Slow Magnetic Relaxation in Mono- and Bimetallic Lanthanide Tetraimido Sulfate S(NtBu)4 2- Complexes.

Invited for the cover of this issue are Selvan Demir and co-worker from the Michigan State University at East Lansing, and Dietmar Stalke and co-workers from the Georg-August Universität at Göttingen. The image illustrates the first coordination of a tetraimido sulfate ligand via two of its nitrogen donors to a lanthanide ion producing mono- and bimetallic lanthanide complexes where specifically the dysprosium congeners, benefitting from the intrinsic oblate-shaped electron density, feature single-molecular magnet behavior as indicated by the observed slow magnetic relaxation. Read the full text of the article at 10.1002/chem.202101076.

Slow Magnetic Relaxation in Mono- and Bimetallic Lanthanide Tetraimido-Sulfate S(NtBu)4 2- Complexes.

Lanthanide ions are particularly well-suited for the design of single-molecule magnets owing to their large unquenched orbital angular momentum and strong spin-orbit coupling that gives rise to high magnetic anisotropy. Such nanoscopic bar magnets can potentially revolutionize high-density information storage and processing technologies, if blocking temperatures can be increased substantially. Exploring non-classical ligand scaffolds with the aim to boost the barriers to spin-relaxation are prerequisite. Here, the synthesis, crystallographic and magnetic characterization of a series of each isomorphous mono- and dinuclear lanthanide (Ln=Gd, Tb, Dy, Ho, Er) complexes comprising tetraimido sulfate ligands are presented. The dinuclear Dy complex [{(thf)2 Li(NtBu)2 S(tBuN)2 DyCl2 }2 ⋅ ClLi(thf)2 ] (1c) shows true signatures of single-molecule magnet behavior in the absence of a dc field. In addition, the mononuclear Dy and Tb complexes [{(thf)2 Li(NtBu)2 S(tBuN)2 LnCl2 (thf)2 ] (2b,c) show slow magnetic relaxation under applied dc fields.

Exchange Coupling in Binuclear Manganese and Cobalt Complexes with the Tetraimido Sulfate Anion [S(NtBu)4]2.

The (hetero)bimetallic complexes [Cl2Mn(NtBu)2S(tBuN)2Mn{ClLi(THF)3}2] (1), [(acac)Co(NtBu)2S(tBuN)2Co(acac)] (2), and [(acac)Co(NtBu)2S(tBuN)2Li(THF)2] (3), with THF = tetrahydrofuran and acac = acetylacetonate [H2C(C(O)Me)2], were synthesized and investigated for their magnetic properties. While the two different MnII sites in 1 gave a weak coupling of J = -1.00 cm-1, we could observe an appreciable antiferromagnetic coupling of J = -6.08 cm-1 between the two CoII cations in 2, proving the tetraimido sulfate anion to be a challenging but promising linker to enhance magnetic communication between paramagnetic centers. The heterobimetallic complex 3 seems a versatile platform for magnetically interesting d/d, f/d, or f/f mixed-metal complexes.

Trigonal Planar Iron(II) and Cobalt(II) Complexes Containing [RS(NtBu)3]n- (R = NtBu, n = 2; CH2PPh2, n = 1) as Acute Bite-Angle Chelating Ligands: Soft P Donor Proves Beneficial to Magnetic Co Species.

We prepared four new complexes, 4a,b and 5a,b, from polyimido sulfur-centered ligands with FeII and CoII amides. Their molecular structures were elucidated by single-crystal X-ray diffraction. Cobalt magnetic investigations and multiconfigurational calculations provided insight into magneto-structural correlations between the acute N,N' chelating bite angle and P-side arm donation. The deviation from an ideal trigonal planar geometry and the magnetic performance correlated in an unprecedented manor. Mononuclear cobalt species 4b and 5b showed slow magnetic relaxation under a small applied dc field with energy barriers of up to 33.0 and 21.9 cm-1, respectively. Although they possess some of the largest zero-field splitting parameters among three-coordinate cobalt single-ion magnets, both theory and experiment suggest that the high rhombicity (E/D) hampers large effective energy barriers to spin reversal at zero field from being obtained.

Tetraimido Sulfuric Acid H2 S(NtBu)4 -Valence Isoelectronic to H2 SO4.

The valence isoelectronic imido analog H2 S(NtBu)4 (1) of sulfuric acid H2 SO4 was synthesized, isolated, and characterized by NMR spectroscopy and high-resolution X-ray charge density analysis. The latter reveals strongly polarized Sδ+ -Nδ- bonds with virtually no double bond character. The easy-to-polarize S-N bonds are an advantageous and versatile feature of sulfur nitrogen ligands, which enables them to adapt to different electron requirements of various metal cations.

Benefits of recombinant adeno-associated virus (rAAV)-mediated insulinlike growth factor I (IGF-I) overexpression for the long-term reconstruction of human osteoarthritic cartilage by modulation of the IGF-I axis.

Administration of therapeutic genes to human osteoarthritic (OA) cartilage is a potential approach to generate effective, durable treatments against this slow, progressive disorder. Here, we tested the ability of recombinant adeno-associated virus (rAAV)-mediated overexpression of human insulinlike growth factor (hIGF)-I to reproduce an original surface in human OA cartilage in light of the pleiotropic activities of the factor. We examined the proliferative, survival and anabolic effects of the rAAV-hIGF-I treatment in primary human normal and OA chondrocytes in vitro and in explant cultures in situ compared with control (reporter) vector delivery. Efficient, prolonged IGF-I secretion via rAAV stimulated the biological activities of OA chondrocytes in all the systems evaluated over extended periods of time, especially in situ, where it allowed for the long-term reconstruction of OA cartilage (at least for 90 d). Remarkably, production of high, stable amounts of IGF-I in OA cartilage using rAAV advantageously modulated the expression of central effectors of the IGF-I axis by downregulating IGF-I inhibitors (IGF binding protein [IGFBP]-3 and IGFBP4) while up-regulating key potentiators (IGFBP5, the IGF-I receptor and downstream mitogen-activated protein kinase/extracellular signal-regulated kinase 1/2 [MAPK/ERK-1/2] and phosphatidylinisitol-3/Akt [PI3K/Akt] signal transduction pathways), probably explaining the enhanced responsiveness of OA cartilage to IGF-I treatment. These findings show the benefits of directly providing an IGF-I sequence to articular cartilage via rAAV for the future treatment of human osteoarthritis.

Fungal periprosthetic hip and knee joint infections clinical experience with a 2-stage treatment protocol.

Fungal periprosthetic joint infections are a rare entity in orthopedic surgery, and there exist no guidelines according to which these infections can be successfully managed. Between 2004 and 2009, 7 patients with fungal periprosthetic joint infections (4 total hip arthroplasties and 3 total knee arthroplasties) have been treated with a 2-stage protocol and implantation of antibiotic-loaded cement spacers. Most of the infection was caused by Candida species. Systemic antifungal agents were administered for 6 weeks in 6 cases and 6 months in 1 case. The mean spacer implantation time was 12 weeks. At a mean follow-up of 28 months (5-70 months), no persistence of infection or reinfection could be observed. A 2-stage treatment protocol with implantation of an antibiotic-loaded cement spacer is an efficient option in the treatment of fungal periprosthetic infections.

Proposal of a New Rating Concept for Digital Health Applications in Orthopedics and Traumatology.

BACKGROUND: Health-related mobile applications (apps) are rapidly increasing in number. There is an urgent need for assessment tools and algorithms that allow the usability and content criteria of these applications to be objectively assessed. The aim of this work was to establish and validate a concept for orthopedic societies to rate health apps to set a quality standard for their safe use. METHODS: An objective rating concept was created, consisting of nine quality criteria. A self-declaration sheet for app manufacturers was designed. Manufacturers completed the self-declaration, and the app was examined by independent internal reviewers. The pilot validation and analysis were performed on two independent health applications. An algorithm for orthopedic societies was created based on the experiences in this study flow. RESULTS: "Sprunggelenks-App" was approved by the reviewers with 45 (98%) fulfilled criteria and one (2%) unfulfilled criterion. "Therapie-App" was approved, with 28 (61%) met criteria, 6 (13%) unfulfilled criteria and 12 (26%) criteria that could not be assessed. The self-declaration completed by the app manufacturer is recommended, followed by a legal and technical rating performed by an external institution. When rated positive, the societies' internal review using independent raters can be performed. In case of a positive rating, a visual certification can be granted to the manufacturer for a certain time frame. CONCLUSION: An objective rating algorithm is proposed for the assessment of digital health applications. This can help societies to improve the quality assessment, quality assurance and patient safety of those apps. The proposed concept must be further validated for inter-rater consistency and reliability.

Imidosulfonate scorpionate ligands in lanthanide single-molecule magnet design: slow magnetic relaxation and butterfly hysteresis in [ClDy{Ph2PCH2S(NtBu)3}2].

Single-molecule magnets (SMMs) harbour vast opportunities for potential pioneering applications upon optimization like big data storage and quantum computing. Lanthanides were found to be highly suitable candidates in the design of such molecules, as they intrinsically hold a large unquenched orbital momentum and a strong spin-orbit coupling, warranting a high magnetic anisotropy. An indispensable element in successfully tailoring SMMs is the ligand design. Polyimido sulfur ligands offer a promising choice because the polar S+-N--bond facilitates both electronic and geometric adaptability to various f-metals. In particular, the acute N-Ln-N bite angle generates advantageous magnetic properties. The [Ph2PCH2S(NtBu)3]- anion, introduced from [(thf)3K{Ph2PCH2S(NtBu)3}] (2) to a series of complexes [ClLn{Ph2PCH2S(NtBu)3}2] with Ln = Tb (3a), Dy (3b), Er (3c), Ho (3d), and Lu (3e), provides tripodal shielding of the metal's hemisphere as well as a side-arm donation of a soft phosphorus atom. For the Tb and Er complexes 3a and 3d, slow magnetic relaxation (Ueff = 235 and 34.5 cm-1, respectively) was only observed under an applied dc field. The dysprosium congener 3b, however, is a true SMM with relaxation at zero field (Ueff = 66 cm-1) and showing a butterfly hysteresis close to 3.5 K. Upon magnetic dilution with the diamagnetic and isostructural lutetium complex 3e or application of a magnetic field, the energy barrier to spin reversal is increased to 74 cm-1.

Long-Term Results of the Modular Physiological Wrist Prosthesis (MPW®) in Patients with Inflammatory Diseases.

The wrist is among the predilection sites of over 90% of cases of rheumatoid arthritis (RA). In advanced cases, total wrist arthroplasty (TWA) is an alternative to arthrodesis. The aim of this study is to present the long-term results of the modular physiological wrist prosthesis (MPW®) and to match them in context with the results of a standard population survey. In a retrospective study with follow-up, patients with an MPW® endoprosthesis were evaluated concerning the clinical and radiological outcome, complications were reviewed (incidence and type), and conversion to wrist fusion was assessed. Patient function measurements included the Mayo wrist score, the patient-specific wrist test, and therefore the DASH score (arm, shoulder, and hand). Thirty-four MPW® wrist prostheses were implanted in 32 patients, including thirty primary implantations and four changes of the type of the endoprosthesis. Sixteen patients (18 prostheses) underwent clinical and radiological follow-up. The average follow-up time was 8.5 years (1 to 16). Poor results of the MPW prosthesis are caused by the issues of balancing with luxation and increased PE wear. Salvage procedures included revision of the TWA or fusion. In successful cases, the flexion and extension movement averaged 40 degrees. The grip force was around 2.5 kg. The common DASH score was 79 points, with limited and problematic joints of the upper extremity. The MPW wrist prosthesis offered good pain relief and functional movement in over 80% of cases. The issues of dislocation and increased PE wear prevent better long-term results, as do the joints affected. A follow-up study with fittings under a contemporary anti-rheumatic therapy with biologicals suggests increasing score results. Type of study/level of evidence: Case series, IV.

The Digital Healthcare Act - a Turning Point in the German Digitisation Strategy? / Das Digitale-Versorgung-Gesetz ­ eine Zäsur der deutschen Digitalisierungsstrategie?

The recently ratified Digital Healthcare Act - DVG - has paved the way, among other issues, for the prescription of health apps. The German DVG creates an entitlement to health apps for the very first time. However, this entitlement is initially limited to low-risk medical devices that have been included in the publicly accessible Register for Digital Health Applications by the German Federal Institute for Drugs and Medical Devices. Listing in the register is granted, if the manufacturer has submitted a health app and verified that it meets basic requirements for medical devices and data security as well as positive health care effects. It is questionable, whether the DVG will lead to sustainable improvements in future patient care. In order to pursue this question and align the DGOUC's digitization strategy closely with its basis, an online survey was conducted among the respective members on the DVG's content and its associated opportunities and risks. A total of 461 German-speaking, predominantly male, experienced and elderly physicians in leading positions took part in the survey. In this study, it was shown that the majority of the participating German orthopaedic and trauma surgeons is not familiar with the DVG's contents. Despite a fundamentally positive attitude towards digitization, scepticism about the use of "apps on prescription" and potential risks still prevails at present. The closing of ranks between medicine, IT and the legislature via interdisciplinary expert groups and the involvement of medical societies might be obligatory.

Analysis of Secure Apps for Daily Clinical Use by German Orthopedic Surgeons: Searching for the "Needle in a Haystack".

BACKGROUND: It is undeniable that appropriate smartphone apps offer enormous opportunities for dealing with future challenges in orthopedic surgery and public health, in general. However, it is still unclear how the apps currently available in the two major app stores can be used in daily clinical routine by German orthopedic surgeons. OBJECTIVE: This study aimed to gain evidence regarding the quantity and quality of apps available in the two major app stores and their suitability for use by orthopedic surgeons in Germany. METHODS: We conducted a systematic, keyword-based app store screening to obtain evidence concerning the quantity and quality of commercially available apps. Apps that met the inclusion criteria were evaluated using the app synopsis-checklist for users and the German Mobile App Rating Scale for secure use, trustworthiness, and quality. RESULTS: The investigation revealed serious shortcomings regarding legal and medical aspects. Furthermore, most apps turned out to be useless and unsuitable for the clinical field of application (4242/4249, 99.84%). Finally, 7 trustworthy and high-quality apps (7/4249, 0.16%) offering secure usage in the daily clinical routine of orthopedists were identified. These apps mainly focused on education (5/7). None of them were CE (Conformité Européenne) certified. Moreover, there are no studies providing evidence that these apps have any positive use whatsoever. CONCLUSIONS: The data obtained in our study suggest that the number of trustworthy and high-quality apps on offer is extremely low. Nowadays, finding appropriate apps in the fast-moving, complex, dynamic, and rudimentarily controlled app stores is most challenging. Promising approaches, for example, systematic app store screenings, app-rating developments, reviews or app libraries, and the creation of consistent standards have been established. However, further efforts are necessary to ensure that these innovative mobile health apps not only provide the correct information but are also safe to use in daily clinical practice.

Correction: Analysis of Secure Apps for Daily Clinical Use by German Orthopedic Surgeons: Searching for the "Needle in a Haystack".

[This corrects the article DOI: 10.2196/17085.].

Complications after spacer implantation in the treatment of hip joint infections.

The aim of this retrospective study was to identify and evaluate complications after hip spacer implantation other than reinfection and/or infection persistence. Between 1999 and 2008, 88 hip spacer implantations in 82 patients have been performed. There were 43 male and 39 female patients at a mean age of 70 [43-89] years. The mean spacer implantation time was 90 [14-1460] days. The mean follow-up was 54 [7-96] months. The most common identified organisms were S. aureus and S. epidermidis. In most cases, the spacers were impregnated with 1 g gentamicin and 4 g vancomycin/80 g bone cement. The overall complication rate was 58.5% (48/82 cases). A spacer dislocation occurred in 15 cases (17%). Spacer fractures could be noticed in 9 cases (10.2%). Femoral fractures occurred in 12 cases (13.6%). After prosthesis reimplantation, 16 patients suffered from a prosthesis dislocation (23%). 2 patients (2.4%) showed allergic reactions against the intravenous antibiotic therapy. An acute renal failure occurred in 5 cases (6%). No cases of hepatic failure or ototoxicity could be observed in our collective. General complications (consisting mostly of draining sinus, pneumonia, cardiopulmonary decompensation, lower urinary tract infections) occurred in 38 patients (46.3%). Despite the retrospective study design and the limited possibility of interpreting these findings and their causes, this rate indicates that patients suffering from late hip joint infections and being treated with a two-stage protocol are prone to having complications. Orthopaedic surgeons should be aware of these complications and their treatment options and focus on the early diagnosis for prevention of further complications. Between stages, an interdisciplinary cooperation with other facilities (internal medicine, microbiologists) should be aimed for patients with several comorbidities for optimizing their general medical condition.

Mechanical complications and reconstruction strategies at the site of hip spacer implantation.

Over the past two decades antibiotic-impregnated hip spacers have become a popular procedure in the treatment of hip joint infections. Besides infection persistence and/or reinfection, major complications after hip spacer implantation include spacer fracture, -dislocation, and bone fracture. Moreover, in cases with extensive loss of femoral and/or acetabular bone alternative reconstructive techniques should be used for a stable spacer fixation and prevention of fractures or dislocations. The present article reviews the different types of spacer fractures and dislocations and offers some suggestions about reconstructive techniques for management of extensive loss of femoral and/or acetabular bone at the site of hip spacer implantation.

Classification of hip joint infections.

Infections still remain one of the most devastating complications in hip joint surgery. Classification of these infections help the orthopaedic surgeon to identify the acuteness or chronicity of the infection, predict the complexity of the treatment procedure and ensure that all necessary device are available at the time of the revision surgery. The present article reviews the actual literature and provides an overview of clinical, arthroscopic, microbiological and radiological staging systems.

Arthroscopic psoas tenotomy.

Tenotomy may be indicated for psoas tendinitis or painful snapping if conservative treatment remains unsuccessful. Because of significant complications with open techniques, endoscopic operations have been developed. We present a new arthroscopic technique to access and release the psoas tendon from the hip joint. This procedure can be performed in addition to other arthroscopic procedures of the hip joint or alone. To exclude additional hip disease, a diagnostic round of the joint should be completed. After hip arthroscopy of the central compartment has been performed, traction is released and the 30 degrees arthroscope is placed via the proximal anterolateral portal lying on the anterior femoral neck. The medial synovial fold can be identified. This fold lies slightly medially underneath the anteromedial capsule at the level of the psoas tendon. The arthroscope is turned toward the anterior capsule. Sometimes, the tendon shines through a thin articular capsule, or it may even be accessed directly via a hole connecting the hip joint and the iliopectineal bursa at the level of the anterior head-neck junction. If this cannot be done, an electrothermic probe is introduced via the anterior portal to make a 2-cm transverse capsular incision. The tendon is released with the back side of the electrothermic device turned to the iliacus muscle that lies anterior to the psoas tendon. A complete release is achieved when the tendon stumps can be seen gapping at a distance and the fibers of the iliacus muscle are visible. The first 9 patients who underwent surgery performed according to this technique developed no complications, and their hip flexion strength was restored to normal within 3 months.

Simultaneous enantioselective analysis of chiral urinary metabolites in patients with Zellweger syndrome.

Enantio-MDGC-MS analysis with heptakis-(2,3-di-O-methyl-6-O-tert.-butyl-dimethylsilyl)-beta-cyclodextrin as the chiral main column is a powerful tool for the separation of chiral compounds. This paper reports on the simultaneous stereodifferentiation of 2-hydroxyisocaproic acid (HICA), 3-methyladipic acid (3-MA), 2-hydroxyglutaric acid (2-HG), 3-(4-hydroxyphenyl)-lactic acid (HPLA), 2-hydroxysebacic acid (2-HS) and 3-hydroxysebacic acid (3-HS) in a single chromatographic run. These chiral urinary metabolites are useful in the diagnosis of peroxisomal diseases such as Zellweger syndrome (ZS). In this investigation, urine samples from nine patients with ZS were analysed in order to reveal the enantiomeric ratio of these chiral metabolites. The stereodifferentiation of the analysed chiral compounds may provide important information on their biochemical origin.

Arthroscopic treatment of an avulsion fracture of the ligamentum teres of the hip in an 18-year-old horse rider.

We present the case of an 18-year-old horse rider with an avulsion fracture of the ligamentum teres causing persistent hip pain and locking for 2 years. The patient had no history of major trauma; however, repeated minor hyperabduction injuries occurred. We were able to successfully treat this patient by arthroscopic removal of the bony fragments and two loose bodies and partial resection of the ligamentum teres.

Intra-articular glucocorticosteroid injection into sternocostoclavicular joints in patients with SAPHO syndrome.

OBJECTIVE: Painful swelling of the anterior chest wall caused by osteitis and hyperostosis in the sternocostoclavicular region are characteristically observed in patients suffering from SAPHO syndrome. Autoimmune triggering of inflammation and bacterial infection is hypothesized to be involved in the pathogenesis. Promising treatment modalities include antirheumatic and antibiotic medications. METHODS: Ten patients with SAPHO syndrome and symptomatic osteitis in the sternocostoclavicular region were treated by a single instillation of glucocorticosteroids (20 mg triamcinolone) into the sternocostoclavicular joints. The disease activity was evaluated on the basis of a questionnaire asking for osteitis activity (quantified for complains on a scale of 0-6), by Health Assessment Questionnaire (HAQ) score, erythrocyte sedimentation rate, C-reactive protein, and magnet resonance imaging (MRI) scanning of the sternocostoclavicular region (osteitis scores quantified for inflammation on a scale of 0-2 by the radiologist) prior to injection and after 12 weeks. No changes of the preexisting antirheumatic therapy were allowed during the observation interval. RESULTS: All patients continued the study during the follow-up. The osteitis score changed from 4.2 (mean; standard error (SE) ±0.3) to 3.2 (±0.4), [P = 0.062], the erythrocyte sedimentation rate from 19.0 (range from 12 to 30) to 19.9 (from 12 to 27), [P = 0.430], and the MRI score from 1.6 (±0.2) to 1.5 (±0.2) [P = 1.0]. One patient developed an increase of the clinical osteitis activity from 3 to 5 according the scoring system; only 2 patients showed a reduction of the MRI activity score from 2 to 1. CONCLUSIONS: Intra-articular glucocorticosteroid instillation does not appear to reduce osteitis in the sternocostoclavicular region in patients with SAPHO syndrome.