Ultrasound-guided fasciotomy in forearm chronic exertional compartment syndrome: Preliminary results in 12 cases.

INTRODUCTION: Forearm chronic exertional compartment syndrome is a rare condition in athletes and musicians who perform repeated prolonged forced gripping movements. It mainly affects young men, and presents with cramp-like pain, beginning on the anteromedial side of the forearm and progressively extending to the entire circumference, and may be associated with muscle weakness and neurologic symptoms. The objective of this study was to report preliminary results of ultrasound-guided fasciotomy in the treatment of forearm chronic exertional compartment syndrome. MATERIAL AND METHODS: A single-center retrospective observational study was conducted. Forearm chronic exertional compartment syndrome was diagnosed on clinical presentation and pathological intramuscular pressure measurement, defined as >30 mmHg at 1 min after effort. The series comprised 7 men, with bilateral involvement. Mean age was 30 years. All patients were motorcyclists. The mean preoperative intramuscular pressure at 1 min after effort was 60.75 mmHg (range: 30-81 mmHg). The main study endpoint was change in pain on visual analogic scale. Secondary endpoints comprised patient satisfaction, change in competitive sports level, and time to return to sport. Complications were noted. RESULTS: Six patients (12 forearms) were evaluated. Mean follow-up was 22.5 months (range: 3-48 months). Mean pain rating was 7.3/10 (range: 6-9) preoperatively, and 0/10 postoperatively. All patients were satisfied with the procedure. Mean time to return to sports was 25.5 days (range: 21-30 days). No patients decreased their competitive sports level after the procedure. One patient presented a postoperative hematoma, not requiring surgery. CONCLUSION: Ultrasound-guided fasciotomy in the treatment of Forearm chronic exertional compartment syndrome is an innovative technique with promising preliminary results. LEVEL OF EVIDENCE: IV; retrospective cohort.

Correction of residual humpback deformity after arthroscopic treatment of scaphoid non-union.

BACKGROUND: The aim of this study was to assess residual humpback deformity after arthroscopic treatment of scaphoid non-union. MATERIAL AND METHOD: We reviewed the medical records of 47 patients with scaphoid non-union who underwent arthroscopic treatment between 2012 and 2018. Patients who did not receive an intraoperative bone graft were excluded (10 patients), as were those who did not achieve bone union (three patients). The radiographic assessment consisted of pre- and postoperative radiographs and CT-scans. RESULTS: The radiolunate angle, scapholunate angle and Youm index were measured. At the final follow-up, the scapholunate angle was 54±8̊ (36-80̊) and the radiolunate angle was 11±7̊ (2-45̊). The scapholunate angle was significantly different between the preoperative measurement and the last follow-up; however, the radiolunate angle and Youm index did not change significantly. CONCLUSION: Our study found that arthroscopic treatment of scaphoid non-union with a cancellous bone graft taken from the distal radius results corrects the humpback deformity. LEVEL OF EVIDENCE: IV.

An Ultrasound-guided Percutaneous Surgical Technique for Trigger Finger Release Using a Minimally Invasive Surgical Knife.

Triggering of the finger at the A1 pulley is one of the most frequent pathologies encountered in hand surgery and a common cause of hand pain. Open release of the A1 pulley is currently still regarded as the golden-standard procedure. Nevertheless, there is an increasing interest in minimally invasive percutaneous techniques for the treatment of this condition. Current techniques range from percutaneous needle techniques without imaging, to the use of hook knives, with ultrasound guidance. Because of concerns about possible complications or incomplete releases, hand surgeons remain wary. The objective of this study was to introduce a new ultrasound-guided percutaneous surgical technique for trigger finger release, using a second-generation minimally invasive surgical knife. In this series of 78 releases, complete resolution of the symptoms was found in 98.7% of the cases. One recurrence of triggering was observed. There were no tendon injuries, infections, or neurovascular lesions recorded. This paper contains technical pearls and possible pitfalls to ensure the surgeon of a complete release and to avoid complications. A video of the technique was also included as Supplemental Digital Content (http://links.lww.com/BTH/A143). We can conclude that the procedure can be considered as safe and highly effective for the treatment of triggering at the A1 pulley.

Using Ultrasonography During the Fixation of Distal Radius and Finger Fractures.

Ultrasonography (US) is a noninvasive examination modality that is devoid of risk, both for the patient and the surgeon, compared with fluoroscopy. The principle is the same for distal radius and finger fractures: replace the fluoroscopy checks with US checks to reduce the patient's, surgeon's, and surgical team's exposure to radiation. In this article, the authors report their experience of the effectiveness of ultrasound imaging during the fixation of a distal radius and long finger fracture. They also describe equipment needed and surgical procedure.

Transcriptional networks in at-risk individuals identify signatures of type 1 diabetes progression.

Type 1 diabetes (T1D) is a disease of insulin deficiency that results from autoimmune destruction of pancreatic islet ß cells. The exact cause of T1D remains unknown, although asymptomatic islet autoimmunity lasting from weeks to years before diagnosis raises the possibility of intervention before the onset of clinical disease. The number, type, and titer of islet autoantibodies are associated with long-term disease risk but do not cause disease, and robust early predictors of individual progression to T1D onset remain elusive. The Environmental Determinants of Diabetes in the Young (TEDDY) consortium is a prospective cohort study aiming to determine genetic and environmental interactions causing T1D. Here, we analyzed longitudinal blood transcriptomes of 2013 samples from 400 individuals in the TEDDY study before both T1D and islet autoimmunity. We identified and interpreted age-associated gene expression changes in healthy infancy and age-independent changes tracking with progression to both T1D and islet autoimmunity, beginning before other evidence of islet autoimmunity was present. We combined multivariate longitudinal data in a Bayesian joint model to predict individual risk of T1D onset and validated the association of a natural killer cell signature with progression and the model's predictive performance on an additional 356 samples from 56 individuals in the independent Type 1 Diabetes Prediction and Prevention study. Together, our results indicate that T1D is characterized by early and longitudinal changes in gene expression, informing the immunopathology of disease progression and facilitating prediction of its course.

Modeling of the Electromechanical Behavior of Barium Titanate Under Mechanical Stress and Comparison With Experimental Measurements.

Barium titanate (BaTiO3) is increasingly studied to replace lead-based piezoelectric materials, such as those which belong to the lead zirconate titanate (PZT) family, due to lead toxicity. In many applications, such as Tonpilz transducers, piezoelectric materials undergo mechanical stress simulation of which is important to control and predict electroacoustic effects. Thus, this article deals with a fully tensorial model that allows to simulate the behaviors of electrical displacements and elastic strains under mechanical stress. Simulated curves are compared with experimental ones obtained for BaTiO3 samples. It can be verified that the hysteretic curves of strains are well predicted for unpoled samples as well as for poled ones. The order of values and global behavior of the theoretical electrical displacement are also verified, even if a less precise agreement is observed. The optimized values of the physical parameters, such as d33 , are discussed, and improvements both of the model and the optimization procedure are finally proposed in order to better predict the mechanical behavior of BaTiO3.

Electromechanical Behavior of a Doped Barium Titanate Piezoceramic Under Mechanical Stress: Modeling and Comparison With Experimental Measurements.

Barium titanate (BaTiO3) is being studied extensively to replace lead-based piezoelectric materials, such as the lead zirconate titanate (PZT) family, due to lead toxicity. As a result, researchers are turning to materials such as BaTiO3 and seek to improve their properties with the use of dopants. In many applications such as Tonpilz transducers, piezoelectric materials undergo mechanical stress which is important to control and predict their electro-acoustic performance. Thus, this study deals with a fully tensorial model that allows us to simulate the behaviors of electrical displacements and elastic strains under mechanical stress. The simulated curves are compared with the experimental ones obtained for a doped BaTiO3 composition and the hysteretic curves of strains are in good agreement both for the unpoled and poled samples. The values and global behavior of the theoretical electrical displacement are also found to be in fair agreement, though some discrepancies are observed. The optimized values of the physical parameters, such as d33 , are discussed and improvements both of the model and the optimization procedure are finally proposed to better predict the mechanical behavior of the doped BaTiO3 piezoceramics.

Self-medication in pain management: The state of the art of pharmacists' role for optimal Over-The-Counter analgesic use.

BACKGROUND AND OBJECTIVE: Self-medication is associated with an important utilization of Over-The-Counter (OTC) analgesics. The medical outcome resulting from therapeutic options bypassing the physician prescription is a major issue. In that context, pharmacists are expected to play a crucial role. The main objective of this review was to analyse the state-of-the art of pharmacists' role in pain management self-medication. DATABASES AND DATA TREATMENT: An expert multidisciplinary group dedicated to self-medication in pain was established. Selection of publications was performed from PubMedand EMBASE databases which was based on the use of "pain" and/or "self-medication" and/or "self-care" and/or "analgesics" and/or "painkillers" keywords, restricted to the past 10 years. RESULTS: A total of 480 papers were identified, 49 of which papers were considered relevant and finally kept for final discussion, on OTC pain management and pharmacist's role. Literature analysis demonstrates that OTC analgesics are generally safe when appropriately used. Risks associated with misuse or inappropriateness depend on patients' vulnerability (elderly, pregnancy) or behaviour. Social cognitive theory-based intervention and multimedia applications improve self-medication but do not replace health care professional advice Pharmacists' interventions may improve the benefits and safety of OTC analgesic medication, with a better management of pain. CONCLUSIONS: Considering the heterogeneity of patients' knowledge and behaviour reported worldwide, inappropriate use of OTC pain medication should not be underestimated. Community pharmacists are ideally placed to guide self-medication or recommend a medical advice when needed. Embedding pharmacists in primary care pain management is essential and pharmacist-led medication coupled with an appropriate training of pharmacy staffs should be encouraged. SIGNIFICANCE: Analgesics are widely used without prescription, all over the world. They represent the largest market of OTC drugs, with an overall benefit/risk ratio favourable when appropriately used. Because of potential individual risks associated to the ailment or to the patient's behaviour, pharmacists' interventions have proven to optimize analgesic self-medication, provided that pharmacy staffs are both available and more specifically trained. In the future, in pain management, especially self-medication, pharmacists should play an increasing role and should be included in educational programmes and pain management guidelines.

Internal Electric Field in Co-Doped BaTiO3 With Co2+/3+, Nb5+, Li+, and F-: Impact on Functional Properties and Charge Compensation With Niobium and Fluorine Ions.

Dense barium titanate (BaTiO3) ceramics ( [Formula: see text]) with a microscale grain size are obtained at 800 °C-1100 °C by a solid-state ceramic process. BaTiO3 (BT) doped with Co2+/3+ leads to a significant improvement in the properties ( pC/N). Soft and hard characteristics of the piezoceramics are observed depending on the dopant ions. The Co/Li acceptor dopants lead to hard piezoceramics and aging phenomena. Aged BT:Co, Li exhibits double loops and a distorted hysteresis cycle for nonpoled and poled ceramics, respectively. Ceramics poled by the increasing field process at room temperature and the field cooling process present different poled and aged states, which are dependent on the thermal history and poling process. The distorted hysteresis loops for BT:Co, Li indicate an increased internal bias field with aging time. Insertion of donor dopants, such as Nb5+ ions, significantly reduces the internal field. These behaviors are related to the presence of defect dipoles ( [Formula: see text]"- [Formula: see text] due to the insertion of acceptor dopants in the B-sites following the oxygen vacancies to equilibrate charge compensation. BT:Co sintered with LiF leads to a quasi-symmetric hysteresis loop, indicating that F- may insert into an oxygen site and counteract the formation of oxygen vacancies. Dielectric drift of BT:Co, Li shows resilience to an ac electric field, which is related to the increased internal field. BT doped with 0.75 mol% Co2+/3+ and 1 mol% Li2CO3 presents hard piezoelectric behavior with a Rayleigh coefficient α = 2.53 10-7 m/V and the capability to handle high electrical stress of up to 400 [Formula: see text]/mm.

Controlled growth of 1D and 2D ZnO nanostructures on 4H-SiC using Au catalyst.

A perfect control of nanostructure growth is a prerequisite for the development of electronic and optoelectronic device/systems. In this article, we demonstrate the growth of various ZnO-derived nanostructures, including well-ordered arrays of high aspect ratio single crystalline nanowires with preferred growth direction along the [0001] axis, nanowalls, and hybrid nanowire-nanowall structures. The growths of the various ZnO nanostructures have been carried out on SiC substrates in a horizontal furnace, using Au thin film as catalyst. From experimental observations, we have ascribed the growth mechanisms of the different ZnO nanostructures to be a combination of catalytic-assisted and non-catalytic-assisted vapor-liquid-solid (VLS) processes. We have also found that the different ZnO nanoarchitectures' material evolution is governed by a Zn cluster drift effects on the SiC surface mainly driven by growth temperature. Au thin film thickness, growth time, and temperature are the parameters to optimize in order to obtain the different ZnO nanoarchitectures.

High Activity Arthroplasty Score has a lower ceiling effect than standard scores after knee arthroplasty.

The tested hypothesis was following: the High Activity Arthroplasty Score has a significant lower ceiling effect than American Knee Society Score and Oxford Knee Score after total knee arthroplasty. One hundred patients operated on for total knee arthroplasty with more than one-year follow-up have been included. The ceiling effect was 53% for the American Knee Society Score, 33% for the Oxford Knee Score, and 0% for the High Activity Arthroplasty Score. High Activity Arthroplasty Score had a significantly lower ceiling effect than American Knee Society Score and Oxford Knee Score. High Activity Arthroplasty Score has the potential to detect more subtle differences in level of function than standard scoring systems among a non-selected total knee arthroplasty population.

Theoretical and experimental study of the electroacoustic behavior of lithium niobate under an initial mechanical stress.

Recently, a second-order formalism of piezoelectric structures under an external mechanical stress was developed. Because the yield strength of lithium niobate was unknown, this study was not able to describe and evaluate realistic benefits of a prestress load on electromechanical properties. Therefore, in this study, experimental determination of the yield strength of lithium niobate sample is performed and shows that this limit is close to 110 MPa. Then, the nonlinearities and evolutions of electroacoustic parameters of this piezoelectric material under mechanical stress are numerically studied. By varying the initial prestress, as well as azimuthal and elevation angles, the cut planes in which a prestress induces significant benefits on velocities and coupling coefficient are identified. Finally, approximate relations describing changes between electroacoustic parameters defined in the two coordinate systems of the study are determined.

Non-planar pad-printed thick-film focused high-frequency ultrasonic transducers for imaging and therapeutic applications.

Pad-printed thick-film transducers have been shown to be an interesting alternative to lapped bulk piezoceramics, because the film is deposited with the required thickness, size, and geometry, thus avoiding any subsequent machining to achieve geometrical focusing. Their electromechanical properties are close to those of bulk ceramics with similar composition despite having a higher porosity. In this paper, padprinted high-frequency transducers based on a low-loss piezoceramic composition are designed and fabricated. High-porosity ceramic cylinders with a spherical top surface are used as the backing substrate. The transducers are characterized in view of imaging applications and their imaging capabilities are evaluated with phantoms containing spherical inclusions and in different biological tissues. In addition, the transducers are evaluated for their capability to produce high-acoustic intensities at frequencies around 20 MHz. High-intensity measurements, obtained with a calibrated hydrophone, show that transducer performance is promising for applications that would require the same device to be used for imaging and for therapy. Nevertheless, the transducer design can be improved, and simulation studies are performed to find a better compromise between low-power and high-power performance. The size, geometry, and constitutive materials of optimized configurations are proposed and their feasibility is discussed.

Braun's flexor tendons transfer in disabled hands by central nervous system lesions.

INTRODUCTION: Since Braun's article, the nonfunctional hand of brain-injured patients has not been the subject of many publications. The objective of surgical treatment is to open the hand for hygiene and cosmetic reasons. The technique consists in lengthening the extrinsic flexor tendons group. HYPOTHESIS: The purpose of this work is to assess eventual functional benefits from superficialis-to-profundus tendon transfer according to Braun. MATERIAL AND METHODS: Our series comprised 15 patients aged a mean 55 years, operated using the Braun procedure for a nonfunctional hand (19 hands). Additional procedures were performed as required by the local condition (neurotomy of the deep branch of the ulnar nerve, wrist fusion, tenotomy of the flexors of the wrist and flexor pollicis longus, tenodesis of the extensors of the wrist). The results were assessed by the analysis of finger opening ability and by a specific scoring system (Mini Hand Score; MHS) rated from 6 (no discomfort) at 20 (major discomfort). RESULTS: The mean follow-up was 6 months. We observed imperfect results: thumb opening incapacity, spasticity of the intrinsic flexors, and hyperextension of the wrist. The preoperative MHS was a mean 13.87 out of 20 and the postoperative MHS was 9.67 out of 20, with a very substantial difference. DISCUSSION: Our easy-to-use system for evaluating the nonfunctional hand (MHS) was shown to be very effective in demonstrating the improvement of the postoperative result. The originality of our series was to show that Braun's original operation goals were only exceptionally and remotely achieved and that an additional technical procedure must be nearly systematically considered. All the patients in our series were followed up in multidisciplinary team visits where the patient's family and caretakers were encouraged to give their point of view. Level of evidence Level IV. Retrospective study.

Nonlinear constant evaluation in a piezoelectric rod from analysis of second harmonic generation.

The design of transducers requires a clear understanding of their electromechanical behavior. This involves precise linear modeling as well as characterization. With the development of novel techniques such as harmonic imaging as well as high-power applications, nonlinear aspects must also be taken into account. In this study, harmonic generation in the mechanical displacement of a piezoceramic rod under high sinusoidal electric fields was measured. Theoretically, the nonlinearity can come from various sources: dielectric, mechanical, and electromechanical. The nonlinearity coming from external sources being eliminated or taken into account, it is shown here that the analysis, over a wide frequency range, of 2 parameters related to the harmonic distortion enables the respective identification of these sources and, at the same time, the evaluation of third-order constants of the material.

Calculation of dissipation resistances in a single-element transducer.

In this paper, a new formulation of the electrical input impedance of a single element transducer is presented. The resistive part of the electrical impedance that takes into account acoustic radiation in the front medium and losses in the transducer is split into a radiation resistance on one hand and into dissipation resistances related to each transducer component on the other hand. To confirm these theoretical results, characterization methods based on temperature measurements and pulse-echo response are presented. Measurements have been conducted on 1 MHz transducers, which consist of a piezoelectric ceramic glued on a backing. The results show a good agreement between experience and theory for dissipation resistance and radiation resistance values, which confirms the theoretical approach.

Lens-focused transducer modeling using an extended KLM model.

The goal of this work was to develop an extended ultrasound transducer model that would optimize the trade-off between accuracy of the calculation and computational time. The derivations are presented for a generalized transducer model, that is center frequency, pulse duration and physical dimensions are all normalized. The paper presents a computationally efficient model for lens-focused, circular (axisymmetric) single element piezoelectric ultrasound transducer. Specifically, the goal of the model is to determine the lens effect on the electro-acoustic response, both on focusing and on matching acoustic properties. The effective focal distance depends on the lens geometry and refraction index, but also on the near field limit, i.e. wavelength and source radius, and on the spectrum bandwidth of the ultrasound source. The broadband (80%) source generated by the transducer was therefore considered in this work. A new model based on a longitudinal-wave assumption is presented and the error introduced by this assumption is discussed in terms of its maximum value (16%) and mean value (5.9%). The simplified model was based on an extension of the classical KLM model for transducer structures and on the related assumptions. The validity of the implemented extended KLM model was evaluated by comparison with finite element modeling, itself previously validated analytically for the one-dimensional planar geometry considered. The pressure field was then propagated using the adequate formulation of the Rayleigh integral for both the extended KLM and finite element results. The simplified approach based on the KLM model delivered the focused response with good accuracy, and hundred-fold lower calculation time in comparison with a mode comprehensive FEM method. The trade-off between precision and time thus becomes compatible with an iterative procedure, used here for the optimization of the acoustic impedance of the lens for the chosen configuration. An experimental comparison was performed and found to be in good agreement with such an extension of the KLM model. The experiments confirm the accuracy of such a model in a validity domain up to -12 dB on the pulse-echo voltage within a relative error of 9% between experiment and modeling. This extended KLM model can advantageously be used for other transducer geometries satisfying the assumption of a predominantly longitudinal vibration or in an optimization procedure involving an adequate criteria for a particular application.

High-frequency transducers based on integrated piezoelectric thick films for medical imaging.

A screen-printed PZT thick film with a final thickness of about 40 microm was deposited on a porous PZT substrate to obtain an integrated structure for ultrasonic transducer applications. This process makes it possible to decrease the number of steps in the fabrication of high-frequency, single-element transducers. The porous PZT substrates allow high acoustic impedance and attenuation to be obtained, satisfying transducer backing requirements for medical imaging. The piezoelectric thick films deliver high electromechanical performance, comparable to that of standard bulk ceramics (thickness coupling factor over 45%). Based on these structures, high-frequency transducers with a center frequency of about 25 MHz were produced and characterized. As a result, good sensitivity and axial resolution were obtained in comparison with similar transducers integrating a lead titanate (PT) disk as active material. The two transducers were integrated into a high-frequency imaging system, and comparative skin images are shown.

Piezoelectric textured ceramics: Effective properties and application to ultrasonic transducers.

Piezoelectric textured ceramics obtained by homo-template grain growth (HTGG) were recently demonstrated. A simple model with several assumptions has been used to calculate effective parameters of these new materials. Different connectivities have been simulated to show that spatial arrangements between the considered phases have little influence on the effective parameters, even through the 3-0 connectivity delivers the highest electromechanical thickness factor. A transducer based on a textured ceramic sample has been fabricated and characterised to show the efficiency of these piezoelectric materials. Finally, in a single element transducer configuration, simulation shows an improvement of 2 dB sensitivity for a transducer made with textured ceramic in comparison with a similar transducer design based on standard soft PZT (at equivalent bandwidths).