Hasil untuk "Orthopedic surgery"

P.I. Codesido Vilar, P. Sucasas Hermida, B. Calvete Vázquez et al.

Resumen: Introducción: Las fracturas de meseta tibial más frecuentes son las tipo AO 41B3/Schatzker tipo 2 (lesiones unicondilares externas con línea de fractura vertical). El objetivo del tratamiento de estas fracturas es la restauración satisfactoria de la alineación mecánica, la reducción anatómica de la superficie articular y la fijación estable para permitir un rango de movimiento temprano. El objetivo de nuestro estudio es conocer los factores que más influyen en los resultados funcionales y de calidad de vida a largo plazo tras el tratamiento quirúrgico mediante la selección estricta de pacientes previamente sanos que afrontan una fractura inesperada de meseta tibial externa. Material y método: Se realizó un estudio retrospectivo en nuestro hospital de tercer nivel tras obtener la aprobación por parte del comité de ética. Se analizaron datos de pacientes con fractura de meseta tibial externa hospitalizados entre los años 2013 y 2018 con más de 3 años de evolución. Todos los pacientes que cumplieron los estrictos criterios de inclusión completaron los cuestionarios KOOS, EQ-5-D Profile y VAS. Además, se les realizó un examen físico y un estudio radiológico mediante telemetría y tomografía computarizada (TC). Los datos clínicos recogidos de los pacientes fueron: edad, sexo, lado de la fractura, uso de implante, uso de injerto, días transcurridos hasta la cirugía, años tras la cirugía, ASA, rango de movilidad en extensión y flexión. Los datos radiológicos fueron: en la telemetría se analizó la desviación en mm del eje de carga respecto al miembro contralateral, el MPTA de ambos miembros y la diferencia en grados entre ellos; en la TC se midió el escalón articular máximo y se calculó el área afecta en cm2 así como el diámetro mayor anteroposterior y la anchura máxima en mm (diámetros máximos anteroposterior y transversal). Resultados: Se analizaron un total de 27 pacientes, con edad media de 53,3 años y tiempo de evaluación medio desde la fractura de 4,8 años. Encontramos correlaciones estadísticamente significativas (p < 0,05) entre: días hasta cirugía y tamaño del área en cm2 (p = 0,042) y del escalón en mm (p = 0,028), es decir, a más días de demora mayor área y mayor escalón; ser hombre presentó una correlación positiva con tener mayor escalón (p = 0,025), mayor área (p = 0,007) y mayor slope (p = 0,039) frente a las mujeres. Se observó relación estadísticamente significativa entre el área de fractura residual y los valores de KOOS síntomas (p = 0,015), KOOS función (p = 0,012), EQ-5D profile (p = 0,038) y VAS (p = 0,049), siendo a mayor área afectada peor estado del paciente. También detectamos correlaciones significativas entre el escalón articular aumentado y KOOS síntomas (p = 0,005), KOOS dolor (p = 0,026), KOOS actividades cotidianas de la vida diaria (p = 0,049) y KOOS función (p = 0,007), siendo a mayor escalón peor situación del paciente. Conclusión: En conclusión, se puede observar que el aspecto más importante a la hora de obtener buenos resultados en cuanto a la satisfacción del paciente a largo plazo es la restauración de la línea articular evitando grandes depresiones y disminuyendo al máximo el área de afectación articular residual. Abstract: Introduction: The most common tibial plateau fractures are AO 41B3/Schatzker type 2 (external unicondylar lesions with a vertical fracture line). The goal of treatment for these fractures is the satisfactory restoration of mechanical alignment, anatomic reduction of the articular surface, and stable fixation to allow early range of motion. The aim of our study is to determine the factors that most influence long-term functional and quality of life outcomes after surgical treatment by strictly selecting previously healthy patients facing an unexpected external tibial plateau fracture. Material and method: A retrospective study was conducted in our tertiary hospital after obtaining approval from the ethics committee. Data from patients with external tibial plateau fracture hospitalized between 2013 and 2018 with more than 3 years of evolution were analyzed. All patients who met the strict inclusion criteria completed the KOOS, EQ-5-D profile and VAS questionnaires. In addition, they underwent a physical examination and radiological study using telemetry and computed tomography (CT). The clinical data collected from the patients were: age, sex, fracture side, implant use, graft use, days elapsed until surgery, years after surgery, ASA, range of motion in extension and flexion. The radiological data were: in the telemetry, the deviation in mm of the load axis with respect to the contralateral limb was analyzed, the MPTA of both limbs and the difference in degrees between them; in the CT, the maximum joint step was measured and the affected area was calculated in cm2 as well as the largest anteroposterior diameter and maximum width in mm (maximum anteroposterior and transverse diameters). Results: A total of 27 patients were analysed, with a mean age of 53.3 years and a mean evaluation time since the fracture of 4.8 years. We found statistically significant correlations (P < .05) between: days until surgery and size of the area in cm2 (P = .042) and step in mm (P = .028), that is, the more days of delay, the greater the area and the greater the step; being a man presented a positive correlation with having a greater step (P = .025), greater area (P = .007) and greater slope (P = .039) compared to women. A statistically significant relationship was observed between the area of residual fracture and the values of KOOS symptoms (P = .015), KOOS function (P = .012), EQ-5D profile (P = .038) and VAS (P = .049); the greater the affected area, the worse the patient's condition. We also detected significant correlations between increased joint step and KOOS symptoms (P = .005), KOOS pain (P = .026), KOOS activities of daily living (P = .049) and KOOS function (P = .007); the higher the step, the worse the patient's situation. Conclusion: In conclusion, it can be observed that the most important aspect when it comes to obtaining good results in terms of patient satisfaction in the long term is the restoration of the joint line, avoiding large depressions and minimizing the area of residual joint involvement.

Clément Poirson, Joschka Roffe, Robert I. Booth

We introduce a framework for implementing logic in CSS quantum error correction codes, building on the surgery methods of Cowtan and Burton [CB24]. Our approach offers a systematic methodology for designing and analysing surgery protocols. At the physical level, we introduce the concept of subcodes, which encapsulate all the necessary data for performing surgery. At the logical level, leveraging homological algebra, subcodes enable us to track the logical operations induced by any surgery protocol, regardless of the choice of logical operator basis. In particular, we make no assumptions on the structure of the logical operators of the code. As a proof of concept, we develop a surgery protocol inspired by lattice surgery that implements a logical CNOT gate between any two logical qubits of any CSS code, with fault-tolerance guarantees.

Alexander Cowtan, Zhiyang He, Dominic J. Williamson et al.

Quantum code surgery is a promising technique to perform fault-tolerant computation on quantum low-density parity-check codes. Recent developments have significantly reduced the space overhead of surgery. However, generic surgery operations still require $O(d)$ rounds of repeated syndrome extraction to be made fault-tolerant. In this work, we focus on reducing the time overhead of surgery. We first present a general set of conditions that ensure fault-tolerant surgery operations can be performed with constant time overhead. This fast surgery necessarily makes use of an auxiliary complex described by a hypergraph rather than a graph. We then introduce a concrete scheme called block reading, which performs transversal surgery across multiple code blocks. We further investigate surgery operations with intermediate time overhead, between $O(1)$ and $O(d)$, which apply to quantum locally testable codes. Finally, we establish a circuit equivalence between homomorphic measurement and hypergraph surgery and derive bounds on the time overhead of generic logical measurement schemes. Overall, our results demonstrate that reducing the time cost of code surgery is not reliant on the quantum memory being single-shot. Instead it is chiefly the connectivity between a code and its measurement ancilla system that determines the achievable measurement time overhead.

Ian Zemke

In previous works, the author described an associative algebra whose $A_\infty$-module categories encode the Heegaard Floer Dehn surgery formulas. In this article, we describe the Koszul dual of this algebra. We construct dualizing bimodules, and prove several equivalences of categories. The constructions of this paper have applications to computational problems involving the link surgery formula.

Jan de Boer, Joshua Kames-King, Boris Post

We extend the correspondence between universal statistical features of large-$c$ 2d CFTs and surgery methods in pure AdS$_3$ quantum gravity. In particular, we introduce a method that we call RMT surgery, which relates a large class of off-shell partition functions in 3d gravity to the spectral statistics of general CFT observables. We apply this method to construct and compute an off-shell Euclidean wormhole whose boundaries are four-punctured spheres, which captures level repulsion in the high-energy sector of the boundary CFT. Using a similar gluing prescription, we also explore a new class of off-shell torus wormholes with trumpet boundaries, contributing to statistical moments of the density of primary states. Lastly, we demonstrate that surgery methods can be used as an intermediate step towards computing Seifert manifolds directly in 3d gravity.

Lyndon Mason BMBS MRCS FRCS, Abdul-Rahman Gomaa, Jejelola Apata-Omisore BMBS MRCS et al.

Research Type: Level 4 – Case series Introduction/Purpose: Fifth metatarsal fractures are common injuries. There is current disagreement on the preferred treatment, with certain fracture types. The aim of this study was to investigate time to discharge across all 5th metatarsal fracture and their respective fracture mapping patterns. Methods: A historic cohort study was performed of all fifth metatarsal fractures presenting to our unit between February 2016 - July 2021 was performed. Date of injury, fracture morphology and zones involved, clinical and radiographic follow up as well as surgical interventions were collected. Results: 1331 fractures were included in this study. The fracture pattern with the longest time before discharge was a fracture spanning zones 2-3 (mean 11.40, 95% CI 5.65, 17.15), followed by a fracture limited to zone 3 (mean 9.72, 95% CI 1.14, 7.31). Both fractures patterns had significantly longer times to discharge than zone 1 (p <.001), zone 1-2 (p <.001), zone 2 (p <.001), zone 2-shaft (p=.001), zone 3-shaft (p=.004) and shaft fractures (p <.001). Fractures spanning zone 2-3 and zone 3 were the highest to undergo surgery (11.63% and 9.09% respectively) which was significantly greater than other fracture types (p=.003). The average time to surgery was 21.85 weeks (95% CI 8.87, 34.82), with the average time to discharge post-surgery of 8.07 weeks (95% CI 5.08, 11.07). Conclusion: Fractures spanning zone 2-3 (typical Jones) and zone 3 fractures have the highest time to discharge and highest rate of surgery. Time to surgery is low, in keeping with surgery proceeding not typically for chronic non unions but for more acute presentations. All fractures undergoing surgery united, with only short follow up required post-surgery.

Oleksii S. Nekhlopochyn, Vadim V. Verbov, Ievgen V. Cheshuk et al.

Introduction: Burst fractures of the thoracolumbar junction (TLJ, T10–L2) are common spinal injuries associated with a high risk of neurological complications. Transpedicular fixation is one of the most effective treatment methods; however, the optimal choice of fixation configuration remains unresolved. This study aims to analyze the stress-strain state of various short-segment transpedicular fixation configurations for Th12 vertebra burst fractures under lateral flexion loading. Materials and methods: A finite element model of the Th9–L5 spinal segment with a simulated Th12 burst fracture was created. Four fixation configurations were considered: M1 – short screws in Th11 and L1 (without intermediate screws), M2 – long screws in Th11 and L1 (without intermediate screws), M3 – short screws in Th11 and L1 with intermediate screws in Th12, and M4 – long screws in Th11 and L1 with intermediate screws in Th12. The models were analyzed using CosmosM software, assessing equivalent von Mises stress at 18 control points. Loads simulated physiological lateral trunk bending. Results: Models with long screws (M2, M4) demonstrated lower maximum stresses in connecting rods (315.5–321.0 MPa) compared to short screws (324.8–324.9 MPa). The inclusion of intermediate screws (M3, M4) significantly reduced stress in the fractured Th12 vertebra (by up to 28%), in adjacent vertebral endplates (by 18–25%), and at screw entry points into vertebral arches (up to 28%). The lowest fixation screw stresses were observed in the model with long and intermediate screws (up to 38% lower compared to the baseline model M1). However, intermediate screws minimally influenced stresses in the connecting rods (up to 1.2%). Conclusions: The optimal short-segment transpedicular fixation configuration is the use of long screws in adjacent vertebrae combined with intermediate fixation in the fractured vertebra (M4). This approach provides optimal load distribution, reduces the risk of construct failure, and preserves mobility of adjacent segments. Long screws improve overall system stiffness, while intermediate screws effectively stabilize the damaged segment and significantly unload critical areas of the construct and adjacent anatomical structures.

Philipp Reiser, Francesca Tripaldi

We consider the problem of preserving weighted Riemannian metrics of positive Bakry-Émery Ricci curvature along surgery. We establish two theorems of this type: One for connected sums, and one for surgeries along higher-dimensional spheres. In contrast to known surgery results for positive Ricci curvature, these results are local, i.e. we only impose assumptions on the weighted metric locally around the sphere along which the surgery is performed. As application we then show that all closed, simply-connected spin 5-manifolds admit a weighted Riemannian metric of positive Bakry-Émery Ricci curvature. By a result of Lott, this also provides new examples of manifolds with a Riemannian metric of positive Ricci curvature.

Samuel Schmidgall, Ji Woong Kim, Jeffrey Jopling et al.

The absence of openly accessible data and specialized foundation models is a major barrier for computational research in surgery. Toward this, (i) we open-source the largest dataset of general surgery videos to-date, consisting of 680 hours of surgical videos, including data from robotic and laparoscopic techniques across 28 procedures; (ii) we propose a technique for video pre-training a general surgery vision transformer (GSViT) on surgical videos based on forward video prediction that can run in real-time for surgical applications, toward which we open-source the code and weights of GSViT; (iii) we also release code and weights for procedure-specific fine-tuned versions of GSViT across 10 procedures; (iv) we demonstrate the performance of GSViT on the Cholec80 phase annotation task, displaying improved performance over state-of-the-art single frame predictors.

Zhi Li, Lihua Song, Baoju Qin et al.

Abstract Background Surgical site infection (SSI) is a common and serious complication of elective clean orthopedic surgery that can lead to severe adverse outcomes. However, the prognostic efficacy of the current staging systems remains uncertain for patients undergoing elective aseptic orthopedic procedures. This study aimed to identify high-risk factors independently associated with SSI and develop a nomogram prediction model to accurately predict the occurrence of SSI. Methods A total of 20,960 patients underwent elective clean orthopedic surgery in our hospital between January 2020 and December 2021, of whom 39 developed SSI; we selected all 39 patients with a postoperative diagnosis of SSI and 305 patients who did not develop postoperative SSI for the final analysis. The patients were randomly divided into training and validation cohorts in a 7:3 ratio. Univariate and multivariate logistic regression analyses were conducted in the training cohort to screen for independent risk factors of SSI, and a nomogram prediction model was developed. The predictive performance of the nomogram was compared with that of the National Nosocomial Infections Surveillance (NNIS) system. Decision curve analysis (DCA) was used to assess the clinical decision-making value of the nomogram. Results The SSI incidence was 0.186%. Univariate and multivariate logistic regression analysis identified the American Society of Anesthesiology (ASA) class (odds ratio [OR] 1.564 [95% confidence interval (CI) 1.029–5.99, P = 0.046]), operative time (OR 1.003 [95% CI 1.006–1.019, P < 0.001]), and D-dimer level (OR 1.055 [95% CI 1.022–1.29, P = 0.046]) as risk factors for postoperative SSI. We constructed a nomogram prediction model based on these independent risk factors. In the training and validation cohorts, our predictive model had concordance indices (C-indices) of 0.777 (95% CI 0.672–0.882) and 0.732 (95% CI 0.603–0.861), respectively, both of which were superior to the C-indices of the NNIS system (0.668 and 0.543, respectively). Calibration curves and DCA confirmed that our nomogram model had good consistency and clinical predictive value, respectively. Conclusions Operative time, ASA class, and D-dimer levels are important clinical predictive indicators of postoperative SSI in patients undergoing elective clean orthopedic surgery. The nomogram predictive model based on the three clinical features demonstrated strong predictive performance, calibration capabilities, and clinical decision-making abilities for SSI.

Hao Yu, Anas M Khanshour, Aki Ushiki et al.

Adolescent idiopathic scoliosis (AIS) is a common and progressive spinal deformity in children that exhibits striking sexual dimorphism, with girls at more than fivefold greater risk of severe disease compared to boys. Despite its medical impact, the molecular mechanisms that drive AIS are largely unknown. We previously defined a female-specific AIS genetic risk locus in an enhancer near the PAX1 gene. Here, we sought to define the roles of PAX1 and newly identified AIS-associated genes in the developmental mechanism of AIS. In a genetic study of 10,519 individuals with AIS and 93,238 unaffected controls, significant association was identified with a variant in COL11A1 encoding collagen (α1) XI (rs3753841; NM_080629.2_c.4004C&gt;T; p.(Pro1335Leu); p=7.07E–11, OR = 1.118). Using CRISPR mutagenesis we generated Pax1 knockout mice (Pax1-/-). In postnatal spines we found that PAX1 and collagen (α1) XI protein both localize within the intervertebral disc-vertebral junction region encompassing the growth plate, with less collagen (α1) XI detected in Pax1-/- spines compared to wild-type. By genetic targeting we found that wild-type Col11a1 expression in costal chondrocytes suppresses expression of Pax1 and of Mmp3, encoding the matrix metalloproteinase 3 enzyme implicated in matrix remodeling. However, the latter suppression was abrogated in the presence of the AIS-associated COL11A1P1335L mutant. Further, we found that either knockdown of the estrogen receptor gene Esr2 or tamoxifen treatment significantly altered Col11a1 and Mmp3 expression in chondrocytes. We propose a new molecular model of AIS pathogenesis wherein genetic variation and estrogen signaling increase disease susceptibility by altering a PAX1-COL11a1-MMP3 signaling axis in spinal chondrocytes.

Cody Ashy MD, Paul Pottanat MD, Harris Slone MD et al.

Background: Anterior shoulder instability is associated with Hill-Sachs lesions (HSLs) in 40% to 90% of cases. When addressing anterior shoulder instability, unaddressed engaging or “off-track” HSL have a recurrence rate of 75%. Remplissage is a known technique to address recurrent instability in the setting of an engaging HSL. In this video, we demonstrate that a double-anchor-pulley technique may be used to address recurrent instability in the setting of engaging HSL. Indications: Patients with recurrent anterior shoulder instability with off-track HSL in patients with glenoid bone loss <20% are candidates for arthroscopic Remplissage. Technique Description: Patients are placed in the lateral decubitus position. Examination under anesthesia is performed to assess for degree of instability and engagement of HSL. Posterior, anterosuperior, and anteroinferior portals are established. Routine diagnostic arthroscopy is performed with identification of the HSL. While viewing from an anterosuperior portal and working through the posterior portal, the HSL bed is prepared with curettage and a bur. A 5.5-mm accessory Cannula is used through an accessory posterior portal. Two knotless all-suture self-tensioning anchors are placed in the anterior and inferior aspect of the defect, passed through the cannula, and tagged for later identification. Bankart stabilization is performed. The knotless anchors are linked to each other to perform a knotless repair with a broad area of compression. Results: Results are excellent with only a 5.6% failure rate, significant patient improvement, low complication rate, and 95.5% return to play. Discussion: We demonstrate the technical aspects of an all-arthroscopic Remplissage technique using all-suture knotless anchors to provide a simple and reproducible method of performing a Remplissage. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Alaa Eldin Abdelaal, Rachelle Van Rumpt, Sayem Nazmuz Zaman et al.

In this paper, we report our discovery of a gaze behavior called Quiet Eye (QE) in minimally invasive surgery. The QE behavior has been extensively studied in sports training and has been associated with higher level of expertise in multiple sports. We investigated the QE behavior in two independently collected data sets of surgeons performing tasks in a sinus surgery setting and a robotic surgery setting, respectively. Our results show that the QE behavior is more likely to occur in successful task executions and in performances of surgeons of high level of expertise. These results open the door to use the QE behavior in both training and skill assessment in minimally invasive surgery.

Natalia Mathá, Klaus Schoeffmann, Konstantin Schekotihin et al.

In the last decade, the need for storing videos from cataract surgery has increased significantly. Hospitals continue to improve their imaging and recording devices (e.g., microscopes and cameras used in microscopic surgery, such as ophthalmology) to enhance their post-surgical processing efficiency. The video recordings enable a lot of user-cases after the actual surgery, for example, teaching, documentation, and forensics. However, videos recorded from operations are typically stored in the internal archive without any domain-specific compression, leading to a massive storage space consumption. In this work, we propose a relevance-based compression scheme for videos from cataract surgery, which is based on content specifics of particular cataract surgery phases. We evaluate our compression scheme with three state-of-the-art video codecs, namely H.264/AVC, H.265/HEVC, and AV1, and ask medical experts to evaluate the visual quality of encoded videos. Our results show significant savings, in particular up to 95.94% when using H.264/AVC, up to 98.71% when using H.265/HEVC, and up to 98.82% when using AV1.

He Lin, Lanjun Nie, Guiqing Lu et al.

Abstract Background Bone fracture is a common orthopedic disease that needs over 3 months to recover. Promoting the osteogenic differentiation of bone mesenchymal stem cells (BMSCs) is beneficial for fracture healing. Therefore, this research aimed to study the roles of long non-coding RNA (lncRNA) KCNQ10T1 in osteogenic differentiation of BMSCs. Methods BMSCs were treated with osteogenic medium and assessed by CCK-8 and flow cytometry assays. Alkaline phosphatase (ALP) staining, alizarin red staining (ARS), as well as concentration of osteoblast markers were measured to evaluate osteogenic differentiation of BMSCs. Western blot was employed to detect proteins; while, qRT-PCR was for mRNA levels. Additionally, targeted relationships between KCNQ10T1 and miR-19a-3p, as well as miR-19a-3p and SMAD5 were verified by dual luciferase reporter gene assay along with RNA pull-down method. Results Upregulation of KCNQ10T1 promoted the ALP staining and ARS intensity, increased the cell viability and decreased the apoptosis rate of BMSCs. Besides, KCNQ10T1 overexpression increased the ALP, OPG, OCN and OPN protein levels. KCNQ10T1 sponges miR-19a-3p, which targets Smad5. Upregulated miR-19a-3p reversed the overexpressed KCNQ10T1-induced effects, and depletion of SMAD5 reversed the miR-19a-3p inhibitor-induced effects on osteogenic medium-treated BMSCs. Conclusions Upregulation of KCNQ10T1 promoted osteogenic differentiation of BMSCs through miR-19a-3p/SMAD5 axis in bone fracture.

Sarah Safavi, Yihang Yu, Dale L. Robinson et al.

Abstract Background Total joint replacements are an established treatment for patients suffering from reduced mobility and pain due to severe joint damage. Aseptic loosening due to stress shielding is currently one of the main reasons for revision surgery. As this phenomenon is related to a mismatch in mechanical properties between implant and bone, stiffness reduction of implants has been of major interest in new implant designs. Facilitated by modern additive manufacturing technologies, the introduction of porosity into implant materials has been shown to enable significant stiffness reduction; however, whether these devices mitigate stress-shielding associated complications or device failure remains poorly understood. Methods In this systematic review, a broad literature search was conducted in six databases (Scopus, Web of Science, Medline, Embase, Compendex, and Inspec) aiming to identify current design approaches to target stress shielding through controlled porous structures. The search keywords included ‘lattice,’ ‘implant,’ ‘additive manufacturing,’ and ‘stress shielding.’ Results After the screening of 2530 articles, a total of 46 studies were included in this review. Studies focusing on hip, knee, and shoulder replacements were found. Three porous design strategies were identified, specifically uniform, graded, and optimized designs. The latter included personalized design approaches targeting stress shielding based on patient-specific data. All studies reported a reduction of stress shielding achieved by the presented design. Conclusion Not all studies used quantitative measures to describe the improvements, and the main stress shielding measures chosen varied between studies. However, due to the nature of the optimization approaches, optimized designs were found to be the most promising. Besides the stiffness reduction, other factors such as mechanical strength can be considered in the design on a patient-specific level. While it was found that controlled porous designs are overall promising to reduce stress shielding, further research and clinical evidence are needed to determine the most superior design approach for total joint replacement implants.

Tomasz Stołtny, Michał Dobrakowski, Aleksander Augustyn et al.

Abstract Purpose Current epidemiological data forecast an almost 40% increase in the number of hip arthroplasty performed in the population of patients with osteoarthritis in 2060, compared to year 2018. On the basis of 10 years of observation, the failure rate after a metal-on-metal hip replacement is between 56.7 and 88.9%, depending on the used implant. Methods Seventy-six men operated using metaphyseal hip prostheses, with modular metal heads: the J&J DePuy ASR and Biomet Recap-Magnum systems, after a period of about 5–7 years after the procedure, were assessed twice (an interval of 6 months) in terms of the parameters of oxidative stress and the concentration of chromium, cobalt and ions nickel, as well as their impact on the current clinical status and quality of life. Results The mean values of the Co and Cr ion concentrations increased in a statistically significant manner at the individual stages of the study (13.20 Co and 18.16 Cr) for J&J DePuy ASR. Using the WOMAC-hip, HHS and SF-12 rating scales, the functional status of operated patients in both study groups did not change in a statistically significant manner during subsequent visits. There was a statistically significant increase in perceived pain in patients operated bilaterally with the J&J DePuy ASR system. The severity of pain could be related to the increase in the concentration of Co and Cr ions; however, it concerned a small group of bilaterally operated patients (n = 3 + n = 4). Conclusions Metal-on-metal configuration in hip arthroplasty significantly influences with the increase in the concentration of chromium and cobalt ions in a double assessment. A statistically significant increase in the concentration of the tested Co and Cr ions in the blood correlates with an increase in the intensity of pain, especially in patients undergoing bilateral surgery. The limitation of this study is the relatively small number of bilaterally operated patients. Elevated levels of Co and Cr ions in the blood of patients operated on with the J&J DePuy ASR system increased steadily during both follow-up visits.

Ewerton Borges deSouza Lima, Gabriel Paris deGodoy, Guilherme Ladeira Osés et al.

Abstract Purpose To evaluate epidemiological data of upper limb injuries in professional athletes who participated in two major Brazilian soccer championships between 2016 and 2019. Methods A prospective cohort study was conducted to evaluate the teams of two divisions over four seasons within the Brazilian Soccer Championship and the Paulista Soccer Championship. Clubs and their doctors were contacted to participate in the study and guided on the correct way to enter data via online platforms: Transfermarkt (Transfermarkt GmbH & Co. KG) and Survey Monkey (Momentive.AI). Demographic data, injury characteristics, and FIFA Incidence Formula were analyzed. Results Overall, the study analyzed 3,828 matches and 126,357 hours of play. Upper limb injuries were registered 169 times, representing 6.8% of total injuries, with a FIFA incidence of 1.34. Most lesions occurred in forward players (21.3%), the shoulder exhibited the highest number of injuries (63.3%). The player’s position was related to the location on the field where the injury occurred (p < 0.001); however, there was no relationship between the type of injury and the location on the body (p > 0.001). The average time to return to play was 19.1 days (range 0–200 days) and it was longer for goalkeepers. The necessity of surgical treatment was statistically associated with additional time to return to play (p < 0.001). Conclusions Shoulder injuries were the most frequent upper limb injury sustained during the two major Brazilian soccer championships. Forward players suffered the most upper limb injuries and goalkeepers experienced the longest time to return to play.

XiaoLi Jin, Yang Li, Yayang Yang et al.

Abstract Background Osteoclast cell increase is a major risk factor for osteoporosis and degenerative bone and joint diseases. At present, RANKL and M-CSF are commonly used to induce osteoclastogenesis. Thioacetamide (TAA) can lead to many types of liver and kidney damage, but less attention has been paid to the association of TAA with bone damage. In this work, we investigated the effects of TAA on the osteoclastogenesis and differentiation of bone marrow macrophages (BMMs). Methods BMMs of SD rat suckling mice were taken for primary culture. CCK-8 was used to detect the toxic effects of TAA on BMMs, and flow cytometry was used to detect the effects of TAA on the cell cycle, cell viability, apoptosis and intracytoplasmic Ca2+ concentration of BMMs. TRAP staining was used to detect the effect of RANKL and M-CSF and TAA on osteoclast differentiation of BMMs. Western Blot was used to detect the expression level of PI3K/AKT pathway and osteoclast-specific proteins (TRAP and cathepsin K). Results The results suggested that TAA inhibited the proliferation of BMMs, while enhancing osteoclastogenesis at 0.5 mg/mL and 1 mg/mL as assayed by TRAP staining. Exposed to TAA, BMMs could differentiate into osteoclast-like cells with overexpression of cathepsin K and TRAP proteins. Western blot results showed that TAA can activate the expression levels of P-PI3K, P-AKT, P-P38, and P-JNK, accompanied by apoptosis of BMMs and increase in intracellular Ca2+. Conclusion TAA may induce osteoclast formation in BMMs by activating the expression of PI3K/AKT pathway proteins, which is comparable to the classic osteoclast differentiation inducer RANKL and M-CSF. This suggests that we may find a cheap osteoclast inducer.

Federico Salmoiraghi

Using bi-contact geometry, we define a new type of Dehn surgery on an Anosov flow with orientable weak invariant foliations. The Anosovity of the new flow is strictly connected to contact geometry and the Reeb dynamics of the defining bi-contact structure. This approach gives new insights into the properties of the flows produced by Goodman surgery and clarifies under which conditions Goodman's construction yields an Anosov flow. Our main application gives a necessary and sufficient condition to generate a contact Anosov flow by Foulon-Hasselblatt Legendrian surgery on a geodesic flow. In particular we show that this is possible if and only if the surgery is performed along a simple closed geodesic. As a corollary we have that any (positive) skewed R-covered Anosov flow obtained by surgery on a closed orbit of a geodesic flow is orbit equivalent to a (positive) contact Anosov flow.