and hemorrhagic shock), followed by intramedullary nailing after reaming with either the RIAI or RIAII system (RIAII: reduced diameter of the reamer, improved control of irrigation and suction). Cardiac function was assessed by transesophageal echocardiography and systemic inflammation as well as local cardiac damage examined. Pigs of both treatment groups showed impaired cardiac function, valvular insufficiency, and cardiac damage. Systemic inflammation and local cardiac alterations were observed which might contribute to early myocardial damage in vivo. Multiple trauma including long-bone fracture and subsequent intramedullary reaming induces cardiac dysfunction and valvular insufficiency, which might be linked to both mechanical cardiac injury and increased systemic inflammation. 6 hours after trauma there are less differences between RIAI and RIAII treatment with regard to post-traumatic cardiac consequences in multiple injured pigs, indicating no beneficial effect of RIAII over RIAI.

Complement C5a Induces Pro-inflammatory Microvesicle Shedding in Severely Injured Patients

Initially underestimated as platelet dust, extracellular vesicles are continuously gaining interest in the field of inflammation. Various studies addressing inflammatory diseases have shown that microvesicles (MVs) originating from different cell types are systemic transport vehicles carrying distinct cargoes to modulate immune responses. In this study, we focused on the clinical setting of multiple trauma, which is characterized by activation and dysfunction of both, the fluid-phase and the cellular component of innate immunity. Given the sensitivity of neutrophils for the complement anaphylatoxin C5a, we hypothesized that increased C5a production induces alterations in MV shedding of neutrophils resulting in neutrophil dysfunction that fuels posttraumatic inflammation. In a mono-centered prospective clinical study with polytraumatized patients, we found significantly increased granulocyte-derived MVs containing the C5a receptor (C5aR1, CD88) on their surface. This finding was accompanied by a concomitant loss of C5aR1 on granulocytes indicative of an impaired cellular chemotactic and pro-inflammatory neutrophil functions. Furthermore, in vitro exposure of human neutrophils (from healthy volunteers) to C5a significantly increased MV shedding and C5aR1 loss on neutrophils, which could be blocked using the C5aR1 antagonist PMX53. Mechanistic analyses revealed that the interaction between C5aR1 signaling and the small GTPase Arf6 acts as a molecular switch for MV shedding. When neutrophil derived, C5a-induced MV were exposed to a complex ex vivo whole blood model significant pro-inflammatory properties (NADPH activity, ROS and MPO generation) of the MVs became evident. C5a-induced MVs activated resting neutrophils and significantly induced IL-6 secretion. These data suggest a novel role of the C5a-C5aR1 axis: C5a-induced MV shedding from neutrophils results in decreased C5aR1 surface expression on the one hand, on the other hand it leads to profound inflammatory signals which likely are both key drivers of the neutrophil dysfunction which is regularly observed in patients suffering from multiple traumatic injuries.

Geriatric patients with dementia show increased mortality and lack of functional recovery after hip fracture treated with hemiprosthesis

PURPOSE

Operative timing, perioperative management and postoperative rehabilitation are rising challenges in orthopedic geriatric trauma. The aim of this study was to determine the outcome of patients with dementia or with a high number of comorbidities treated with hemiprosthesis after hip fracture. Literature regarding patients with high comorbidities is scarce, leaving nothing but endoprosthetic treatment for even the sickest, immobile patients.

METHODS

A retrospective chart review of 326 patients (mean age 81 ± 9 years; 230 women and 96 men) with hip fractures treated between 2012 and 2017 with a hemiprosthesis was performed. Primary outcome measures were surgical and nonsurgical complication rates, best achievable mobilisation during the hospital stay and mortality.

RESULTS

Patients with dementia had 20-fold increased risk to be bedridden after surgery and ninefold increased risk of dying (p < 0.005). Furthermore, they needed significantly more revision surgeries because of surgical complications. Patients classified ASA IV and V had significantly lower postoperative mobilization levels with only 10% able to walk with crutches and 53% bedridden. They also had significantly more non-surgical complications while dementia had no effect on non-surgical complication rate.

CONCLUSION

Patients classified ASA IV and V or suffering dementia show poor outcome after hip fracture treated with hemiprosthesis. Multidisciplinary approaches including surgeons, geriatricians, physiotherapists and psychiatrists are needed to improve the outcome of these patients. Especially in a subgroup of patients, where no mobilization is expected, alternative treatment options may be considered.

Thirty-Eight-Negative Kinase 1 Is a Mediator of Acute Kidney Injury in Experimental and Clinical Traumatic Hemorrhagic Shock

Trauma represents a major socioeconomic burden worldwide. After a severe injury, hemorrhagic shock (HS) as a frequent concomitant aspect is a central driver of systemic inflammation and organ damage. The kidney is often strongly affected by traumatic-HS, and acute kidney injury (AKI) poses the patient at great risk for adverse outcome. Recently, thirty-eight-negative kinase 1 (TNK1) was proposed to play a detrimental role in organ damage after trauma/HS. Therefore, we aimed to assess the role of TNK1 in HS-induced kidney injury in a murine and a post hoc analysis of a non-human primate model of HS comparable to the clinical situation. Mice and non-human primates underwent resuscitated HS at 30 mmHg for 60 min. 5 h after the induction of shock, animals were assessed for systemic inflammation and TNK1 expression in the kidney. In vitro, murine distal convoluted tubule cells were stimulated with inflammatory mediators to gain mechanistic insights into the role of TNK1 in kidney dysfunction. In a translational approach, we investigated blood drawn from either healthy volunteers or severely injured patients at different time points after trauma (from arrival at the emergency room and at fixed time intervals until 10 days post injury; identifier: NCT02682550, https://clinicaltrials.gov/ct2/show/NCT02682550). A pronounced inflammatory response, as seen by increased IL-6 plasma levels as well as early signs of AKI, were observed in mice, non-human primates, and humans after trauma/HS. TNK1 was found in the plasma early after trauma-HS in trauma patients. Renal TNK1 expression was significantly increased in mice and non-human primates after HS, and these effects with concomitant induction of apoptosis were blocked by therapeutic inhibition of complement C3 activation in non-human primates. Mechanistically, in vitro data suggested that IL-6 rather than C3 cleavage products induced upregulation of TNK1 and impaired barrier function in renal epithelial cells. In conclusion, these data indicate that C3 inhibition in vivo may inhibit an excessive inflammatory response and mediator release, thereby indirectly neutralizing TNK1 as a potent driver of organ damage. In future studies, we will address the therapeutic potential of direct TNK1 inhibition in the context of severe tissue trauma with different degrees of additional HS.

Modified Candy-Package technique vs Cerclage technique for refixation of the lesser trochanteric fragment in pertrochanteric femoral fractures. A biomechanical comparison of 10 specimens

OBJECTIVES

Separation of the lesser trochanteric fragment in pertrochanteric 3-part fractures leads to a significant weakening of the medial cortical wall. Because of the attachment of the Iliopsoas muscle to this structure, the lesser trochanteric fragment tends to cranial dislocation along this muscle's action direction. Refixation of these fractures using an intramedullary nail and an additional wiring osteosynthesis can be considered an operative standard. Based on an intramedullary osteosynthesis procedure, the question was raised whether a 2-point fixation method was favourable over a 1-point method regarding the pull-out resistance of the lesser trochanteric fragment against the Iliopsoas muscle's force.

METHODS

Based on an intramedullary osteosynthesis (PFNA, DePuy/Synthes/SUI), two groups á five human femora were defined depending on the refixation technique of the lesser trochanteric fragment (1-point supertrochanteric "Cable" vs 2-point super/subtrochanteric fixation "Candy-Package" performed with a 1.25-mm steel cerclage). The specimens were tested using a novel traction setup, simulating the activity pattern of the Iliopsoas muscle. The target value was the resistance of the refixated lesser trochanteric fragment against a defined pull-out force produced by the Iliopsoas muscle. The main parameters considered were the peak traction force (Fmax) and the maximum summative work (WFmax) at construct failure.

RESULTS

The Fmax and WFmax displayed a significant difference in favour of the Candy-Package (2-point super/subtrochanteric fixation) group (822 N vs. 476 N, 13.8 k Nmm vs 4.4 k Nmm, respectively; P = 0.01).

CONCLUSIONS

The Candy-Package technique is a method that displays significantly more resistance than a single cerclage osteosynthesis regarding fragment loosening under the application of a simulated Iliopsoas muscle force in the course of a biomechanical proximal femoral 3-part fracture model.

Differential innate immune response based on surgical treatment strategy after multiple trauma

Background

The complement system is part of the innate immunity, is activated immediately after trauma and is associated with ARDS, MOF and with death of multiply injured patients. The aim of the study was to investigate the complement activation in multiply injured pigs as well as its effects on the heart in vivo and in vitro. Moreover, the impact of reamed vs. non-reamed intramedullary nailing was examined with regard to the complement activation.

Methods

Male pigs received multiple trauma (blunt chest trauma, liver laceration, femur fracture, hemorrhagic shock), followed by femoral nailing with/without prior conventional reaming. Systemic complement hemolytic activity as well as the local cardiac expression of complement receptors was determined in vivo after trauma. Human cardiomyocytes were exposed to C3a or C5a and analyzed regarding calcium signaling and mitochondrial respiration.

Results

Systemic complement activation increased within 6h after trauma and was mediated via the classical and the alternative pathway. The expression of receptors for complement activation were altered locally in vivoin left ventricles. C3a and C5a acted detrimentally on human cardiomyocytes in vitro.

Conclusion

After multiple trauma, an early activation of the complement system is triggered, affecting the heart in vivo as well as in vitro, leading to complement-induced cardiac dysfunction. The intensity of complement activation after multiple trauma correlated with the invasiveness of fracture treatment. Consequently, the choice of fracture treatment might imply the clinical outcome of the critically injured patients and might be therefore crucial for their survival.

DAMP-mediated cardiac dysfunction: cardiomyocytes as actors and target of innate immune response

Objective

Severe trauma often led to a systemic inflammatory response, accompanied by release of danger associated molecular patterns such as the high mobility group box-1 protein (HMGB-1) and extracellular histones. The aim of this study was to clarify the influence of HMGB-1 and extracellular histones on human cardiomyocytes, in context of posttraumatic cardiac dysfunction.

Material and Methods

Cell viability, mitochondrial respiration and calcium handling of human cardiomyocytes in presence of extracellular histones or HMGB-1 were evaluated. A hemadsorption filter was tested to eliminate extracellular histones in vitro and from blood samples of multiple trauma patients (mean injury severity score &gt;16).

Results

Incubation of human cardiomyocytes with HMGB-1 or histones were associated with impaired calcium handling, mitochondrial respiration and reduction of cell viability. Furthermore, human cardiomyocytes release further cardio-depressive cytokines in the presence of extracellular histones and HMGB-1 such as IL-1b and TNF. Hemadsorption of human plasma after multiple trauma showed a significant reduction of histone levels. Furthermore, in vitro analysis of hemofiltration capacity detected a dose dependant reduction of extracellular histones.

Conclusion

Despite their positive intention as part of the immune reaction, HMGB-1 and extracellular histones are associated with detrimental effects on cardiomyocyte viability, calcium handling and mitochondrial function. Moreover, presence of DAMPs resulted in additional release of cardiodepressive cytokines. Therefore, in the context of tissue trauma cardiomyocytes are target and actor at the same time.

Systemic and Cardiac Alterations After Long Bone Fracture

The purpose of this study was to reveal possible consequences of long-bone fracture on cardiac tissue and to analyze the role of systemically elevated danger associated molecular patterns, complement anaphylatoxins and cytokines. Blood samples of mice, pigs, and humans after a fracture were analyzed by ELISAs for complement component 5a (C5a), tumor necrosis factor (TNF), and extracellular histones. In vivo results were completed by in vitro experiments with human cardiomyocytes treated with TNF and extracellular histones. The influence of histones and human plasma after fracture on isolated human polymorphonuclear leukocytes (PMNs) was investigated. An elevation of TNF, C5a, and extracellular histones after long bone fracture was measured. Moreover, the appearance of systemic troponin I levels was observed and structural changes in connexin 43 and desmin were detected. Further, the presence of TNF leads to elevation of reactive oxygen species, troponin I release, and histone appearance in supernatant of human cardiomyocytes. Incubation of human PMNs with histones and plasma of patients after fracture lead to formation of neutrophil extracellular traps. Present results suggest that structural alterations in the heart might be consequences of the complement activation, the release of extracellular histones, and the systemic TNF elevation in the context of a long bone fracture.

Complement Activation and Organ Damage After Trauma-Differential Immune Response Based on Surgical Treatment Strategy

Background: The complement system is part of the innate immunity, is activated immediately after trauma and is associated with adult respiratory distress syndrome, acute lung injury, multiple organ failure, and with death of multiply injured patients. The aim of the study was to investigate the complement activation in multiply injured pigs as well as its effects on the heart in vivo and in vitro. Moreover, the impact of reamed vs. non-reamed intramedullary nailing was examined with regard to the complement activation after multiple trauma in pigs.

Materials and Methods: Male pigs received multiple trauma, followed by femoral nailing with/without prior conventional reaming. Systemic complement hemolytic activity (CH-50 and AH-50) as well as the local cardiac expression of C3a receptor, C5a receptors1/2, and the deposition of the fragments C3b/iC3b/C3c was determined in vivo after trauma. Human cardiomyocytes were exposed to C3a or C5a and analyzed regarding calcium signaling and mitochondrial respiration.

Results: Systemic complement activation increased within 6 h after trauma and was mediated via the classical and the alternative pathway. Furthermore, complement activation correlated with invasiveness of fracture treatment. The expression of receptors for complement activation were altered locally in vivo in left ventricles. C3a and C5a acted detrimentally on human cardiomyocytes by affecting their functionality and their mitochondrial respiration in vitro.

Conclusion: After multiple trauma, an early activation of the complement system is triggered, affecting the heart in vivo as well as in vitro, leading to complement-induced cardiac dysfunction. The intensity of complement activation after multiple trauma might correlate with the invasiveness of fracture treatment. Reaming of the femoral canal might contribute to an enhanced “second hit” response after trauma. Consequently, the choice of fracture treatment might imply the clinical outcome of the critically injured patients and might be therefore crucial for their survival.

Functional immune monitoring in severely injured patients-A pilot study

After severe trauma, the resulting excessive inflammatory response is countered by compensatory anti-inflammatory mechanisms. The systemic inflammatory response to trauma enhanced by inappropriately timed surgical second hits may be detrimental for the patient. On the other hand, overwhelming anti-inflammatory mechanisms may put patients at increased risk from secondary local and systemic infections. The ensuing sepsis and organ dysfunction due to immune dysregulation remain the leading causes of death after injury. To date, there are no clinically applicable techniques to monitor the pro-/anti-inflammatory immune status of the patients and the remaining ability to react to microbial stimuli. Therefore, in the present study, we used a highly standardized and easy-to-use system to draw peripheral whole blood from polytraumatized patients (ISS ≥ 32, n = 7) and to challenge it with bacterial lipopolysaccharide. Secreted cytokines were compared with those in samples from healthy volunteers. We observed a significant decrease in the release of monocyte-derived mediators. Surprisingly, we detected stable or even increased concentrations of cytokines related to T cell maturation and function. For clinical practicability, we reduced the incubation time before supernatants were collected. Even after an abbreviated stimulation period, a stable release of almost all analysed parameters in patient blood could be detected. In conclusion, the data are indicative of a clinically well-applicable approach to monitor the immune status in severely injured patients in a short time. This may be used to optimize the timing of necessary surgical interventions to avoid a boost of proinflammation and reduce risk of secondary infections.

Impact of oral anticoagulation on proximal femur fractures treated within 24 h - A retrospective chart review

BACKGROUND

About one third of all patients with proximal femur fractures take oral anticoagulation like aspirin (ASS), direct platelet aggregation inhibitors like Clopidogrel and Ticagrelor (PAI), vitamin-K-antagonists like Warfarin (VKA) and direct oral anticoagulants like Rivaroxaban, Dabigatran and Apixaban (DOAC). The management and timing of fracture stabilization of these patients is a rising challenge in orthopedic trauma. Our objective was to determine the effect of oral anticoagulation on patients with proximal femur fractures, which received a proximal femur nail antirotation (PFNA) within 24 h after trauma.

MATERIAL AND METHODS

A retrospective chart review of 327 patients (mean age 80 ± 13 years; 223 women and 104 men) with sub- or intertrochanteric fractures between January 2013 and December 2017 was performed. All patients underwent surgery in the first 24 h after admission. Solely patients without or with only one type of oral anticoagulation were included. There were 74 patients with ASS, 30 with PAI, 52 with DOAC and 25 with VKA medication. All patients taking VKA received high dose Vitamin K or coagulation factors to normalize INR prior to surgery. Primary outcome measures were transfusion rate and pre- and postoperative hemoglobin (Hb) difference. Secondary outcome measures were mortality and complications like infection, hematoma and acute cardiovascular events.

RESULTS

Patients undergoing treatment with DOAC had a 3.4-fold increased risk for intraoperative blood transfusion. The risk for blood transfusion for patients taking ASS, PAI or VKA did no differ from the control group. Patients without an intraoperative blood transfusion on oral anticoagulation showed no increase in pre- and postoperative Hb-difference compared with controls. Anticoagulation showed no significant effect on complication rates and mortality in patients operated within the first 24 h.

CONCLUSION

Early surgical care of proximal femur fractures is safe even in patients with anticoagulant medication. All patients should be preoperatively prepared for possibly intraoperative transfusion, especially patients on DOAC.

Midkine Is Elevated After Multiple Trauma and Acts Directly on Human Cardiomyocytes by Altering Their Functionality and Metabolism

Background and Purpose: Post-traumatic cardiac dysfunction often occurs in multiply injured patients (ISS ≥ 16). Next to direct cardiac injury, post-traumatic cardiac dysfunction is mostly induced by the release of inflammatory biomarkers. One of these is the heparin-binding factor Midkine, which is elevated in humans after fracture, burn injury and traumatic spinal cord injury. Midkine is associated with cardiac pathologies but the exact role of Midkine in the development of those diseases is ambiguous. The systemic profile of Midkine after multiple trauma, its effects on cardiomyocytes and the association with post-traumatic cardiac dysfunction, remain unknown.

Experimental Approach: Midkine levels were investigated in blood plasma of multiply injured humans and pigs. Furthermore, human cardiomyocytes (iPS) were cultured in presence/absence of Midkine and analyzed regarding viability, apoptosis, calcium handling, metabolic alterations, and oxidative stress. Finally, the Midkine filtration capacity of the therapeutic blood absorption column CytoSorb ®300 was tested with recombinant Midkine or plasma from multiply injured patients.

Key Results: Midkine levels were significantly increased in blood plasma of multiply injured humans and pigs. Midkine acts on human cardiomyocytes, altering their mitochondrial respiration and calcium handling in vitro. CytoSorb®300 filtration reduced Midkine concentration ex vivo and in vitro depending on the dosage.

Conclusion and Implications: Midkine is elevated in human and porcine plasma after multiple trauma, affecting the functionality and metabolism of human cardiomyocytes in vitro. Further examinations are required to determine whether the application of CytoSorb®300 filtration in patients after multiple trauma is a promising therapeutic approach to prevent post-traumatic cardiac disfunction.

Cement augmentation of the Proximal Femoral Nail Antirotation (PFNA) - A multicentre randomized controlled trial

INTRODUCTION

New implant designs like the Proximal Femoral Nail Antirotation (PFNA) were developed to reduce failure rates in unstable pertrochanteric fractures in the elderly. Standardized implant augmentation with up to 6 mL of polymethylmethacrylate (PMMA) cement has been introduced to enhance implant anchorage by increasing the implant-bone interface in osteoporotic bone conditions. Biomechanically, loads to failure were significantly higher with augmentation. The primary objective of this study was to compare the mobility of patients with closed unstable trochanteric fractures treated by PFNA either with or without cement augmentation.

PATIENTS AND METHODS

A prospective multicentre, randomized, patient-blinded trial was conducted with ambulatory patients aged 75 or older who sustained a closed, unstable trochanteric fracture. Surgical fixation had to be performed within 72 h after admission. Outcomes were evaluated at baseline, during surgery, 3 to 14 days after surgery, 3 months, 6 months, and 12 months after surgery. To evaluate the primary objective, patients' walking speed was assessed by the Timed Up and Go (TUG) test. Secondary objectives included the analysis of implant migration assessed on radiographs, quality of life measured by the Barthel Index, mobility measured by the Parker Mobility Score, and complications.

RESULTS

Of 253 randomized patients, 223 patients were eligible: 105 patients were allocated to the PFNA Augmentation group and 118 to PFNA group. At 3 to 14 days after surgery, there was no statistical significant difference in mean walking speed between the treatment groups. For the secondary objectives, also no statistical significant differences were found. However, no patient in the PFNA Augmentation group had a reoperation due to mechanical failure or symptomatic implant migration compared to 6 patients in the PFNA group.

CONCLUSIONS

Augmentation of the PFNA blade did not improve patients' walking ability compared to the use of a non-augmented PFNA but might have the potential to prevent reoperations by strengthening the osteosynthesis construct.

Correction to: Radiation exposure for intraoperative 3D scans in a hybrid operating room: how to reduce radiation exposure for the surgical team

The original version of this article unfortunately contained a mistake. In abstract, results section should read.

New advances in intra-operative imaging in trauma

The invention of flat-panel detectors led to a revolution in medical imaging. The major benefits of this technology are a higher image quality and dose reduction. Flat-panel detectors have proved to be superior to standard C-arms (= C-arm with radiograph source and image intensifier).

Cone-beam computed tomography (cone-beam CT) is a 3D data set, which can be acquired with a flat-panel detector. The cone-shaped beam is used for 3D data generation. For cone-beam CT acquisition, the flat-panel detector rotates around the patient lying on the operating table. Intra-operative cone-beam CT can be a very helpful tool in orthopaedic surgery. Immediate control of fracture reduction and implant positioning in high image quality can reduce the need for secondary revision surgery due to implant malposition.

In recent years there has been a revival of standard fan beam CT technology in operating rooms. Fixed and mobile systems are available. Fixed systems are typically placed on a sliding gantry. Different mobile intra-operative CT scanners were recently introduced. Due to their mobility, they are not bound to a specific operating room. The use of standard intra-operative CT scanners results in high 3D image quality but, in comparison with a cone-beam CT scanner, fluoroscopy is not possible.

The introduction of flat-panel detectors has led to improvements in intra-operative image quality combined with dose reduction. The possibility of high-quality 3D imaging in combination with navigation can assure optimal implant placement. Due to immediate control of the osteosynthesis, revision surgery at a later time can be prevented.

Cite this article: EFORT Open Rev 2018;3 DOI: 10.1302/2058-5241.3.170055