Osteomyelitis is associated with increased anti-inflammatory response and immune exhaustion

Introduction

Osteomyelitis (OMS) is a bone infection causing bone pain and severe complications. A balanced immune response is critical to eradicate infection without harming the host, yet pathogens manipulate immunity to establish a chronic infection. Understanding OMS-driven inflammation is essential for disease management, but comprehensive data on immune profiles and immune cell activation during OMS are lacking.

Methods

Using high-dimensional flow cytometry, we investigated the detailed innate and adaptive systemic immune cell populations in OMS and age- and sex-matched controls.

Results

Our study revealed that OMS is associated with increased levels of immune regulatory cells, namely T regulatory cells, B regulatory cells, and T follicular regulatory cells. In addition, the expression of immune activation markers HLA-DR and CD86 was decreased in OMS, while the expression of immune exhaustion markers TIM-3, PD-1, PD-L1, and VISTA was increased. Members of the T follicular helper (Tfh) cell family as well as classical and typical memory B cells were significantly increased in OMS individuals. We also found a strong correlation between memory B cells and Tfh cells.

Discussion

We conclude that OMS skews the host immune system towards the immunomodulatory arm and that the Tfh memory B cell axis is evident in OMS. Therefore, immune-directed therapies may be a promising alternative for eradication and recurrence of infection in OMS, particularly in individuals and areas where antibiotic resistance is a major concern.

Proximal Femur Fractures - How Decisive are Reduction and the Chosen Implant?

Proximal femoral fractures are frequent and complex injuries requiring prompt and targeted care. Numerous treatment strategies have been described, some of which have been assessed and clinically implemented clinically. The aim of surgical is always the restoration of a pain-free and stable extremity. Mostly elderly patients are affected and treatment is associated with high postoperative complications and mortality rates. With increasing numbers of patients, the topic is of great medical and economic relevance. In this work, the choice of implants for the osteosynthesis of proximal femoral fractures - as depending on the fracture type - will be examined, as based on a review of current literature. Standard care includes cannulated screws, sliding hips screws and cephalomedullary nails. In addition, the influence of implant positioning, fracture reduction and additional measures such as cement augmentation are evaluated and discussed. Careful fracture reduction and the quality of implant positioning are paramount in order to avoid complications.

Comparison of Minced Cartilage Implantation with Autologous Chondrocyte Transplantation in an In Vitro Inflammation Model

The current gold standard to treat large cartilage defects is autologous chondrocyte transplantation (ACT). As a new surgical method of cartilage regeneration, minced cartilage implantation (MCI) is increasingly coming into focus. The aim of this study is to investigate the influence of chondrogenesis between isolated and cultured chondrocytes compared to cartilage chips in a standardized inflammation model with the proinflammatory cytokine TNFα. Articular chondrocytes from bovine cartilage were cultured according to the ACT method to passage 3 and transferred to spheroid culture. At the same time, cartilage was fragmented (<1 mm3) to produce cartilage chips. TNFα (20 ng/mL) was supplemented to simulate an inflammatory process. TNFα had a stronger influence on the passaged chondrocytes compared to the non-passaged ones, affecting gene expression profiles differently between isolated chondrocytes and cartilage chips. MCI showed less susceptibility to TNFα, with reduced IL-6 release and less impact on inflammation markers. Biochemical and histological analyses supported these findings, showing a greater negative influence of TNFα on the passaged pellet cultures compared to the unpassaged cells and MCI constructs. This study demonstrated the negative influence of TNFα on chondrogenesis in a chondrocyte spheroid culture and cartilage fragment model. Passaged chondrocytes are more sensitive to cytokine influences compared to non-passaged cells and chondrons. This suggests that MCI may have superior regeneration potential in osteoarthritic conditions compared to ACT. Further investigations are necessary for the translation of these findings into clinical practice.

An Updated Overview of Risk Factors for Shoulder Stiffness

A painful reduction in shoulder mobility, known as "shoulder stiffness", can occur both as a primary idiopathic condition and as a secondary condition, for example, following surgical procedures. Various factors can contribute to the development of primary shoulder stiffness. In this review we summarize the pathophysiological mechanisms, genetic influences, endocrine disorders, metabolic conditions, as well as other diseases and medical-therapeutic approaches that might have an impact on the development of primary shoulder stiffness.

Economic Effects of the SARS-CoV-2 Pandemic in 2020

INTRODUCTION

In 2020, the SARS-CoV-2 pandemic necessitated an adjustment to the care structure in all medical facilities in Germany. In this study we analysed the effects of the SARS-CoV-2 pandemic using the data from the annual balance sheet of a university department and maximum care provider for orthopaedics and trauma surgery.

METHODS

Data analysis was performed on the clinic's performance parameters from 2019 and 2020. The analysis included 52943 outpatient and 7980 inpatient cases, together with the Case Mix Index (CMI), and the costs and revenues.

RESULTS

As a result of the reduction in scheduled surgeries, the mean number of inpatients in March and April 2020 decreased by 10.4% (p = 0.004). Due to the focus on complex cases, the CMI increased by 29.5% (p = 0.007). The number of outpatient surgical procedures increased by 16.9% (n = 84). Rising costs of consumables due to the purchase of protective equipment were offset by a reduced need for orthopaedic implants.

CONCLUSION

By reducing the number of elective inpatient surgical treatments, the focus was shifted to treating complex cases; this is reflected in the increased CMI. Due to internal compensation mechanisms, the clinic was able to conserve intensive care capacities while still achieving an increase in revenue.

Effects of single and repeated shock wave application on the osteogenic differentiation potential of human primary mesenchymal stromal cells and the osteoblastic cell line MG63 in vitro

Introduction: Extracorporeal shock wave therapy is a non-invasive and effective option for treating various musculoskeletal disorders. Recent literature indicates that the parameters for extracorporeal shock wave therapy, such as the optimal intensity, treatment frequency, and localization, are yet to be determined. Studies reporting on the effects of shock wave application on primary mesenchymal stromal cells (MSCs) as well as osteoblastic cell lines in vitro are barely available and not standardized. Methods: In this study, we designed a special setup to precisely expose primary MSCs and the osteoblastic cell line MG63 to shock waves and subsequently analyzed the resulting cellular responses using standardized protocols to investigate their viability, proliferation behavior, cytokine secretion, and osteogenic differentiation potential in vitro. The shock wave transducer was coupled to a specifically designed water bath containing a 5 mL tube holder. Primary human MSCs and MG63 cells were trypsinated and centrifuged in a 5 mL tube and exposed to single and repeated shock wave application using different intensities and numbers of pulses. Results: Single treatment of MSCs using intensities 5, 10, 15, and 20 and pulse numbers 100, 250, 500, 750, and 1,000 at a constant pulse repetition frequency of 1 Hz resulted in a decreased viability and proliferation of both cell types with an increase in the intensity and number of pulses compared to controls. No significant difference in the osteogenic differentiation was observed at different time intervals in both cell types when a single shock wave application was performed. However, repeated shock wave sessions over three consecutive days of primary MSCs using low intensity levels 0.1 and 1 showed significant osteogenic differentiation 4-fold higher than that of the extracted Alizarin Red S at day 14, whereas MG63 cells showed no significant osteogenic differentiation compared to their corresponding controls. More specifically, repeated shock wave application triggered a significant downregulation of COL1A1, upregulation of RUNX2, and sustained increase of OCN in primary MSCs but not in the cell line MG63 when induced toward the osteogenic differentiation. Discussion: The effects of shock wave application on MSCs make it an effective therapy in regenerative medicine. We established a protocol to analyze a standardized shock wave application on MSCs and were able to determine conditions that enhance the osteogenic differentiation of MSCs in vitro.

The Influence of Sagittal Pin Angulation on the Stiffness and Pull-Out Strength of a Monolateral Fixator Construct

Monolateral pin-to-bar-clamp fixators are commonly used to stabilize acute extremity injuries. Certain rules regarding frame geometry have been established that affect construct stability. The influence of sagittal pin angulation on construct stiffness and strength has not been investigated. The purpose of this biomechanical study was to demonstrate the effect of a pin angulation in the monolateral fixator using a composite cylinder model. Three groups of composite cylinder models with a fracture gap were loaded with different mounting variants of monolateral pin-to-bar-clamp fixators. In the first group, the pins were set parallel to each other and perpendicular to the specimen. In the second group, both pins were set convergent each in an angle of 15° to the specimen. In the third group, the pins were set each 15° divergent. The strength of the constructions was tested using a mechanical testing machine. This was followed by a cyclic loading test to produce pin loosening. A pull-out test was then performed to evaluate the strength of each construct at the pin-bone interface. Initial stiffness analyses showed that the converging configuration was the stiffest, while the diverging configuration was the least stiff. The parallel mounting showed an intermediate stiffness. There was a significantly higher resistance to pull-out force in the diverging pin configuration compared to the converging pin configuration. There was no significant difference in the pull-out strength of the parallel pins compared to the angled pin pairs. Convergent mounting of pin pairs increases the stiffness of a monolateral fixator, whereas a divergent mounting weakens it. Regarding the strength of the pin-bone interface, the divergent pin configuration appears to provide greater resistance to pull-out force than the convergent one. The results of this pilot study should be important for the doctrine of fixator mounting as well as for fixator component design.

A Worldwide Analysis of Adipose-Derived Stem Cells and Stromal Vascular Fraction in Orthopedics: Current Evidence and Applications

The biological enhancement of tissue regeneration and healing is an appealing perspective in orthopedics. We aimed to conduct a systematic review to describe the global distribution of studies investigating the use of adipose tissue derivates in orthopedics and to provide information on their quality and on the products available. The quality of the included studies was assessed using the modified Coleman Methodology Score (mCMS) and the Cochrane risk-of-bias tool for randomized trials. Eighty-two studies were included, with a total of 3594 patients treated. In total, 70% of the studies investigated the treatment of knee disorders, predominantly osteoarthritis; 26% of all studies dealt with expanded adipose-derived stem/stromal cells (ADSCs), 72% of which had stromal vascular fraction (SVF); 70% described the injection of adipose tissue derivates into the affected site; and 24% described arthroscopies with the addition of adipose tissue derivates. The mean mCMS for all studies was 51.7 ± 21.4 points, with a significantly higher score for the studies dealing with expanded ADSCs compared to those dealing with SVF (p = 0.0027). Our analysis shows high heterogeneity in terms of the types of performed procedures as well as the choice and processing of adipose tissue derivates.

Epidemiology and specific features of shoulder injuries in patients affected by epileptic seizures

PURPOSE

Epileptic seizures can cause multiple shoulder injuries, the most common of which are dislocations, recurrent instability, fractures, and isolated lesions of the rotator cuff. Currently, only limited literature exists which describes the frequency and types of lesions in cohorts of epileptic patients and the corresponding treatment outcome. This study aims to document the occurrence of shoulder lesions in patients affected by seizures and to provide detailed information on trauma dynamics, specific lesion characteristics and treatment complications.

METHODS

All patients referring to a tertiary epilepsy center were screened for shoulder injuries and the clinical records of those sustaining them during a seizure were reviewed. Demographic information, lesions' characteristics and trauma dynamics were analysed, as wells as-when carried out-the type of surgical intervention and any postoperative complications.

RESULTS

The average age at the time of injury of 106 included patients was 39.7 ± 17.5 years and a male predominance was recorded (65%). Bilateral injuries occurred in 29 patients, simultaneously in 17 cases. A younger age, bilateral shoulder injuries and shoulder dislocations were significantly associated with the occurrence of a shoulder injury solely by muscular activation (p = 0.0054, p = 0.011, p < 0.0001). The complication rate in 57 surgically treated patients with follow-up data was 38.7%, with recurring instability being the most frequently reported complication (62.5%).

CONCLUSIONS

Uncontrolled muscle activation during a seizure is a distinctive but not exclusive dynamic of injury in epileptic patients, accounting for more than the half of all shoulder lesions, especially in the younger. This can lead both to anterior and posterior dislocations or fracture-dislocations and is frequently cause of bilateral lesions and of instability recurrence after surgery. The high complication rates after surgical treatment in this selected subgroup of patients require that appropriate preventative measures are taken to increase the probability of treatment success.

LEVEL OF EVIDENCE

Cohort study, level III.

COVID-19 measures as an opportunity to reduce the environmental footprint in orthopaedic and trauma surgery

Background

Climate change and its consequences on our everyday life have also tremendous impacts on public health and the health of each individual. The healthcare sector currently accounts for 4.4% of global greenhouse gas emissions. The share of the emissions in the health care system caused by the transportation sector is 7%. The study analyses the effect of video consultation on the CO₂ emissions during the Covid-19 pandemic in an outpatient clinic of the department of orthopaedics and traumatology surgery at a German university hospital.

Methods

The study participants were patients who obtained a video consultation in the period from June to December 2020 and voluntarily completed a questionnaire after the consultation. The type of transport, travel time and waiting time as well as patient satisfaction were recorded by questionnaire.

Results

The study comprised 51 consultations. About 70% of respondents would have travelled to the clinic by car. The reduction in greenhouse gas emissions of video consultations compared to a face-to-face presentation was 97% in our model investigation.

Conclusion

The video consultation can be a very important part of the reduction of greenhouse gas emissions in the health care system. It also saves time for the doctor and patient and can form an essential part of individual patient care.

Agonistic and antagonistic targeting of immune checkpoint molecules differentially regulate osteoclastogenesis

Introduction

Immune checkpoint inhibitors are used in the treatment of various cancers and have been extensively researched with regard to inflammatory and autoimmune diseases. However, this revolutionary therapeutic strategy often provokes critical auto-inflammatory adverse events, such as inflammatory reactions affecting the cardiovascular, gastrointestinal, nervous, and skeletal systems. Because the function of these immunomodulatory co-receptors is highly cell-type specific and the role of macrophages as osteoclast precursors is widely published, we aimed to analyze the effect of immune checkpoint inhibitors on these bone-resorbing cells.

Methods

We established an in vitro model of osteoclastogenesis using human peripheral blood mononuclear cells, to which various immune checkpoints and corresponding antagonistic antibodies were administered. Formation of osteoclasts was quantified and cell morphology was analyzed via immunofluorescence staining, cell size measurements, and calculation of cell numbers in a multitude of samples.

Results

These methodical approaches for osteoclast research achieved objective, comparable, and reproducible results despite the great heterogeneity in the form, size, and number of osteoclasts. In addition to the standardization of experimental analyses involving osteoclasts, our study has revealed the substantial effects of agonistic and antagonistic checkpoint modulation on osteoclastogenesis, confirming the importance of immune checkpoints in bone homeostasis.

Discussion

Our work will enable more robust and reproducible investigations into the use of immune checkpoint inhibitors in conditions with diminished bone density such as osteoporosis, aseptic loosening of endoprostheses, cancer, as well as the side effects of cancer therapy, and might even pave the way for novel individualized diagnostic and therapeutic strategies.

The German version of the Nottingham Clavicle Score is a reliable and valid patient-reported outcome measure to evaluate patients with clavicle and acromioclavicular pathologies

PURPOSE

The Nottingham Clavicle Score (NCS) is a patient-reported outcome measure developed to evaluate treatment results of clavicle, acromioclavicular and sternoclavicular joint pathologies. Valid, reliable and user-friendly translations of outcome measure instruments are needed to allow comparisons of international results. The aim of this cross-sectional study was to translate and adapt the NCS into German and evaluate the psychometric properties of the German version.

METHODS

The translation and cross-cultural adaptation of the NCS were completed using a 'translation-back translation" method and the final version was administered to 105 German-speaking patients. The psychometric properties of this version (NCS-G) were evaluated in terms of feasibility, reliability, validity and sensitivity to change.

RESULTS

No major differences occurred between the NCS translations into German and back into English, and no content- or linguistic-related difficulties were reported. The Cronbach's alpha for the NCS-G was 0.885, showing optimal internal consistency. The Intraclass Correlation Coefficient for test-retest reliability was 0.907 (95% CI 0.844-0.945), with a standard error of measurement of 5.59 points and a minimal detectable change of 15.50 points. The NCS-G showed moderate to strong correlation with all other investigated scales (Spearman correlation coefficient: qDASH: ρ =  - 0.751; OSS: ρ = 0.728; Imatani Score: ρ = 0.646; CMS: ρ = 0.621; VAS: ρ =  - 0.709). Good sensitivity to change was confirmed by an effect size of 1.17 (95% CI 0.89-1.47) and a standardized response mean of 1.23 (95% CI 0.98-1.45).

CONCLUSIONS

This study demonstrated that NCS-G is reliable, valid, reproducible and well accepted by patients, showing analogous psychometric properties to the original English version.

LEVEL OF EVIDENCE

Level III.

Video Based Assessment of Treatment Urgency in Outpatient Orthopaedic and Trauma Patients - a Pilot Trial

INTRODUCTION

When consulting a specialist in orthopaedics and trauma surgery, personal assessment and manual clinical examination by the doctor on site are essential. Nevertheless, implementation of video consultation hours has been made legally easier in Germany. The present pilot study examines the possibility of video-based assessment of the urgency of treatment in outpatient orthopaedic and trauma patients.

MATERIALS AND METHODS

Within an ex ante study design, 40 patients with an orthopaedic clinical picture for trauma surgery with elective, urgent or emergency indication were selected from consultation hours. A short questionnaire was filled in based on the information provided and a medical colleague simulated a movement sequence based on the patient information. After modification to the "red flags" and "yellow flags" established in spinal orthopaedics, nine short questions were recorded, which inquire about the urgency of a medical consultation. The video-based movement sequence is based on a 60 s long instruction video in which motor tests and movement sequences are demonstrated: Cervical spine movement in all levels, elevation of the upper extremity, test of the finger-floor distance when "bending forward over-bending", possibility of crouching from standing and getting up again, standing on heels and toes.

RESULTS

In 91.1% (n = 328) of the cases, the diagnosis was associated with the same joint or the same pathological entity. In 37.5% (n = 135) of the cases an emergency indication was seen, in 10.8% (n = 39) of the cases an urgent indication and in 51.6% (n = 186) of the cases it was seen to offer an elective indication. 12.5% (n = 45) of the cases were evaluated as "false positives" with regard to an emergency or urgent presentation. This means that the test persons were classified as "emergency" or "urgent", although there was no preventable dangerous course or medical emergency. 18 cases (5%) were evaluated as "false negative".

DISCUSSION

The screening questionnaire presented and the short video assessment are technically feasible and practicable method for the initial evaluation in video-based online medical consultation. In addition, the questionnaire presented in combination with the short video assessment was suitable as an instrument for assessing the urgency of the consultation and selecting preventable dangerous processes and acute emergencies.

CONCLUSION

The questionnaire, in combination with the short video assessment, is a suitable method for the social distancing requirements during limited accessibility of the medical system. Nevertheless, a false negative rate of 5% is too high to implement the questionnaire presented into daily clinics without further optimisation.

The Role of Immune Checkpoint Molecules on Macrophages in Cancer, Infection, and Autoimmune Pathologies

Immune checkpoint inhibitors have revolutionized immunotherapy against various cancers over the last decade. The use of checkpoint inhibitors results in remarkable re-activation of patients’ immune system, but is also associated with significant adverse events. In this review, we emphasize the importance of cell-type specificity in the context of immune checkpoint-based interventions and particularly focus on the relevance of macrophages. Immune checkpoint blockade alters the dynamic macrophage phenotypes and thereby substantially manipulates therapeutical outcome. Considering the macrophage-specific immune checkpoint biology, it seems feasible to ameliorate the situation of patients with severe side effects and even increase the probability of survival for non-responders to checkpoint inhibition. Apart from malignancies, investigating immune checkpoint molecules on macrophages has stimulated their fundamental characterization and use in other diseases as well, such as acute and chronic infections and autoimmune pathologies. Although the macrophage-specific effect of checkpoint molecules has been less studied so far, the current literature shows that a macrophage-centered blockade of immune checkpoints as well as a stimulation of their expression represents promising therapeutic avenues. Ultimately, the therapeutic potential of a macrophage-focused checkpoint therapy might be maximized by diagnostically assessing individual checkpoint expression levels on macrophages, thereby personalizing an effective treatment approach for each patient having cancer, infection, or autoimmune diseases.

The base of coracoid process as a reference for glenoid reconstruction in primary or revision reverse shoulder arthroplasty: CT-based anatomical study

INTRODUCTION

Joint replacement surgery as a treatment for glenohumeral arthritis with glenoid bone loss is challenging. The aim of this study is to offer an anatomical orientation for glenoid reconstruction.

METHODS

In this study, we measured size, inclination and version of the glenoid surface, as well as the distance between the articular line of the glenoid, base of the coracoid process, and acromion using computer tomographic (CT) imaging of 131 study participants aged 19-88 years in the period of 2010-2013.

RESULTS

We measured a mean distance of 6.5 ± 0.2 mm from the glenoid articular line to the base of the coracoid process in the transverse CT plane. Body height has shown no significant impact on the glenoid morphology. We observed significant differences between males and females: The glenoid appeared to be located 5.2 ± 0.9 mm higher and the humeral head was 4.5 ± 0.7 mm larger in male subjects compared with females (r = .699; p < .01).

CONCLUSION

In our study, the base of the coracoid offers an anatomical reference during reconstruction of the glenoid in primary and revision shoulder arthroplasty. As only 2D-CT imaging allows for accurate assessment of glenoid bone defects, we consider conventional X-ray imaging insufficient for proper preoperative planning before shoulder arthroplasty.

LEVEL OF EVIDENCE

III.

[Climate change: how surgery contributes to global warming]

BACKGROUND

Surgery as an important part of the healthcare sector contributes to environmental pollution and therefore to the climate crisis. The aim of this review is to create an overview of the current data situation and possibilities for improvement.

METHODS

A literature search was performed in PubMed/MEDLINE using the following five terms: "carbon footprint and surgery", "climate change and surgery", "waste and surgery" and "greening the operating room" focusing on energy, waste, water and anesthesia.

RESULTS

The greatest part of emissions in surgery is generated by the use of energy. The operating rooms (OR) need 3-6 times more energy than the other hospital rooms. Of the total hospital waste 20-30% is produced during operations, which is particularly due to the increasing use of disposable articles and 50-90% of waste classified as hazardous is incorrectly sorted. The disposal of this waste is not only more environmentally harmful but also much more expensive. The processing of surgical items by autoclaving consumes large amounts of water. Modern sterilization methods, for example using plasma could be future alternatives. Up to 20% of volatile nonmetabolized anesthetic agents are vented into the stratosphere and destroy the ozone layer. Intravenous anesthetic drugs should be used whenever possible instead. The choice of operating method can also contribute to the environmental impact of an operation.

CONCLUSION

The surgical disciplines are a relevant producer of environmental pollutants. Through diverse interdisciplinary approaches surgery can also contribute to protecting the environment.

Practicability of a Virtual Consultation to Evaluate the Shoulder Joint

OBJECTIVE

In the course of the corona pandemic, resource conservation and the protection of further infections have made it necessary to break new ground in the organisation of orthopaedic and trauma surgery consultations. One solution is consistent digitisation and the offer of video consultation hours. In this study, non-contact examination of patients with shoulder disorders is described and critically examined.

METHODS

Thirty patients who presented with pathologies of the shoulder joint in a university outpatient clinic were subjected to a physical examination in a conventional and contactless manner. The data obtained on mobility, function and provocation test of both examinations were compared to draw conclusions about the virtual feasibility.

RESULTS

46% of the patients suffered from a traumatic shoulder lesion, and 54% showed degenerative lesions. The assessment of mobility showed a high correlation of 70 - 90% between the two examinations. Common tests to evaluate the supraspinatus, infraspinatus, subscapularis and the long head of the biceps could be adequately performed in a contactless version by more than three quarters of the patients, but with low-to-moderate performance values.

CONCLUSION

Contact-less examination is particularly disadvantageous when evaluating stability criteria. For the medical history and functional test, there were no significant differences between the classic consultation and contactless consultation. Although virtual consultation is a widespread and valuable addition in pandemic times, it cannot replace a safe assessment and indication by personal examination.

sCD28, sCD80, sCTLA-4, and sBTLA Are Promising Markers in Diagnostic and Therapeutic Approaches for Aseptic Loosening and Periprosthetic Joint Infection

Aseptic prosthetic loosening and periprosthetic joint infections (PJI) are among the most frequent complications after total knee/hip joint arthroplasty (TJA). Current research efforts focus on understanding the involvement of the immune system in these frequent complications. Different immune cell types have already been implicated in aseptic prosthetic loosening and PJI. The aim of this study was to systematically analyze aspirates from knee and hip joints, evaluating the qualitative and quantitative composition of soluble immunoregulatory markers, with a focus on co-inhibitory and co-stimulatory markers. It has been shown that these molecules play important roles in immune regulation in cancer and chronic infectious diseases, but they have not been investigated in the context of joint replacement. For this purpose, aspirates from control joints (i.e., native joints without implanted prostheses), joints with TJA (no signs of infection or aseptic loosening), joints with aseptic implant failure (AIF; i.e., aseptic loosening), and joints with PJI were collected. Fourteen soluble immunoregulatory markers were assessed using bead-based multiplex assays. In this study, it could be shown that the concentrations of the analyzed immunoregulatory molecules vary between control, TJA, AIF, and PJI joints. Comparing TJA patients to CO patients, sCD80 was significantly elevated. The marker sBTLA was significantly elevated in AIF joints compared to TJA joints. In addition, a significant difference for eight markers could be shown when comparing the AIF and CO groups (sCD27, sCTLA-4, sCD137, sCD80, sCD28, sTIM-3, sPD-1, sBTLA). A significant difference was also reached for nine soluble markers when the PJI and CO groups were compared (sLAG-3, sCTLA-4, sCD27, sCD80, sCD28, sTIM-3, sPD-1, IDO, sBTLA). In summary, the analyzed immunoregulatory markers could be useful for diagnostic purposes as well as to develop new therapeutic approaches for AIF and PJI.

Extravasation Injuries of the Limbs in Neonates and Children-Development of a Treatment Algorithm

BACKGROUND

Hospitalized children and neonates very often receive intravenous treatment. There has not yet been any systematic study of the incidence of extravasation injuries in this age group. In a few studies of neonates in intensive care receiving intravenous treatment, incidence figures in the range of 18-46% have been reported; 2.4-4% sustain serious complications, such as necrosis and ulceration, that can lead over the long term to contractures, deformities, and impaired limb function due to unfavorable scarring. No guidelines currently exist for the care of pediatric extravasation injuries.

METHODS

This review is based on pertinent publications (from 1979 to June 2020) retrieved by a selective search in PubMed, as well as on experience from the authors' own institution.

RESULTS

In the absence of randomized controlled trials on the care of pediatric extravasation injuries, the available evidence is limited to small-scale comparative studies and case series. Conservative, medical, or surgical treatment can be used, depending on the volume of the extravasate, the nature of the substrate, and individual patient-related factors. It should first be determined whether the extravasated substance has no primary toxic properties or is a tissue irritant or a necrosis-inducing substance (vesicant). The skin and subcutaneous tissue should be examined for injury, coloration, swelling, capillary refill time, and pulses distal to the injury. Depending on the volume of the extravasate, the substrate, and the degree of tissue damage, the injury can be treated conservatively; medically, with the administration of an antidote, hyaluronidase, or a vasodilator such as phentolamine; or surgically, with multiple puncture procedures, washouts, or liposuction.

CONCLUSION

As there is no clear evidence that one form of treatment is superior to any other, the treatment of pediatric extravasation injuries remains an individual decision, with the known attendant risks of off-label treatment.

The Association between Tumour Markers and Meta-iodobenzylguanidine Scans in South African Children with High-risk Neuroblastoma

AIMS

Diagnostic and post-induction ¹²³I-meta-iodobenzylguanidine (¹²³I-mIBG) scans have prognostic significance in the treatment of neuroblastoma, but data from low- and middle-income countries are limited due to resource constraints. The aim of this study was to determine the association between neuroblastoma-associated tumour markers (lactate dehydrogenase [LDH], ferritin and MYCN amplification) and ¹²³I-mIBG scans (modified Curie scores and metastatic disease patterns) in predicting complete metastatic response rates (mCR) and overall survival.

MATERIALS AND METHODS

Two hundred and ninety patients diagnosed with high-risk neuroblastoma in South Africa between January 2000 and May 2018 and a subanalysis of 78 patients with diagnostic ¹²³I-mIBG scans were included. Data collection included LDH, ferritin and MYCN amplification at diagnosis. Two nuclear physicians independently determined the modified Curie scores and pattern of distribution for each diagnostic and post-induction ¹²³I-mIBG scans with high inter-rater agreement (r = 0.952) and reliability (K = 0.805). The cut-off values for the diagnostic and post-induction modified Curie scores of ≥7.0 (P = 0.026) and 3 (P = 0.009), respectively, were generated. The association between the tumour markers and the modified Curie score of the ¹²³I-mIBG scans was determined using post-induction mCR and 2-year overall survival.

RESULTS

Diagnostic LDH (P < 0.001), ferritin (P < 0.001) and the diagnostic modified Curie scores (P = 0.019) significantly predicted mCR. Only ferritin correlated with diagnostic modified Curie scores (P = 0.003) but had a low correlation coefficient of 0.353. On multivariable analysis, the only significant covariate for 2-year overall survival at diagnosis was LDH <750 U/l (P = 0.024). A post-induction chemotherapy modified Curie score ≤3.0 had a 2-year overall survival of 46.2% compared with 30.8% for a score >3.0 (P = 0.484).

CONCLUSION

LDH, ferritin and the diagnostic ¹²³I-mIBG scans significantly predicted mCR, but only LDH predicted 2-year overall survival. Ferritin and the modified Curie scores correlated with each other. MYCN amplification neither correlated with any aspect of the ¹²³I-mIBG scans nor significantly predicted mCR or 2-year overall survival. LDH and ferritin are therefore appropriate neuroblastoma tumour markers to be used in low- and middle-income countries with limited or no access to mIBG scans and/or MYCN amplification studies.

Spine Examination during COVID-19 Pandemic via Video Consultation

INTRODUCTION

During the current COVID-19 pandemic video consultations are increasingly common in order to minimize the risk of infection for staff and patients. The aim of this study was to evaluate the feasibility of a spine examination via video.

METHODS

A total of 43 patients were recruited. Each participant underwent a video-based (VB) and a conventional face-to-face (FTF) spine examination. Pain intensity, active range of motion, inspection, a neurophysiologic basic exam and provocations tests were evaluated using video-based and face-to-face methods.

RESULTS

The intra-rater reliability (IRR) was measured between both examinations. Good to very good IRR values were obtained in inspection (Kappa between 0,752 und 0,944), active range of motion and basic neurophysiological examination (Kappa between 0,659 und 0,969). Only moderate matches were found in specific provocation tests (Kappa between 0,407 und 0,938). A video-based spine examination is a reliable tool for measuring pain intensity, active range of motion and a basic neurophysiologic exam.

CONCLUSION

A basic spine examination during a video consultation is possible. A good agreement of the test results between video-based and face-to-face examination could be found.

Examining the Hand in the Video Consultation

BACKGROUND

Video consultations could support patient care in hand surgery during social distancing in the COVID-19 era. According to the literature, images of hand and fingers can support telediagnosis in hand emergencies. We present this feasibility study on online video consultation in hand surgery.

METHODS

A structured examination was designed to query the medical history and examine motor skills, sensitivity, strength and function tests of the hand. Thirty examinations on both hands were carried out by online video consultation, then in direct contact and compared with each other.

RESULTS

With 4560 evaluated range of movement of the hand and finger joints, there was a high correlation between the measurement methods of R = 0.995 (p < 0.0001, confidence interval 0.9946 - 0.9954). In the video-based examination, 84.6% of the measured values showed a deviation of less than 5° compared to the direct examination, 92.8% less than 10° deviation. Good accordance was also found in the patient's medical history. An estimating examination of sensitivity, function and strength during video examination is feasible with simple auxiliary aids. Deficits are evident in the detection of scars, in function tests and the absence of haptic findings.

CONCLUSION

Online video consultation allows hand examination with sufficient documentation of hand and finger movements (range of motion) and proper evaluation of symptoms. It cannot replace direct examination but complement patient care in hand surgery even beyond the current COVID-19 pandemic.

Evaluation of the Feasibility of a Telemedical Examination of the Hip and Pelvis - Early Lessons from the COVID-19 Pandemic

Introduction Due to the current COVID-19 pandemic, the German Health Ministry has issued restrictions applying to the field of orthopaedics and trauma surgery. Besides postponement of elective surgeries, outpatient consultations have been drastically reduced. Parallel to these developments, an increase in telemedical consultations has reflected efforts to provide sufficient patient care. This study aims to evaluate the feasibility of a clinical examination of the hip joint and pelvis by way of a telemedical consultation.

Materials and Methods Twenty-nine patients of a German university clinic were recruited and assessed in both telemedical and conventional examinations. Agreement between the two examinations was then assessed, and connections between the observed agreement and patient-specific factors such as age, BMI and ASA classification were investigated.

Results The inspections agreed closely with a mean Cohenʼs kappa of 0.76 ± 0.37. Palpation showed adequate agreement with a mean Cohenʼs kappa of 0.38 ± 0.19. Function showed good agreement with a mean Cohenʼs kappa of 0.61 ± 0.26 and range of motion showed adequate agreement with a mean Cohenʼs kappa of 0.36 ± 0.19. A significant positive correlation was observed between the number of deviations in the different examinations and age (p = 0.05), and a significant positive correlation was shown between the number of non-feasible examinations and age (p < 0.01), BMI (p < 0.01) and ASA classification score (p < 0.01).

Discussion Inspection and function can be reliably evaluated, whereas the significance of palpation, provocation and measurement of range of motion is limited. The small sample size puts limitations on the significance of a statistically relevant correlation between patient-specific factors such as age, BMI and ASA classification score and valid and successful implementation of a telemedical examination. The authors recommend targeted patient selection. If, however, patients are being evaluated who are very old (> 75 years), obese (BMI > 30) or with multiple comorbidities (ASA 3 and above), caution is advised. Large, prospective studies are needed in the future to fully validate telemedical consultations in the fields of orthopaedics and trauma surgery.

Conclusion A telemedical examination of the hip joint and pelvis can be performed with certain limitations. Patient-specific factors such as age, BMI, and extent of comorbidities appear to have a relevant impact on validity and execution of the examination. Patients with multiple comorbidities (ASA 3 and above), advanced age (> 75 years) or obesity (BMI > 30) should, whenever possible, be examined in a conventional outpatient setting.

A Feasibility Pilot Study on the Use of Telemedicine for the Examination of the Knee Joint

BACKGROUND

In times of a pandemic threat, such as COVID-19, and the need for reduced direct doctor-patient contact, internet-based telemedicine has attracted more and more attention as a surrogate service. Suspending the diagnosis and treatment of non-virus related diseases for longer periods of time is not a viable option since this would only exacerbate problems on the patient and national level. The need for alternative treatment modalities increased rather quickly. So far, telemedical applications have mainly focused on teleradiological diagnosis, follow-up and monitoring of psychiatric and internal diseases, as well as geriatric patient care. As far as these authors are aware, orthopaedic physical examination of the knee joint, including trauma work-up, has not been the subject of any studies to date. This feasibility study explores how video consultation can be designed and implemented in the context of history taking and physical examination in knee joint complaints.

MATERIAL AND METHOD

21 patient actors (PA) with simulated complaints of the knee joint were examined individually for each diagnosis, first via video consultation and then directly by a specialist (SP). One PA group has a medical background, the other was made up of laypersons. The time was measured for both types of consultation. The physician documented the detected symptoms, the quality of implementation of the self-examination steps, and the derived diagnosis on an assessment form. After completion of both consultation sessions, the PAs were handed a questionnaire on the respective examination modality.

RESULTS

With the video consultation the examination lasted 8.63 (± 2.5) minutes on average and with the regular consultation in person 5.63 (± 1.7) minutes (p < 0.001). For the group with medical background the examination lasted 7.67 (± 1.4) minutes on average, while for the lay group the video consultation took 9.7 (± 3.1) minutes (p = 0.049). With increased age, the video consultation was prolonged (p = 0.032; r = 0.47). The mean value for self-examination of leg axis, gait pattern and degrees of freedom was 9.32 (± 0.4) of 10 points. The following functional tests resulted in lower mean values (points): Payr 7.2 (± 2.3), Merke 5.9 (± 2.8), no-touch Lachmann 6.4 (± 2.7), gravity sign-recurvatum 6.7 (± 2.4). The mean grade by the PAs for the feasibility of self-examination was 2.43 (± 0.98) out of 5 points.

CONCLUSION

The video consultation for musculoskeletal complaints of the knee joint allows exploratory remote examination and helps to minimise the number of patients in hospitals and practices. It takes longer for the physician to perform and does not permit functional testing for ligament injuries of the knee joint. In its present form, telemedical examination is not able to fully replace personal consultation.

Local Cellular Responses to Metallic and Ceramic Nanoparticles from Orthopedic Joint Arthroplasty Implants

Over the last decades, joint arthroplasty has become a successful treatment for joint disease. Nowadays, with a growing demand and increasingly younger and active patients accepting these approaches, orthopedic surgeons are seeking implants with improved mechanical behavior and longer life span. However, aseptic loosening as a result of wear debris from implants is considered to be the main cause of long-term implant failure. Previous studies have neatly illustrated the role of micrometric wear particles in the pathological mechanisms underlying aseptic loosening. Recent osteoimmunologic insights into aseptic loosening highlight the important and heretofore underrepresented contribution of nanometric orthopedic wear particles. The present review updates the characteristics of metallic and ceramic nanoparticles generated after prosthesis implantation and summarizes the current understanding of their hazardous effects on peri-prosthetic cells.

The Impact of Lead Aprons on Posture of Orthopaedic Surgeons

BACKGROUND

Surgeons working in orthopedics and trauma surgery are frequently exposed to repetitive actions and non-ergonomic positions in their operative activities with the regular use of lead aprons. Musculoskeletal complaints of the neck and back among surgeons are reported in the literature as up to 80%. In this study, the effects of lead aprons on the posture of surgeons are examined using videorasterstereography, foot pressure measurement and questionnaires.

METHODOLOGY

All subjects (n = 31) were examined before and after exposure to wearing lead aprons during surgery using videorasterstereography and pedography. In addition, a survey with a separately created questionnaire and the Cornell Musculoskeletal Discomfort Questionnaire (CMDQ) was carried out.

RESULTS

An average duration of lead apron use of 102.6 min showed an increase in forefoot load (p = 0.002) especially in the elderly subjects and thoracic kyphosis (p < 0.001) especially in the younger doctors with a significant lateral deviation (p = 0.006). In addition, the lateral deviation was shown to correlate with an increasing body size or a shorter period of employment (p = 0.008; r = 0.51/p = 0.026; r = - 0.44). Significantly fewer surgeons experienced back complaints on working days without lead apron use in the operating room compared to days in the OR (p = 0.011).

CONCLUSION

The impact of wearing front covered lead aprons during operations in the field of orthopaedics and trauma surgery leads to more frequent back complaints, even among young and healthy doctors. Under an average duration of surgery of 102 min a temporary postural deviation occurs that can be demonstrated by means of videorasterstereography and foot pressure measurement. The subjects showed a shifted weight distribution on the forefoot, a gain in thoracic kyphosis and an increase in lateral deviation, which also correlated with an increasing height and shorter length of employment.

Molecular and Functional Phenotypes of Human Bone Marrow-Derived Mesenchymal Stromal Cells Depend on Harvesting Techniques

Mesenchymal stromal cells (MSC) harvested in different tissues from the same donor exhibit different phenotypes. Each phenotype is not only characterized by a certain pattern of cell surface markers, but also different cellular functionalities. Only recently were different harvesting and processing techniques found to contribute to this phenomenon as well. This study was therefore set up to investigate proteomic and functional properties of human bone marrow-derived MSCs (hBM-MSC). These were taken from the same tissue and donor site but harvested either as aspirate or bone chip cultures. Both MSC populations were profiled for MSC markers defined by the International Society for Cellular Therapy (ISCT), MSC markers currently under discussion and markers of particular interest. While classic ISCT MSC markers did not show any significant difference between aspirate and outgrowth hBM-MSCs, our additional characterization panel revealed distinct patterns of differentially expressed markers. Furthermore, hBM-MSCs from aspirate cultures demonstrated a significantly higher osteogenic differentiation potential than outgrowth MSCs, which could be confirmed using a transcriptional approach. Our comparison of MSC phenotypes obtained by different harvesting techniques suggests the need of future standardized harvesting, processing and phenotyping procedures in order to gain better comparability in the MSC field.

The Effects of Biomaterial Implant Wear Debris on Osteoblasts

Aseptic loosening subsequent to periprosthetic osteolysis is the leading cause for the revision of arthroplasty failure. The biological response of macrophages to wear debris has been well established, however, the equilibrium of bone remodeling is not only dictated by osteoclastic bone resorption but also by osteoblast-mediated bone formation. Increasing evidence shows that wear debris significantly impair osteoblastic physiology and subsequent bone formation. In the present review, we update the current state of knowledge regarding the effect of biomaterial implant wear debris on osteoblasts. The interaction of osteoblasts with osteoclasts and macrophages under wear debris challenge, and potential treatment options targeting osteoblasts are also presented.

[Challenges of discharge management in geriatric traumatology : Example of an integrated orthogeriatric service]

BACKGROUND

Geriatric patients are currently responsible for almost one third of all emergency hospital admissions. An increase of 50% is expected in the next decade. This age redistribution poses new challenges for inpatient care and discharge management. The requirements of an orthopedic trauma surgery clinic in the care of this patient group can be clarified with the help of this first collaboratively created geriatric orthopedic trauma surgery complex treatment unit of a university hospital.

OBJECTIVE

What influence do age and delirium have on discharge management, length of inpatient stay and discharge destination in a geriatric cohort?

MATERIAL AND METHODS

All patients who received inpatient treatment as part of the orthopedic trauma surgery geriatric complex treatment (GKB) between May 2017 and December 2019 were evaluated. An analysis of the demographics, length of inpatient stay, discharge destinations and evaluation of the Barthel index collected on admission and discharge, the mini-mental state examination (MMSE) and the geriatric depression scale (GDS) were carried out.

RESULTS

Out of 312 patients, 110 men and 193 women with a median age of 81 years, 77 patients (24.6%) showed delirium when enrolled in the GKB and 39 (12.5%) dementia. Older patients presented more often with delirium than younger people (p = 0.013), especially those aged 70-79 years (p = 0.037). Dementia patients suffered more frequently from postoperative delirium (p < 0.01). The mean hospital stay was 17.79 days (±4.6 days). The GKB was regularly completed in 60.7% of all cases and 39.3% patients dropped out early. Patients with delirium were discharged significantly less often into their own home but into short-term care or nursing homes (p = 0.038). A general correlation between delirium development and the discharge destination was noticeable (p = 0.004).

CONCLUSION

Patients with dementia are more likely to develop delirium postoperatively, which leads to an increase in the length of inpatient stay, an increase in treatment costs and more work for the discharge management team. In addition, the discharge to the patients' home is impaired by delirium, which means that the growing need for places in short-term care and nursing homes also creates socioeconomic burdens.

The Role of PD-1 in Acute and Chronic Infection

PD-1 as an immune checkpoint molecule down-regulates T cell activity during immune responses in order to prevent autoimmune tissue damage. In chronic infections or tumors, lasting antigen-exposure leads to permanent PD-1 expression that can limit immune-mediated clearance of pathogens or degenerated cells. Blocking PD-1 can enhance T cell function; in cancer treatment PD-1 blockade is already used as a successful therapy. However, the role of PD-1 expression and blocking in the context of acute and chronic infections is less defined. Building on its success in cancer therapy leads to the hypothesis that blocking PD-1 in infectious diseases is also beneficial in acute or chronic infections. This review will focus on the role of PD-1 expression in acute and chronic infections with virus, bacteria, and parasites, with a particular focus on recent studies regarding PD-1 blockade in infectious diseases.

Osteoimmunology: A Current Update of the Interplay Between Bone and the Immune System

Immunology, already a discipline in its own right, has become a major part of many different medical fields. However, its relationship to orthopedics and trauma surgery has unfortunately, and perhaps unjustly, been developing rather slowly. Discoveries in recent years have emphasized the immense breadth of communication and connection between both systems and, importantly, the highly promising therapeutic opportunities. Recent discoveries of factors originally assigned to the immune system have now also been shown to have a significant impact on bone health and disease, which has greatly changed how we approach treatment of bone pathologies. In case of bone fracture, immune cells, especially macrophages, are present throughout the whole healing process, assure defense against pathogens and discharge a complex variety of effectors to regulate bone modeling. In rheumatoid arthritis and osteoporosis, the immune system contributes to the formation of the pathological and chronic conditions. Fascinatingly, prosthesis failure is not at all solely a mechanical problem of improper strain but works in conjunction with an active contribution of the immune system as a reaction to irritant debris from material wear. Unraveling conjoined mechanisms of the immune and osseous systems heralds therapeutic possibilities for ailments of both. Contemplation of the bone as merely an unchanging support pillar is outdated and obsolete. Instead it is mandatory that this highly diverse network be incorporated in our understanding of the immune system and hematopoiesis.

The Role of 18F-FDG PET/CT in Suspected Intraocular Sarcoidosis and Tuberculosis

Purpose: To determine the utility of fluorine-18 fluorodeoxyglucose Positron Emission Tomography Computed Tomography (FDG PET/CT) in patients with suspected ocular sarcoidosis (OS) or intraocular tuberculosis (IOTB) in a resource-constrained, TB endemic area.Methods: Independent review of the FDG PET/CTs, Computed Tomography (CT) scans and chest radiographs (CXRs) of patients with suspected OS or IOTB and inconclusive conventional workup.Results: Twenty-nine PET/CTs and CXRs were reviewed, with 38% of PET/CTs and CTs demonstrating evidence of TB or sarcoidosis, compared to 21% of CXRs. The sensitivity, specificity, positive and negative predictive values for PET/CT and CT were similar - 85.7%, 95.5%, 85.7% and 95.5% for OS, and 33.3%, 100%, 100% and 68% for IOTB respectively and for CXR, 57.1%, 100%, 100% and 88% for OS, and 16.7%, 100%, 100% and 63% for IOTB.Conclusion: PET/CT added no significant additional benefit over Chest CT in patients with suspected OS or IOTB.

Modified anteromedial and anterolateral elbow arthroscopy portals show superiority to standard portals in guiding arthroscopic radial head screw fixation

PURPOSE

Arthroscopic fixation of radial head radial head fractures is an appealing alternative to open reduction and internal fixation, which presents the advantage of minimal surgical trauma. The aim of this study was to evaluate if modifications to the standard anteromedial (AM) and anterolateral (AL) portals could allow screw placement for radial head fracture osteosynthesis closer to the plane of the radial head articular surface.

METHODS

Eight fresh-frozen specimens were prepared to mimic arthroscopic setting. Standard AL (ALst) and AM (AMst) and distal AL (ALdi) and AM (AMdi) portals were established. Eleven independent examiners were asked to indicate the optimal trajectory, when aiming to place a cannulated screw parallel to the radial head surface for radial head osteosynthesis. A three-dimensional digital protractor was used to measure the angle between the indicated position and a Kirschner wire placed parallel to the radial head articular surface (α). The Shapiro-Wilk normality test was used to evaluate the normal distribution of the samples. Means, standard deviations, and 95% confidence intervals (95% CI) were calculated for each portal. A coefficient of variation (CoV) was calculated to determine agreement among observers and intra-observer variability.

RESULTS

Mean α angles were 25.1 ± 11.5° for AMst, 13.8 ± 4.8° for AMdi, 17.1 ± 13.4° for ALst, -2.6 ± 9.2° for ALdi. No overlapping in the 95% CI of ipsilateral standard and distal portals was observed, indicating that the difference between these means was statistically significant. The distal portals showed smaller inter-observer CoV as compared to the standard ones (AMst: 10.0%; AMdi: 4.6%; ALst: 12.5%; ALdi: 10.6%). Intra-observer CoV was similar for all portals (AMst: 5.5%; AMdi: 6.1%; ALst: 7.7%; ALdi: 7.1%).

CONCLUSIONS

The use of distal AM and AL portals permits to obtain α angles closer to the radial head articular surface than standard AM and AL portals. This is expected to allow screw placement in a flatter trajectory, which should correlate with a superior biomechanical performance of fixation. Good reproducibility of Kirschner wire placement from distal portals was observer among different examiners. Modifications to the standard AM and AL elbow arthroscopy portals allow to place screws for radial head fracture osteosynthesis in a position which should guarantee superior biomechanical performance of fixation.

Comparison of the Subjective Elbow Value with the DASH, MEPS und Morrey Score after Olecranon Fractures

Background Olecranon fractures are common injuries that can occur in patients of any age. To assess the postoperative outcome, multiple scoring systems like the DASH, MEPS und Morrey Score have been described. The goal of this paper is to compare the subjective elbow value (SEV) to these commonly used scoring systems. We hypothesized that the SEV would have a high correlation and practicability for the evaluation of elbow function after isolated olecranon injury.

Patients and Methods Clinical data of 40 patients were collected and retrospectively analysed. All patients suffered an isolated olecranon fracture and were surgically treated by tension band wiring or plate fixation. In the follow-up examinations the Mayo Score, DASH Score, Morrey Score and SEV were measured for correlation purposes.

Results The mean follow-up time was 70.5 ± 45.6 months. The median DASH Score was 9.9 (4.1 – 20.4) and 100 (85 – 100) for the MEPS. The median Morrey Score was 98 (92 – 100). The median SEV was 90% (80 – 95%). The Pearson correlation between the DASH and SEV was −0.85 and 0.80 between the MEPS and the SEV.

Conclusions The SEV shows a high correlation to the most commonly used scoring systems for outcome evaluation after elbow injury. It is easy to use and can be seen as a valuable tool to assess patients after olecranon fractures.

C-06 Differential and Dual Diagnosis of Alzheimer’s Disease and Personality Disorders: Performance on WAIS-IV Subtests

Objective

Certain personality disorder (PD) diagnoses are related to the development of dementing disorders. There is a higher rate of comorbidity of PD in samples of patients with dementing disorders compared to healthy controls, which can lead to difficulties during the diagnostic process. The present study seeks to identify the neurocognitive correlates of those diagnosed with Alzheimer’s dementia (AD) compared to PD, potentially aiding in differential diagnosis.

Method

Data was collected as part of a large assessment outpatient clinical practice. The data contained 580 participants who came to the clinic with a variety of referral questions (e.g., neurological diagnosis, personality functioning, ADHD assessment). To measure cognitive functioning, participants were administered the WAIS-IV. Participants included 43 people diagnosed with AD and 18 with PD.

Results

Subtest scores for participants diagnosed with AD were lower than participants with PD. We adjusted the mean level difference using vocabulary. Using regression, we pulled out the variance associated with vocabulary as it is not susceptible to cognitive decline. Block design was significantly different for the two groups even after controlling for vocabulary (r-square = .06; p = .017). Matrix reasoning was significantly different for the two groups even after controlling for vocabulary (r-square = .09; p = .005).

Conclusions

The differential diagnosis of PD and dementing disorders is important, and thus these findings are important in beginning to understand the cognitive patterns in those with AD and PD. Past research has not controlled for intellectual functioning. However, additional research utilizing larger sample sizes and an extensive test battery is necessary.

C-11 Neurocognitive Differences in Alzheimer’s Dementia Compared to Healthy Controls on the WAIS-IV

Objective

The present study seeks to identify neurocognitive patterns of those diagnosed with Alzheimer’s dementia (AD) compared to those with no diagnosis (ND), potentially aiding in the diagnostic process. Previous research found visuospatial differences, but on previous versions of the WAIS.

Method

Participants (n = 580) were referred to a large assessment outpatient clinic with a variety of presenting problems, such as neurological diagnosis, personality functioning, and ADHD assessment. To measure cognitive functioning, participants were administered the WAIS-IV. Participants included individuals diagnosed with AD (n = 43) and those with ND (n = 40).

Results

Subtest scores for those diagnosed with AD were lower than participants with ND. We adjusted the mean level difference using vocabulary (VC). Using regression, variance associated with VC was pulled out, as it is not susceptible to cognitive decline. Both Matrix Reasoning (MR) (r-square = .04; p =.001) and Digit Span (DS) (r-square = .04; p = .001) were significantly different for the two groups even after controlling for VC. Block Design (BD) was not significantly different (p = 0.07).

Conclusions

While previous research indicates patterns of visuospatial difficulties in neurocognitive functioning among those with AD, the current findings suggest impairments in perceptual reasoning and working memory. Previous research also suggests that BD predicts AD. However, the current study indicates MR and DS predicts AD, whereas BD does not. While these results may be due to small sample size, this study did control for intellectual functioning. Additional research involving an extensive test battery is needed to further examine these findings.

Erratum to: Three-dimensional thoracoscopic vertebral body replacement at the thoracolumbar junction

Erratum to:Oper Orthop Traumatol 2018 https://doi.org/10.1007/s00064-018-0559-3 The article was wrongly published under the article type "Review". Please note that the article is an "Original Paper".The publisher apologizes to authors and ….

Three-dimensional thoracoscopic vertebral body replacement at the thoracolumbar junction

OBJECTIVE

The aim is to stabilize the thoracolumbar spine with a thoracoscopically implanted vertebral body replacement (VBR). To improve intraoperative depth perception and orientation, implantation is performed under three-dimensional (3D) thoracoscopic vision.

INDICATIONS

Vertebral burst fractures at the thoracolumbar junction (A4 AOSpine classification), pseudarthrosis, and posttraumatic instability with increasing kyphosis.

CONTRAINDICATIONS

Severe pulmonary dysfunctions, pulmonary or thoracic infections, previous thoracic surgery, and pulmonary adhesions.

SURGICAL TECHNIQUE

The patient is lying in a right lateral decubitus position. Localization of the fractured vertebra. Minimally invasive transthoracic approach. Perform single lung ventilation and insert the 3D thoracoscope two intercostal spaces above the working portal. Utilization of special binocular glasses for 3D vision of the operation field and secure resection of the fractured vertebra. Measurement of the bony defect and insertion of the expandable cage. Control of correct cage position under fluoroscopy. Insertion of a chest tube and inflate the left lung.

POSTOPERATIVE MANAGEMENT

Chest × ray Remove chest tube when output is <500 ml/24 h Early mobilization on the ward 6 weeks no weight-bearing >5 kg RESULTS: Between 2012 and 2017, 12 patients received a VBR under 3D thoracoscopic vision. After a mean follow up of 26 months, no cage dislocation was noticed and all patients recovered from the initial back pain. Complications were notable in two cases (17%) with a small pneumothorax after removal of the chest tube and postoperative pneumonia in one patient (8%). All responded to conservative treatment. Revision surgery was not necessary.

3-D Optics for Thoracoscopic Vertebral Body Replacement - Essential Technical Progress or Just Nice to Have?

BACKGROUND

Three-dimensional (3-D) endoscopic optics use 2 cameras to simulate the different perspectives of the right and left eye, creating the illusion of spatial depth. Optimised orientation as well as improved hand-eye coordination compared to 2-D-optics could be proven in standardised test setups (black box) and in laparoscopic use. This retrospective study examines whether these results can also be applied to thoracoscopic vertebral body replacement at the thoracolumbar junction.

HYPOTHESES

1. Ventral vertebral body replacement using 3-D-thoracoscopy results in a shorter operation time than with 2-D-thoracoscopy. 2. Perioperative blood loss is less, due to better spatial orientation (faster haemostasis) and reduced tissue laceration.

MATERIAL AND METHODS

29 patients met the inclusion criteria of this retrospective study. Between 08 - 2012 and 08 - 2017, all of these received ventral thoracoscopic vertebral replacement at the thoracolumbar junction (Th11 to L2). Patients with additional anterior procedures (e.g. anterolateral plate) were excluded. Perioperative data such as blood loss, duration of surgery and length of hospital stay were analysed. Conventional 2-D-optics were used in n = 14 patients and 3-D-optics in 15 patients. Aesculap EinsteinVision^® 2.0 was used as the 3-D-optics. Statistical significance was calculated using Student's t-test.

RESULTS

The most common diagnosis was a L1 fracture (n = 18, 62%). Mean OR time was 24 minutes shorter in the 3-D group (149 ± 29, 107 - 198 min) than in the 2-D group (173 ± 39, 125 - 260 min), but this difference was not significant. Total perioperative blood loss in the 3-D group was significantly lower than in the 2-D group (**p = 0.043). Proportional intraoperative blood loss in the 3-D group was also lower (mean around 115 ml), but not significantly so. Significantly lower values were found for the delivery rate of the thoracic drainage in the 3-D group (248 vs. 560 ml, *p = 0.195). Inpatient stay with the 3-D group was on average 1.5 days (d) shorter (8.7 d for the 3-D group, 10.2 d for the 2-D group) but this difference was not significant (p = 0.27).

CONCLUSION

Thoracoscopic-assisted vertebral body replacement at the thoracolumbar junction is a safe and reliable surgical procedure using conventional 2-D-optics or the new 3-D-optics. Both methods allow thoracoscopic vertebral body replacement in comparable operation times but in our study the 3-D group presented with significantly lower postoperative blood loss. Due to the small number of cases and because of the retrospective design, the present study is considered to be a pilot study only.

Time-resolved nuclear dynamics in bound and dissociating acetylene

We have investigated nuclear dynamics in bound and dissociating acetylene molecular ions in a time-resolved reaction microscopy experiment with a pair of few-cycle pulses. Vibrating bound acetylene cations or dissociating dications are produced by the first pulse. The second pulse probes the nuclear dynamics by ionization to higher charge states and Coulomb explosion of the molecule. For the bound cations, we observed vibrations in acetylene (HCCH) and its isomer vinylidene (CCHH) along the CC-bond with a periodicity of around 26 fs. For dissociating dication molecules, a clear indication of enhanced ionization is found to occur along the CH- and CC-bonds after 10 fs to 40 fs. The time-dependent ionization processes are simulated using semi-classical on-the-fly dynamics revealing the underling mechanisms.

Development and validation of the simultaneous determination of artemisone, clofazimine and decoquinate with HPLC

The aim of this study was to develop and validate a novel HPLC method for the simultaneous analysis of artemisone, clofazimine and decoquinate. Detection was obtained at two wavelengths; 284 nm (clofazimine) and 210 nm (artemisone and decoquinate). Gradient elution was used with mobile phase A (A) consisting of 0.005 M sodium octanesulphonic-acid (pH 3.5) and mobile phase B (B) of HPLC grade acetonitrile. The flow rate was set to 1.0 ml/min with (A) at 35% and (B) at 65% for 2 min, followed by a gradient shift of 10/90% ((A)/(B)) over a duration of 4 min. After 10 min, the initial gradient conditions were readjusted to 35/65% ((A)/(B)). Distinctive peaks were identified for clofazimine, artemisone and decoquinate, respectively. The proposed HPLC assay method was validated and found to be reliable, reproducible and accurate for simultaneous analysis of the three compounds.

Transfer, loss and physical processing of water in hit-and-run collisions of planetary embryos

Collisions between large, similar-sized bodies are believed to shape the final characteristics and composition of terrestrial planets. Their inventories of volatiles such as water are either delivered or at least significantly modified by such events. Besides the transition from accretion to erosion with increasing impact velocity, similar-sized collisions can also result in hit-and-run outcomes for sufficiently oblique impact angles and large enough projectile-to-target mass ratios. We study volatile transfer and loss focusing on hit-and-run encounters by means of smooth particle hydrodynamics simulations, including all main parameters: impact velocity, impact angle, mass ratio and also the total colliding mass. We find a broad range of overall water losses, up to 75% in the most energetic hit-and-run events, and confirm the much more severe consequences for the smaller body also for stripping of volatile layers. Transfer of water between projectile and target inventories is found to be mostly rather inefficient, and final water contents are dominated by pre-collision inventories reduced by impact losses, for similar pre-collision water mass fractions. Comparison with our numerical results shows that current collision outcome models are not accurate enough to reliably predict these composition changes in hit-and-run events. To also account for non-mechanical losses, we estimate the amount of collisionally vaporized water over a broad range of masses and find that these contributions are particularly important in collisions of ∼  Mars-sized bodies, with sufficiently high impact energies, but still relatively low gravity. Our results clearly indicate that the cumulative effect of several (hit-and-run) collisions can efficiently strip protoplanets of their volatile layers, especially the smaller body, as it might be common, e.g., for Earth-mass planets in systems with Super-Earths. An accurate model for stripping of volatiles that can be included in future planet formation simulations has to account for the peculiarities of hit-and-run events and track compositional changes in both large post-collision fragments.

Compact and flexible harmonic generator and three-color synthesizer for femtosecond coherent control and time-resolved studies

Intense, multi-color laser fields permit the control of the ionization of atoms and the steering of electron dynamics. Here, we present the efficient collinear creation of the second and third harmonic of a 790 nm femtosecond laser followed by a versatile field synthesizer for the three color fields' composition. Using the device, we investigate the strong-field ionization of neon by fields composed of the fundamental, and the second or third harmonic. The three-color device offers sufficient flexibility for the coherent control of strong-field processes and for time-resolved pump-probe studies.

Radiofrequency-activated PMMA-augmentation through cannulated pedicle screws: A cadaver study to determine the biomechanical benefits in the osteoporotic spine

INTRODUCTION

PMMA-augmentation of pedicle screws strengthens the bone-screw-interface reducing cut-out risk. Injection of fluid cement bears a higher risk of extravasation, with difficulty of application because of inconsistent viscosity and limited injection time.

OBJECTIVE

To test a new method of cement augmentation of pedicle screws using radiofrequency-activated PMMA, which is suspected to be easier to apply and have less extravasations.

METHODS

Twenty-seven fresh-frozen human cadaver lumbar spines were divided into 18 osteoporotic (BMD ≤ 0.8 g/cm2) and 9 non-osteoporotic (BMD > 0.8 g/cm2) vertebral bodies. Bipedicular cannulated pedicle screws were implanted into the vertebral bodies; right screws were augmented with ultra-high viscosity PMMA, whereas un-cemented left pedicle screws served as negative controls. Cement distribution was controlled with fluoroscopy and CT scans. Axial pullout forces of the screws were measured with a material testing machine, and results were analyzed statistically.

RESULTS

Fluoroscopy and CT scans showed that in all cases an adequately big cement depot with homogenous form and no signs of extravasation was injected. Pullout forces showed significant differences (p < 0.001) between the augmented and non-augmented pedicle screws for bone densities below 0.8 g/cm2 (661.9 N ± 439) and over 0.8 g/cm2 (744.9 N ± 415).

CONCLUSIONS

Pullout-forces were significantly increased in osteoporotic as well as in non-osteoporotic vertebral bodies without a significant difference between these groups using this standardized, simple procedure with increased control and less complications like extravasation.

Sub-cycle steering of the deprotonation of acetylene by intense few-cycle mid-infrared laser fields

Directional breaking of the C-H/C-D molecular bond is manipulated in acetylene (C₂H₂) and deuterated acetylene (C₂D₂) by waveform controlled few-cycle mid-infrared laser pulses with a central wavelength around 1.6 μm at an intensity of about 8 × 10¹³ W/cm². The directionality of the deprotonation of acetylene is controlled by changing the carrier-envelope phase (CEP). The CEP-control can be attributed to the laser-induced superposition of vibrational modes, which is sensitive to the sub-cycle evolution of the laser waveform. Our experiments and simulations indicate that near-resonant, intense mid-infrared pulses permit a higher degree of control of the directionality of the reaction compared to those obtained in near-infrared fields, in particular for the deuterated species.