Benchmarking several van der Waals dispersion approaches for the description of intermolecular interactions.

Seven methods, including three van der Waals density functionals (vdW-DFs) and four different variants of the Tkatchenko-Scheffler (TS) methods, are tested on the A24, L7, and Taylor et al.'s "blind" test sets. It is found that for these systems, the vdW-DFs perform better that the TS methods. In particular, the vdW-DF-cx functional gives binding energies that are the closest to the reference values, while the many-body correction of TS does not always lead to an improvement in the description of molecular systems. In light of these results, several directions for further improvements to describe van der Waals interactions are discussed.

ORIF versus arthroplasty for open proximal humerus fractures: Nationwide Inpatient Sample data between 1998 and 2013.

BACKGROUND: Limited data exists in analyzing open reduction and internal fixation (ORIF) and arthroplasty in the management of open proximal humerus fractures. We analyzed differences in hospital course between these procedures, patient demographics, complication rate, length of stay, hospital charges, and mortality rate. MATERIALS AND METHODS: This is a retrospective review of the Nationwide Inpatient Sample database. ICD-9 codes identified patients hospitalized for open proximal humerus fractures from 1998 to 2013 who underwent ORIF or shoulder arthroplasty (hemi-, total, or reverse). Demographics and in-hospital complications were compared. Logistic regression controlling for age, gender, and Deyo index tested the impact of ORIF vs ARTH on any complications. RESULTS: Seven hundred thirty patients were included (ORIF, n = 662 vs ARTH, n = 68). ORIF patients were younger (p < 0.001), more likely to be males (p < 0.001), and had a lower Deyo score (p = 0.012). Both groups had comparable complication rates (21.4% vs 18.0%, p = 0.535), lengths of stay (7.86 days vs 7.44 days, p = 0.833), hospital charges ($76,998 vs $64,133, p = 0.360), and mortality rates (0.2% vs 0%, p = 0.761). Type of surgery was not a predictor of any complications (OR = 0.67 [95% CI 0.33-1.35], p = 0.266), extended length of stay (OR = 1.01 [95% CI 0.58-1.78], p = 0.967), or high hospital charges (OR = 1.39 [95% CI 0.68-2.86], p = 0.366). CONCLUSION: We revealed no differences in hospital course between ORIF and arthroplasty for management of open proximal humerus fractures. Although differences in demographics existed, no differences in complication rates, length of stay, hospital charges and mortality rates were noted. Future studies can evaluate the long-term outcomes of these procedures. LEVEL OF EVIDENCE: Level III.

Communication: A novel implementation to compute MP2 correlation energies without basis set superposition errors and complete basis set extrapolation.

By using a formulation based on the dynamical polarizability, we propose a novel implementation of second-order Møller-Plesset perturbation (MP2) theory within a plane wave (PW) basis set. Because of the intrinsic properties of PWs, this method is not affected by basis set superposition errors. Additionally, results are converged without relying on complete basis set extrapolation techniques; this is achieved by using the eigenvectors of the static polarizability as an auxiliary basis set to compactly and accurately represent the response functions involved in the MP2 equations. Summations over the large number of virtual states are avoided by using a formalism inspired by density functional perturbation theory, and the Lanczos algorithm is used to include dynamical effects. To demonstrate this method, applications to three weakly interacting dimers are presented.

Improving the accuracy of ground-state correlation energies within a plane-wave basis set: The electron-hole exchange kernel.

A new formalism was recently proposed to improve random phase approximation (RPA) correlation energies by including approximate exchange effects [B. Mussard et al., J. Chem. Theory Comput. 12, 2191 (2016)]. Within this framework, by keeping only the electron-hole contributions to the exchange kernel, two approximations can be obtained: An adiabatic connection analog of the second order screened exchange (AC-SOSEX) and an approximate electron-hole time-dependent Hartree-Fock (eh-TDHF). Here we show how this formalism is suitable for an efficient implementation within the plane-wave basis set. The response functions involved in the AC-SOSEX and eh-TDHF equations can indeed be compactly represented by an auxiliary basis set obtained from the diagonalization of an approximate dielectric matrix. Additionally, the explicit calculation of unoccupied states can be avoided by using density functional perturbation theory techniques and the matrix elements of dynamical response functions can be efficiently computed by applying the Lanczos algorithm. As shown by several applications to reaction energies and weakly bound dimers, the inclusion of the electron-hole kernel significantly improves the accuracy of ground-state correlation energies with respect to RPA and semi-local functionals.

Application of machine learning in predicting frailty syndrome in patients with heart failure.

Prevention and diagnosis of frailty syndrome (FS) in patients with heart failure (HF) require innovative systems to help medical personnel tailor and optimize their treatment and care. Traditional methods of diagnosing FS in patients could be more satisfactory. Healthcare personnel in clinical settings use a combination of tests and self-reporting to diagnose patients and those at risk of frailty, which is time-consuming and costly. Modern medicine uses artificial intelligence (AI) to study the physical and psychosocial domains of frailty in cardiac patients with HF. This paper aims to present the potential of using the AI approach, emphasizing machine learning (ML) in predicting frailty in patients with HF. Our team reviewed the literature on ML applications for FS and reviewed frailty measurements applied to modern clinical practice. Our approach analysis resulted in recommendations of ML algorithms for predicting frailty in patients. We also present the exemplary application of ML for FS in patients with HF based on the Tilburg Frailty Indicator (TFI) questionnaire, taking into account psychosocial variables.

Management of Massive Rotator Cuff Tears Without Arthropathy.

Arthroplasty is not an optimal treatment for massive rotator cuff tears in patients who are active and without glenohumeral arthritis. Several surgical techniques have been developed for these patients, including arthroscopic rotator cuff repair with single-/double-row repair (with or without interval slides, margin convergence, graft augmentation), graft bridging, superior capsular reconstruction, tuberoplasty, and tendon transfers. Complete, tension-free, anatomic repair is ideal; however, tendon atrophy and retraction associated with massive tears often complicate repairs. All surgical treatments significantly increase patient-reported functional outcomes 1 year after intervention, with many treatments demonstrating improved mid-term and long-term outcomes. [Orthopedics. 2023;46(1):e1-e12.].

Importance analysis of psychosociological variables in frailty syndrome in heart failure patients using machine learning approach.

The prevention and diagnosis of frailty syndrome (FS) in cardiac patients requires innovative systems to support medical personnel, patient adherence, and self-care behavior. To do so, modern medicine uses a supervised machine learning approach (ML) to study the psychosocial domains of frailty in cardiac patients with heart failure (HF). This study aimed to determine the absolute and relative diagnostic importance of the individual components of the Tilburg Frailty Indicator (TFI) questionnaire in patients with HF. An exploratory analysis was performed using machine learning algorithms and the permutation method to determine the absolute importance of frailty components in HF. Based on the TFI data, which contain physical and psychosocial components, machine learning models were built based on three algorithms: a decision tree, a random decision forest, and the AdaBoost Models classifier. The absolute weights were used to make pairwise comparisons between the variables and obtain relative diagnostic importance. The analysis of HF patients' responses showed that the psychological variable TFI20 diagnosing low mood was more diagnostically important than the variables from the physical domain: lack of strength in the hands and physical fatigue. The psychological variable TFI21 linked with agitation and irritability was diagnostically more important than all three physical variables considered: walking difficulties, lack of hand strength, and physical fatigue. In the case of the two remaining variables from the psychological domain (TFI19, TFI22), and for all variables from the social domain, the results do not allow for the rejection of the null hypothesis. From a long-term perspective, the ML based frailty approach can support healthcare professionals, including psychologists and social workers, in drawing their attention to the non-physical origins of HF.

Return to play rates after ulnar nerve transposition and decompression surgery: a retrospective analysis.

BACKGROUND: Medial elbow pain is a common complaint in overhead throwing athletes. The throwing motion places repetitive tensile and compressive forces on the elbow resulting in significant stress across the ulnohumeral joint. This stress can result in soft-tissue, ligamentous, and ulnar nerve injury. The purpose of this study was to retrospectively investigate the clinical findings and outcomes, including return to play rates, of patients who underwent ulnar nerve transposition surgery for isolated ulnar neuritis. METHODS: Throwing athletes who underwent isolated, primary ulnar nerve transposition surgery over an eight-year period, 2009 to 2017, were identified and included in our analysis. Nonthrowing athletes, those who underwent revision ulnar nerve transposition surgery, and those who underwent concomitant ulnar collateral ligament reconstruction or repair were excluded. Patients were contacted to complete the Kerlan-Jobe Orthopaedic Clinic Shoulder and Elbow Score as well as a return to play rate questionnaire. The minimum follow-up was 2 years. RESULTS: Fifteen patients met the inclusion criteria: 13 (86.7%) men and 2 (13.3%) women. The average age at the time of surgery was 19.2 years old (range, 15.6-28.0). Preoperatively, 13 (86.7%) patients played baseball and 2 (13.3%) patients played softball. Two patients (13.3%) underwent a previous ulnar collateral ligament reconstruction. There were no complications. The average final follow-up was 65.26 (range, 24.44-113.29) months with an average Kerlan-Jobe Orthopaedic Clinic Score of 64.51 (range, 28.60-100.00). Thirteen (86.7%) patients were able to return to their preinjury sport, 2 to a higher level of competition, 8 to the same level, and 3 to a lower level. Seven of the 13 (53.8%) patients sustained a postoperative ipsilateral shoulder or elbow injury at an average of 19.57 (range, 7.00-36.00) months postoperatively. All patients reported sustaining the injury as a result of throwing. CONCLUSION: The results of our study indicate that ulnar nerve transposition surgery in throwing athletes allows athletes to return to throwing with low reoperation rates. However, more than half of the athletes in our analysis sustained a subsequent ipsilateral shoulder or elbow injury. Further investigation regarding outcomes in throwing athletes after ulnar nerve transposition surgery is warranted.

Ultrasonographic Technique, Appearance, and Diagnostic Accuracy for Common Shoulder Sports Injuries: A Narrative Review.

¼: Ultrasonography (US) is valued for its availability, tolerability, low cost, and utility in real-time dynamic evaluation. Its use in diagnosing upper-extremity shoulder injury has expanded, but several features require definition before more widespread adoption can be realized. ¼: In particular, the evaluation of rotator cuff tears (RCTs) with US has been extensively studied, and authors generally agree that US is comparable with magnetic resonance imaging for the detection of full-thickness RCTs, whereas partial-thickness RCTs are more difficult to accurately identify with US. Dynamic evaluation is particularly useful for pathologies such as subacromial impingement and glenohumeral instability. ¼: US has shown particular usefulness for the assessment of athletes, where there is additional motivation to delay more invasive techniques. US has demonstrated promising results as a diagnostic modality for common shoulder injuries in athletes, and it is an important imaging tool that complements a thorough history and physical examination.

Ultrasonographic Technique, Appearance, and Diagnostic Accuracy for Common Elbow Sports Injuries.

Ultrasonography is a valuable diagnostic imaging tool because of its availability, tolerability, low cost, and utility in real-time dynamic evaluation. Its use in diagnosing elbow injuries has expanded recently and continues to do so. In particular, stress ultrasonography represents a unique imaging technique that directly visualizes the ulnar collateral ligament (UCL) and allows the assessment of ligament laxity, offering an advantage over magnetic resonance imaging and magnetic resonance arthrography in this patient population. Furthermore, ultrasonography has shown particular usefulness in instances where invasive techniques might be less desirable. This is particularly important in athletes since more invasive procedures potentially result in lost time from their sport. Ultrasonography is an important imaging tool that complements a thorough history and physical examination in the evaluation of elbow injuries in athletes. The use of ultrasonography in orthopaedic sports medicine has been investigated previously; however, to our knowledge, there has been no comprehensive review regarding the utility of ultrasonography for common elbow injuries in athletes. The current study provides a comprehensive, detailed review of the utility and indications for the use of ultrasonography for common elbow injuries in athletes.

Total shoulder arthroplasty in octogenarians: Is there a higher risk of adverse outcomes?

This study used the National Surgical Quality Improvement Program to evaluate octogenarians who underwent total shoulder arthroplasty (TSA). Specifically, we evaluated: (1) patient demographics; (2) perioperative factors; and (3) 30-day postoperative complications. Compared to controls, the octogenarians had more females, white patients, lower BMIs, fewer smokers, less functionally independent, higher ASA scores, shorter operative times, and longer LOS. Octogenarians had greater odds for developing any (OR = 2.05; 95%CI, 1.70-2.46), any major (OR = 2.28; 95%CI, 1.66-3.13), and any minor (OR = 1.99; 95%CI, 1.63-2.45) complications. Perioperative risk management strategies for elective TSA in the elderly may help mitigate the increased perioperative risks associated with age.

A Systematic Review and Meta-Analysis of Procalcitonin as a Marker of Postoperative Orthopedic Infections.

Procalcitonin is a serologic marker that increases in response to inflammatory stimuli, especially those of bacterial origin. Postoperative orthopedic periprosthetic infections are often difficult to diagnose. This study systematically reviewed the literature to evaluate the statistical measures of performance of procalcitonin as a marker of postoperative orthopedic infection. This study showed that procalcitonin has a weighted pooled sensitivity of 67.3%, specificity of 69.4%, positive likelihood ratio of 1.778, negative likelihood ratio of 0.423, and diagnostic odds ratio of 5.770. These results illustrate that procalcitonin is an effective serologic marker for postoperative bacterial infections. [Orthopedics. 2018; 41(3):e303-e309.].

Demographics and rates of surgical arthroscopy and postoperative rehabilitative preferences of arthroscopists from the Arthroscopy Association of North America (AANA).

Survey of 869 arthroscopists regarding joint-specific arthroscopic procedures and postoperative rehabilitative preferences revealed comparable support for use of supervised physical therapy (SPT) and home exercise programs (HEPs) but stronger preference for joint-specific HEP applications (wrist, knee). Among respondents utilizing HEPs, modality of delivery (verbal/handout/web-based) didn't differ by joint, yet only 2.9% utilized web-based HEPs. This is the first known study to identify postoperative rehabilitation preferences. With 1.77 million estimated arthroscopic procedures annually (mean: 325.4 procedures/respondent), this study highlights under-utilization of web-based HEPs. Reliable, web-based HEPs can improve post-arthroscopic outcomes for patients, arthroscopic surgeons, and rehabilitative specialists while being cost efficient.

Improving the Efficiency of Beyond-RPA Methods within the Dielectric Matrix Formulation: Algorithms and Applications to the A24 and S22 Test Sets.

Within a formalism based on dielectric matrices, the electron-hole time-dependent Hartree-Fock (eh-TDHF) and the adiabatic connection second-order screened exchange (AC-SOSEX) are promising approximations to improve ground-state correlation energies by including exchange effects beyond the random phase approximation (RPA). We introduce here an algorithm based on a Gram-Schmidt orthogonalization (GSO) procedure that significantly reduce the number of matrix elements to be computed to evaluate the response functions that enter in the formulation of these two methods. By considering the A24 test set, we show that this approach does not lead to a significant loss of accuracy and can be effectively applied to compute the small interaction energies involved in weakly bound dimers. Importantly, the GSO method significantly extends the applicability of the eh-TDHF and AC-SOSEX to large systems. This is shown by considering the S22 test set, which includes dimers with up to one hundred valence electrons requiring hundreds of thousands of plane-waves in the basis set. By comparing our results to coupled-cluster benchmark values, we show that the inclusion of exchange effects beyond the RPA significantly improves the accuracy, with mean absolute errors that decrease by almost 40% for the A24 test set and by almost 50% for the S22 test set. This approach based on dielectric matrices is particularly suited for plane-wave implementations and might be used in the future to improve the description of the correlation energy in solid state applications.

A novel index for quantifying the risk of early complications for patients undergoing cervical spine surgeries.

OBJECTIVE It is becoming increasingly necessary for surgeons to provide evidence supporting cost-effectiveness of surgical treatment for cervical spine pathology. Anticipating surgical risk is critical in accurately evaluating the risk/benefit balance of such treatment. Determining the risk and cost-effectiveness of surgery, complications, revision procedures, and mortality rates are the most significant limitations. The purpose of this study was to determine independent risk factors for medical complications (MCs), surgical complications (SCs), revisions, and mortality rates following surgery for patients with cervical spine pathology. The most relevant risk factors were used to structure an index that will help quantify risk and anticipate failure for such procedures. METHODS The authors of this study performed a retrospective review of the National Inpatient Sample (NIS) database for patients treated surgically for cervical spine pathology between 2001 and 2010. Multivariate models were performed to calculate the odds ratio (OR) of the independent risk factors that led to MCs and repeated for SCs, revisions, and mortality. The models controlled for age (< and > 65 years old), sex, race, revision status (except for revision analysis), surgical approach, number of levels fused/re-fused (2-3, 4-8, ≥ 9), and osteotomy utilization. ORs were weighted based on their predictive category: 2 times for revision surgery predictors and 4 times for mortality predictors. Fifty points were distributed among the predictors based on their cumulative OR to establish a risk index. RESULTS Discharges for 362,989 patients with cervical spine pathology were identified. The mean age was 52.65 years, and 49.47% of patients were women. Independent risk factors included medical comorbidities, surgical parameters, and demographic factors. Medical comorbidities included the following: pulmonary circulation disorder, coagulopathy, metastatic cancer, renal failure, congestive heart failure, alcohol abuse, neurological disorder, nonmetastatic cancer, liver disease, rheumatoid arthritis/collagen vascular diseases, and chronic blood loss/anemia. Surgical parameters included posterior approach to fusion/re-fusion, ≥ 9 levels fused/re-fused, corpectomy, 4-8 levels fused/re-fused, and osteotomy; demographic variables included age ≥ 65 years. These factors increased the risk of at least 1 of MC, SC, revision, or mortality (risk of death). A total of 50 points were distributed among the factors based on the cumulative risk ratio of every factor in proportion to the total risk ratios. CONCLUSIONS This study proposed an index to quantify the potential risk of morbidity and mortality prior to surgical intervention for patients with cervical spine pathology. This index may be useful for surgeons in patient counseling efforts as well as for health insurance companies and future socioeconomics studies in assessing surgical risks and benefits for patients undergoing surgical treatment of the cervical spine.

Probing a Device's Active Atoms.

Materials science and device studies have, when implemented jointly as "operando" studies, better revealed the causal link between the properties of the device's materials and its operation, with applications ranging from gas sensing to information and energy technologies. Here, as a further step that maximizes this causal link, the paper focuses on the electronic properties of those atoms that drive a device's operation by using it to read out the materials property. It is demonstrated how this method can reveal insight into the operation of a macroscale, industrial-grade microelectronic device on the atomic level. A magnetic tunnel junction's (MTJ's) current, which involves charge transport across different atomic species and interfaces, is measured while these atoms absorb soft X-rays with synchrotron-grade brilliance. X-ray absorption is found to affect magnetotransport when the photon energy and linear polarization are tuned to excite FeO bonds parallel to the MTJ's interfaces. This explicit link between the device's spintronic performance and these FeO bonds, although predicted, challenges conventional wisdom on their detrimental spintronic impact. The technique opens interdisciplinary possibilities to directly probe the role of different atomic species on device operation, and shall considerably simplify the materials science iterations within device research.

Does the saline load test still have a role in the orthopaedic world? A systematic review of the literature.

INTRODUCTION: The aim of this systematic review was to assess the efficacy of Saline load tests (SLTs) to evaluate extension of periarticular wounds into capsule in emergent settings. METHODS: We systematically reviewed the literature to evaluate the accuracy of the SLT in diagnosing penetrating joint injuries in the elbow, wrist, shoulder, knee, or ankle. RESULTS: The SLT values to determine knee arthrotomies vary from 73.8 mL to 194 mL with sensitivities ranging between 91% and 99% depending on the size of the laceration. A SLT of 30 mL in the ankle yields sensitivities ranging from 95% to 99% in assessing joint penetration. A SLT of 45 mL in the elbow yields a sensitivity of 95% in assessing joint penetration. The addition of methylene blue does not change the sensitivity of the SLT. CONCLUSION: Several studies have demonstrated the utility of the SLT as a diagnostic modality for penetrating joint injuries. However, the literature analyzed in this study was inconclusive and more studies are required to make definitive recommendations. In addition, more studies will be needed on joints other than the knee, pediatric patients, and the use of methylene blue dye in conjunction with SLT. LEVEL OF EVIDENCE: Level II, Diagnostic study.

Thirty-day complications in rheumatoid patients following total knee arthroplasty.

Although total knee arthroplasty (TKA) is highly successful for patients with end-stage rheumatoid arthritis (RA), the risks and complications associated with surgery in this cohort are less defined. The objectives of our study were to analyze the demographic and perioperative factors of RA patients that may affect post-TKA outcomes, as well as to assess the 30-day complication rates compared to osteoarthritis patients. We retrospectively evaluated the National Surgical Quality Improvement Program (NSQIP) database from 2006 to 2012 to assess all patients who underwent a primary TKA and had a diagnosis of rheumatoid arthritis (n = 141) or primary knee osteoarthritis (n = 7125). We evaluated and compared the demographic factors, social factors, preoperative factors, operative factors, and postoperative complications. The RA cohort had a lower mean age and body mass index than patients in the OA group. There was also a significantly higher incidence of women and Hispanics in the RA cohort. There was a lower incidence of diabetes and hypertension requiring medication in the rheumatoid cohort, but also a higher incidence of bleeding disorders. The RA cohort had an increased proportion of patients requiring blood transfusions and had a longer mean length of stay. The incidence of pneumonia and postoperative bleeding that required transfusion was also higher in RA patients. Rheumatoid patients had higher rates of wound infections, pulmonary embolisms, and deep vein thrombosis; however, these findings were not significant. Although RA patients with end-stage knee arthritis may benefit from TKA, these patients should be preoperatively optimized to minimize complication risks.