3D C-arm navigated suture button implantation for AC joint dislocations - the pilot study.

PURPOSE: The surgical treatment of acute traumatic AC joint dislocations is still a subject of scientific debate in the literature. The arthroscopically assisted stabilization procedure with a suture button system has been successfully established and is widely used in daily practice. It is minimally invasive and allows the anatomical reconstruction of the torn coracoclavicular ligaments in one step with a permanent implant that does not have to be removed in a second operation. This clinical pilot study is the first to describe the new method of navigated suture button implantation with the future aim of further reducing surgical invasiveness and further increasing surgical precision. MATERIALS AND METHODS: 10 patients with a Rockwood 3b/5 injury could be included in the prospective study (DRKS00031855) within 5 months according to inclusion and exclusion criteria. Surgical stabilization was performed with a suture button system via a navigated coracoclavicular drill tunnel. Demographic and radiological data as well as information on health and shoulder function were collected from patient records, X-rays, DVT scan and 3 questionnaires (DASH, NHS and Eq. 5D) at the preoperative, intraoperative and postoperative (discharge, 6 weeks and 3 months) time points. RESULTS: All operations could be performed within 8.8 days (± 6.81) after trauma. The average operation time was 50.3 min (± 8.81). The mean distance of the drill hole in the clavicle to the AC joint was 26.6 mm (± 2.63). The radiologically measured vertical coracoclavicular distance was 38.8 mm (± 6.16) at discharge and 41.11 mm (± 7.51) at 3 months. This loss of reduction was not statistically significant. In contrast, the DASH, NHS and Eq. 5D results showed significant improvement from discharge to 3 months postoperatively. CONCLUSION: Image-guided 3D C-arm navigated AC joint suture button stabilization is feasible in everyday surgical practice. It may be possible to achieve a further reduction in invasiveness while at the same time increasing the accuracy of implant positioning. Further clinical studies with a larger number of patients and a longer follow-up period are necessary to enable a comparison with conventional methods.

The Application of a Surgery Supporting Computer System Does Not Seem to Influence the Surgeons' Radiation Exposure: A Retrospective Analysis.

Since 2019, a surgery supporting system (SPM, surgical process manager; Johnson & Johnson, New Brunswick, New Jersey, Vereinigte Staaten) has been used in a Level I trauma center for common trauma surgery procedures (distal radius fractures, proximal femur fractures, ankle fractures, proximal humerus fractures, and spine fractures). The hypothesis of this study was that implementing standardized procedures (by using SPM) may reduce radiation exposure, especially for unexperienced surgeons.Workflows were developed for different surgical procedures (distal radius fractures, proximal femur fractures, ankle fractures, proximal humerus fractures, and spine fractures) and added into the SPM. Between October 2019 and June 2022, 90 surgeries using the SPM were included in the study. A control group was included with 107 surgeries using the same surgical technique. The values measured were the radiation exposure during the surgical procedure, the experience of the head surgeon, and whether or not the SPM was used. A statistical analysis was performed by using the chi square and Fischer exact tests, with significance set at a p value < 0.05.SPM was applicated in 51 cases for the distal radius (control group 54 patients), 20 cases for distal fibula fractures (control group 21 patients), 9 cases for the proximal femur (control group 19 patients), 5 cases for vertebral fractures (control group 7 patients), and 5 cases for the proximal humerus (control group 6 patients). No difference concerning the median radiation exposure was observed by plating distal radius fractures with 5.7 Gy/cm² in the SPM group and a median radiation exposure of 6.4 Gy/cm² in the control group (p = 0.96). The distal fibula fractures showed no significant difference in the intraoperative radiation (17.4 Gy/cm² vs. 6.4 Gy/cm², p value 0.53). Radiation exposure was lower when a consultant performed surgery without showing any significance, independent if SPM was used or not.In this study, no significant difference in the intraoperative radiation dose was observed when using a surgery supporting computer system. The experience of the surgeon showed no influence as well, regardless if SPM was used or not. Additional data should be collected questioning these findings.

Impact of COVID-19 pandemic-induced surgical restrictions on operational performance: a case study at the University Hospital of Ulm.

INTRODUCTION: The operating room (OR) is a high-cost and high-revenue area in a hospital comprising extremely complex process steps to treat patients. The perioperative process quality can be optimized through an efficiency-oriented central OR management based on performance indices. However, during the COVID-19 pandemic with the corresponding OR restrictions, there was a significant nation- and worldwide decline in the performance, which may have a lasting impact. Therefore, we proposed the hypothesis that COVID-19 pandemic-related OR restrictions could reduce operative performance in the long term. METHODS: A retrospective, descriptive analysis of perioperative processing times was conducted exemplarily at the University Hospital Ulm using a pre-post design, examining the corresponding second quarters of 2019 to 2022. In total, n = 18,489 operations with n = 314,313 individual time intervals were analyzed. The statistical analyses included the Kruskal-Wallis test adjusted for multiple testing, and the significance level was set at p < 0.01. RESULTS: The results revealed not only a significant decrease in the case volume by 31% (2020) and 23% (2021) during the COVID-19 crisis years, but also significant time delays in various process steps; e.g. the median patient's OR occupancy time (column time) rose from 65 min (2019) to 87 min (2020) and remained elevated (72 min in 2021 and 74 min in 2022, respectively). Even in 2022, beyond the pandemic, the net anaesthesia time was permanently enhanced by 9 min per case. Furthermore, both, the incision-to-closure time and surgeon attachment time were each significantly prolonged by 7 additional minutes, and the time from the end of anaesthesia to the release of the next patient was extended by 4 min. Selected standardized index operations showed only a trend towards these changes, even with a decrease in the incision-to-closure time over time. CONCLUSION: Overall, long-term changes were found in essential perioperative process times even after retraction of the COVID-19 restrictions, indicating some processual "slow down" after the Covid-19-induced "shut down". Further analyses are needed to determine the appropriate targeted control measures to improve processing times and increase the process quality.

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.

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.

[Augmentation techniques for the treatment of osteoporosis-associated fractures of the extremities]. / Augmentationstechniken zur Versorgung osteoporoseassoziierter Frakturen der Extremitäten.

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.

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.

First experiences with a surgery supporting computer system in regard to education, efficiency and complications.

Purpose: Since October 2019 a computer software named SPM (surgical process manager) is used in a Level I Trauma center. Workflows were developed for distinct surgical procedures (distal radius fractures, proximal femur fractures, ankle fractures, proximal humerus fractures and vertebral fractures). In addition, these workflows were separated in a shortened "Expert"-versions for consultants and a more detailed "Learner"- versions for residents.This investigation was intended to show, if and what kind of benefits in regard to efficiency (incision to suture and suture to incision time), education and complications a surgery supporting software can bring. Methods: SPM was used in 90 cases during October 2019 to June 2022. A control trial with 108 patients was developed, including patients of the same age, having same kind of injuries, receiving the same surgery technique without using the SPM.The software was installed on the computer in the operation room, projected on head monitors and operated by a foot pedal. Complications could also be documented using the pedal.Groups were divided in surgical procedures and fracture type, qualification of the surgeon, complications and surgery time. Surgery times were taken from the hospital computer system (SAP IS-H). A statistical analysis was performed by using the chi square and Fischer exact test with significance set at a P value <0.05. Results: In 51 cases the software was used for the distal radius (control group 54 patients), in 20 cases for Weber fractures (control group 21 patients), in 9 cases for the proximal femur (control group 19 patients), in 5 cases for vertebral fractures (control group 7 patients) and in 5 cases for the proximal humerus (control group 6 patients).Time from incision to closure was significant higher in the intervention group (49 vs 42 min, p- value 0,018) and wasn't significant lower in the "expert" group, fixing radius and ancle fractures (39 to 46 min, p value 0,186).Comparing the SPM and control group concerning closing to incision time, no difference could be observed (56 to 58,5 min, p value 0,828).The greatest time deviation between "Learners"und "Experts"was observed in reduction and fixation (p value 0,006) in ankle fractures. The "Expert"group also needed less time for the approach (p value 0,008) in case of distal radius fractures.Unexpected events were more often observed in the intervention group (5,5 vs 3,7 %). Conclusions: A surgery supporting computer system might be a good tool for detecting and optimizing workflows in the operation room and for improving and analyzing the training of residents and surgical assistants.In addition, it offers the opportunity to document intraoperative complications. However, a saving of time wasn't observed in this study. Further investigations with bigger number of cases and a longer follow-up are necessary to proof these findings statistically.

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.

[Keeping the big picture in Terror-MASCAL-A new hospital concept]. / Überblick im Terror-MANV ­ ein neues Klinikkonzept.

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.

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.

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 ß2-adrenoceptor-deficient mice are also protected from stress-induced bone growth retardation. In summary, our preclinical data identify locally secreted catecholamines in concert with ß2-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.

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.

Intraoperative 3D imaging in plate osteosynthesis of proximal humerus fractures.

INTRODUCTION: Proximal humerus fractures are common and often associated with osteoporosis in the elderly. Unfortunately, the complication and revision rate for joint-preserving surgical treatment using locking plate osteosynthesis is still high. Problems include insufficient fracture reduction and implant misplacement. Using conventional intraoperative two dimensional (2D) X-ray imaging control in only two planes, a completely error-free assessment is not possible. MATERIALS AND METHODS: The feasibility of intraoperative three-dimensional (3D) imaging control for locking plate osteosynthesis with screw tip cement augmentation of proximal humerus fractures was retrospectively studied in 14 cases with an isocentric mobile C-arm image intensifier set up parasagittal to the patients. RESULTS: The intraoperative digital volume tomography (DVT) scans were feasible in all cases and showed excellent image quality. One patient showed inadequate fracture reduction in the imaging control, which then could be corrected. In another patient, a protruding head screw was detected, which could be replaced before augmentation. Cement distribution in the humeral head was consistent around the screw tips with no leakage into the joint. CONCLUSION: This study shows that insufficient fracture reduction and implant misplacement can be easily and reliably detected by intraoperative DVT scan with an isocentric mobile C-arm set up in the usual parasagittal position to the patient.

Blade Augmentation in Nailing Proximal Femur Fractures-An Advantage despite Higher Costs?

BACKGROUND: Proximal femoral fractures occur with increasing incidence, especially in the elderly. Commonly used implants for surgical treatment are cephalomedullary nails. To increase stability, a perforated femoral neck blade can be augmented with cement. The study investigated whether this results in a relevant clinical advantage and justifies the higher cost. MATERIALS AND METHODS: This is a single-center retrospective study of 620 patients with proximal femur fractures treated with cephalomedullary nailing. Between January 2016 and December 2020, 207 male and 413 female patients were surgically treated with a proximal femur nail (DePuy Synthes) using a perforated blade and cement augmentation in cases with severe osteoporosis. Primary outcome measures were the rate of cut-out, tip apex distance and the positioning of the blade in the femoral head. Secondary outcome measures were the implant costs and operating times. RESULTS: Of the 620 femoral neck blades, 299 were augmented with cement. A total of six cut-outs were seen in the first 3 months after the operation. There were three in the cement-augmented group (CAB = cement-augmented blade) and three in the conventional group (NCAB = non-cement-augmented blade). There was a significant positive correlation between age and augmentation, with a mean difference of 11 years between the two groups (CAB 85.7 ± 7.9 vs. NCAB 75.3 ± 15.1; p < 0.05). There was no difference in the tip-apex distance (CAB 15.97 vs. 15.69; p = 0.64) or rate of optimal blade positions between the groups (CAB 81.6% vs. NCAB 83.2%; p = 0.341). Operation times were significantly longer in the cemented group (CAB 62.6 21.2 min vs. NCAB 54.1 7.7 min; p < 0.05), and the implant cost nearly doubled due to augmentation. CONCLUSION: When the principles of anatomic fracture reduction, optimal tip-apex distance and optimal blade position are combined with cement augmentation in cases of severe osteoporosis, a cut-out rate of less than 1% can be achieved. Nevertheless, it should be noted that augmentation remains expensive and prolongs surgery time without definite proof of mechanical superiority.