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Energy functionals of the Green's function can simultaneously provide spectral and thermodynamic properties of interacting electrons' systems. Although powerful in principle, these formulations need to deal with dynamical (frequency-dependent) quantities, increasing the algorithmic and numerical complexity and limiting applications. We first show that, when representing all frequency-dependent propagators as sums over poles—a truncated Lehmann representation—, the typical operations of dynamical formulations become closed (i.e., all quantities are expressed as sums over poles) and analytical. In the framework, the Dyson equation is mapped into a nonlinear eigenvalue problem that can be solved exactly; this is achieved by introducing a fictitious noninteracting system with additional degrees of freedom, which shares, upon projection, the same Green's function of the real system. In addition, we introduce an approximation to the exchange-correlation part of the Klein functional adopting a localized GW approach; this is a generalization of the static Hubbard extension of density-functional theory with a dynamical screened potential U(ω). We showcase the algorithmic efficiency of the method, and the physical accuracy of the functional, by computing the spectral, thermodynamic, and vibrational properties of SrVO_{3}, finding results in close agreement with experiments and state-of-the-art methods, at highly reduced computational costs and with a transparent physical interpretation.

Abstract The automation of ab initio simulations is essential in view of performing high-throughput (HT) computational screenings oriented to the discovery of novel materials with desired physical properties. In this work, we propose algorithms and implementations that are relevant to extend this approach beyond density functional theory (DFT), in order to automate many-body perturbation theory (MBPT) calculations. Notably, an algorithm pursuing the goal of an efficient and robust convergence procedure for GW and BSE simulations is provided, together with its implementation in a fully automated framework. This is accompanied by an automatic GW band interpolation scheme based on maximally localized Wannier functions, aiming at a reduction of the computational burden of quasiparticle band structures while preserving high accuracy. The proposed developments are validated on a set of representative semiconductor and metallic systems.

Abstract Many-body perturbation theory methods, such as the G 0 W 0 approximation, are able to accurately predict quasiparticle (QP) properties of several classes of materials. However, the calculation of the QP band structure of two-dimensional (2D) semiconductors is known to require a very dense BZ sampling, due to the sharp q-dependence of the dielectric matrix in the long-wavelength limit (q → 0). In this work, we show how the convergence of the QP corrections of 2D semiconductors with respect to the BZ sampling can be drastically improved, by combining a Monte Carlo integration with an interpolation scheme able to represent the screened potential between the calculated grid points. The method has been validated by computing the band gap of three different prototype monolayer materials: a transition metal dichalcogenide (MoS2), a wide band gap insulator (hBN) and an anisotropic semiconductor (phosphorene). The proposed scheme shows that the convergence of the gap for these three materials up to 50meV is achieved by using k-point grids comparable to those needed by DFT calculations, while keeping the grid uniform.

Abstract Background The timing of a return to sport (RTS) after anterior cruciate ligament reconstruction (ACLR) represents a major subject of debate in sports medicine practice. Recently, the Knee Santy Athletic Return to Sport (K-STARTS) composite test was validated. This consists of a battery of physical tests and a psychological evaluation using the anterior cruciate ligament–return to sport after injury scale (ACL-RSI). This study aimed to translate the ACL-RSI and K-STARTS from English to Italian and determine the scale’s reliability and validity in an Italian context. Methods The translation and cultural adaptation process was performed according to the guidelines for the cross-cultural adaptation of self-report measures. The patients were asked to fill an anonymized online form created for this purpose that included the KOOS, the Lysholm, the IKDC-SKF, and the Italian translation of the ACL-RSI (ACL-RSI-It). After 1 week, the attendees were asked to repeat the ACL-RSI-It to investigate the test–retest reliability. Results The final study population comprised 115 patients who underwent ACLR, with a mean follow-up of 37.37 ± 26.56 months. The ACL-RSI-It showed axcellent internal consistency (Cronbach’s α = 0.963), reliability (test–retest ICC = 0.966), and good construct validity (positive correlations with the other scales were above 75%). Conclusions The ACL-RSI-It is valid, reliable, and comparable to the original English version of the questionnaire for Italian-speaking patients. It can be used to assess the psychological readiness of patients for a RTS after primary and unilateral ACLR, and can be integrated into the Italian K-STARTS test. Level of evidence Level II.

Purpose The anterior cruciate ligament is probably one of the ligaments with the lowest healing potential. Many authors have reported cases of spontaneous healing but nowadays it is difficult to predict successful healing of an anterior cruciate ligament rupture and, even more, residual functionality and capability to return to sport. The aim of this study was to investigate cases of spontaneous healing in a population that received non‐surgical treatment after anterior cruciate ligament rupture and to perform an updated review of contemporary literature. Methods The authors retrospectively reviewed patients who suffered from an acute complete anterior cruciate ligament rupture and underwent non‐surgical treatment. No specific rehabilitation protocol was prescribed. A new magnetic resonance imaging study was conducted 6 months after the injury for all patients. A literature review was conducted regarding spontaneous healing of the anterior cruciate ligament. The papers included in the analysis were reports of any level of evidence, written in English, Italian, or French languages; articles were excluded if they reported non‐human studies, histological studies, studies conducted without magnetic resonance imaging or arthroscopic second look, or partial anterior cruciate ligament tear. Results Case series: Six patients were enrolled in the study. All patients had a proximal anterior cruciate ligament lesion. The minimum follow‐up was 13 months (range 6–20 months). At the last follow‐up the mean score on the Lysholm scale was 97, the mean IKDC score was 94, and the mean KOOS score was 96. All patients returned to their own sport activities; no one reported significant differences. The magnetic resonance imaging study at 6 months revealed an end‐to‐end continuous anterior cruciate ligament with homogeneous signal. No one had any new knee injury at last follow‐up. Literature review: A search of comprehensive databases retrieved 1057 articles; 8 full‐text articles met the eligibility criteria. The studies were heterogeneous regarding the populations analysed, sport activity level, treatment applied, healing definition, and follow‐up. The failure rate of non‐surgical management ranged among the papers from 0 to 73%. Conclusions The study findings show that spontaneous anterior cruciate ligament healing is possible and there are chances of clinical recovery for patients not suitable for surgery. However, there is still a lack of evidence about predictors, clinical outcomes, and adequate rehabilitation protocols.

Abstract. Introduction:. Neuroendocrine tumours (NETs) are rare tumors. 55% of NETs originate in the gastrointestinal tract and the liver is the most common site of distant metastases. Serum chromogranin A is the most common biomarker for assessing the extent of disease and monitoring treatment; carcinoid syndrome occurs in 19% of NETs and is characterized by chronic diarrhea or flushing. Primary mesenteric NETs are rare and have been described only in case reports in literature; our case is an apparent primary mesenteric NETs with a surgical program to remove the mesenteric mass and subrenal interaortocaval and retrocaval lymphadenectomies. Patient concerns:. A 73-year old man came to us because he had been experiencing abdominal pain for a year and he had recently developed diabetes mellitus. He was an active smoker with arterial hypertension. Diagnosis:. After a computed tomography scan and 68 Gallium-positron emission tomography, a diagnosis of what appeared to be a primary mesenteric NET with retrocaval and interaortocaval lymph nodes was made. Laparoscopic biopsy showed NET G2 positive for serotonin, chromogranin A, synaptophysin. Interventions:. The intraoperative finding of a primitive ileum-NET changed the surgical program. We removed the mesenteric mass with the lymph nodes of the superior mesenteric vessel and the middle distal ileum along with the cecum. Outcomes:. The postoperative course was normal, and the patient was discharged on the seventh postoperative day without signs of short bowel syndrome. Follow-up at 6 months revealed no evidence of short bowel syndrome or disease progression. Conclusion:. 68 Gallium-positron emission tomography does not show NETs smaller than 0.5 mm. Accurate palpation of the intestine is essential during surgery for NETs for two reasons: to find the primitive, and because of the risk of multiple intestinal primitives.

Abstract Background Recently, there has been renewed interest in primary anterior cruciate ligament (ACL) repair. The aim of this study is to report early clinical and radiological results of a consecutive series of acute ACL tears treated with arthroscopic primary ACL repair within 14 days from injury. Patients and methods A consecutive series of patients with acute ACL tears were prospectively included in the study. Based on MRI appearance, ACL tears were classified into five types, and tissue quality was graded as good, fair, and poor. Patients with type I, II, and III tears and at least 50% of ACL tibial remnant intact with good tissue quality were ultimately included. Clinical outcomes were measured using the Tegner Lysholm Knee Scoring Scale (TLKSS), the Knee Injury and Osteoarthritis Outcome Score (KOOS), subjective and objective International Knee Documentation Committee (IKDC) scores, and KT-1000. Patients were also followed up with MRI evaluations at 1, 3, and 6 months postoperatively. ACL appearance was graded based on morphology (normal or abnormal) and signal intensity (isointense, intermediate, and hyperintense). Results The mean TLKSS was 98.1, the mean subjective IKDC was 97.6, and the mean KOOS was 98.2. The objective IKDC score was A in eight of ten patients and B in two patients. KT-1000 measurements showed a maximum manual side-to-side difference of less than 2 mm in eight of ten patients, whereas two patients showed a difference of 3 mm. The morphology of the repaired ACL was normal (grade 1) at 1 month follow-up in ten of ten cases, and this appearance persisted at 3 and 6 months postoperatively. The signal intensity at 1 month postoperatively was graded as isointense (grade 1) in four of ten patients, intermediate (grade 2) in five of ten patients, and hyperintense (grade 3) in one of ten patients. At both 3 and 6 months postoperatively, the signal intensity was graded as isointense (grade 1) in nine of ten patients and intermediate (grade 2) in one of ten patients. Conclusions Arthroscopic primary ACL repair performed acutely in a carefully selected group of patients with proximal ACL tears and good tissue quality showed good early clinical and radiological results. Level of evidence Level 4.

Abstract Purpose The aim of this study was to determine the inter- and intra-observer reliability of knee laxity assessment using a non-invasive navigation system in a population of healthy young athletes. It was hypothesized that knee laxity parameters recorded using non-invasive computer navigation would demonstrate good inter- and intra-observer reliability. Methods Healthy volunteers aged between 18 to 30 years were recruited to the study. Static and dynamic knee laxity parameters including anterior tibial translation and tibial rotation during the pivot shift test were recorded on awake patients using non-invasive computer navigation by two independent observers: at the first visit each athlete was evaluated by the consultant and resident surgeons independently; 6 weeks after the first visit all the participants were re-tested only by the resident surgeon. Inter- and intra-observer reliability was calculated and then interpreted according to Cicchetti’s criteria. Results One hundred healthy volunteers were recruited to the study, of these 38 were women (38%), and the average age was 25.5 ± 2.4 years. According to Cicchetti’s criteria the intra- and inter-observer reliability for static measurements were fair for anterior tibial translation (0.572 and 0.529, respectively) and excellent for total passive tibial rotation (0.859 and 0.883, respectively). For the dynamic measurements of translation and rotation during the pivot shift maneuver both measurements demonstrated good to excellent reliability with intra and inter observer reliability ranging from 0.684 to 0.936. Conclusion Non-invasive navigation for the assessment of knee laxity is associated with fair to excellent inter- and intra-observer reliability in a population of healthy volunteers.

Purpose. The purpose is to evaluate knee preference and functional outcomes of patients with primary anterior cruciate ligament (ACL) repair in one knee and ACL reconstruction in the contralateral side. Methods. All patients who underwent both procedures were retrospectively reviewed at minimum two-year follow-up. Patients were asked to complete questionnaires regarding their operated knees’ preferences during rehabilitation, daily activities, sports activities, and overall function. Furthermore, the Subjective International Knee Documentation Committee, Forgotten Joint Score-12, and Anterior Cruciate Ligament-Return to Sport after Injury were completed. Results. Twenty-one patients were included. All patients underwent ACL reconstruction first, which was displayed at younger age at surgery (24 vs. 33 years, p=0.010) and longer follow-up (10.2 vs. 2.3 years, p0.4). Objective laxity assessment showed mean side-to-side difference of 0.6 mm between both sides in favor of the reconstructed knee. Conclusion. This study showed that ACL repair and ACL reconstruction lead to similar functional outcomes. However, patients undergoing both procedures may have less pain, earlier ROM return, and faster rehabilitation progression following primary repair.

Abstract Purpose In‐office needle arthroscopy has been reported as a diagnostic tool for different knee pathologies. In addition, ACL repair has seen a resurgence with the advent of innovative orthopedic devices. The aim of this study was to assess clinical, radiological, and in‐office needle arthroscopic findings in 15 adult patients who underwent acute (within 14 days from injury) anterior cruciate ligament (ACL) repair. Methods Fifteen patients voluntarily participated in the study. A second‐look arthroscopy was performed with an in‐office needle arthroscopy at an average of 7.2 months after the primary repair. The parameters included in the investigation were the continuity of the anatomical footprint of the repaired ACL, subjective assessment of the ACL tension with the probe, and synovial coverage of the ACL. All patients had a Magnetic Resonance Imaging (MRI) at 6 months after repair and an arthrometric evaluation with the KT‐1000. Clinical evaluation with the scores, Tegner Lysholm Knee Scoring Scale (TLKSS), the Knee Injury and Osteoarthritis Outcome Score (KOOS), and International Knee Documentation Committee (IKDC) was performed at the final follow‐up of 2 years. Moreover, a correlation between the characteristics of ACL appearance at the time of the second look in‐office needle arthroscopy, MRI and KT‐1000 was performed. Results The mean TLKSS was 97.86, the mean KOOS was 98.08 and the mean subjective IKDC was 96.71. The objective IKDC was A in 10 patients and B in 5 patients. ACL healing was graded as A in 11 patients and B in 4 patients. Synovial coverage was graded as good in 10 patients and fair in 5 while MRI assessment showed a type I ACL in 10 patients, type II in 4 patients and type III in 1 patient. Conclusion In‐office needle arthroscopy is a reliable tool to assess the condition of a repaired ACL. In addition, ACL repair performed in acute proximal tears demonstrated excellent clinical results.

Recent advancements in orthopaedic devices have instilled a renewed interest in repair of the anterior cruciate ligament. Biological augmentation of the repair has also recently been investigated with the hopes of improving repair outcomes and improving biological healing. The advent of needle arthroscopy allows for potentially decreased recovery times and potentially reduced complication rates compared with traditional arthroscopy. The purpose of this article is to present a percutaneous technique to repair the anterior cruciate ligament with suture tape augmentation while also augmenting with the biological byproducts from the native effusion using needle arthroscopy.

The COVID-19 outbreak strongly affected Italy, putting a strain on the National healthcare system. Hospitals quickly reorganized the activity to cope with the emergency. This retrospective comparative study aimed to analyze the impact of the lockdown imposed in Italy during the COVID-19 outbreak on acute orthopedic trauma, in order to identify critical issues for improvement and future planning. We collected data on all the trauma admissions to a single University hospital DEA (Department of Emergency and Acceptance) in Rome during the COVID- 19 pandemic lockdown in Italy, comparing them with the corresponding period in 2019. We reported demographic data; the characteristics of the injury, including the anatomical location, fracture, sprain, dislocation, contusion, laceration, whether the injury site was exposed or closed, where the injury occurred, and polytrauma. We also recorded the waiting time in the emergency room and mode of transportation. The study sample was composed of 1199 patients, 636 (53.04%) males and 563 (46.96%) females. The overall number of admissions in 2019 (pre-COVID-19 period) was 995; then it was 204 during COVID-19 outbreak in 2020. The average age of the 2020 group was 51.9 ± 24.8 years, significantly higher than that of the 2019 group (41.4 ± 25.7) (p

Gentamicin-impregnated cement beads and spacers are frequently used in case of infective complications after Total Knee Arthroplasty (TKA). A great number of studies in the literature demonstrated that the local administration of gentamicin produces high local antibiotic levels but low serum and urine gentamicin concentrations. Gentamicin-impregnated cement spacer can induce nephrotoxicity in patients presenting major renal impairment susceptibility. We report a case of acute renal failure using a gentamicin-impregnated block spacer. An 83-year-old woman underwent a gentamicinimpregnated bone–cement spacer implant because of an infected TKA removal. Three days later patient clinical status got worse reporting a decreased urine output and increasing C-reactive protein (CRP), Serum Creatinine (SCr) and Blood Urea Nitrogen (BUN). Because the symptoms could be related to the knee spacer lead us to the decision of gentamicin-impregnated cement spacer removal. The day following the removal procedure showed progressive improvement of general condition with evidence of SCr and BUN normalization. Gentamicin-impregnated cement spacer can induce nephrotoxicity in patients presenting major renal impairment susceptibility.

Transverse patellar fractures are a relatively common injury and typically require surgical fixation. An adequate restoration of patella integrity is essential for proper functioning of the extensor mechanism of the knee and for the prevention of patellofemoral osteoarthritis. Currently, the treatment of transverse fractures of the patellar bone involves several surgical techniques, most of which involve the use of metallic implants. Despite good clinical results following surgery, numerous complications exist, including primarily symptomatic hardware following surgical treatment. The purpose of this article is to describe the technique for treatment of a transverse patellar fracture using a high-resistance tape (FiberTape; Arthrex) and a tensioner (Arthrex) instead of traditional metallic implants.

Dynamical potentials appear in many advanced electronic-structure methods, including self-energies from many-body perturbation theory, dynamical mean-field theory, electronic-transport formulations, and many embedding approaches. Here, we propose a novel treatment for the frequency dependence, introducing an algorithmic inversion method that can be applied to dynamical potentials expanded as sum over poles. This approach allows for an exact solution of Dyson-like equations at all frequencies via a mapping to a matrix diagonalization, and provides simultaneously frequency-dependent (spectral) and frequency-integrated (thermodynamic) properties of the Dyson-inverted propagators. The transformation to a sum over poles is performed introducing nth order generalized Lorentzians as an improved basis set to represent the spectral function of a propagator. Numerical results for the homogeneous electron gas at the G_{0}W_{0} level are provided to argue for the accuracy and efficiency of such unified approach.

Abstract Background Several studies have recently shown better restoration of normal knee kinematics and improvement of rotator knee stability after reconstruction with higher femoral tunnel obliquity. The aim of this study is to evaluate tunnel obliquity, length, and posterior wall blowout in single-bundle anterior cruciate ligament (ACL) reconstruction, comparing the transtibial (TT) technique and the out–in (OI) technique. Materials and methods Forty consecutive patients operated on for ACL reconstruction with hamstrings were randomly divided into two groups: group A underwent a TT technique, while group B underwent an OI technique. At mean follow-up of 10 months, clinical results and obliquity, length, and posterior wall blowout of femoral tunnels in sagittal and coronal planes using computed tomography (CT) scan were assessed. Results In sagittal plane, femoral tunnel obliquity was 38.6 ± 10.2° in group A and 36.6 ± 11.8° in group B (p = 0.63). In coronal plane, femoral tunnel obliquity was 57.8 ± 5.8° in group A and 35.8 ± 8.2° in group B (p = 0.009). Mean tunnel length was 40.3 ± 1.2 mm in group A and 32.9 ± 2.3 mm in group B (p = 0.01). No cases of posterior wall compromise were observed in any patient of either group. Clinical results were not significantly different between the two groups. Conclusions The OI technique provides greater obliquity of the femoral tunnel in coronal plane, along with satisfactory length of the tunnel and lack of posterior wall compromise. Level of evidence II, prospective study.

Several extra-articular surgical techniques in addition to anterior cruciate ligament reconstruction have been proposed to better restore rotational instability of the knee. One option is surgical repair of the anterolateral ligament in acute cases to achieve an anatomic reconstruction. An additional augmentation to the repair could allow a load-sharing—and thus protective—effect for the repair during the healing process. The purpose of this Technical Note is to describe a primary repair of the anterolateral ligament with suture tape augmentation (Internal Brace; Arthrex, Naples, FL) in a patient with an acute anterior cruciate ligament tear.

Introduction. Intra-articular ganglion cysts of the knee joint are rare and mostly incidental findings in magnetic resonance imaging (MRI) or arthroscopy. Posterior cruciate ligament (PCL) ganglion cyst in a child is an extremely rare finding, and to the best of our knowledge, only one case has been described in the literature. We report a case of a large intra-articular ganglion cyst of the knee arising from the PCL in an autistic child. Case Presentation. An 8-year-old Caucasian boy affected by autism presented with nontraumatic knee pain. His parents, observing child’s gait, reported recurrent limp while walking, sometimes accompanied by knee locking. Clinical examination was hindered by the noncompliance of the patient and revealed painful limitation of terminal flexion and extension. MRI scans showed a large ganglion cyst located in the intercondylar notch. Arthroscopy confirmed an intrasubstance PCL ganglion cyst, extending both anteriorly and posteriorly. Complete excision of the cyst was performed, with full recovery of the child and no recurrence. Conclusion. In pediatric patients with pain or limited knee range of motion, physicians should consider the possibility of a ganglion cyst arising from the PCL, despite its rarity. Arthroscopic excision is a safe and effective procedure that guarantees a complete recovery of the patient with the lowest rate of recurrence.

Background: Periprosthetic joint infection (PJI) represents 25% of failed total knee arthroplasties (TKA). The European Knee Associates (EKA) formed a transatlantic panel of experts to perform a literature review examining patient-related risk factors with the objective of producing perioperative recommendations in PJI high-risk patients. Methods: Multiple databases (Pubmed/MEDLINE, EMBASE, Scopus, Cochrane Library) and recommendations on TKA PJI prevention measures from the International Consensus Meetings on PJI from the AAOS and AAHKS were reviewed. This represents a Level IV study. Results: Strong evidence was found on poor glycemic control, obesity, malnutrition, and smoking being all associated with increased rates of PJI. In the preoperative period, patient optimization is key: BMI < 35, diet optimization, Hemoglobin A1c < 7.5, Fructosamine < 292 mmol/L, smoking cessation, and MRSA nasal screening all showed strong evidence on reducing PJI risk. Intraoperatively, a weight-based antibiotic prophylaxis, accurate fluid resuscitation, betadine and chlorhexidine dual skin preparation, diluted povidone iodine solution irrigation, tranexamic acid administration, and monofilament barbed triclosan-coated sutures for soft tissues closure all represented effective prevention measures. In the postoperative period, failure to reach normalization of ESR, CRP, D-dimer, and IL-6 six weeks postoperatively suggested early PJI. Conclusion: The current recommendations from this group of experts, based on published evidence, support risk stratification to identify high-risk patients requiring implementation of perioperative measures to reduce postoperative PJI.

A technique for anatomic reconstruction of the anterolateral complex addressing anterolateral rotatory instability both in primary anterior cruciate ligament reconstruction and in revision cases is presented. The extra-articular reconstruction is performed with a pedicle strip of iliotibial tract, fixed on the anatomic origin and insertion points of the anterolateral ligament of the knee in a double-bundle V-shaped fashion.

The dysplasia epiphysealis hemimelica (DEH) is a rare disease of unknown etiology consisting in an abnormal osteocartilaginous growth at the epiphysis, usually hemimelic with histological findings similar to benign osteochondroma. In this case series, we described the results of the arthroscopic treatment of 2 consecutive cases of intra-articular ankle localization of DEH in 2 patients aged 9 and 10 years. The good result obtained, persistent at the 5-year follow-up, leads us to consider the arthroscopic approach as a reliable treatment in patient affected by intra-articular ankle DEH.