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The aim of this study was to compare the remaining motion of an immobilized cervical spine using an innovative cervical collar as well as two traditional cervical collars. The study was performed on eight fresh human cadavers. The cervical spine was immobilized with one innovative (Lubo Airway Collar) and two traditional cervical collars (Stifneck and Perfit ACE). The flexion and lateral bending of the cervical spine were measured using a wireless motion tracker (Xsens). With the Weinman Lubo Airway Collar attached, the mean remaining flexion was 20.0 ± 9.0°. The mean remaining flexion was lowest with the Laerdal Stifneck (13.1 ± 6.6°) or Ambu Perfit ACE (10.8 ± 5.8°) applied. Compared to that of the innovative Weinmann Lubo Airway Collar, the remaining cervical spine flexion was significantly decreased with the Ambu Perfit ACE. There was no significant difference in lateral bending between the three examined collars. The most effective immobilization of the cervical spine was achieved when traditional cervical collars were implemented. However, all tested cervical collars showed remaining motion of the cervical spine. Thus, alternative immobilization techniques should be considered., (© 2021. The Author(s).)

Background: Intraoperative imaging is regularly used for intraoperative reduction control and evaluation of the implant position in trauma surgery. 2D imaging is limited, especially in complex anatomical regions such as the pelvis. The introduction of mobile 3D C-arms (CBCT: cone-beam computed tomography) has significantly improved intraoperative assessment. Nevertheless, there are still limitations regarding the field of view and metal artifacts. The purpose of this study was to evaluate the potential of intraoperative computed tomography (iCT) in surgical treatment of sacroiliac (SI) injuries., Methods: Twenty-five cases with injuries of the posterior pelvic ring involving the SI region that were surgically treated with navigated SI screws using the mobile iCT Airo (Brainlab, Munich, Germany) were analysed. Subsequently, the data were compared with historical control groups (CBCT with and without navigation; 2D fluoroscopy only)., Results: The average score for subjective image quality achieved using the Likert scale is significantly higher for the iCT (4.48 ± 0.65) than for the CBCT (3.04 ± 0.69) with p = 0.00. The average duration of surgery using iCT was 189.32 ± 88.64 min, which was not significantly different from the control groups (p = 0.14 - 0.70). The average fluoroscopy time using iCT was 81.96 ± 97.34 s, which was significantly shorter than in all of the control groups (p = 0.00 - 0.03). The rate for postoperatively detected complications after using iCT was 0% (n = 0). Compared with the 2D-only control group (25%; n = 1), there is a significant difference (p = 0.01). The remaining two control groups showed no significant differences (p = 0.09 - 0.19)., Conclusions: The iCT provides excellent image quality that allows reliable assessment of fracture reduction and implant placement even in complex anatomical regions. The radiation exposure for the medical staff is reduced by decreasing the fluoroscopy time without significantly prolonging the surgical time. Overall, the possibility of intraoperative correction improves clinical outcome and patient treatment in the long term., Competing Interests: Declaration of Competing Interest Holger Keil is a paid lecturer for the Brainlab AG (Munich, Germany). This cooperation influenced neither the outcome of the study nor the manuscript., (Copyright © 2020. Published by Elsevier Ltd.)

Purpose: Acute unstable syndesmotic lesions are regularly treated with closed or open reduction and fixation with either a positioning screw or tight rope. Conventional fluoroscopy is limited to identify a malreduction of the ankle mortise. The aim of the study was to validate the reduction criteria of intraoperative cone beam CT in unstable syndesmotic injuries by analyzing the clinical outcome., Methods: Acute unstable syndesmotic injuries were treated with a positioning screw fixation, and the reduction in the ankle mortise was evaluated with intraoperative cone beam CT. The patients were grouped postoperatively according to the radiological reduction criteria in the intraoperative 3D images. The reduction criteria were unknown to the surgeons. Malreduction was assumed if one or more reduction criteria were not fulfilled., Results: Seventy-three of the 127 patients could be included in the study (follow-up rate 57.5%). For 41 patients (56.2%), a radiological optimal reduction was achieved (Group 1), and in 32 patients (43.8%) a radiological adverse reduction was found (Group 2). Group 1 scored significantly higher in the Olerud/Molander score (92.44 ± 10.73 vs. 65.47 ± 28.77) (p = 0.003), revealed a significantly higher range of motion (ROM) (53.44 vs. 24.17°) (p = 0.001) and a significantly reduced Kellgren/Lawrence osteoarthritis score (1.24 vs. 1.79) (p = 0.029). The linear regression analysis revealed a correlation for the two groups with the values scored in the Olerud/Molander score (p < 0.01)., Conclusion: The reduction criteria in intraoperative cone beam CT applied to unstable syndesmotic injuries could be validated. Patients with an anatomic reduced acute unstable syndesmotic injury according to the criteria have a significantly better clinical outcome., (© 2020. The Author(s).)

Purpose: The aim of the study is to identify an ideal location to measure fibular rotation in the ankle joint using axial computed tomography (CT) scans. Another objective was to detect the average fibular rotation in the uninjured ankle joint in a large cohort., Methods: Standardised axial CT with coronal/sagittal reconstructions was performed in healthy ankle joints. Three investigators performed the measurements. In the axial view, each investigator appointed the ideal location to measure the angle of fibular rotation with the use of reference lines either 4, 6, 8 or 10 mm distal from the talar joint line. Inter- and intraobserver reliability, as well as the intraclass correlation coefficient, were determined., Results: CT scans of one hundred individuals-78 males and 22 females-were analysed. The most common locations for measuring the fibular rotation were in 31% of cases 4 mm and in 51% of cases 6 mm distal the talar joint line. The external rotation of the fibula averaged 8.42° ± 4.86° (range 0°-26°). The intraclass coefficient correlations (ICC) for interrater and intrarater reliability were 0.75., Conclusions: The results of the study demonstrate a reproducible location to measure the fibular rotation in the ankle joint. The most convenient location to measure fibular rotation with a high reliability was 6 mm distal to the talar joint line., (© 2019. Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: The aim of this study was to identify to what extent a dissection of the syndesmosis and an avulsed posterior edge of the tibia can change the tibiofibular diastasis and fibular rotation., Methods: Three-dimensional scans with a mobile C-arm of 22 cadaver legs were taken of the intact fibula, after dissection of the anterior part of the syndesmosis and the interosseous membrane, osteotomy of the posterior malleolus, and osteosynthesis. The tibiofibular diastasis as well as the angle of fibular rotation was identified in the four steps and the means compared to each other using a t test for paired samples., Results: The distinction between the intact fibula vs. the osteotomy of the posterior tibia was 0.082 ± 0.332 mm for the tibiofibular distance in the incisura tibiofibularis (p 0.261) and 0.046 ± 0.486 degrees for the angle of the fibular rotation (p 0.665)., Conclusion: Neither the dissection of the syndesmosis nor the osteotomy of the posterior malleolus significantly influenced the position of the fibula in the incisura tibiofibularis in the cadaveric model. However, in the nonweight-bearing situation, a lesion of the syndesmotic complex might not be evident in intraoperative three-dimensional imaging., (© 2020. Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Although the risk of exposure to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is higher for frontline healthcare workers, not all personnel have similar risks. Determining infection rate is difficult due to the limits on testing and the high rate of asymptomatic individuals. Detection of antibodies against SARS-CoV-2 may be useful for determining prior exposure to the virus and assessing mitigation strategies, such as isolation, masks, and other protective equipment., Methods: An online assessment that included demographic, clinical, and exposure information and a blood sample was collected from 20 614 participants out of ~43 000 total employees at Beaumont Health, which includes 8 hospitals distributed across the Detroit metropolitan area in southeast Michigan. The presence of anti-SARS-CoV-2 IgG was determined using the EUROIMMUN assay., Results: A total of 1818 (8.8%) participants were seropositive between April 13 and May 28, 2020. Among the seropositive individuals, 44% reported that they were asymptomatic during the month prior to blood collection. Healthcare roles such as phlebotomy, respiratory therapy, and nursing/nursing support exhibited significantly higher seropositivity. Among participants reporting direct exposure to a Coronavirus Disease 2019 (COVID-19) positive individual, those wearing an N95/PAPR mask had a significantly lower seropositivity rate (10.2%) compared to surgical/other masks (13.1%) or no mask (17.5%)., Conclusions: Direct contact with COVID-19 patients increased the likelihood of seropositivity among employees but study participants who wore a mask during COVID-19 exposures were less likely to be seropositive. Additionally, a large proportion of seropositive employees self-reported as asymptomatic. (Funded by Beaumont Health and by major donors through the Beaumont Health Foundation)., Clinicaltrials.gov Number: NCT04349202., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Introduction: Demographic changes have resulted in an increase in injuries among geriatric patients. For these patients, a rigid cervical collar is crucial for immobilizing the cervical spine. However, evidence suggests that patients with a geriatric facial structure require a different means of immobilization than patients with an adult facial structure. This study aimed to analyze the remaining motion of the immobilized cervical spine based on facial structure., Materials and Methods: This study was performed on 8 fresh human cadavers. Facial structure was evaluated via ascertaining the mandibular angle by computer tomography. A mandibular angle below 130°, belongs to the adult facial structure group ( n = 4) and a mandibular angle above 130°, belongs to the geriatric facial structure group ( n = 4). The flexion and lateral bending of the immobilized cervical spine were analyzed in both groups using a wireless motion tracker system., Results: A flexion of up to 19.0° was measured in the adult facial structure group. The mean flexion in the adult vs. geriatric facial structure groups were 14.5° vs. 6.5° (ranges: 9.0-19.0 vs. 5.0-7.0°), respectively. Thus, cervical spine motion was ( p = 0.0286) significantly more reduced in the adult facial structure group. No ( p = 0.0571) significant difference was oberserved in the mean lateral bending of the adult facial structure group (14.5°) compared to the geriatric facial structure group (7.5°)., Conclusion: Emergency medical service personnel should therefore follow current guidelines and recommendations and perform cervical spine immobilization with a cervical collar, including in patients with a geriatric facial structure., Competing Interests: Declaration of Conflicting Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2021.)

Aims: Complex joint fractures of the lower extremity are often accompanied by soft-tissue swelling and are associated with prolonged hospitalization and soft-tissue complications. The aim of the study was to evaluate the effect of vascular impulse technology (VIT) on soft-tissue conditioning in comparison with conventional elevation., Methods: A total of 100 patients were included in this prospective, randomized, controlled monocentre study allocated to the three subgroups of dislocated ankle fracture (n = 40), pilon fracture (n = 20), and intra-articular calcaneal fracture (n = 40). Patients were randomized to the two study groups in a 1:1 ratio. The effectiveness of VIT (intervention) compared with elevation (control) was analyzed separately for the whole study population and for the three subgroups. The primary endpoint was the time from admission until operability (in days)., Results: The mean length of time until operability was 8.2 days (SD 3.0) in the intervention group and 10.2 days (SD 3.7) in the control group across all three fractures groups combined (p = 0.004). An analysis of the subgroups revealed that a significant reduction in the time to operability was achieved in two of the three: with 8.6 days (SD 2.2) versus 10.6 days (SD 3.6) in ankle fractures (p = 0.043), 9.8 days (SD 4.1) versus 12.5 days (SD 5.1) in pilon fractures (p = 0.205), and 7.0 days (SD 2.6) versus 8.4 days (SD 1.5) in calcaneal fractures (p = 0.043). A lower length of stay (p = 0.007), a reduction in pain (p preop = 0.05; p discharge < 0.001) and need for narcotics (p preop = 0.064; p postop = 0.072), an increased reduction in swelling (p < 0.001), and a lower revision rate (p = 0.044) could also be seen, and a trend towards fewer complications (p = 0.216) became apparent., Conclusion: Compared with elevation, VIT results in a significant reduction in the time to achieve operability in complex joint fractures of the lower limb. Cite this article: Bone Joint J  2021;103-B(4):746-754.

Background: This study evaluates image quality of a new flat-panel three-dimensional (3D) C-arm to the current generation and to intraoperative and stationary computed tomography (CT) in spinal surgery., Methods: Three-dimensional-imaging of 44 posterior screws acquired with two generations of 3D C-arms (Arcadis Orbic, AO and Cios Spin, CS, Siemens, Germany) and CT scans (mobile intraoperative CT Airo, iCT, Brainlab, Germany and stationary CT Aquilion 32, sCT, Toshiba, Japan) were performed. Evaluation regarded assessability and measurements of implant position., Results: Assessability score was 0.11 in AO, 0.56 in sCT, 0.91 in iCT and 1.46 in CS (p < 0.0005). AO and CS showed a significant difference in accuracy (p = 0.001) as well as CS and iCT (p < 0.001). Measurements of protrusion over the anterior edge did not show a significant difference (p = 0.341)., Conclusions: Image quality of the new generation of flat-panel 3D C-arms competes with CT imaging and offers significant advantages compared to the former generation., (© 2020 John Wiley & Sons Ltd.)

So far, several publications have discussed the bonding concepts in polyhalides on a theoretical basis. In particular, the trichlorine monoanion is of great interest because its structure should be symmetrical and show two equidistant Cl-Cl bonds. However, apart from matrix-isolation studies, only asymmetric trichlorine anions have been reported so far. Herein, the trichlorine monoanions in 2-chloroethyltrimethylammonium trichloride [NMe 3 EtCl][Cl 3 ], 1, tetramethylammonium trichloride [NMe 4 ][Cl 3 ], 2, and tetrapropylammonium trichloride [NnPr 4 ][Cl 3 ], 3, are analysed. High-resolution X-ray structures and experimental charge density analyses supported by periodic quantum-chemical calculations provide insight into the influence of the crystalline environment on the structure of these [Cl 3 ] - anions as well as into the progress of the bond formation between a dichlorine molecule and a Cl - anion., (© 2020 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

The aim of our study was to evaluate whether software-based artifact reduction can achieve an improved image quality, using intraoperative 3D imaging in spinal surgery. A total of 49 intraoperative 3D image datasets of patients, who underwent surgery with pedicle screw placement, were retrospectively evaluated. The visibility of anatomical structures and the diameter of the pedicle screws were examined, with and without the application of the artifact reduction software. All software prototypes can improve the visibility of anatomical structures (P < 0.01), except MAR (metal artifact reduction) combined with IRIS (iterative reconstruction in image space) (P = 0.04). The algorithms MAR and MAR-2 can reduce the blooming artifacts significantly (P < 0.01), but SL (Shepp & Logan) cannot (P = 0.08-0.988). In summary, software-based artifact reduction for intraoperative 3D datasets can improve the current image quality. Additional information regarding the implant placement and the fracture reduction is therefore generated for the surgeon.

Background: Traumatic pelvic fracture (TPF) is a significant injury that results from high energy impact and has a high morbidity and mortality., Purpose: We aimed to describe the epidemiology, incidence, patterns, management, and outcomes of TPF in multinational level 1 trauma centers., Methods: We conducted a retrospective analysis of all patients with TPF between 2010 and 2016 at two trauma centers in Qatar and Germany., Results: A total of 2112 patients presented with traumatic pelvic injuries, of which 1814 (85.9%) sustained TPF, males dominated (76.5%) with a mean age of 41 ± 21 years. In unstable pelvic fracture, the frequent mechanism of injury was motor vehicle crash (41%) followed by falls (35%) and pedestrian hit by vehicle (24%). Apart from both extremities, the chest (37.3%) was the most commonly associated injured region. The mean injury severity score (ISS) of 16.5 ± 13.3. Hemodynamic instability was observed in 44%. Blood transfusion was needed in one third while massive transfusion and intensive care admission were required in a tenth and a quarter of cases, respectively. Tile classification was possible in 1228 patients (type A in 60%, B in 30%, and C in 10%). Patients with type C fractures had higher rates of associated injuries, higher ISS, greater pelvis abbreviated injury score (AIS), massive transfusion protocol activation, prolonged hospital stay, complications, and mortality (p value < 0.001). Two-thirds of patients were managed conservatively while a third needed surgical fixation. The median length of hospital and intensive care stays were 15 and 5 days, respectively. The overall mortality rate was 4.7% (86 patients)., Conclusion: TPF is a common injury among polytrauma patients. It needs a careful, systematic management approach to address the associated complexities and the polytrauma nature.

Study Design: Retrospective cohort study., Objectives: Doubts still remain whether a sufficient reduction of vertebral body fractures can be achieved if a percutaneous surgical approach is adopted. The aim of this retrospective cohort study was to analyze the reduction and perioperative complications using a percutaneous versus open surgical approach for dorsal stabilization., Methods: Patients suffering from a traumatic injury of the thoracic or lumbar spine who were treated with dorsal stabilization at our level 1 trauma center were included. From January 2007 through June 2009, only the open approach was used; from June 2009 through March 2014, only the percutaneous approach with a special reduction technique was used. Retrospectively, total reduction, perioperative and intraoperative data, and postoperative complications were analyzed., Results: Using the percutaneous (n=185) versus open surgical approach (n=91), the mean reduction over all spinal injuries was 7.7±6.6 versus 8.3±5.5 degrees, respectively. The mean operation time was 75.5±50.2 versus 71.5±41.9 minutes, respectively. There was no significant difference between the 2 treatment groups in terms of the total reduction (P=0.753) or operation time (P=0.814).After the percutaneous and open surgical approach, 7 (3.8%) and 22 (24.2%) complications were documented. Complications requiring interventions were more frequent in the open treatment group., Conclusions: Percutaneous dorsal stabilization seems to be a good alternative to the traditional open surgical approach. The fracture's reduction is similar, whereas severe complications are reduced and the operation time is not prolonged., Level of Evidence: Level III-retrospective cohort study.

The silicon atom in LSiCl or LSiMes (L = PhC(N t Bu) 2 , Mes = 2,4,6-Me 3 C 6 H 2 ) inserts into the B-X bond of RBX 2 (R = Ph, Mes, N(SiMe 3 ) 2 ; X = Cl, Br), which is followed by the migration of the amidinate ligand and the halide atom. By this way, LB(R)SiCl 3 (R = Ph, 2 ; Mes, 3 ; N(SiMe 3 ) 2 , 4 ) and LB(R)SiX 2 Mes (R = Ph, X = Cl, 5 ; R = Mes, X = Cl, 6 ; R = Mes, X = Br, 7 ) were obtained. Furthermore, a silylene-borane adduct LClSi → BPhCl 2 ( 1 ) was obtained as an intermediate in the formation of compound 2 . Compounds 2 - 7 are rare examples of borylhalosilanes.

A 50-year-old male suffered a crash landing while paragliding and sustained a posterior dislocation of the hip with a Pipkin fracture type 4 (fracture of the posterior acetabular wall and Pipkin fracture type 2) and a lesion of the sciatic nerve. After primary treatment in an external hospital, the patient was transferred to this hospital 4 days following the trauma. An operative stabilization of the acetabular fracture and the Pipkin fracture was performed using a trochanter flip osteotomy. Despite a large central defect of the femoral head it was decided to attempt a reconstruction. Following fixation of the Pipkin fragment an autologous bone graft harvested from the intertrochanteric region was used to fill the defect. Subsequently, a collagen matrix was applied onto the filled defect and a perineural adaptation of the sciatic nerve was performed.

Background: Currently available procedures for the treatment of minimally displaced acetabular fractures include conservative treatment and minimally invasive percutaneous screw fixation. Screw fixation of acetabular fractures allows patients' early full-weight bearing due to improved biomechanic stability. Can the range of motion, pain and mobility and quality of life in patients with acetabular fractures be improved by minimally invasive screw fixation, compared to conservative treatment in the long term?, Methods: Patients treated for a minimally displaced acetabular fracture, either conservatively or by closed reduction percutaneous screw fixation, in the period from 2001 to 2013 were included in this retrospective study. Minimal displacement was considered to be less than 5 mm. As well as the collection and analysis of baseline data, Harris Hip Score, Merle d'Aubigné score and Short Form 12 (SF-12) questionnaire data were recorded in the context of a clinical study. To better account for confounding factors, patients of each group were matched. The matched-pair criteria included age, BMI, Letournel fracture classification and the presence of associated injuries., Results: Twenty-five patients from each group were matched. On the Harris Hip Score, conservatively treated patients obtained 96 points (52-100, SD 17) vs. 89 points (45-100, SD 17, p = 0.624). On the Merle d'Aubigné score, conservatively treated patients obtained 17 points (10-18, SD 2) vs. 17 points (11-18, SD 2, p = 0.342). Patients with acetabular fractures treated by minimally invasive screw fixation did not result in improved quality of life, measured by SF-12 questionnaire, compared to conservatively treated patients (PCS 47, SD 9 vs. 44, SD 10; p = 0.294 and MCS 51, SD 7 vs. 53, SD 7; p = 0.795)., Conclusions: The clinical results of the two groups revealed no statistically significant differences. From the data, it cannot be deduced that minimally invasive surgical therapy is superior to conservative treatment of minimally displaced acetabular fractures. Prospective randomised studies are recommended to allow reliable evaluation of both treatment options., Trial Registration: Retrospectively registered.

An extensive characterization of Co 3 (PO 4 ) 2 was performed by topological analysis according to Bader's Quantum Theory of Atoms in Molecules from the experimentally and theoretically determined electron density. This study sheds light on the reactivity of cobalt orthophosphate as a solid-state heterogeneous oxidative-dehydration and -dehydrogenation catalyst. Various faces of the bulk catalyst were identified as possible reactive sites given their topological properties. The charge accumulations and depletions around the two independent five- and sixfold-coordinated cobalt atoms, found in the topological analysis, are correlated to the orientation and population of the d-orbitals. It is shown that the (011) face has the best structural features for catalysis. Fivefold-coordinated ions in close proximity to advantageously oriented vacant coordination sites and electron depletions suit the oxygen lone pairs of the reactant, mainly for chemisorption. This is confirmed both from the multipole refinement as well as from density functional theory calculations. Nearby basic phosphate ions are readily available for C-H activation., (© 2019 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.)

Purpose: Fracture reduction and fixation of syndesmotic injuries is a common procedure in trauma surgery. An intra-operative evaluation of the surgical outcome is challenging due to high inter-individual anatomical variation. A comparison to the contralateral uninjured ankle would be highly beneficial but would also incur additional radiation and time consumption. In this work, we pioneer automatic contralateral side comparison while avoiding an additional 3D scan., Methods: We reconstruct an accurate 3D surface of the uninjured ankle joint from three low-dose 2D fluoroscopic projections. Through CNN complemented 3D shape model segmentation, we create a reference model of the injured ankle while addressing the issues of metal artifacts and initialization. Following 2D-3D multiple bone reconstruction, a final reference contour can be created and matched to the uninjured ankle for contralateral side comparison without any user interaction., Results: The accuracy and robustness of individual workflow steps were assessed using 81 C-arm datasets, with 2D and 3D images available for injured and uninjured ankles. Furthermore, the entire workflow was tested on eleven clinical cases. These experiments showed an overall average Hausdorff distance of [Formula: see text] mm measured at clinical evaluation level., Conclusion: Reference contours of the contralateral side reconstructed from three projection images can assist surgeons in optimizing reduction results, reducing the duration of radiation exposure and potentially improving postoperative outcomes in the long term.

Background: The aim of the study was to evaluate the impact of reduction quality, using intraoperative 3D imaging, on quality of life and functional outcome in the operative treatment of tibial plafond fractures., Methods: A group of patients with tibial plafond fractures was re-examined. The operative treatment was performed between September 2001 and October 2011. The follow-up examination was at least 2 years after the final surgical procedure. Final reduction result was assessed intraoperatively using a mobile 3D C-arm. A categorization with regard to descriptive parameters as well as type and size of joint surface irregularities was performed. Follow-up results were evaluated using: Olerud and Molander (O & M) score, Short-Form-36 (SF-36) score, movement deficit, Kellgren and Lawrence grade of osteoarthritis, and pain intensity., Results: 34 patients with operatively treated tibial plafond fracture could be re-examined. Reduction quality had the greatest influence on functional result measured by the O & M score (p = 0.001) and the PCS domain of the SF-36 score (p = 0.018). Significant differences with regard to O & M score (p = 0.000), SF-36 score (p = 0.001 to p = 0.02; without MCS domain), movement deficit (p = 0.001), grade of osteoarthritis (p = 0.005) and pain (p = 0.001) could be verified under consideration of the reduction quality. The group with the anatomically more accurate reduction also showed a better result for clinical follow-up and quality of life. Furthermore, it is not the type of joint surface irregularity that is always decisive, but rather the size., Conclusions: Despite other relevant factors, it appears that reduction quality -which can be analyzed with intraoperative 3D imaging- plays the most important role in postoperative quality of life and functional outcome. Corrections should therefore be performed on joint surface irregularities with a size above 2 mm.

Introduction: The aim of this study was to evaluate a radiographic measurement method for assessment of overlengthening of the MoPyC radial head prosthesis., Materials and Methods: Seven cadaver specimens were studied in ten stages: native specimen (1), radial head resection (2), and implantation of the MoPyC radial head prostheses (Bioprofile, Tornier, Montbonnot-Saint-Martin, France) in four increasing length (correct length, overlengthening of 1.5 mm, 3 mm, and 5 mm) with an intact medial collateral ligament (MCL 3-6) and following transection of the MCL (7-10). The radiographic measurement method according to Athwal et al. was evaluated to detect overlengthening. Statistical analysis included calculation of the diagnostic accuracy of the radiographic method., Results: The radiographic measurement method correctly determined the size of the radial head prosthesis within ± 1 mm in 224 of 336 scenarios (67%) and within ± 2 mm in 320 of 336 scenarios (95%). With a threshold value of ≥ 1 mm, the overall diagnostic sensitivity for detecting overlengthening when it was present and was 90% and the specificity was 79%. The sensitivity was higher with increasing size of the prosthesis: in cases with overlengthening of 1.5 mm, the sensitivity was 76%, with an overlengthening of 3 mm, the sensitivity was 95%, and with an overlengthening of 5 mm, the sensitivity was 100%., Conclusion: The radiographic measurement method of Athwal et al. can be used to estimate and to diagnose the magnitude overlengthening of the MoPyC radial head prosthesis. However, the sensitivity is limited (76%) in cases with a small amount of overlengthening of 1.5 mm.

Purpose: Pelvic ring fractures in the elderly gain increasing importance. Nonetheless, data on factors influencing treatment decision in relation to fracture classification, age, and the resulting treatment are still rare., Methods: Prospectively collected data of the German Pelvic Injury Registry from patients aged over 65 years with a pelvic ring fracture were evaluated retrospectively. Acetabular fractures, as well as type A1 and A3 fractures, were excluded. The variables age, injury pattern, type of treatment, the reason for conservative treatment, and Orthopaedic Trauma Association (OTA)/Tile classification were analyzed. Furthermore, the fracture distribution was examined after dividing patients into six age groups., Results: A total of 1814 patients with a mean age of 80.7 ± 7.6 years, predominantly female (79.0%), were available for evaluation. The majority of patients suffered from isolated pelvic ring fractures (70.1%) and 8.2% were severely injured (ISS > 16). The most common fracture types were type A2 (35.4%), type B2 (38.0%), and type C1 (7.3%). Especially pelvic ring fractures of type A2 (96.9%) and type B2 (83.0%) were treated conservatively (overall 76.9%). Fracture instability according to the OTA/Tile classification increased the probability for an operative treatment (generalized odds ratio [OR] 6.90 [5.62; 8.52]). In contrary, increasing age independent of the fracture pattern decreased this probability (OR 0.47 [0.41-0.53]). With increasing fracture instability, general health conditions were up to 50% of the reasons for conservative treatment., Conclusion: The results of the present study underline the importance of the factors age and general health besides fracture classification for therapeutic decision-making in the treatment of pelvic ring fractures in the elderly.

In order to achieve a clinically satisfying result and to prevent posttraumatic osteoarthritis in the treatment of unstable syndesmotic injuries, anatomically correct reduction is crucial. The objective of the study was to investigate three different reduction methods of the ankle mortise in unstable syndesmotic injuries. In a specimen model with 38 uninjured fresh-frozen lower legs, a complete syndesmotic dissection was performed. The ankle mortise was reduced with either a collinear reduction clamp, a conventional reduction forceps or manually with crossing K-wires. The reduction clamps and the K-wires were placed in a 0°-angle to the leg axis. The clamps were positioned on the posterolateral ridge of the fibula 20 mm proximal to the ankle joint line. A cone beam computed tomography was performed after dissection and after each reduction. Tibio-fibular distances and angles were determined. Despite significant differences in terms of overcompression (0.09-0.33 mm; p = 0.000-0.063) and the slight external rotation (0.29-0.47°; p = 0.014-0.07), the results show a satisfying reduction of the ankle mortise. There were no considerable differences between the reduction methods. It can therefore be concluded that the ankle mortise can be reduced with any of the methods used, but that the positioning and the contact pressure must be considered.

Pelvic fractures may range from highly severe, life-threatening injuries to less acute clinical entities. There are several sub-entities that are summed up as pelvic injuries. Anatomically, there are fractures of the anterior or posterior pelvic ring. Apart from these, there are fractures of the acetabulum that make up about one fifth of all pelvic injuries. The indication for surgical treatment of pelvic ring injuries depends on the type of injury, involvement of anterior and/or posterior elements of the pelvic ring, demands and the general condition of the patient. In acetabular fractures, indications depend on the dislocation of the fracture and of course also the needs of the patient and his general condition. An intraarticular step-off of more than 2 mm is usually considered as an indication for open reduction and osteosynthesis. Usually in all these injuries, a preoperative CT scan is mandatory to allow precise planning of the operative approach and technique. Intraoperatively, the surgeon should be familiar with the acquisition of the 2D standard views, including 2D imaging of the pelvic ring and the acetabulum. These consist of the anteroposterior view for both pelvic ring and acetabular osteosyntheses. For further assessment of pelvic ring treatments, inlet and outlet views are achievable by angulating the C-arm cranially and caudally. To assess aspects of the anterior and posterior column of the acetabulum, iliac oblique views are used. Here, the C-arm is rotated laterally. As evaluation of 2D views can be limited due to anatomy and superposing structures, intraoperative 3D imaging has become common in the last decade. Special C-arms allow the automatic acquisition of large numbers of projections and create CT-like views of the central volume. Although this method has significantly widened the possibilities of intraoperative imaging, some issues remain. Depending on the amount of implants placed in the imaging field, assessment can be seriously impaired due to artefacts caused by the implants. Intraoperative CT imaging promises enhanced image quality for artefacts and allows a considerably larger field of view. The use of radiation-free navigation facilitates implant placement in minimally invasive procedures like screw placement in the sacroiliacal joint or the acetabulum by visualisation of instruments and implants in a pre- or intraoperative 3D data set., Competing Interests: One of the authors received lecture fees from Brainlab AG (Munich)./Einer der Autoren erhielt Vortragshonorare von der Brainlab AG (München)., (Georg Thieme Verlag KG Stuttgart · New York.)

Introduction: The aim of this study was to evaluate the intraoperative revision rate and reasons for revision following 3D imaging in the management of dislocated articular tibial plateau fractures based on a large patient sample., Methods: This retrospective cohort study included all patients who underwent open reduction and internal fixation due type B or C tibial plateau fracture according to the AO/OTA classification between August 2001 and December 2017 using intraoperative cone beam CT (3D imaging) for the analysis of fracture reduction and implant placement. The findings of the 3D scan were categorized regarding the amount and type of revision. Furthermore, demographic data was examined., Results: Five hundred and fifty-nine consecutive fractures were included in the study. Evaluation of the image data records revealed an intraoperative revision due to the usage of 3D imaging in 148 out of 559 cases (26.5%). The most common reasons for an intraoperative revision were insufficient fracture reduction (114 cases) and screw length (21 cases)., Conclusion: This study reveals indications for a limited analysis of fracture reduction and implant placement during the operative treatment of dislocated articular tibial plateau fractures using conventional fluoroscopy. In view of the high revision rate during open reduction and internal fixation of tibial plateau fractures due to 3D imaging the usage of intraoperative cone beam, CT may be considered. If this is not possible, a postoperative computed tomography may therefore be reasonable.

Background: The precise anatomical reduction of the ankle mortise is crucial for the clinical outcome in unstable syndesmotic injuries. Intraoperative cone beam computed tomography (CT), in addition to two-dimensional fluoroscopy, provides detailed information about the reduction and implant placement. The aim of this study was to analyze the influence of the joint position on the fibula position in the incisural notch and to determine the inter- and intraindividual anatomical differences in the intact ankle joints., Methods: A total of 20 fresh-frozen lower legs disarticulated in the knee joint of 10 individuals were included. The measurements were performed using a cone beam CT. The distances and angles were measured in the standard imaging planes. The mean values of distances and angles were compared during the different joint positions: 10° dorsiflexion, 0° neutral position and 20° plantar flexion., Results: The influence of the joint position was on average as follows: The anterior tibiofibular distance was 3.68 mm in 10° dorsiflexion, 3.66 mm (0° neutral position) and 3.59 mm (20° plantar flexion). The posterior tibiofibular distance measured 7.82mm, 7.76mm and 7.82mm. The rotation of the fibula measured ten millimeters proximal the joint line was 1.2°, 1.3° and 1.05°. The fibular rotation determined 4mm was 9.3°, 9.4° and 9.4°. On average, the following intraindividual variations were observed: superior tibiotalar clear space of 0.27mm and 0.15mm medial; and anterior tibiofibular distance of 0.42mm, 0.38mm posterior and 0.24mm in the incisural notch. The proximal angle of the fibular rotation was 0.2° and distal 0.4°. The interindividual variations of the angles and distances exceeded the intraindividual values partly by 3 to 4 fold., Conclusions: Within the scope of this study neither the tibiofibular distance, nor the tibiofibular angle changed significantly through the different joint positions. The intraindividual differences were little while the interindividual variations of the parameters were distinctive., Competing Interests: The MINTOS research group received grants pending from Siemens (Erlangen, Germany). The following authors declared potential conflicts of interest: Jochen Franke, MD, is a paid lecturer for Siemens; Paul A Grützner, MD, is a paid lecturer for Siemens. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Background: In professional motorbike racing falls with high velocities are common. Nonetheless, severe injuries or deaths are rare when compared to regular road traffic., Methods: In this study, falls in all courses of the largest German race series IDM*Superbike between 2007 and 2013 were analyzed regarding injury patterns and hospital admissions. All races were accompanied by a medical team, including at least one physician who assessed every patient., Results: A total of 728 falls were included. A specific fall mechanism could be determined in 45.5% of the cases. 40.5% were admitted to a trauma center for further diagnostics. A definitive diagnosis was found in 45.4%. In most cases (29.9%) the injury pattern was a fracture of the extremities. In collisions a significantly higher odds ratio of 2.52 (P=0.0001) and in undetermined falls a significantly lower odds ratio of 0.47 (P<0.0001) was observed., Conclusions: Fall patterns in professional motorbike racing do not significantly correlate with the severity of the injury. Thus, as in regular patient evaluation, each patient has to be examined thoroughly to avoid misinterpretation.

Background: Being a proven method in trauma and spine surgery, intraoperative 3D imaging (CBCT) has intrinsic deficits in difficult anatomy and with artifacts because of metal implants. The purpose of this study was to evaluate the use of intraoperative computed tomography (iCT) in acetabular surgery., Methods: Ten cases of acetabular fractures that were operated with intraoperative use of the mobile CT scanner Brainlab Airo were analyzed. Data were compared with a historical group of 17 patients., Results: Additional fluoroscopy time was 24.2 seconds (6-91), which was significantly lower than in the control group where it was 211.4 seconds (77-446; P < 0.000). Operation time did not differ significantly (iCT group 196.8 min [122-288], control group 240.8 min [71-411], P = 0.234)., Conclusion: iCT provides images of a reliable high quality and assessability. Radiation exposure to the staff is reduced while surgery time is not altered significantly. Quality of intraoperative imaging and thus patient care can substantially improve patient outcome., (© 2019 John Wiley & Sons, Ltd.)

A silicon-aluminum heterocycle LAl(SiH2SiH2)2AlL (L = PhC(NtBu)2) (1) was prepared. Compound 1 exhibits a unique (N2Al)2(SiH2)4 centrosymmetric six-membered ring structure with a chair conformation, which is comparable with that of cyclohexane. Furthermore, two intermediate analogues, silylene-alane adduct LSi(AlMe3)-Si(AlMe3)L (2) and silylene-alane oxidative product [LAlHSiH2Mes]2 (3) were obtained. Compound 3 has an interesting arrangement of an Al-H and an SiH2 unit, which are in close vicinity to each other. 3 might be important to function as a catalyst, due to the already activated bridging Al-H bonds.

Introduction: The objective of the study was to compare the radiologic and clinical outcome of patients with an isolated displaced talus fracture treated intra-operatively with either conventional fluoroscopy or additional cone beam computed tomography (CT)., Methods: Conventional intraoperative fluoroscopy was performed in group 1 and cone beam CT was added in group 2. Clinical outcome was assessed using the Foot Function Index (FFI), American Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale, and the Short-Form 12 (SF-12) survey. In addition, the Kellgren-Lawrence score using X-rays was determined., Results: Overall, 24 cases were examined (group 1: 8 cases; group 2: 16 cases), with a mean follow up of 6.66 years. The FFI (group 1: 28.85 ± 22.78; group 2: 14.96 ± 15.11 points; p = 0.768), the AOFAS (group 1: 69.00 ± 24.71; group 2: 78.79 ± 17.07 points; p = 0.438), and the physical and mental component of the SF-12 (group 1: 44.79 ± 12.55; group 2: 47.63 ± 10.69 points; p = 0.136) (group 1: 46.19 ± 9.72; group 2: 53.57 ± 8.51; p = 0.242) did not differ significantly. Osteoarthritis of the talonavicular, subtalar, and ankle joints assessed using the Kellgren-Lawrence score appeared to be minor in the cone beam CT group but did not show significant differences (p = 0.309; p = 0.663; p = 0.082 respectively)., Discussion: Intraoperative cone beam CT in addition to conventional fluoroscopy might be beneficial in the operative treatment of talar fractures but a statistical significance could not be demonstrated.

The reconstruction of anatomical joint surfaces, limb alignment and rotational orientation are crucial in the treatment of fractures in terms of preservation of function and range of motion. To assess reduction and implant position intra-operatively, mobile C-arms are mandatory to immediately and continuously control these parameters.Usually, these devices are operated by OR staff or radiology technicians and assessed by the surgeon who is performing the procedure. Moreover, due to special objectives in the intra-operative setting, the situation cannot be compared with standard radiological image acquisition. Thus, surgeons need to be trained and educated to ensure correct technical conduct and interpretation of radiographs.It is essential to know the standard views of the joints and long bones and how to position the patient and C-arm in order to acquire these views. Additionally, the operating field must remain sterile, and the radiation exposure of the patient and staff must be kept as low as possible.In some situations, especially when reconstructing complex joint fractures or spinal injuries, complete evaluation of critical aspects of the surgical results is limited in two-dimensional views and fluoroscopy. Intra-operative three-dimensional imaging using special C-arms offers a valuable opportunity to improve intra-operative assessment and thus patient outcome.In this article, common fracture situations in trauma surgery as well as special circumstances that the surgeon may encounter are addressed. Cite this article: EFORT Open Rev 2018;3:541-549. DOI: 10.1302/2058-5241.3.170074., Competing Interests: ICMJE Conflict of interest statement: H. Keil declares grants from Siemens Healthcare AG; payment for lectures from Brainlab AG, activities outside the submitted work. P. Grützner declares grants and payment for lectures from Siemens Healthcare AG, activities outside the submitted work. J. Franke declares grants, consultancy, support for travel to meetings and payment for lectures from Siemens Healthcare AG, activities outside the submitted work.

Background: A virtual guidance framework is used to assist the conventional method of virtual implant planning system (VIPS). The study null hypothesis was that its screw placement accuracy is equal to that of conventional VIPS., Methods: In 34 distal radius sawbone models, 3D implant planning was performed. A camera attached to the surgical drill was used to support screw positioning. Differences of angles/tip distances between planned and placed screws were identified in intraoperative cone beam Computer tomography (CT) and compared with already existing data from 22 patients treated by conventional VIPS., Results: The virtual guidance group showed tip distances of 1.02 ± 0.56 mm, azimuth of 3.69° ± 4.34°, and inclination of 1.75° ± 1.37°, whereas the VIPS group showed tip distances of 2.23 ± 0.99 mm (P < 0.001), azimuth of 23.17° ± 33.50° (P < 0.001), and inclination angle of 4.18° ± 6.29° (P = 0.001)., Conclusions: The results reveal that using a guidance framework leads to a higher accuracy in screw placement compared with the conventional VIPS itself., (© 2018 John Wiley & Sons, Ltd.)

Background: In acetabular fractures, the assessment of reduction and implant placement has limitations in conventional 2D intraoperative imaging. 3D imaging offers the opportunity to acquire CT-like images and thus to improve the results. However, clinical experience shows that even 3D imaging has limitations, especially regarding artifacts when implants are placed. The purpose of this study was to assess the difference between intraoperative 3D imaging and postoperative CT regarding reduction and implant placement., Methods: Twenty consecutive cases of acetabular fractures were selected with a complete set of intraoperative 3D imaging and postoperative CT data. The largest detectable step and the largest detectable gap were measured in all three standard planes. These values were compared between the 3D data sets and CT data sets. Additionally, possible correlations between the possible confounders age and BMI and the difference between 3D and CT values were tested., Results: The mean difference of largest visible step between the 3D imaging and CT scan was 2.0 ± 1.8 mm (0.0-5.8, p = 0.02) in the axial, 1.3 ± 1.4 mm (0.0-3.7, p = 0.15) in the sagittal and 1.9 ± 2.4 mm (0.0-7.4, p = 0.22) in the coronal views. The mean difference of largest visible gap between the 3D imaging and CT scan was 3.1 ± 3.6 mm (0.0-14.1, p = 0.03) in the axial, 4.6 ± 2.7 mm (1.2-8.7, p = 0.001) in the sagittal and 3.5 ± 4.0 mm (0.0-15.4, p = 0.06) in the coronal views. A positive correlation between the age and the difference in gap measurements in the sagittal view was shown (rho = 0.556, p = 0.011)., Conclusions: Intraoperative 3D imaging is a valuable adjunct in assessing reduction and implant placement in acetabular fractures but has limitations due to artifacts caused by implant material. This can lead to missed malreduction and impairment of clinical outcome, so postoperative CT should be considered in these cases.

Introduction: In operative treatment of distal radius fractures satisfying outcome mainly relies on anatomical fracture reduction and correct implant placement. Examination with two-dimensional fluoroscopy may not provide reliable information about this. The aim of this study was to determine the effectiveness of additional intraoperative three-dimensional imaging in the operative treatment of comminuted distal radius fractures., Materials and Methods: From August 2001 to June 2015, patients with a distal radius fracture who were treated operatively and received intraoperative three-dimensional scan were included. The findings of the three-dimensional scan were documented by the operative surgeon and analyzed retrospectively with regard to incidence and the need for intraoperative revisions. Clinical evaluation included the patient's medical history, the injury pattern of the affected wrist (according to the OTA/AO fracture classification) and concomitant injuries. Intraoperative and postoperative complications and revision surgeries were evaluated as well., Results: Of 4515 operatively treated distal radius fractures, 307 (6.8%) received additional intraoperative three-dimensional imaging during surgery. 263 of 307 patients (85.7%) had a distal radius fracture type C. Intraoperative three-dimensional imaging revealed findings in 125 patients (40.7%) that were not detected on conventional two-dimensional fluoroscopy. In 54 patients (17.6%) these findings led to an immediate revision. Most commonly, revision was done in the case of remaining steps in the articular surface ≥ 1 mm (n = 25, 8.1%) followed by intra-articular screw placement (n = 23, 7.5%)., Conclusions: Intraoperative three-dimensional imaging can provide additional information compared to conventional two-dimensional fluoroscopy in the operative treatment of distal radius fractures with the possibility of immediate intraoperative revision.

Background: Indirect screw fixation of the sustentaculum tali in the lateral-medial direction can be challenging due to the complex calcaneal anatomy. A novel 2-dimensional (2D) projection-based software application detects Kirschner wires (K-wires) and visualizes their intended direction as a colored trajectory. The aim of this prospectively randomized cadaver study was to investigate whether the software would facilitate the indirect K-wire placement in the sustentaculum tali., Methods: In 20 cadaver foot specimens, K-wires were placed indirectly in the sustentaculum tali by an experienced and an inexperienced surgeon, with and without using the application. Number of placement attempts, duration of procedure, fluoroscopy time, and number of individual fluoroscopy images were recorded. Each wire's position was analyzed in a 3-dimensional (3D) C-arm scan by an experienced blinded investigator., Results: Use of the software by the inexperienced surgeon significantly reduced the number of placement attempts from 3.2 to 1.2 ( P = .006). The application also reduced operating time, from 273 s to 199 s ( P = .15), and fluoroscopy time, from 41 s to 29 s ( P = .15). Using the software, the experienced surgeon had a longer operating time (139 s to 183 s; P = .30), longer fluoroscopy time (5.6 s to 9.2 s; P = .17), and more individual fluoroscopy images (11.6 to 14.8; P = .30). Wire position did not show significant differences in both cases., Conclusion: During indirect K-wire placement in the sustentaculum tali, the software appeared to be a useful tool for the inexperienced surgeon. In our chosen study setting, the experienced surgeon did not benefit from the software., Clinical Relevance: Possible indications for the software would be fractures of the proximal femur, sacrum, sacroiliac instabilities, vertebral bodies, scaphoid, Lisfranc joint, talus and calcaneus.

Background: The aim of this study is to determine the functional long-term outcome after non-operative and operative treatment of radial neck fractures in adults., Methods: Thirty-four consecutive patients with a mean age of 46.4 (18.0 to 63.0) years with a fracture of the radial neck who were treated between 2000 and 2014 were examined regarding the clinical and radiological outcome. Twenty patients were treated non-operatively, and 14 patients underwent surgery., Results: After a mean follow-up of 5.7 (2.0 to 15.7) years, the clinical scores showed good results in both groups. The Disabilities of Arm, Shoulder and Hand score was 16.1 (0 to 71.6) in the non-operative group and 8.8 (0 to 50.8) in the operative group, respectively. The Mayo Elbow Performance Score was 80.0 (30 to 95) in the non-operative group and 82.5 (35 to 95) in the non-operative group, respectively. The initial angle of the radial head towards the shaft (RHSA) was significantly higher in the operative group in the anterior-posterior plane (12.8° [2 to 23] vs. 26.3° [1 to 90], p = 0.015). In the follow-up radiographs, the RHSA was significantly lower in the operative group (15.1° [3 to 30] vs. 10.9° [3 to 18], p = 0.043). Five patients developed 7 complications in the non-operative group, and 7 patients developed 12 complications in the operative group. Revision rates were higher in the operative groups as 1 patient received radial head resection in the non-operative (5%) group while 7 patients in the operative group (50%) needed revision surgery., Conclusion: A good functional long-term outcome can be expected after operative and non-operative treatment of radial neck fractures in adults. If needed due to major displacement, open reduction is associated with a higher risk of complications and the need for revision surgery but can achieve similar clinical results., Trial Registration: DRKS DRKS00012836 (retrospectively registered).

Highly enantioselective iron-catalyzed C-H alkylations by inner-sphere C-H activation were accomplished with ample scope. High levels of enantiocontrol proved viable through a novel ligand design that exploits a remote meta-substitution on N-heterocyclic carbenes within a facile ligand-to-ligand H-transfer C-H cleavage., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Purpose: A new software application can be used without fixed reference markers or a registration process in wire placement. The aim was to compare placement of Kirschner wires (K-wires) into the proximal femur with the software application versus the conventional method without guiding. As study hypothesis, we assumed less placement attempts, shorter procedure time and shorter fluoroscopy time using the software. The same precision inside a proximal femur bone model using the software application was premised., Methods: The software detects a K-wire within the 2D fluoroscopic image. By evaluating its direction and tip location, it superimposes a trajectory on the image, visualizing the intended direction of the K-wire. The K-wire was positioned in 20 artificial bones with the use of software by one surgeon; 20 bones served as conventional controls. A brass thumb tack was placed into the femoral head and its tip targeted with the wire. Number of placement attempts, duration of the procedure, duration of fluoroscopy time and distance to the target in a postoperative 3D scan were recorded., Results: Compared with the conventional method, use of the application showed fewer attempts for optimal wire placement (p=0.026), shorter duration of surgery (p=0.004), shorter fluoroscopy time (p=0.024) and higher precision (p=0.018). Final wire position was achieved in the first attempt in 17 out of 20 cases with the software and in 9 out of 20 cases with the conventional method., Conclusions: The study hypothesis was confirmed. The new application optimised the process of K-wire placement in the proximal femur in an artificial bone model while also improving precision. Benefits lie especially in the reduction of placement attempts and reduction of fluoroscopy time under the aspect of radiation protection. The software runs on a conventional image intensifier and can therefore be easily integrated into the daily surgical routine., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Purpose: Determination of the appropriate treatment of unstable simple elbow dislocations is difficult and a topic of ongoing discussion. The aim of this study was to analyse the outcome and complications after surgery and conservative treatment, with special focus on post-traumatic joint laxity., Methods: In this retrospective study, 118 consecutive patients with simple elbow dislocations underwent stability testing by fluoroscopy after joint reduction and were assigned to groups 1 (slight), 2 (moderate) or 3 (gross) depending on post-traumatic joint laxity. All patients of group 1 underwent conservative treatment, and of group 3 primary ligament repair. In patients with moderate elbow laxity, the treatment was decided individually. All patients underwent a similar functional rehabilitation programme during treatment. Clinical outcome was determined after an average of 3.4 ± 1.5 years using the Mayo Elbow Performance Score (MEPS), and treatment-associated complications and revisions were recorded., Results: Forty-nine patients (41.5 %) were assigned to group 1, 41 patients (34.7 %) to group 2 and 28 patients (23.7 %) to group 3. In group 2, 22 patients underwent ligament repair, while 19 patients were treated conservatively. On average, an excellent MEPS was achieved in group 1 after conservative treatment (MEPS 95.8 ± 9.0), similar to results after ligament repair of grossly unstable elbows in group 3 (91.6 ± 11.7). Interestingly, in group 2 conservative treatment was associated with a slightly lower MEPS (90.0 vs. 95.7), and significantly fewer patients achieved an excellent MEPS (81.8 vs. 52.6 %, p = 0.045). Similarly, conservative treatment in group 2 was associated with a fivefold to sixfold risk of complications (p = 0.032) and revision surgery (p = 0.023)., Conclusions: This study supports the notion that patients with slight elbow laxity can be treated non-operatively, while primary surgical treatment should be performed in patients with moderate and gross laxity to avoid post-traumatic sequelae and decrease revision rates., Level of Evidence: Retrospective Cohort Study, Level III.

The amount of high-quality habitat patches, their distribution, and the resource accessibility therein play a key role in regulating habitat effects on reproductive success. Heterogeneous habitats offer non-substitutable resources (e.g. nest sites and food) and substitutable resources (e.g. different types of food) in close proximity, thereby facilitating landscape complementation and supplementation. However, it remains poorly understood how spatial resource separation in homogeneous agricultural landscapes affects reproductive success. To fill this gap, we investigated the relationships between farmland heterogeneity and little owl (Athene noctua) reproductive success, including potential indirect effects of the heterogeneity-dependent home-range size on reproduction. Little owl home-ranges were related to field heterogeneity in summer and to structural heterogeneity in winter. Clutch size was correlated with the amount of food-rich habitat close to the nest irrespective of female home-range size, suggesting importance of landscape complementation. Nestling survival was positively correlated with male home-range size, suggesting importance of landscape supplementation. At the same time, fledgling condition was negatively correlated with male home-range size. We conclude that decreasing farmland heterogeneity constrains population productivity by two processes: increasing separation of food resources from nest or roost sites results in low landscape complementation, and reduction of alternative food resources limits landscape supplementation. Our results suggest that structural heterogeneity affects landscape complementation, whereas the heterogeneity and management of farmland fields affect landscape supplementation. Thus, to what extent a reduction of the heterogeneity within agricultural landscapes results in species-specific habitat degradation depends on the ecological processes (i.e. landscape complementation or supplementation) which are affected.

The reaction of LAl: (L = HC[C(Me)N(Ar)] 2 , Ar = 2,6-iPr 2 C 6 H 3 ) and cAAC:→AlX 3 (X = Cl, I) (cAAC = cyclic alkyl amino carbene) results in strikingly asymmetric Al(ii)-Al(ii) compounds LAl(X)-Al(X) 2 -cAAC [X = Cl (2a); I (2b)]. In these dialuminum(ii) compounds the two Al atoms bear different ligand environments. For a detailed insight into the structures, theoretical calculations were carried out.

Background: The primary objective of this study was to assess the interobserver and intraobserver agreement on ligamentous injuries on conventional magnetic resonance imaging (MRI) in acute simple elbow dislocation. The secondary objectives were to determine the interobserver agreement on the assessment of joint congruity, joint effusion, loose bodies and chondral lesions on conventional MRI., Methods: Conventional MRIs (1.5 Tesla, elbow specific surface coil) of 30 patients (40.7 years; range 14-72) with simple elbow dislocations were evaluated by four blinded examiners. An analysis of the interobserver agreement of all raters and for several subgroups (radiologists, orthopaedics, experienced, non-experienced) was performed. The examiners assessed the integrity (intact, partial tear, complete tear) of the lateral collateral ligament (LCL), medial collateral ligament (MCL), extensor and flexor tendons, as well as the presence of joint congruity, joint effusion, loose bodies and chondral lesions. Agreement strength, correlation and proportion of exact agreement were determined for interobserver agreement, and intraobserver agreement analyses., Results: Interobserver agreement of all examiners was fair to moderate for collateral ligaments (LCL: 0.441, MCL: 0.275). Exact agreement of all raters was found in 33.3% for the LCL and in 26.7% for the MCL. The both experienced examiners showed highest agreement strength for the LCL (0.619) and the radiologists showed highest agreement strength for the MCL (0.627), the proportion of exact agreement was 60.0% in both categories. A high proportion of exact agreement regarding joint congruity (90%), joint effusion (100%), loose bodies (96.7%) and chondral lesion (80%) was found among the radiologists. The evaluation of the intraobserver agreement revealed slight to substantial agreement (0.227 to 0.718) for the collateral ligaments., Conclusions: This study shows difficulties in the evaluation of ligaments by conventional MRI technique as demonstrated by a weak inter- and intraobserver agreement. This should be the basis to develop new MRI quality standards with special focus on coronal oblique reconstructions to improve the evaluation of ligament injuries after simple elbow dislocations.

Background: Fractures of the extremities are often complicated by a variable degree of swelling secondary to hemorrhage and soft tissue injury. Patients typically require up to 7 days of inpatient bed rest and elevation to reduce swelling to an acceptable level for operative treatment with internal fixation. Alternatively, an intermittent pneumatic compression device, such as the Vascular Impulse Technology (VIT) system, can be used at the injured extremity to reduce the posttraumatic swelling. The VIT system consists of a pneumatic compressor that intermittently rapidly inflates a bladder positioned under the arch of the hand or the foot, which results in compression of the venous hand or foot plexus. That intermittent compression induces an increased venous velocity and aims to reduce the soft tissue swelling of the affected extremity., Methods/design: The VIT study is a prospective, monocenter, randomized controlled trial to compare the VIT system with elevation in the treatment of posttraumatic swelling in the case of a fracture of the upper and lower extremity. This study will include 280 patients with fractures of the upper and the lower extremity with nine different injury types. For each of the nine injury types a separate randomization to the two intervention groups (VIT group or control group) will be performed. The primary outcome parameter is the time taken for the swelling to resolve sufficiently to permit surgery. A separate analysis for each of the nine injury types will be performed., Discussion: In the proposed study, the effectiveness of the VIT system in the treatment of posttraumatic swelling of upper and lower extremity fractures will be evaluated., Trial Registration: German Clinical Trial Register, No. DRKS00010510 . Registered on 17 July 2016.

The neutral radical (Me 2 -cAAC) 2 AlCl 2 (2) is stabilized by cyclic (alkyl)(amino)carbenes (cAACs). Complex 2 was synthesized by reduction of the Me 2 -cAAC:→AlCl 3 (1) adduct with KC 8 in the presence of another equivalent of Me 2 -cAAC. The crystal structure of 2 shows that the Al-C bond lengths of the two carbenes bound to the Al center are considerably different, which is likely the result of intermolecular interactions. Quantum-chemical calculations from the gas phase give an equilibrium structure with identical Al-C bond lengths. Compound 2 exhibits monoradical character, which was confirmed by EPR measurements. A bonding analysis indicates that the unpaired electron resides mainly at the carbene carbon atoms. Compound 2 is an example for an unusual neutral Al radical., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

This article presents the case of a high-grade deformity of the thoraco-lumbar spine. The patient suffered from a sarcoma that was radically resected. Due to adjuvant radiation, the patient suffered from a radiation injury with chronic fistula. In a two-stage approach, the deformity was corrected by a closing-wedge osteotomy of L3 with elongation of the present dorsal spondylodesis (Th10-L4) to Th8 and the iliac bone. Soft-tissue reconstruction was achieved by a free latissimus dorsi flap that was anastomosed to an axillary arterio-venous loop. The presented interdisciplinary approach allowed an almost complete correction of the deformity and stable soft-tissue coverage.

Background: The aim of this study was to develop and validate a novel self-administered questionnaire for assessing the patient's own range of motion (ROM) of the wrist and the elbow., Methods: In a prospective clinical study from January 2015 to June 2015, 101 consecutive patients were evaluated with a novel, self-administered, diagram-based, wrist motion assessment score (W-MAS) and elbow motion assessment score (E-MAS). The questionnaire was statistically evaluated for test-retest reliability, patient-physician agreement, comparison with healthy population, and influence of covariates (age, gender, affected side and involvement in workers' compensation cases)., Results: Assessment of patient-physician agreement demonstrated almost perfect agreement (k > 0.80) with regard to six out of eight items. There was substantial agreement with regard to two items: elbow extension (k = 0.76) and pronation (k = 0.75). The assessment of the test-retest reliability revealed at least substantial agreement (k = 0.70). The questionnaire revealed a high discriminative power when comparing the healthy population with the study group (p = 0.007 or lower for every item). Age, gender, affected side and involvement in workers' compensation cases did not in general significantly influence the patient-physician agreement for the questionnaire., Conclusion: The W-MAS and E-MAS are valid and reliable self-administered questionnaires that provide a high level of patient-physician agreement for the assessments of wrist and elbow ROM., Level of Evidence: Diagnostic study, Level II.

Objective: The aim of our Internet survey was to assess the preferences of burn specialists who use skin substitutes in patients with burns covering 20% or more of their total body surface area (TBSA)., Methods: An open, voluntary Internet-based cross-sectional survey was performed. Responses to 19 noncompulsory questions, and participant career and location information were collected., Results: One hundred eleven specialists from 36 countries responded to our questionnaire. Sixty participants were located in Europe (54%), followed by 31 (28%) in North America, 15 (14%) in Asia, three (3%) in South America, one (1%) in Africa, and one (1%) in Australia. The importance of skin substitutes in medium-sized burns (covering 20%-60% TBSA) was rated as "essential" by 28% and "desirable" by 56% of the respondents. In severe burns >60% of TBSA, 81% of responders rated the use of skin substitutes as "essential" and 14% as "desirable". Skin substitutes were used in daily clinical practice by 96% of all participants. Biological and synthetic dressings were used by 53%. A majority (86%) think that biological dressings do not pose a risk to patients. Allografts represent the most frequently used wound coverage (51%), followed by xenografts (28%). All participants of the survey indicated that as of yet, there is no ideal skin substitute available., Conclusions: Split-thickness autografts still represent the most used wound cover for definitive treatment of severe burns. However, creation and implementation of an ideal skin substitute have yet to be achieved and therefore should be the focus of future work., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Three-dimensional (3D) imaging with a mobile C-arm has proven to be a valuable intraoperative tool in trauma surgery. However, little data is available concerning its use in the treatment of elbow fractures. The aim of the current study was to determine the intraoperative findings and consequences of 3D imaging in the treatment of elbow fractures., Methods: Between 2001 and 2015, prospectively collected data of 36 patients who underwent intraoperative 3D imaging during elbow surgery were recorded. The findings and consequences of the intraoperative 3D scans were analyzed in a retrospective chart review. For clinical evaluation the analysis included the patients' medical history, the injury pattern of the affected elbow and concomitant injuries. Intraoperative and postoperative complications and revision surgeries were evaluated as well., Results: In 6 patients (16.7%) analysis of the intraoperative 3D scan led to an immediate revision due to the detection of intra-articular screw placement (n = 3, 8.3%) and remaining intra-articular step of >2 mm (n = 3, 8.3%). In all of these patients, correct implant positioning and anatomical reduction could be achieved after immediate intraoperative revision, which was verified by a repeated intraoperative 3D scan. None of the 36 patients needed surgical revision based on postoperative radiological examinations due to secondary dislocation, wrong implant placement or remaining steps in the articular surface., Conclusions: Intraoperative 3D imaging offers additional information about fracture reduction and implant positioning in the treatment of elbow fractures compared to conventional intraoperative 2D imaging. It may therefore reduce the need for revision surgery. The value of intraoperative 3D imaging for clinical outcomes still needs to be assessed.

The Me-cAAC:-stabilized dimer of silicon disulfide (SiS2 ) has been isolated in the molecular form as (Me-cAAC:)2 Si2 S4 (2) at room temperature [Me-cAAC:=cyclic alkyl(amino) carbene]. Compound 2 has been synthesized from the reaction of (Me-cAAC:)2 Si2 with elemental sulfur in a 1:4 molar ratio under oxidative addition. This is the smallest molecular unit of silicon disulfide characterized by X-ray crystallography, electron ionization mass spectrometry, and NMR spectroscopy. Structures with three sulfur atoms arranged around a silicon atom are known; however, 2 is the first structurally characterized silicon-sulfur compound containing one terminal and two bridging sulfur atoms at each silicon atom. Compound 2 shows no decomposition after storing for three months in an inert atmosphere at ambient temperature. The bonding of 2 has been further studied by theoretical calculations., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Lithium in the gel: The NMR spectroscopic properties of common organolithium and lithium amide reagents are investigated in the anisotropic environment of a stretched polystyrene (PS) gel. PS is stable towards reactive organometallic compounds and can be used at low temperatures. The residual quadrupolar couplings (RQCs) from a single (7)Li NMR spectrum can distinguish between high (hexamer, tetramer) and low (dimer, monomer) aggregation states (see scheme)., (Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Enhancement of flap survival through extracorporeal shock wave treatment (ESWT) is a promising new technique; however, no attempt has been made to define the optimal time point and frequency of ESWT to optimize treatment with ESWT for ischemic indications. Twenty-eight male Wistar rats were randomized into 4 groups and an oversized, random-pattern flap was raised and reattached in place in each animal. ESWT was applied 7 days before (group E7) or immediately after the surgical intervention (group E0). The third group was treated with ESWT 7 days before and additionally immediately after the operation (group E7/0). The fourth group served as a control group and did not receive any ESWT (group C). Seven days after flap harvest the results of flap survival, perfusion, microvessel density, and vascular endothelial growth factor concentrations were assessed. Flap survival was significantly increased in all ESWT groups as compared with the control group. The groups (E7 and E0) that received ESWT pre- or postoperatively showed a significant increase in flap perfusion and microvessel density. Combined pre- and postoperative ESWT application (group E0/E7) did not demonstrate a cumulative effect in any evaluation. In this study, we were be able to prove the effectiveness of ESWT in the protection of ischemic tissue flaps. This study suggests that single postoperative application is the most efficacious protocol for clinical applications of ESWT in the treatment of ischemic tissue.