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Background The purpose of this study was to compare initial fixation strength between various stemless and stemmed humeral components and to correlate implant fixation strength with bone mineral density (BMD). Methods Five humeral stem designs were investigated: Stemless-A (four hollow fins), Stemless-B (central body, three solid fins), Stemless-C (central screw, peripheral rim-fit), Short stem (50 mm), and Standard stem (130 mm). Fifty cadaveric human humerii were obtained and divided into five groups. BMD within the humeral head was determined for all samples. The mean BMD was similar between groups. The 25 samples with the lowest and highest BMDs were categorized as “Low” and “High,” respectively, with a BMD threshold of 0.35 g/cm2, creating BMD subgroups. After implantation, each sample underwent a standardized biomechanical testing protocol, with axial loading followed by torsional loading. Sensors attached to the specimen recorded micromotion throughout testing. Axial loading consisted of cyclic loading for 100 cycles at 3 peak forces (220, 520, and 820 N). Torsional loading consisted of 100 cycles of internal/external rotation at 0.1 Hz at 6 peak torques, or until failure (±2.5, 5, 7.5, 10, 12.5, and 15 Nm). Failure was defined as the torque at which any bone fracture, implant detachment from anchor/stem, or an excess of 50° internal/external rotation occurred. Groups and BMD subgroups were compared. Results At maximal axial loading, Stemless-B demonstrated greater micromotion (540 μm) than Stemless-C (192 μm) (P = .003). Stemless-B and Stemless-A (387 μm) also had greater micromotion than Short stem (118 μm, P Conclusion Stemless humeral implants should be used with caution in low-BMD settings ( Level of evidence Basic Science Study; Cadaveric Study

Background Treatment of glenohumeral osteoarthritis (OA) with Walch type B glenoid poses a challenge for orthopedic surgeons. Although various techniques have been described, it is still a major concern in terms of management and long-term results. We hypothesized that total shoulder arthroplasty (TSA) using a combination of non-spherical humeral head resurfacing (HHR) and inlay glenoid replacement would re-center the glenohumeral joint in patients with Walch type B glenoid without surgical correction of glenoid version. Methods We retrospectively screened patients who underwent TSA using a combination of non-spherical HHR and inlay glenoid replacement for primary glenohumeral OA with posteriorly subluxated humeral head (HH) (Walch Type B1, B2 and B3) between 2015 and 2019. Ratios of preoperative and postoperative HH subluxation were compared using Walch index and the point of contact ratio method. Two orthopedic surgeons performed radiographic measurements blinded to each other. Means of 2 independent measurements were included in the final analysis for each shoulder. We also screened for postoperative complications, dislocation events and radiographic loosening. Results Initial cohort included 49 patients. A total of 29 shoulders in 28 patients were eligible for screening. The numbers of shoulders with Walch type B1, B2, and B3 glenoids were 3, 22, and 4, respectively. Mean preoperative and postoperative Walch indices were 56.57 ± 6.08% and 49.47 ± 4.78%, respectively. The mean preoperative and postoperative point of contact ratios were 62.97 ± 8.45% and 50.08 ± 3.87%, respectively. The difference between preoperative and postoperative subluxation ratios was significant for both methods (P Conclusion When coupled with an inlay glenoid component in patients with eccentric glenoid wear and posterior subluxation, glenohumeral re-centering was consistently observed in this challenging patient population without the use of joint correction or augmentation procedures. It will be important to follow the clinical outcomes over the long-term to determine whether these observations translate to better clinical results than other techniques currently employed to deal with eccentric erosion and posterior subluxation of the arthritic glenohumeral joint although recent published mid-term results suggest results equal to or better than previously reported results in literature with different reconstructive techniques Level of evidence Level IV; Retrospective cohort

Dopamine (DA) is an important catecholamine neuromodulator that is present in the brain of mammal, and changes of its level can be related to some neurological diseases such as Parkinson, Huntington and Alzheimer. As a consequence, rapid, cost-effective and sensitive approaches are required to monitor the dopamine changes, especially in the brain. In this paper, we report the development of a frugal electrochemical platform for the development of an affordable organ-on-screen-printed strip to monitor the dopamine release from mice's brain. Coupling diagnostics, engineering and neuroscience, a flexible screen-printed platform has been applied to the determination of dopamine release from brain slice finely anchored onto the working area of the platform. After the experimental condition were optimized both in standard and PC-12 cell culture media, with a detection limit of ca. 1 μM and a linear range up to 160 μM (with a relative standard deviation of 9%), the platform was tested toward different areas of the brain, namely striatum and cerebellum. The printed strip was capable to monitor the release of dopamine following the stimulation with potassium chloride drop, highlighting the difference amount of dopamine in these areas. This work demonstrates how affordable facilities may produce frugal innovation to be used for low-cost organ-on-chip platforms.

Background Variations in glenoid morphology affect surgical treatment and outcome of advanced glenohumeral osteoarthritis (OA). The purpose of this study was to assess the inter- and intraobserver reliability of the modified Walch classification using 3-dimensional (3D) computed tomography (CT) imaging in a multicenter research group. Methods Deidentified preoperative CTs of patients with primary glenohumeral OA undergoing anatomic or reverse total shoulder arthroplasty (TSA) were reviewed with 3D imaging software by 23 experienced shoulder surgeons across 19 institutions. CTs were separated into 2 groups for review: group 1 (96 cases involving all modified Walch classification categories evaluated by 12 readers) and group 2 (98 cases involving posterior glenoid deformity categories [B2, B3, C1, C2] evaluated by 11 readers other than the first 12). Each case group was reviewed by the same set of readers 4 different times (with and without the glenoid vault model present), blindly and in random order. Inter- and intraobserver reliabilities were calculated to assess agreement (slight, fair, moderate, substantial, almost perfect) within groups and by modified Walch classification categories. Results Interobserver reliability showed fair to moderate agreement for both groups. Group 1 had a kappa of 0.43 (95% confidence interval [CI]: 0.38, 0.48) with the glenoid vault model absent and 0.41 (95% CI: 0.37, 0.46) with it present. Group 2 had a kappa of 0.38 (95% CI: 0.33, 0.43) with the glenoid vault model absent and 0.37 (95% CI: 0.32, 0.43) with it present. Intraobserver reliability showed substantial agreement for group 1 with (0.63, range 0.47-0.71) and without (0.61, range 0.52-0.69) the glenoid vault model present. For group 2, intraobserver reliability showed moderate agreement with the glenoid vault model absent (0.51, range 0.30-0.72), which improved to substantial agreement with the glenoid vault model present (0.61, range 0.34-0.87). Discussion Inter- and intraobserver reliability of the modified Walch classification were fair to moderate and moderate to substantial, respectively, using standardized 3D CT imaging analysis in a large multicenter study. The findings potentially suggest that cases with a spectrum of posterior glenoid bone loss and/or dysplasia can be harder to distinguish by modified Walch type because of a lack of defined thresholds, and the glenoid vault model may be beneficial in determining Walch type in certain scenarios. The ability to reproducibly separate patients into groups based on preoperative pathology, including Walch type, is important for future studies to accurately evaluate postoperative outcomes in TSA patient cohorts.

The optimal surgical approach for recurrent anterior shoulder instability remains controversial, particularly in the face of glenoid and/or humeral bone loss. The purpose of this study was to use a contingent-behavior questionnaire (CBQ) to determine which factors drive surgeons to perform bony procedures over soft tissue procedures to address recurrent anterior shoulder instability.A CBQ survey presented each respondent with 32 clinical vignettes of recurrent shoulder instability that contained 8 patient factors. The factors included (1) age, (2) sex, (3) hand dominance, (4) number of previous dislocations, (5) activity level, (6) generalized laxity, (7) glenoid bone loss, and (8) glenoid track. The survey was distributed to fellowship-trained surgeons in shoulder/elbow or sports medicine. Respondents were asked to recommend either a soft tissue or bone-based procedure, then specifically recommend a type of procedure. Responses were analyzed using a multinomial-logit regression model that quantified the relative importance of the patient characteristics in choosing bony procedures.Seventy orthopedic surgeons completed the survey, 33 were shoulder/elbow fellowship trained and 37 were sports medicine fellowship trained; 52% were in clinical practice ≥10 years and 48%10 years; and 95% reported that the shoulder surgery made up at least 25% of their practice. There were 53% from private practice, 33% from academic medicine, and 14% in government settings. Amount of glenoid bone loss was the single most important factor driving surgeons to perform bony procedures over soft tissue procedures, followed by the patient age (19-25 years) and the patient activity level. The number of prior dislocations and glenoid track status did not have a strong influence on respondents' decision making. Twenty-one percent glenoid bone loss was the threshold of bone loss that influenced decision toward a bony procedure. If surgeons performed 10 or more open procedures per year, they were more likely to perform a bony procedure.The factors that drove surgeons to choose bony procedures were the amount of glenoid bone loss with the threshold at 21%, patient age, and their activity demands. Surprisingly, glenoid track status and the number of previous dislocations did not strongly influence surgical treatment decisions. Ten open shoulder procedures a year seems to provide a level of comfort to recommend bony treatment for shoulder instability.

Background Management of bone loss in recurrent traumatic anterior shoulder instability remains a topic of debate and controversy in the orthopedic community. The purpose of this study was to survey members of 4 North American orthopedic surgeon associations to assess management trends for bone loss in recurrent anterior shoulder instability. Methods An online survey was distributed to all members of the American Shoulder and Elbow Surgeons, American Orthopaedic Society for Sports Medicine, and Canadian Orthopaedic Association and to fellow members of the Arthroscopy Association of North America. The survey comprised 3 sections assessing the demographic characteristics of survey respondents, the influence of prognostic factors on surgical decision making, and the operative management of 12 clinical case scenarios of varying bone loss that may be encountered in clinical practice. Results A total of 150 survey responses were returned. The age of the patient and quantity of bone loss were consistently considered important prognostic criteria. However, little consensus was reached for critical thresholds of bone loss and how this affected the timing (ie, primary or revision surgery) and type of bony augmentation procedure to be performed once a critical threshold was reached, especially in the context of critical humeral and bipolar bone loss. Conclusions Consistent trends were found for the management of recurrent anterior shoulder instability in cases in which no bone loss existed and when isolated critical glenoid bone loss was present. However, inconsistencies were observed when isolated critical humeral bone loss and bipolar bone loss were present.

Background Limited studies have been conducted to determine the minimum amount and sensitivity of the saline load test of the ankle. Prior studies, only performed in arthroscopic models, have suggested a wide range of volumes necessary to confirm arthrotomy. The purpose of this study was to investigate the amount of fluid required and the sensitivity of the saline load test to identify an intra-articular arthrotomy of the ankle. Using cadavers without prior ankle trauma or surgeries we aim to assess volume needed to detect ankle arthrotomies at varying arthrotomy locations. We hypothesized that the volume needed would vary based on site of arthrotomy. Methods Twenty thawed, fresh-frozen below knee cadavers were divided into four groups based on arthrotomy location. An ankle arthrotomy was made using a 4 mm trochar at the four standard ankle portal sites; anteromedial, anterolateral, posteromedial, and posterolateral. To confirm intra-articular location, a arthroscope was inserted for direct visualization of the ankle joint. An 18-gauge needle was then inserted into the ankle joint, and saline mixed with methylene blue was injected. During the injection, the known arthrotomy site was viewed for extravasation. Amount of saline required to diagnose arthrotomy was recorded. All injections were confirmed as intra-articular by demonstrating methylene blue staining of the anterior joint. Results The saline volume required to achieve extravasation ranged from 3 mL to 11 mL. The mean saline volume required to achieve extravasation was 5.3 mL. A total of 8 mL was required to achieve 90% sensitivity, 10 mL for 95% sensitivity and 11 mL for 99% sensitivity. For the anterolateral, anteromedial, posteromedial, and posterolateral arthrotomy sites the mean saline volume needed to detect a traumatic arthrotomy was 5.2 mL, 6.2 mL, 5 mL, and 4.8 mL respectively. There was no statistically significant difference in volume needed to detect arthrotomies across all four locations (p = 0.69). Conclusion In this cadaveric model, an injection of 10 mL identified 95% of arthrotomies approximately 4 mm in size. No difference in volume needed to detect extravasation was found across all four arthrotomy locations. Prior studies performed in arthroscopic models with patients undergoing ankle arthroscopy may overestimate volume needed to detect arthrotomies. Level of evidence V

Numerous studies indicate that the cerebellum undergoes structural and functional neurodegenerative changes in Alzheimer's disease. The purpose of this study was to examine the extent of cerebellar alterations at early, preplaque stage of the pathology in TgCRND8 mice through behavioral, electrophysiological, and molecular analysis. Balance beam test and foot-printing analysis revealed significant motor coordination and balance deficits in 2-month-old TgCRND8 mice compared to their littermates. Patch-clamp recordings performed on cerebellar slices of transgenic mice showed synaptic plasticity deficit and loss of noradrenergic modulation at parallel fiber-Purkinje cell synapse suggesting an early dysfunction of the cerebellar circuitry due to amyloid precursor protein overexpression. Finally, western blot analysis revealed an enhanced expression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunits p47(phox) and p67(phox) as well as Ca2+/calmodulin-dependent protein kinase and protein kinase C alpha in the cerebellum of 2-month-old transgenic mice. Therefore, we propose the existence of self-sustaining feedback loop involving the formyl peptide receptor 2-reactive oxygen species-Ca2+/calmodulin-dependent protein kinase II-protein kinase C alpha pathway that may promote reactive oxygen species generation in the early stage of Alzheimer's disease and eventually contribute to the exacerbation of pathological phenotype.

Alzheimer's disease (AD) is a common form of dementia mainly characterized by the deposition of neurofibrillary tangles and β-amyloid (Aβ) peptides in the brain. Additionally, increasing evidence demonstrates that a neuro-inflammatory state plays a key role in the development of this disease. Beside synthetic drugs, the use of natural compounds represents an alternative for the development of new potential drugs for the treatment of AD. Among these, the root of Salvia miltiorhiza Bunge (also known as Danshen) used for the treatment of cardiovascular, cerebrovascular disease and CNS functional decline in Chinese traditional medicine is one of the most representative examples. We therefore evaluated the effects of tanshinone IIA (TIIA) and cryptotanshinone (CRY) (the two major lipophilic compounds of Danshen) in a non-genetic mouse model of β-amyloid (Aβ)-induced AD, which is mainly characterized by reactive gliosis and neuro-inflammation in the brain. To this aim, mice were injected intracerebroventricularly (i.c.v.) with Aβ1-42 peptide (3μg/3μl) and after with TIIA and CRY (1, 3, or 10mg/kg) intraperitoneally (i.p.) 3 times weekly for 21days following the induction of experimental AD. Spatial working memory was assessed as a measure of short-term memory in mice, whereas the level of GFAP, S100β, COX-2, iNOS and NF-kBp65 monitored by western blot and ELISA assay, were selected as markers of reactive gliosis and neuro-inflammation. Finally, by docking studies, the modulation of key pro-inflammatory enzymes and pathways involved in the AD-related neuro-inflammation were also investigated. Results indicate that TIIA and CRY alleviate memory decline in Aβ1-42-injected mice, in a dose dependent manner. Moreover, the analysis of gliosis-related and neuro-inflammatory markers in the hippocampal tissues reveal a remarkable reduction in the expression of GFAP, S100β, COX-2, iNOS and NF-kBp65 after CRY (10mg/kg) treatment. These effects were less evident, but still significant, after TIIA (10mg/kg). Finally, in silico analysis also revealed that both compounds were able to interact with the binding sites of NF-kBp65 endorsing the data from biochemical analysis. We conclude that TIIA and CRY display anti-inflammatory and neuroprotective effect in a non- genetic mouse model of AD, thus playing a role in slowing down the course and onset of AD.

Bone loss in the setting of shoulder instability increases the likelihood of recurrent instability and increases the failure rate of arthroscopic interventions. Bone loss of the anteroinferior glenoid can be addressed via autograft (coracoid transfer or iliac crest bone graft) or allograft (iliac crest or osteochondral). We describe a technique for managing glenoid bone loss with a preshaped allograft. The Glenojet (Arthrosurface Inc.) is an allograft cortical bone augment for the glenoid. It is placed with a standard deltopectoral approach. The graft is predrilled and has a disposable targeting guide that fits 2 3.5 mm cortical screws. It offers an easy solution for addressing anteroinferior glenoid bone loss that preserves normal patient anatomy. It is particularly appealing for revision procedures of failed coracoid transfers.

The paper presents a hybrid numerical method for the computation of the dispersion characteristics of ultrasonic guided waves propagating in isotropic and viscoelastic thin-walled waveguides in contact with fluids along their inner or outer wall. To this end, the solid waveguide is modeled by means of a Semi-Analytical Finite Element method implementing the first order shear deformation theory, while the effects of the fluid are taken into account by means of a regularized 2.5D Boundary Element Method with Helmholtz-type kernels. By coupling the two methods along the mid-surface of the solid waveguide, the dispersion relations of the elastic-acoustic system are obtained as the solution of a nonlinear eigenvalue problem in the complex axial wavenumbers for any fixed circular frequency. Two different case studies are presented: an oil-filled pipe and a water-loaded steel rectangular waveguide.

Our goal was to determine whether readmissions within 30 or 90 days following discharge are associated with Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) scores for total hip arthroplasty (THA) patients.HCAHPS surveys from all patients who underwent THA between January 2016 and September 2016 in our institution were analyzed. Readmissions, demographics, baseline joint pain, joint function, and Veterans RAND-12 scores were collected. Statistical analyses involved Pearson's chi-squared tests for categorical variables and Student's t-tests for continuous variables. Multivariable logistic regression models were used to determine whether 30-day or 90-day readmissions were independently associated with HCAHPS scores.A total of 1868 patients were identified, the survey was sent to 969 patients and 578 completed the survey (59.6%). Eight patients (1.4%) were readmitted within 30 days, and 28 patients (4.8%) within 90 days. These patients were more likely to undergo revision THA (P.001). For the 30-day readmission cohort, 4 of 8 patients (50.0%) rated the hospital a 9 or 10 out of 10 compared to 466 of 567 patients (82.2%) of the non-readmitted cohort (P = .019). Thirty-day readmissions were associated with significantly lower likelihood of rating the hospital a 9 or 10 out of 10 (odds ratio 0.18).Our results demonstrate a significant negative association between readmission and HCAHPS scores under several dimensions of the survey including nurse communication, doctor communication, pain management, and global satisfaction with the hospital experience.

We develop a structural econometric model to elicit household-specific expectations about future financial asset returns and risk attitudes by using data on observed portfolio holdings and self-assessed willingness to bear financial risk. Our framework assumes that household portfolios are subject to short-selling constraints in stocks and bonds, and that financial investment decisions are taken conditional on real estate and business wealth. We derive an explicit solution for the model, and estimate its parameters using the US Survey of Consumer Finances from 1995 to 2013. The results show that our modified mean-variance model fits the data adequately, and that the demographic, occupational and educational characteristics of the investors are relevant in shaping risk aversion and return expectations. In contrast, wealth, income, and past market performance have limited impacts on expectations and risk aversion.

This work presents sound insulation and sound reflection measurements conducted over sonic crystal noise barriers according to the European standards EN 1793-2, EN 1793-5 and EN 1793-6. In most of the reference literature, sound insulation and reflection properties of sonic crystals are measured or a diffuse sound field or in a direct sound field including the top and side edge diffraction effects together with the transmitted (or reflected) components. The aim of this work is to perform free-field measurements over a real-sized sample in order to window out all diffraction components and to verify the points of strength and weakness of the application of standardised measurements to sonic crystals. Diffuse field measurements in laboratory are also done for comparison purposes. Since the target frequency range for traffic noise spectrum is centred at around 1000 Hz, a finite element based parametric investigation is performed to design unit cells capable of generating band gaps in the one-third octave bands ranging from 800 Hz to 1250 Hz. Then, 3 × 3 m sonic crystal noise barriers are installed in the Laboratory of the University of Bologna and sound insulation and sound reflection measurements are performed according to the mentioned active standards for normal incidence. Sound insulation is measured for diffuse incidence too. The two methods give different results. The method more directly comparable to calculations is the free-field one. However, if on the one hand the application of a time window allows to compute the transmitted or reflected component only, on the other hand the time window itself limits the maximum width of the sample for which all reflections of the n -th order having a significant spectral content are included, and thus results critical in the analysis of this kind of noise barriers. Nevertheless, the standardised measurements allow a direct comparison between the performance of sonic crystals and common noise barriers.

The aim of this paper is to extract the dispersion parameters, i.e. phase velocity, energy velocity and attenuation, of orthotropic thin-walled waveguides with generic cross-section. To this end, a semi-analytical finite element (SAFE) formulation is presented, which is based on the Reissner–Mindlin theory of curved shells. Complex axial wavenumbers and mode shapes of guided wave modes are extracted from a second-order polynomial eigenvalue problem, while the energy velocity is post-processed using the computed eigensolutions and SAFE operators. Different numerical examples are proposed, for which the obtained results are in very good agreement with those computed using other well-stated SAFE formulations.

The 5-HT7 receptor (5-HT7R) mediates important physiological effects of serotonin, such as memory and emotion, and is emerging as a therapeutic target for the treatment of cognitive disorders and depression. Although previous studies have revealed an expression of 5-HT7R in cerebellum, particularly at Purkinje cells, its functional role and signaling mechanisms have never been described. Using patch-clamp recordings in cerebellar slices of adult mice, we investigated the effects of a selective 5-HT7R agonist, LP-211, on the main plastic site of the cerebellar cortex, the parallel fiber-Purkinje cell synapse. Here we show that 5-HT7R activation induces long-term depression of parallel fiber-Purkinje cell synapse via a postsynaptic mechanism that involves the PKC-MAPK signaling pathway. Moreover, a 5-HT7R antagonist abolished the expression of PF-LTD, produced by pairing parallel fiber stimulation with Purkinje cell depolarization; whereas, application of a 5-HT7R agonist impaired LTP induced by 1 Hz parallel fiber stimulation. Our results indicate for the first time that 5-HT7R exerts a fine regulation of cerebellar bidirectional synaptic plasticity that might be involved in cognitive processes and neuropsychiatric disorders involving the cerebellum.