Managing longitudinal melanonychia.

Longitudinal melanonychia (LM) is a pigmented band extending from the matrix to the distal edge of a nail. It is caused by increased production of melanin within the matrix, and integration into the nail plate. The origin of this production is usually benign, due to activation, hyperplasia or proliferation of melanocytes normally present in the matrix. In some cases, however, LM is the manifestation of a subungual melanoma, the diagnosis of which must be made early. Biographical, clinical and dermoscopic criteria make it possible to suspect melanoma and decide whether to perform biopsy. None of these criteria, however, are specific and definitive diagnosis requires pathologic examination of a matrix biopsy. The biopsy technique should enable reliable histological study while limiting the risk of secondary nail dystrophy. Initial resection should ideally involve the entire lesion. Complete elevation of the nail plate enables the lesion to be precisely located. Lesions up to 3 mm can be removed by longitudinal resection biopsies without significant sequelae. In more extensive lesions, incision or tangential ("shave") biopsy can be performed without impairing prognosis. In clinical presentations strongly suggestive of melanoma, immediate complete resection of the entire nail unit may be proposed.

Stochastic simulation of successive waves of COVID-19 in the province of Barcelona.

Analytic compartmental models are currently used in mathematical epidemiology to forecast the COVID-19 pandemic evolution and explore the impact of mitigation strategies. In general, such models treat the population as a single entity, losing the social, cultural and economical specificities. We present a network model that uses socio-demographic datasets with the highest available granularity to predict the spread of COVID-19 in the province of Barcelona. The model is flexible enough to incorporate the effect of containment policies, such as lockdowns or the use of protective masks, and can be easily adapted to future epidemics. We follow a stochastic approach that combines a compartmental model with detailed individual microdata from the population census, including social determinants and age-dependent strata, and time-dependent mobility information. We show that our model reproduces the dynamical features of the disease across two waves and demonstrates its capability to become a powerful tool for simulating epidemic events.

Progression and variation of competitive 100 and 200m performance at the 2021 European Swimming Championships.

Competitive progressions are necessary to ensure that peak performance occurs when medals are decided. This study aimed to: i) study the coefficient of variation (CV) and performance changes (%Δ) among swimmers who participated in different rounds (i.e., heats, semi-finals and finals); ii) study the CV changes as a function of FINA-points. A total of 1447 performances were analysed in the 100 and 200 m-races during the Budapest 2021 European-Championships. Linear mixed-effects models were applied for total and split-times to obtain intra-athlete CV and %Δ. The FINA-points were studied with two-way ANOVA and Pearson's correlation assessed the relations with CV. The CV in 100 m-races was: 0.48 ± 0.21% for males and 0.50 ± 0.20% for females (Δ = -0.66%); in 200 m-races: 0.63 ± 0.36% and 0.60 ± 0.34% (Δ = -0.82%). There were differences in FINA-points between strokes and distances (p < 0.02) associated with higher CV for the 200 m-races (r = 0.37; p = 0.003), indicating changes in performance over the rounds. Swimmers' finalists performed easier during the heats by going slower in the first 50 m-lap; however, some of them would have little chance of qualifying during major championships because some events were below FINA-points world-standards.

Outcomes of ulnar shortening osteotomy using a new compression plate.

Ulnar impaction syndrome (UIS) is a frequent cause of ulnar-sided wrist pain. Several open and arthroscopic surgery techniques have been described. Ulnar shortening osteotomy (USO) is often the method of choice. It has the advantage of leveling the distal radioulnar joint extra-articularly while maintaining the integrity of the soft tissues that stabilize the joint. This retrospective study reports the short-term outcomes of 20 patients who underwent surgery between 2013 and 2015. USO was performed with a locked plate and a new compression device (Alians®, Newclip™, Haute Goulaine, France). Preoperative and postoperative ulnar variance were measured on wrist X-rays in neutral pronation-supination. Functional outcomes were evaluated with the QuickDASH score and the pain on VAS (visual analog scale). Postoperative range of motion and grip strength were compared to those of the contralateral wrist. The average follow-up was 16 months (4 to 28 months). Preoperative ulnar variance was positive with an average of 4mm (1-11mm). The average length of the final ulna shortening was 3.5mm (1.5-6mm); the mean time to union was 4 months (3-12 months). The average QuickDASH was 12 and pain had decreased 2.4mm on the VAS. The results achieved with this new compression plate designed specifically for USO are similar to those described in the literature. This kind of device has an easily reproducible technique and can reduce the operative time. LEVEL OF EVIDENCE: IV.

Risk factors for return visits and rehospitalizations to the child emergency psychiatric unit: A retrospective study over 2 years at Saint-Étienne University Hospital.

PURPOSE: This retrospective study aimed to achieve a better understanding of risk factors leading children and adolescents hospitalized in an emergency psychiatric ward to return visits, and to propose preventive devices. METHOD: From January 2, 2010 through February 29, 2012, 180 children and adolescents younger than 17 years were hospitalized in a total of 261 stays in the emergency psychiatric ward of University hospital of Saint-Étienne (France). We assessed clinical and sociodemographic characteristics of these patients and traced any of their return visits to the same unit through December 31, 2012. Risk factors for patients' repeated visits were calculated using multivariate analysis, and the cumulative incidence of returns using the Kaplan-Meier method for censored data. We used confidence interval of relative risk, considering 0.05 to reflect significance. RESULTS: Over the 2 years of the study, 77 (42.8%) of the 180 patients revisited the emergency psychiatric ward; 62 (80.7%) of these required further hospitalizations. Multivariate analysis linked the patients' psychiatric history (RR=2.5) and pursuit of vocational education (RR=4) with the risk of return. Return visits rose from 27.2% at 6 months to 41.2% at 2 years. CONCLUSION: Knowledge of risk factors would allow implementation of secondary or tertiary preventive devices. Students could undergo early screening of psychiatric pathologies using mobile screening teams which would save money, avoid hospitalizations, and when necessary, facilitate both hospitalization and return visits.

In situ insight into the unconventional ruthenium catalyzed growth of carbon nanostructures.

We report on the in situ analysis of the growth process of carbon nanostructures catalyzed by Ru nanoparticles using syngas, a mixture of hydrogen and CO, as the carbon source at a medium temperature (500 °C). The structural modifications of the dual nanotube/nanoparticle system and the general dynamics of the involved processes have been directly followed during the growth, in real time and at the atomic scale, by transmission electron microscopy in an environmental gas cell at atmospheric pressure. After a reduction step under hydrogen and syngas, the particles became very active for the carbon growth. The growth rate is independent of the particle size which mainly influences the nanotube wall thickness. Other subtle information on the general behavior of the system has been obtained, as for instance the fact that the regular changes in the direction of the particle originate generally from the particle shape fluctuation. The main result is the evidence of a new growth mode in relation to the presence and the high instability of the ruthenium carbide phase which acts as a carbon reservoir. For the first time, a relaxation oscillation of the growth rate has been observed and correlated with the metal-carbide structural transition at the particle sub-surface.

What is the influence of tonsillectomy on the level of periodontal pathogens on the tongue dorsum and in periodontal pockets.

BACKGROUND: For periodontal treatment, the full mouth disinfection approach suggests disinfection of oral soft tissues, such as tongue and tonsils concomitant to scaling and root planning since patients might benefit from treatment of these oral niches either. Periodontopathogenes in tonsillar tissue support this hypothesis. This prospective controlled clinical study investigated the change in the oral flora of patients who underwent tonsillectomy. Pockets were tested for eleven bacterial species before and six weeks after the surgical intervention. METHODS: Fifty generally healthy adults were included in this study. The test group consisted of 25 patients with tonsillectomy. The control group included 25 patients with otorhinolarynologic surgery without involvement of the oral cavity. Clinical parameters such as probing pocket depth, bleeding-on-probing index and plaque index were registered the evening before surgery. Also bacterial samples from the gingival sulcus and dorsum linguae were taken, and an additional sample from the removed tonsils in the test group. Six weeks after the intervention microbial samples of pockets and tongue were taken again. Data were tested for significant differences using Wilcoxon rank and Whitney-u-test. RESULTS: No relevant intra- or intergroup differences were found for the change of the eleven investigated species. CONCLUSION: Based on the results of the present study, tonsillectomy does not seem to have an immediate relevant effect on the bacterial flora of tongue or periodontium. This study design was approved by the ethical committee of Zurich (KEK-ZH-Nr.2013-0419). TRIAL REGISTRATION: The trial was retrospectively registered in the German Clinical Trials Register ( DRK00014077 ) on February 20, 2018.

Reactivity and structural evolution of urchin-like Co nanostructures under controlled environments.

In situ transmission electron microscopy (TEM) of samples in a controlled gas environment allows for the real time study of the dynamical changes in nanomaterials at high temperatures and pressures up to the ambient pressure (105 Pa) with a spatial resolution close to the atomic scale. In the field of catalysis, the implementation and quantitative use of in situ procedures are fundamental for a better understanding of the behaviour of catalysts in their environments and operating conditions. By using a microelectromechanical systems (MEMS)-based atmospheric gas cell, we have studied the thermal stability and the reactivity of crystalline cobalt nanostructures with initial 'urchin-like' morphologies sustained by native surface ligands that result from their synthesis reaction. We have evidenced various behaviors of the Co nanostructures that depend on the environment used during the observations. At high temperature under vacuum or in an inert atmosphere, the migration of Co atoms towards the core of the particles is activated and leads to the formation of carbon nanostructures using as a template the initial multipods morphology. In the case of reactive environments, for example, pure oxygen, our investigation allowed to directly monitor the voids formation through the Kirkendall effect. Once the nanostructures were oxidised, it was possible to reduce them back to the metallic phase using a dihydrogen flux. Under a pure hydrogen atmosphere, the sintering of the whole structure occurred, which illustrates the high reactivity of such structures as well as the fundamental role of the present ligands as morphology stabilisers. The last type of environmental study under pure CO and syngas (i.e. a mixture of H2 :CO = 2:1) revealed the metal particles carburisation at high temperature.

Biomechanical causes of trapeziometacarpal arthroplasty failure.

Trapeziometacarpal joint prosthesis revision has been widely reported, mainly due to loosening of the trapezium cup. Our hypothesis is that current prostheses do not sufficiently respect the kinematics of this joint. CT scan acquisitions enabled us to determine the position of the first metacarpal relative to the trapezium in three different characteristic postures, in subjects in different stages of arthrosis. A CAD model of a current prosthesis was inserted into the numerical 3D model of the joint under the different postures. In the numerical model, we observe penetration of the cup by the head of the prosthesis. This virtual penetration could, in vivo, amount to overstressing the prosthetic elements, which would lead to loosening of the cup or of the metacarpal stem and luxation of the prosthesis.

A scaling method to individualise muscle force capacities in musculoskeletal models of the hand and wrist using isometric strength measurements.

Because the force-generating capacities of muscles are currently estimated using anatomical data obtained from cadaver specimens, hand musculoskeletal models provide only a limited representation of the specific features of individual subjects. A scaling method is proposed to individualise muscle capacities using dynamometric measurements and electromyography. For each subject, a strength profile was first defined by measuring net moments during eight maximum isometric contractions about the wrist and metacarpophalangeal joints. The capacities of the five muscle groups were then determined by adjusting several parameters of an initial musculoskeletal model using an optimisation procedure which minimised the differences between measured moments and model estimates. Sixteen volunteers, including three particular participants (one climber, one boxer and one arthritic patient), were recruited. Compared with the initial literature-based model, the estimated subject-specific capacities were on average five times higher for the wrist muscles and twice as high for the finger muscles. The adjustments for particular subjects were consistent with their expected specific characteristics, e.g. high finger flexor capacities for the climber. Using the subject-specific capacities, the model estimates were markedly modified. The proposed protocol and scaling procedure can capture the specific characteristics of the participants and improved the representation of their capacities in the musculoskeletal model.

A single session of repetitive transcranial magnetic stimulation of the prefrontal cortex reduces cue-induced craving in patients with gambling disorder.

BACKGROUND: Gambling disorder (GD) is common and disabling addictive disorder. In patients with substance use disorders, the application of repetitive transcranial magnetic stimulation (rTMS) over the dorsolateral prefrontal cortex (DLPFC) offers promise to alleviate craving. We hypothesized that applying real compared to sham rTMS over the left DLPFC would reduce gambling craving in patients with GD. METHODS: In a randomized sham-controlled crossover design, 22 treatment-seeking patients with GD received real or sham treatment with high frequency rTMS over the left DLPFC followed a week later by the other type of treatment. Before and after each rTMS session, participants rated their gambling craving (from 0 to 100) before and after viewing a gambling video used as a cue. We used the Yale-Brown Obsessive Compulsive Scale adapted for Pathological Gambling to assess gambling behavior before and 7 days after each rTMS session. RESULTS: As compared to sham (mean +0.74; standard deviation±3.03), real rTMS significantly decreased cue-induced craving (-2.12±3.39; F(1,19)=4.87; P=0.04; partial η2=0.05; 95% CI: 0.00-0.21). No significant effect of rTMS was observed on gambling behavior. CONCLUSIONS: Patients with GD reported decreased cue-induced craving following a single session of high frequency rTMS applied over the left DLPFC. Further large randomized controlled studies are needed to determine the usefulness of rTMS in GD.

[Complete intra-articular distal radius fractures in young active patients]. / Fractures articulaires complètes de l'extrémité distale du radius chez le sujet jeune actif.

Management of complex intra-articular fractures of the distal radius in young active patients must aim to restore normal anatomy. For optimal planning of the surgical procedure, a thorough analysis of the fracture with appropriate radiological exams and diagnosis of frequently associated lesions are necessary. Surgical management involves use of various types of internal or external fixation. Routine use of standardized analysis tools for these fractures along with prospective follow-up should allow us to define guidelines for each situation in the near future.

Surgery for trapeziometacarpal osteoarthritis.

Trapeziometacarpal (TMC) osteoarthritis is a common, disabling condition that mostly affects women. The demand for surgical treatment is growing and the patients are becoming younger, adding to the challenge. Surgery can only be proposed after failure of well-conducted conservative treatment and requires a complete X-ray assessment. In the early stages, conservative surgery measures can be used to stabilize the joint or realign it in cases of dysplasia, but in most cases, patients are seen with more advanced arthritis and joint replacement must be considered. The ideal arthroplasty technique has yet to be defined but nevertheless, the chosen technique must be well-suited to the patient's condition. Although many studies have been published on this topic, they do not help us define the treatment indications. Prospective studies focusing on the patient rather than evaluating a certain surgical technique are needed. Trapeziectomy with or without ligament reconstruction is still considered the gold standard, but the challenges associated with treating its complications limit its indications. Arthrodesis, interposition or arthroplasty are also viable therapeutic options. The patient must be sufficiently informed to be able to contribute to choosing the indication.

Clinical features and outcome of bone and joint infections with streptococcal involvement: 5-year experience of interregional reference centres in the south of France.

Streptococcal bone and joint infections are less common than staphylococcal cases. Few studies have reported the cases with well-identified Streptococcus species. Their clinical features and prognosis are not clearly known to date. Moreover, no treatment regimen has yet been clarified. We reviewed the streptococcal bone and joint infection cases managed in our centres from January 2009 to December 2013. We described the epidemiology, clinical and microbiologic characteristics, treatment approach and outcome. Among the 93 cases, 83% of patients were men with a median age of 60 years, and 90% of patients had comorbidities or risk factors. Bacteraemia occurred in 14% of cases. Serious complications occurred in six patients, including severe sepsis (two cases) and infective endocarditis (two cases). Orthopaedic device infections were observed in 35% of cases, including 17 patients with internal osteosynthesis device infection, 14 with prosthetic joint infection and three with vertebral osteosynthesis device infection. The median time between orthopaedic device implantation and onset of infection was 447 days. Fourteen species of Streptococcus were identified, including 97 isolates using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and three isolates using molecular identification. The five most represented species included S. agalactiae (37%), S. dysgalactiae (12%), S. anginosus (11%), S. constellatus (10%) and S. pneumoniae (9%). Streptococci isolates were susceptible to amoxicillin, with the exception of one S. mitis isolate. Remission 1 year after the end of treatment was recorded in 83%. One patient died of infection; eight patients had infections that failed to respond to treatment; and seven patients experienced relapse. Twenty patients (22%) had an unfavourable functional outcome, including 19 amputations and one arthrodesis. Five significant prognostic factors associated with an unfavourable clinical outcome were identified, including peripheral neuropathy (p 0.009), peripheral arterial disease (p 0.019), diabetes mellitus (p 0.031), location in the femur (p 0.0036), location in the foot (p 0.0475), osteitis without an orthopaedic device (p 0.041) and infection caused by S. dysgalactiae (p 0.020). The rate of poor outcomes remains high despite the low number of Streptococcus isolates resistant to antibiotics. Some prognostic factors, such as the presence of S. dysgalactiae, are associated with an unfavourable clinical outcome. Antibiotic regimens of streptococcal bone and joint infections are not standardized and need to be further investigated.

Can we achieve bone healing using the diamond concept without bone grafting for recalcitrant tibial nonunions?

The purpose of this study was to evaluate the efficacy and safety of a combination of recombinant human bone morphogenetic protein 7 (rhBMP-7) and resorbable calcium phosphate bone substitute (rCPBS) as a salvage solution for recalcitrant tibial fracture nonunions. Twenty consecutive patients, 16 male and four female, with a mean age of 46.8±15.7 years (21-78) and a mean body mass index (BMI) of 24.2±5.3kgm(-2) (21.5-28.5), suffering from 20 recalcitrant tibial fracture nonunions were included. The mean number of operations performed prior to the procedure was 3.3, with homolateral iliac crest bone grafts being used for all of the patients. All patients were treated with a procedure including debridement and decortications of the bone ends, nonunion fixation with a locking plate, and filling of the bony defect with a combined graft of rhBMP-7 (as osteoinductor) with an rCPBS (as scaffold). The mean follow-up was 14±2.7 months. Both clinical and radiological union occurred in 18 cases, within a mean time of 4.7±3.2 months. A recurrence of deep infection was diagnosed for one of the non-consolidated patients. No specific complication of rCPBS or rhBMP-7 was encountered. This study supports the view that the application of rCPBS combined with rhBMP-7, without any bone grafting, is safe and efficient in the treatment of recalcitrant bone union.

Evaluation of a new tourniquet for hand surgery: Comparison of 76 carpal tunnel syndrome cases operated using a Hemaclear(®) Model-F tourniquet versus a pneumatic tourniquet.

The aim of this study was to compare a forearm-specific, sterile, single-use, non-pneumatic tourniquet to a conventional pneumatic tourniquet during carpal tunnel syndrome procedures. Patients with a systolic blood pressure exceeding 160 mmHg were excluded. The study included 76 patients. In 38 patients, surgery was performed with a pneumatic tourniquet on the forearm. In the remaining 38 patients, surgery was performed with a Hemaclear(®) Model-F tourniquet. There were no significant differences between the two groups in terms of quality of the exsanguination or pain experienced by the patient. The duration of surgery was significantly faster by 30 seconds with the Hemaclear(®) tourniquet but the procedure cost was about €30 more. The forearm-specific Hemaclear(®) tourniquet has several theoretical advantages, but our clinical results do not support these advantages in terms of quality of the surgical exsanguination and pain experienced by the patient. The duration of surgery was significantly shorter, but at the price of a higher surgery cost.

Retrograde percutaneous screw fixation for scaphoid type II non-union in Schernberg zones 2 to 4: a series of 38 cases.

Regardless of the treatment used, 25 to 45% of scaphoid fractures do not heal. Open surgery compromises vascularization and destabilizes ligament attachments. The aim of this retrospective study was to assess the value of retrograde percutaneous screw fixation of Alnot stage IIA and IIB scaphoid non-union in Schernberg zones 2 to 4. This series included 38 patients with a mean age of 31 years. Based on the Alnot classification, there were 16 stage IIA non-unions (12 in zone 3 and 4 in zone 2 according to the Schernberg classification) and 22 stage IIB non-unions (9 in zone 3 and 13 in zone 2). The time elapsed between the initial trauma and the surgical treatment was 10 months on average. Percutaneous retrograde fixation was performed with a cannulated 2.7mm compression screw. At 25 months follow-up, 31 of the non-union cases had healed (81.6%), of which 14 were stage IIA (87.5%) and 17 were stage IIB (77.3%), after an average 6.3 months. Average pain was 1.6. The average Quick DASH was 17.3/100. Compared to the opposite side, the average range of motion was 84.8% in flexion, 84.7% in extension, 98.9% in pronation, 96.5% in supination, 96.8% in ulnar deviation and 86.4% in radial deviation. The grip strength was 80.4% of the contralateral side. Seven patients did not heal after screw fixation; four of them healed after additional electromagnetic stimulation and three after addition of a vascularized bone graft. Based on this study's results, stage IIA non-unions can heal with simple retrograde percutaneous screw fixation. The same procedure could be enough for stage IIB non-union cases, however we recommend adding a cancellous bone graft by arthroscopy. Open surgery procedures are preferred when percutaneous procedures have failed.

[Mycetoma of the foot: a case report]. / Mycétome actino-mycosique du pied, à propos d'un cas.

Mycetoma is a chronic inflammatory cutaneous and subcutaneous pathology caused by either a fongic (eumycetoma) or bacterial (actinomycetoma) infection, which lead to a granulomatous tumefaction with multiple sinuses. When localized in the foot this infection is named "Madura foot". This infection is endemic to tropical and subtropical regions and rarely occurs in western countries. A historical case in Europe of a foot mycetoma evolving since 20 years without any treatment is presented. A histopathologic diagnosis of actinomycetoma has been done in 1987. The patient presented a severe Staphylococcus aureus chronic osteitis leading to a trans-tibial amputation. This case allows to present this infection which, even if rarely presented in France, can be meet especially among a migrant's population.

[Superficial ulnar artery while harvesting a radial forearm flap]. / Artère ulnaire superficielle, découverte fortuite lors du prélèvement d'un lambeau antébrachial radial.

Forearm vascular anatomical variations are common and may have complications during flaps harvesting. This article describes the presence of an ulnar superficial artery, revealed while harvesting a radial forearm flap. The prevalence of this anatomical variation is between 0.7 and 9.4%. It may have important consequences while covering loss of substance with a radial forearm flap. Unknown, there is a risk of vascular injury which may lead to distal ischemia of the upper limb. Preoperative diagnosis can anticipate this risk and harvest a fascio-cutaneous flap centered on a perforator of this artery.