Bidentate boron Lewis acids: synthesis by tin boron exchange reaction and host-guest complex formation.

Four bidentate boron Lewis acids based on the 1,8-diethynylanthracene backbone have been synthesized by a tin-boron exchange reaction with various chloroboranes, yielding the products in good to excellent yields. Complexation experiments of the host compounds with pyridine, pyrimidine and TMEDA demonstrated striking differences in terms of formation and solubility of the supramolecular adducts. The host-guest complexes were investigated by multinuclear NMR spectroscopy and structurally characterized by X-ray diffraction experiments, illustrating the adaptation of the host system upon adduct formation with different neutral guest molecules.

Selectivity in Adduct Formation of a Bidentate Boron Lewis Acid.

A bidentate boron Lewis acid based on 1,8-diethynylanthracene has been studied in detail with respect to its adduct formation with diamines and diphosphanes of different linker lengths between the donor functions. A clear correlation between the linker length of the bifunctional base and the formation of 1 : 1 adducts, 1 : 2 adducts or oligomers was found. The adducts were characterized in solution by NMR titration experiments and structurally by X-ray diffraction. In addition, adduct formation and competition experiments of the host system with ZR3 (Z=N, P; R=H, Me) demonstrated the generally higher stability of alkylphosphane adducts compared to alkylamine adducts with boron functions. The results provide a general insight into the adduct formation of bidentate Lewis acids with guests of different sizes as well as the differences in stability between borane-amine and borane-phosphane adducts.

Poly-pnictogen bonding: trapping halide ions by a tetradentate antimony(iii) Lewis acid.

A highly halide affine, tetradentate pnictogen-bonding host-system based on the syn-photodimer of 1,8-diethynylanthracene was synthesized by a selective tin-antimony exchange reaction. The host carries four C[triple bond, length as m-dash]C-Sb(C2F5)2 units and has been investigated regarding its ability to act as a Lewis acidic host component for the cooperative trapping of halide ions (F-, Cl-, Br-, I-). The chelating effect makes this host-system superior to its bidentate derivative in competition experiments. It represents a charge-reversed crown-4 and has the ability to dissolve otherwise poorly soluble salts like tetra-methyl-ammonium chloride. Its NMR-spectroscopic properties make it a potential probe for halide ions in solution. Insights into the structural properties of the halide adducts by X-ray diffraction and computational methods (DFT, QTAIM, IQA) reveal a complex interplay of attractive pnictogen bonding interactions and Coulomb repulsion.

A Bidentate Antimony Pnictogen Bonding Host System.

A bidentate pnictogen bonding host-system based on 1,8-diethynylanthracene was synthesized by a selective tin-antimony exchange reaction and investigated regarding its ability to act as a Lewis acidic host component for the complexation of Lewis basic or anionic guests. In this work, the novel C≡C-Sb(C2 F5 )2 unit was established to study the potential of antimony(III) sites as representatives for the scarcely explored pnictogen bonding donors. The capability of this partly fluorinated host system was investigated towards halide anions (Cl- , Br- , I- ), dimethyl chalcogenides Me2 Y (Y=O, S, Se, Te), and nitrogen heterocycles (pyridine, pyrimidine). Insights into the adduct formation behavior as well as the bonding situation of such E⋅⋅⋅Sb-CF moieties were obtained in solution by means of NMR spectroscopy, in the solid state by X-ray diffraction, by elemental analyses, and by computational methods (DFT, QTAIM, IQA), respectively.

The impact of stigmatization of psoriasis, atopic dermatitis and mastocytosis in different areas of life-A qualitative interview study.

Background: Stereotypes and false assumptions about chronic and visible skin diseases can determine the behaviour towards affected individuals and result in stigmatization or discrimination. Objective: The aim of this study was to analyze the perceived disease-related stigmatization of individuals with psoriasis, atopic dermatitis (AD) or mastocytosis. The study also aims to broaden people-centred knowledge of the effects of stigmatization in different areas of life, namely in everyday life, at work, in sports and in relationships. Methods: Qualitative in-depth semi-structured interviews were conducted among individuals with either psoriasis, AD or mastocytosis. Participants were recruited via self-help networks and were asked to express their experience of stigmatization in different areas of life. All interviews were audio recorded, transcribed verbatim and evaluated based on Mayring's content analysis. Results: In total, 24 individuals aged 19-79 years and living in Germany were included in the study-eight for each disease. Stigmatization was experienced in all three diseases in all mentioned areas of life as well as in interaction with medical professionals. Self-exclusion, negative self-perception and negative behaviour of others were the most frequent experiences with stigmatization. Conclusion: Stigmatization, both internal and external, is an important factor contributing to the mental burden of people with chronic skin diseases. More research is needed to gain deeper insight into stigmatization and its psychological burden in various contexts to enhance people-centred care in chronic skin diseases.

Synthesis of bi- and tetradentate poly-Lewis acids by hydroalumination of poly-alkynyl-anthracene derivatives.

Photo-dimers of 1,5-diethynylanthracene and 1,5-bis[(trimethylsilyl)ethynyl]anthracene, obtained by UV radiation of the monomers, were treated with the bulky aluminium hydride [(SiMe3)2HC]2AlH in hydroalumination reactions. Hydroalumination of the tetraethynyl-substituted anthracene photo-dimers (syn and anti) led to fourfold aluminium-functionalized Janus-like products with two aluminium functions on each side oriented towards the same direction. The reactions of the monomeric anthracene derivatives with [(SiMe3)2HC]2AlH afforded semi-flexible bidentate Lewis acids, which are interesting building blocks for molecular chains bearing multiple Lewis-acidic functions. The aluminium-functionalized anti-photo-dimer was treated with various donor molecules to gain insight into its host-guest chemistry. All poly-Lewis acids and their adducts were characterized by X-ray diffraction experiments, multinuclear NMR spectroscopy and by elemental analyses.

Status and future of modern technologies in arthroplasty : Results of a survey of the German Society for Orthopedics and Trauma Surgery (DGOU).

BACKGROUND: The orthopedic community is divided on the question of whether modern technologies in arthroplasty improve outcomes. Therefore, the aim of this initiative of the working group on intraoperative imaging and technology integration (Arbeitsgemeinschaft intraoperative Bildgebung und Technologieintegration, AGiTEC) is to initiate the collection of additional data for the scientific evaluation of modern technologies. QUESTION: To what extent are modern technologies currently used and which implementations are planned? Do the members of the German Society for Orthopedics and Trauma Surgery (DGOU) consider the acquisition of additional data for scientific assessment necessary? METHODS: Members of the DGOU were asked via an e­mail survey about the distribution and projected introduction of modern technologies in arthroplasty. They were also asked whether sufficient data were collected for scientific evaluation and whether acquisition of additional data in studies or arthroplasty registries were considered necessary. RESULTS: Of the 7923 probands surveyed, 428 completed the questionnaire in full (5.4%). It was found that individual implants and navigation are currently the most frequently used (31% and 29%, respectively). The largest increases in the next 2 years are projected for virtual reality and robotics (+30% and +23%, respectively), 85% of respondents indicated that insufficient data were collected for scientific evaluation, and 89% each requested initiation of multicenter studies and inclusion of technologies in the arthroplasty registry. CONCLUSION: The results of this study should motivate the scientific community, industry, and those responsible for the arthroplasty registries to collect and analyze data for the scientific assessment of modern technologies.

[Sense and nonsense of patient apps in arthroplasty]. / Sinn und Unsinn von Patienten-Apps in der Endoprothetik.

Apps have played a minor role in the treatment of patients in arthroplasty so far, but they represent an interesting tool for optimizing care and can become an integral part of fast-track surgery. The data in the literature is currently very limited, but promising approaches for the future are emerging. Assessing the quality of apps provided in app stores is difficult. The "DiGA listing" includes prescribable apps, which can support the patient in both the preoperative and postoperative course by optimizing lifestyle habits and providing exercise material. Patient contact with each other and with medical experts seems to have a positive impact on outcome. Most patients also rate the support provided by the app as positive. The development of the app should be done by medical experts, app developers, and patients together.

Bariatric surgery in liver cirrhosis.

Introduction: Obesity is frequently associated with its hepatic manifestation, the nonalcoholic fatty liver disease (NAFLD). The most effective treatment for morbid obesity is bariatric surgery (BS) also improving NAFLD and liver function. In patients where NAFLD has already progressed to liver cirrhosis, BS can be considered a high-risk procedure. Hence, consideration of the procedure and the most appropriate timing is crucial. Material and Methods: Obese patients suffering from NAFLD who underwent BS from two German University Medical Centers were retrospectively analyzed. Results: Twenty-seven patients underwent BS. Most common procedures were laparoscopic Roux-en-Y-gastric (RYGB) and laparoscopic sleeve gastrectomy (SG). All patients suffered from liver cirrhosis Child A. A preoperative transjugular portosystemic shunt (TIPS) was established in three patients and failed in another patient. Postoperative complications consisted of wound healing disorders (n = 2), anastomotic bleeding (n = 1), and leak from the staple line (n = 1). This patient suffered from intraoperatively detected macroscopic liver cirrhosis. Excess weight loss was 73% and 85% after 1 and 2 years, respectively. Two patients suffered from postoperative aggravation of their liver function, resulting in a higher Child-Pugh score, while three could be removed from the waiting list for a liver transplantation. Conclusion: BS leads to weight loss, both after SG and RYGB, and potential improvement of liver function in liver cirrhosis. These patients need to be considered with care when evaluated for BS. Preoperative TIPS implantation may reduce the perioperative risk in selected patients.

Addictions in patients with atopic dermatitis: a cross-sectional pilot study in Germany.

BACKGROUND: Atopic dermatitis (AD) is the most common chronic inflammatory skin disease worldwide and displays many atopic, but also non-atopic comorbidities. Among the latter, mental health disorders such as depression have been extensively studied. However, data on addictions are still rare. OBJECTIVES: The aim of this study was to assess the prevalence of different kinds of addictions in adult AD patients using a single-centre approach. METHODS: This non-interventional cross-sectional study was performed from 03/2020 to 05/2020 at the Department of Dermatology of a large German university hospital. Participants with a diagnosis of AD confirmed by a dermatologist answered questions about disease severity (patient-oriented eczema measure, POEM), quality of life (Dermatology Life Quality Index, DLQI) and smoking habits. They were screened for problematic alcohol consumption, drug abuse, internet addiction and pathological gambling using internationally established and validated questionnaires. RESULTS: 157 patients (56.1% female; mean age of 49.9 ± 20.4) with an average POEM of 13.7 ± 7.5 and DLQI of 6.1 ± 5.4 were evaluated. 14.1% were identified as regular smokers, 12.1% screened positive for alcohol dependency, 6.4% for drug use disorders, 4.5% for Internet addiction and 3.2% for pathological gambling. Co-occurrences of different addictions were observed, and a positive correlation was noted between DLQI scores and smoking. CONCLUSIONS: In summary, this study hints at elevated positive screening rates for problematic alcohol consumption, drug use disorders, Internet addiction and problem gambling compared with the general population. Screening routinely for addictions may improve patient-centred health care of AD patients.

[Recommendations for unicondylar knee replacement in the course of time : A current inventory]. / Empfehlungen zur unikondylären Schlittenendoprothetik im Wandel der Zeit : Eine aktuelle Bestandsaufnahme.

BACKGROUND: A higher patient satisfaction stands in contrast to higher revision rates of unicondylar knee joint endoprosthetics (UKE) compared to total knee joint endoprosthetics (TKE). Furthermore, old "dogmas" regarding indications and contraindications persist, which is still reflected in the significantly different case numbers. AIM: The aim of this article is to provide an overview of the current literature regarding 1. indication and contraindication (BMI, age, sport, arthrosis of other compartments, ligament status) and 2. the "eternal rival" fixed or mobile bearing for UKE. RESULTS: The choice of the right patient remains essential, even if all the old "dogmas" of contraindications have been relativized or even outdated. Arthroses of the contralateral (in medial UKE correspondingly lateral) compartment and advanced arthroses of the lateral patella facet remain the only persistent contraindications. In contrast, a high BMI, age, chondrocalcinosis, medial patella facet and a defective (but particularly functionally stable) ACL are not contraindications; however, severe obesity is responsible for a significantly higher complication rate and probably a higher rate of loosening. Rather, the experience and thus the number of UKEs of the individual surgeon is decisive for the outcome, to which the discussion about mobile or fixed inlays must also be completely subordinated. CONCLUSION: The indications for UKE can, therefore, be extended with a clear conscience on the basis of literature, and the current 1:10 UKE:TKE ratio in Germany can be shifted significantly.

Patient-related outcome measurements after operative and conservative management of traumatic proximal adductor longus avulsion injuries.

PURPOSE: In the rare case of complete proximal adductor longus avulsion injuries, scientific recommendations of surgical or conservative injury management are limited to small case series and reviews of small cohorts about treatment examples. A clear consensus regarding optimal management so far has not been made. Thus, the aim of our study was to investigate patient-related outcome measurements (PROM) after either operatively or conservatively treated patients in order to evaluate and display own decision criteria for one of the two treatment options. METHODS: In this retrospective case control study, two cohorts after MRI-confirmed, isolated, acute proximal adductor longus avulsion injury without concomitant injuries was investigated. Depending on stump retraction (less or more than 2 cm), patients of the particular cohorts had either been treated conservatively or by surgical refixation with suture anchors. All patients were asked to complete different PROM forms (Hip Osteoarthritis Outcome Score (HOS), Modified Harris Hip Score (MHHS)) in order to evaluate the particular procedures outcome. RESULTS: Between July 2015 and July 2018, eighteen avulsion injuries met our inclusion criteria, of which 14 were treated conservatively and operatively in equal parts and could be included into the study. The mean stump retraction of the conservative group was 1.3 cm (SD ± 0.5); patients in the surgical group had a mean stump retraction of 3.0 cm (± 1.5). Irrespective of the treatment option, all patients achieved a maximum score using the MHHS. Also in the HOS subscale respecting all day activities, almost all patients (13/14) achieved a maximum score. Instead, using the HOS subscale respecting sportive activities, one surgically and one conservatively treated patient described little restrictions compared with their pre-injury level. CONCLUSION: Conservative as well as operative treatment leads to very good patient-related outcome measurements if the decision for either of the two treatment options is made upon a stump retraction above or below 2 cm. Smaller restrictions regarding pre-injury level could rather be seen in the conservative instead of the operative group, favouring a more generous perspective for surgical refixation.

Customised bi-compartmental knee arthroplasty shows encouraging 3-year results: findings of a prospective, multicenter study.

PURPOSE: The purpose of this study was to assess the clinical and patient-reported outcomes of a customised, individually made (CIM) bi-compartmental knee arthroplasty (BKA). METHODS: A prospectively recruited cohort of 79 patients was implanted with a CIM-BKA (patello-femoral plus either medial or lateral tibio-femoral, iDuo G2 system, Conformis, Billerica MA) at eight centres in the US and Germany. Patients were assessed for the 2011 KSS, KOOS, and ROM pre-operatively and at 2 weeks, 6 weeks, 12 weeks, 1 year, and 2 years post-operatively. RESULTS: The objective KSS score significantly improved from 69 at the pre-operative visit, to 94 at the 2-year post-operative time-point. Similar improvements were observed for the KSS function and satisfaction domains. Significant improvements from pre-operative levels were observed across all five domains of the KOOS. Two patients have undergone surgery to revise their CIM-BKA implant to total knees, resulting in a survivorship rate of 97.5% at an average follow-up of 2.6 years. CONCLUSIONS: CIM-BKA compares favourably to published scores as well as revision rates for previously available monolithic OTS-BKA implants. CIM-BKA implants provide surgeons with a viable and patient-specific monolithic implant solution as an option for patients presenting with bi-compartmental disease, who might, otherwise, be treated by performing uni-condylar + patello-femoral joint or bicruciate sparing TKA surgeries. Longer follow-up and higher numbers have to be awaited for further validation of these encouraging early results. LEVEL OF EVIDENCE: 3b (individual case-controlled study).

[Core decompression ("conventional method") in atraumatic osteonecrosis of the hip]. / Die "klassische" Entlastungsbohrung bei atraumatischer Hüftkopfnekrose.

OBJECTIVE: Retrograde drilling of a necrotic zone within the femoral head to reduce intraosseous pressure and stimulate revascularization. INDICATIONS: Atraumatic osteonecrosis of the hip ARCO stage I (reversible) and ARCO stage II (potentially reversible) with a medial or central necrotic zone <30% or ARCO stage III with a subchondral fracture for reduction of pain. CONTRAINDICATIONS: ARCO stage III C, ARCO stage IV (secondary osteoarthritis), stage-independent necrotic zone > 30%, infections. SURGICAL TECHNIQUE: Supine position. Visualization of the necrotic zone via an image intensifier, approach is determined by using a Kirschner wire, laterodorsal skin incision on a level with the wire, longitudinal incision of iliotibial band and vastus lateralis muscle, drilling the necrotic zone with a 2-3 mm Kirschner wire, optionally placing more wires or a hollow drill, wound closure. POSTOPERATIVE MANAGEMENT: Partial weightbearing with 20 kg for 6 weeks due to risk of fracture, followed by avoidance of jumping or sprinting for another 6 weeks; physiotherapy from day 1 after surgery, thromboembolic prophylaxis until full weightbearing is possible. RESULTS: Results are dependent on ARCO stages and are promising in early stages.

[Medical care of adults with congenital heart diseases : Present and future]. / Medizinische Versorgung von Erwachsenen mit angeborenen Herzfehlern : Gegenwart und Zukunft.

Congenital heart diseases (CHD) are the most common types of congenital organ defects. Thanks to medical progress in congenital cardiology and heart surgery, most children with CHD reach adulthood. Despite primarily successful treatment residual and subsequent conditions as well as (non)cardiac comorbidities can influence the chronic course of the disease and lead to a higher morbidity and mortality. Adults with congenital heart disease (ACHD) in Germany are not tied to the healthcare structure despite the great need for aftercare. According to the results of the medical care of ACHD (MC-ACHD) study, ACHD centers and specialists in Germany are insufficiently perceived despite increased complication rates and the great need for specialist guidance. General practitioners and patients are not adequately informed about existing ACHD facilities. A better awareness of the ACHD problem should be created at the level of primary medical supply in order to optimize care and to reduce morbidity and mortality. Improved future-oriented patient care includes lifelong regular follow-up and the possibility of interdisciplinary, integrated medical care of CHD.

[Revision total hip arthroplasty : Significance of instability, impingement, offset and gluteal insufficiency]. / Revisionsendoprothetik der Hüfte : Bedeutung von Instabilität, Impingement, Offset und Glutealinsuffizienz.

BACKGROUND: Instability is a common cause of failure in primary and, especially, revision total hip arthroplasty. The reasons for instability include implant malpositioning, impingement, inadequate offset reconstruction, and gluteal insufficiency. Impingement following THA and revision THA is divided into prosthetic and bony impingement, and in addition to instability also causes pain in the area of the hip joint. Offset reconstruction during revision THA is of particular biomechanical importance, since insufficient reconstruction leads not only to instability and pain but also to dislocation. Abductor deficiency often occurs after revision THA and leads to a change in gait pattern, instability and pain. AIM: Current diagnostic and treatment procedures for instability, impingement, insufficient offset reconstruction and abductor deficiency after THA and revision THA are summarized. RESULTS AND DISCUSSION: Diagnosis of an instable THA and painful THA includes patient history, physical examination and medical imaging. Thus, in almost all cases, the cause can be determined and treated. Dislocation after primary THA in the early postoperative period can often be treated conservatively if accurate component placement is observed, while a late-onset and recurrent dislocation after primary and revision THA usually needs surgical procedures. To avoid bony and prosthetic THA impingement intraoperative control is absolutely necessary. If possible, the offset reconstruction is based on the condition of the native hip joint and can be achieved by using modular prostheses, neck adapters and different head lengths. Abductor deficiency also occurs frequently after revision THA and can be treated surgically if severe clinical symptoms and fatty degeneration of the abductors have been diagnosed.

[Total hip arthroplasty in young patients : Bearings and custom-made prostheses]. / Hüftendoprothetik beim jungen Patienten : Gleitpaarungen und Individualendoprothesen.

BACKGROUND: Carefully and correctly implanted components are the prerequisite for the lifespan of a prosthesis. Whether higher levels of activity lead to prior failure of total hip arthroplasty in young patients is controversially discussed. The right choice of bearings is still of great relevance. BEARINGS: Ceramic-on-ceramic as well as polyethylene-on-ceramic bearings achieve comparable results, although ceramic-on-ceramic bearings should be avoided in patients with high demands on their range of motion. Polyethylene-on-metal bearings also show good clinical results, if corrosion between head and stem is absent. Metal-on-metal bearings lead to adverse systemic effects due to metal wear and should be implanted in individual cases only, e. g. as hip resurfacing. Alternative bearings have to give proof of effectivity first. Custom-made prostheses constitute an option for young patients with special conditions of hip anatomy. Planning and study results of these prostheses are elucidated in this review article.

Patella alta and patellar subluxation might lead to early failure with inlay patello-femoral joint arthroplasty.

PURPOSE: With the growing interest in resurfacing procedures, several new implants have been recently introduced for isolated patello-femoral joint arthroplasty (PFA). However, not much data are available for these new techniques or about the right indications for each type of implant. METHODS: Out of a retrospective cohort of 20 inlay PFA, 11 PFA with an elevated Insall-Salvati index and an increased patello-femoral congruence angle showed an initial satisfactory result, but presented thereafter with recurrent pain and "clunk" phenomena. They were all revised after a median time of 25 months (range 8-28 months) into an onlay technique PFA and analyzed for their failure mode and revision technique. RESULTS: Clinical symptoms such as clunking, as well as abraded areas craniolateral of the inlay implant found intraoperatively, were the main observations of this study. The modified Insall-Salvati index (mISI) was significantly higher in the revised knees compared to the unrevised (median 1.8 versus 1.6; p = 0.041). VAS and KSS significantly improved after revision (median VAS reduction in pain of 4.0 points, median KSS improvement of 20.0 points; p < 0.05). CONCLUSION: Patients with high-normal patellar height index or patella alta, as well as a craniolateral type of arthritis with additional lateralization, should be considered contra-indicated for an inlay technique PFA. They could be considered for a PFA system reaching further proximal into the distal femur. An onlay PFA can be an option for early revision of failed inlay implants. The clinical relevance of this study is that patella alta and patellar subluxation are more difficult to adjust for with an inlay PFJ component. LEVEL OF EVIDENCE: Level IV.